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Pilgrim-Morris JH, Collier GJ, Takigawa M, Strickland S, Thompson R, Norquay G, Stewart NJ, Wild JM. Mapping the amplitude and phase of dissolved 129Xe red blood cell signal oscillations with keyhole spectroscopic lung imaging. Magn Reson Med 2024. [PMID: 39423219 DOI: 10.1002/mrm.30296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 07/11/2024] [Accepted: 08/28/2024] [Indexed: 10/21/2024]
Abstract
PURPOSE To assess the regional amplitude and phase of dissolved 129Xe red blood cell (RBC) signal oscillations in the lung vasculature with keyhole spectroscopic imaging and to compare with previous methodology, which does not account for oscillation phase. METHODS 129Xe gas transfer was measured with a four-echo 3D radial spectroscopic imaging sequence. Keyhole reconstruction-based RBC signal oscillation amplitude mapping was applied retrospectively to data acquired from 28 healthy volunteers, 4 chronic thromboembolic pulmonary hypertension (CTEPH) patients, and 5 patients who were hospitalized due to COVID-19 pneumonia and had residual lung abnormalities. Using a sliding window keyhole reconstruction, maps of RBC oscillation amplitude were corrected for regional phase difference. Repeatability of the phase-adjusted oscillation amplitude was assessed in 8 healthy volunteers across three scans. RESULTS With sliding window keyhole reconstruction, regional phase differences were observed in the RBC signal oscillations: mean phase = (0.27 ± 0.19) rad in healthy volunteers, (0.24 ± 0.13) rad in CTEPH patients, and (0.33 ± 0.19) rad in patients with post-COVID-19 residual lung abnormality. The oscillation amplitude and phase maps were more heterogeneous (i.e., they showed increased coefficient of variation) for the CTEPH patients. The RBC oscillation amplitude was repeatable, and the mean three-scan coefficient of variation was smaller when the phase adjustment was made (0.07 ± 0.04 compared with 0.16 ± 0.05). CONCLUSION Sliding window keyhole reconstruction of radial dissolved 129Xe imaging reveals regional phase differences in the RBC oscillations, which are not captured when performing two phase keyhole reconstruction. This regional phase information may reflect the hemodynamic effect of the cardiac pulse wave in the pulmonary microvasculature.
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Affiliation(s)
- Jemima H Pilgrim-Morris
- POLARIS, Section of Medical Imaging and Technologies, Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
- Insigneo Institute, University of Sheffield, Sheffield, UK
| | - Guilhem J Collier
- POLARIS, Section of Medical Imaging and Technologies, Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
- Insigneo Institute, University of Sheffield, Sheffield, UK
| | - Mika Takigawa
- POLARIS, Section of Medical Imaging and Technologies, Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
| | - Scarlett Strickland
- Biomedical Research Centre, University of Sheffield, Sheffield, UK
- Sheffield Teaching Hospitals, Sheffield, UK
| | - Roger Thompson
- POLARIS, Section of Medical Imaging and Technologies, Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
- Sheffield Teaching Hospitals, Sheffield, UK
| | - Graham Norquay
- POLARIS, Section of Medical Imaging and Technologies, Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
- Insigneo Institute, University of Sheffield, Sheffield, UK
| | - Neil J Stewart
- POLARIS, Section of Medical Imaging and Technologies, Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
- Insigneo Institute, University of Sheffield, Sheffield, UK
| | - Jim M Wild
- POLARIS, Section of Medical Imaging and Technologies, Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
- Insigneo Institute, University of Sheffield, Sheffield, UK
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Burrowes KS, Seal M, Noorababaee L, Pontré B, Dubowitz D, Sá RC, Prisk GK. Vaping causes an acute BMI-dependent change in pulmonary blood flow. Physiol Rep 2024; 12:e70094. [PMID: 39424421 PMCID: PMC11489000 DOI: 10.14814/phy2.70094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2024] [Revised: 10/09/2024] [Accepted: 10/09/2024] [Indexed: 10/21/2024] Open
Abstract
Vaping use has skyrocketed especially among young adults, however there is no consensus on how vaping impacts the lungs. We aimed to determine whether there were changes in lung function acutely after a standard vaping session or if there were differences in lung function metrics between a healthy never-vaping cohort (N = 6; 27.3 ± 3.0 years) and a young asymptomatic vaping cohort (N = 14; 26.4 ± 8.0 years) indicating chronic changes. Pulmonary function measurements and impulse oscillometry were obtained on all participants. Oxygen-enhanced and Arterial Spin Labelling MRI were used to measure specific ventilation and perfusion, respectively, before and after vaping, and in the control cohort at baseline. MRI metrics did not show any significant differences in specific ventilation or perfusion after vaping. Heart rate increased post-vaping (68.1 ± 10.5 to 71.3 ± 8.7, p = 0.020); however, this and other metrics did not show a nicotine dose-dependent effect. There was a significant negative correlation between BMI and change in mean perfusion post-vaping (p = 0.003); those with normal/low BMI showing an increase in perfusion and vice versa for high BMI. This may be due to subjects lying supine during vaping inhalation. Pulmonary function metrics indicative of airways resistance showed significant differences between the vaping and control cohorts indicating early airway changes.
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Affiliation(s)
- K. S. Burrowes
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | - M. Seal
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | - L. Noorababaee
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | - B. Pontré
- Department of Anatomy and ImagingUniversity of AucklandAucklandNew Zealand
| | | | - R. C. Sá
- Department of MedicineUniversity of CaliforniaSan DiegoCaliforniaUSA
| | - G. K. Prisk
- Department of MedicineUniversity of CaliforniaSan DiegoCaliforniaUSA
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3
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Sato A, Ajimi A, Omiya Y, Shimizu JI. Interventional study of comparing body pressure in different prone positions in healthy young women. J Phys Ther Sci 2024; 36:571-576. [PMID: 39239414 PMCID: PMC11374175 DOI: 10.1589/jpts.36.571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Accepted: 06/16/2024] [Indexed: 09/07/2024] Open
Abstract
[Purpose] Although prone positioning is used to increase oxygenation in various respiratory conditions, this positioning can lead to facial and limb pressure ulcers. The aim in this study was to investigate body pressure variations in the prone position for different facial orientations and upper extremity positions. [Participants and Methods] Nineteen healthy young women participated in this study. Body pressure (maximum body pressure on the face, chest, elbows, and knees) was measured in six different prone positions with different face orientations and upper extremity positions, and the median value of each body pressure measurement was compared among postures. [Results] Face pressure tended to decrease when face orientation coincided with the raised side of the upper limb. In contrast, elbow pressure tended to be lower when the orientation of the face did not coincide with that of the raised side of the upper limb. [Conclusion] Pressure on the face and elbows can be reduced by placing the upper limbs in the prone position. This suggests that targeted and specific positioning may be useful for limiting the incidence and severity of pressure ulcers in these areas.
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Affiliation(s)
- Akihiro Sato
- Department of Occupational Therapy, Mejiro University: 320 Ukiya, Iwatsuki-ku, Saitama-shi, Saitama 339-8501, Japan
- Doctoral Program in Human Life Science, Tokyo Kasei University, Japan
| | - Akiko Ajimi
- Department of Physical Therapy, Mejiro University, Japan
| | - Yuko Omiya
- Department of Nursing, Mejiro University, Japan
| | - Jun-Ichi Shimizu
- Graduate School of Human Life Science, Tokyo Kasei University, Japan
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Le Terrier C, Walter T, Lebbah S, Hajage D, Sigaud F, Guérin C, Desmedt L, Primmaz S, Joussellin V, Della Badia C, Ricard JD, Pugin J, Terzi N. Impact of intensive prone position therapy on outcomes in intubated patients with ARDS related to COVID-19. Ann Intensive Care 2024; 14:100. [PMID: 38935175 PMCID: PMC11211313 DOI: 10.1186/s13613-024-01340-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Accepted: 06/17/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Previous retrospective research has shown that maintaining prone positioning (PP) for an average of 40 h is associated with an increase of survival rates in intubated patients with COVID-19-related acute respiratory distress syndrome (ARDS). This study aims to determine whether a cumulative PP duration of more than 32 h during the first 2 days of intensive care unit (ICU) admission is associated with increased survival compared to a cumulative PP duration of 32 h or less. METHODS This study is an ancillary analysis from a previous large international observational study involving intubated patients placed in PP in the first 48 h of ICU admission in 149 ICUs across France, Belgium and Switzerland. Given that PP is recommended for a 16-h daily duration, intensive PP was defined as a cumulated duration of more than 32 h during the first 48 h, whereas standard PP was defined as a duration equal to or less than 32 h. Patients were followed-up for 90 days. The primary outcome was mortality at day 60. An Inverse Probability Censoring Weighting (IPCW) Cox model including a target emulation trial method was used to analyze the data. RESULTS Out of 2137 intubated patients, 753 were placed in PP during the first 48 h of ICU admission. The intensive PP group (n = 79) had a median PP duration of 36 h, while standard PP group (n = 674) had a median of 16 h during the first 48 h. Sixty-day mortality rate in the intensive PP group was 39.2% compared to 38.7% in the standard PP group (p = 0.93). Twenty-eight-day and 90-day mortality as well as the ventilator-free days until day 28 were similar in both groups. After IPCW, there was no significant difference in mortality at day 60 between the two-study groups (HR 0.95 [0.52-1.74], p = 0.87 and HR 1.1 [0.77-1.57], p = 0.61 in complete case analysis or in multiple imputation analysis, respectively). CONCLUSIONS This secondary analysis of a large multicenter European cohort of intubated patients with ARDS due to COVID-19 found that intensive PP during the first 48 h did not provide a survival benefit compared to standard PP.
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Affiliation(s)
- Christophe Le Terrier
- Division of Intensive Care, Faculty of Medicine, Geneva University Hospitals and the University of Geneva, Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland.
| | - Thaïs Walter
- Division of Intensive Care, Saint-Louis Hospital, Greater Paris Hospital, Paris, France
| | - Said Lebbah
- Département de Santé Publique, Centre de Pharmaco-épidémiologie, AP-HP, Paris, France
| | - David Hajage
- Département de Santé Publique, Centre de Pharmaco-épidémiologie, AP-HP, Paris, France
| | - Florian Sigaud
- Division of Intensive Care, Grenoble Alpes University Hospital, Grenoble, France
| | - Claude Guérin
- Division of Intensive Care, Edouard Herriot University Hospital, Lyon, France
| | - Luc Desmedt
- Medical Intensive Care Unit, Nantes Hôtel-Dieu University Hospital, Nantes, France
| | - Steve Primmaz
- Division of Intensive Care, Faculty of Medicine, Geneva University Hospitals and the University of Geneva, Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
| | - Vincent Joussellin
- Medical Intensive Care Unit, University Hospital of Rennes, Rennes, France
| | - Chiara Della Badia
- Division of Intensive Care, Faculty of Medicine, Geneva University Hospitals and the University of Geneva, Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
| | - Jean-Damien Ricard
- UMR1137 IAME, INSERM, Université Paris Cité, 75018, Paris, France
- DMU ESPRIT, Service de Médecine Intensive Réanimation, Université Paris Cité, AP-HP, Hôpital Louis Mourier, 92700, Colombes, France
| | - Jérôme Pugin
- Division of Intensive Care, Faculty of Medicine, Geneva University Hospitals and the University of Geneva, Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland
| | - Nicolas Terzi
- Medical Intensive Care Unit, University Hospital of Rennes, Rennes, France
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5
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Kizhakke Puliyakote AS, Tedjasaputra V, Petersen GM, Sá RC, Hopkins SR. Assessing the pulmonary vascular responsiveness to oxygen with proton MRI. J Appl Physiol (1985) 2024; 136:853-863. [PMID: 38385182 PMCID: PMC11343071 DOI: 10.1152/japplphysiol.00747.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/05/2024] [Accepted: 02/19/2024] [Indexed: 02/23/2024] Open
Abstract
Ventilation-perfusion matching occurs passively and is also actively regulated through hypoxic pulmonary vasoconstriction (HPV). The extent of HPV activity in humans, particularly normal subjects, is uncertain. Current evaluation of HPV assesses changes in ventilation-perfusion relationships/pulmonary vascular resistance with hypoxia and is invasive, or unsuitable for patients because of safety concerns. We used a noninvasive imaging-based approach to quantify the pulmonary vascular response to oxygen as a metric of HPV by measuring perfusion changes between breathing 21% and 30%O2 using arterial spin labeling (ASL) MRI. We hypothesized that the differences between 21% and 30%O2 images reflecting HPV release would be 1) significantly greater than the differences without [Formula: see text] changes (e.g., 21-21% and 30-30%O2) and 2) negatively associated with ventilation-perfusion mismatch. Perfusion was quantified in the right lung in normoxia (baseline), after 15 min of 30% O2 breathing (hyperoxia) and 15 min normoxic recovery (recovery) in healthy subjects (7 M, 7 F; age = 41.4 ± 19.6 yr). Normalized, smoothed, and registered pairs of perfusion images were subtracted and the mean square difference (MSD) was calculated. Separately, regional alveolar ventilation and perfusion were quantified from specific ventilation, proton density, and ASL imaging; the spatial variance of ventilation-perfusion (σ2V̇a/Q̇) distributions was calculated. The O2-responsive MSD was reproducible (R2 = 0.94, P < 0.0001) and greater (0.16 ± 0.06, P < 0.0001) than that from subtracted images collected under the same [Formula: see text] (baseline = 0.09 ± 0.04, hyperoxia = 0.08 ± 0.04, recovery = 0.08 ± 0.03), which were not different from one another (P = 0.2). The O2-responsive MSD was correlated with σ2V̇a/Q̇ (R2 = 0.47, P = 0.007). These data suggest that active HPV optimizes ventilation-perfusion matching in normal subjects. This noninvasive approach could be applied to patients with different disease phenotypes to assess HPV and ventilation-perfusion mismatch.NEW & NOTEWORTHY We developed a new proton MRI method to noninvasively quantify the pulmonary vascular response to oxygen. Using a hyperoxic stimulus to release HPV, we quantified the resulting redistribution of perfusion. The differences between normoxic and hyperoxic images were greater than those between images without [Formula: see text] changes and negatively correlated with ventilation-perfusion mismatch. This suggests that active HPV optimizes ventilation-perfusion matching in normal subjects. This approach is suitable for assessing patients with different disease phenotypes.
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Affiliation(s)
- Abhilash S Kizhakke Puliyakote
- Pulmonary Imaging Laboratory, UC San Diego Health Sciences, La Jolla, California, United States
- Department of Radiology, University of California, San Diego, La Jolla, California, United States
| | - Vincent Tedjasaputra
- Pulmonary Imaging Laboratory, UC San Diego Health Sciences, La Jolla, California, United States
- Department of Medicine, University of California, San Diego, La Jolla, California, United States
| | - Gregory M Petersen
- Pulmonary Imaging Laboratory, UC San Diego Health Sciences, La Jolla, California, United States
| | - Rui Carlos Sá
- Pulmonary Imaging Laboratory, UC San Diego Health Sciences, La Jolla, California, United States
- Department of Medicine, University of California, San Diego, La Jolla, California, United States
| | - Susan R Hopkins
- Pulmonary Imaging Laboratory, UC San Diego Health Sciences, La Jolla, California, United States
- Department of Radiology, University of California, San Diego, La Jolla, California, United States
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6
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Freire RS, Barros CMSS, Valente J, Goulart CDL, Santos AGR, Fonseca FH, Saenz ST, Dias AS, Rodrigues MGA, Silva BM, Fernandes E, Cubas-Vega N, Sampaio V, Simão M, Baía-da-Silva D, Severin R, Arêas GPT, Gonçalves RL, Mendes RG, Martinez-Espinosa FE, Val F. Prone positioning in awake patients without ventilatory support does not alter major clinical outcomes in severe COVID-19: results from a retrospective observational cohort study, systematic review and meta-analysis. Expert Rev Respir Med 2024; 18:219-226. [PMID: 38712558 DOI: 10.1080/17476348.2024.2350587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 04/29/2024] [Indexed: 05/08/2024]
Abstract
OBJECTIVES During the Coronavirus disease (COVID-19) pandemic, clinicians recommended awake-prone positioning (APP) to avoid the worst outcomes. The objectives of this study were to investigate if APP reduces intubation, death rates, and hospital length of stay (HLOS) in acute COVID-19. METHODS We performed a retrospective cohort with non-mechanically ventilated patients hospitalized in a reference center in Manaus, Brazil, 2020. Participants were stratified into APP and awake-not-prone positioning (ANPP) groups. Also, we conducted a systematic review and performed a meta-analysis to understand if this intervention had different outcomes in resource-limited settings (PROSPERO CRD42023422452). RESULTS A total of 115 participants were allocated into the groups. There was no statistical difference between both groups regarding time to intubation (HR: 0.861; 95CI: 0.474-1.1562; p=0.622) and time to death (HR: 1.666; 95CI: 0.939-2.951; p=0.081). APP was not significantly associated with reduced HLOS. A total of 86 articles were included in the systematic review, of which 76 (88,3%) show similar findings after APP. Also, low/middle, and high-income countries were similar regarding such outcomes. CONCLUSION APP in COVID-19 does not present clinical improvement that affects mortality, intubation rate and HLOS. The lack of a prone position protocol, obtained through a controlled study, is necessary. After 3 years, APP benefits are still inconclusive.
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Affiliation(s)
- Raíssa S Freire
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Camila M S S Barros
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Jefferson Valente
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Cássia da Luz Goulart
- Research department, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
| | - Anna G R Santos
- Programa de Pós-graduação em Ciências da Saúde, Universidade Federal do Amazonas, Manaus, Brazil
| | - Fernando H Fonseca
- Programa de Pós-graduação em Ciências da Saúde, Hospital and Pronto Socorro Delphina Rinaldi Abdel Aziz, Manaus, Brazil
| | - Sabrina T Saenz
- Clinical department, Maternidade de Referência da Zona Leste Ana Braga, Manaus, Brazil
| | - Andiana S Dias
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Maria G A Rodrigues
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Bernardo Maia Silva
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Eduardo Fernandes
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Nadia Cubas-Vega
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
- Clinical department, Postgrado Medicina de Rehabilitación, Universidad Nacional Autónoma de Honduras, Tegucigalpa, Honduras
| | - Vanderson Sampaio
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Mariana Simão
- Programa de Pós-graduação em Pesquisa Clínica em Doenças Infecciosas, Instituto Nacional de Infectologia Evandro Chagas, Rio de Janeiro, Brazil
| | - Djane Baía-da-Silva
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
- Programa de Pós-graduação em Ciências da Saúde, Universidade Federal do Amazonas, Manaus, Brazil
| | - Richard Severin
- Department of Physical Therapy, Integrative Physiologic Laboratory, College of Applied Health Sciences, University of Illinois at Chicago (UIC), Chicago, IL, USA
| | | | | | - Renata Gonçalves Mendes
- Programa de pós-graduação em Fisioterapia, Universidade Federal de São Carlos, São Carlos, Brazil
| | - Flor E Martinez-Espinosa
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
- Research department, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
- ILMD/Fiocruz Amazônia, Instituto Leônidas & Maria Deane, Manaus, Brazil
| | - Fernando Val
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
- Research department, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
- Programa de Pós-graduação em Ciências da Saúde, Universidade Federal do Amazonas, Manaus, Brazil
- Universidade Federal do Amazonas, Manaus, Brazil
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Chiappero C, Mattei A, Guidelli L, Millotti S, Ceccherini E, Oczkowski S, Scala R. Prone positioning during CPAP therapy in SARS-CoV-2 pneumonia: a concise clinical review. Ther Adv Respir Dis 2024; 18:17534666231219630. [PMID: 38159215 PMCID: PMC10757797 DOI: 10.1177/17534666231219630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 11/23/2023] [Indexed: 01/03/2024] Open
Abstract
During the COVID-19 pandemic, the number of patients with hypoxemic acute respiratory failure (ARF) due to SARS-CoV-2 pneumonia threatened to overwhelm intensive care units. To reduce the need for invasive mechanical ventilation (IMV), clinicians tried noninvasive strategies to manage ARF, including the use of awake prone positioning (PP) with continuous positive airway pressure (CPAP). In this article, we review the patho-physiologic rationale, clinical effectiveness and practical issues of the use of PP during CPAP in non-intubated, spontaneously breathing patients affected by SARS-CoV-2 pneumonia with ARF. Use of PP during CPAP appears to be safe and feasible and may have a lower rate of adverse events compared to IMV. A better response to PP is observed among patients in early phases of acute respiratory distress syndrome. While PP during CPAP may improve oxygenation, the impact on the need for intubation and mortality remains unclear. It is possible to speculate on the role of PP during CPAP in terms of improvement of ventilation mechanics and reduction of strain stress.
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Affiliation(s)
- Chiara Chiappero
- Cardiovascular and Thoracic Department, Pneumology, AOU Città della Salute e della Scienza di Torino – Molinette hospital, c.so Bramante 88, Turin 10126, Italy
| | - Alessio Mattei
- Cardiovascular and Thoracic Department, Pneumology, AOU Città della Salute e della Scienza di Torino – Molinette hospital, Turin, Italy
| | - Luca Guidelli
- CardioThoraco-Neuro-Vascular Department, Pulmonology and RICU, S Donato Hospital USL Toscana Sudest, Arezzo, Italy
| | - Serena Millotti
- UOP RF Arezzo, Department of Healthcare technical professions, Rehabilitation and Prevention, USL Toscana Sudest, Arezzo, Italy
| | - Emiliano Ceccherini
- UOP RF Arezzo, Department of Healthcare technical professions, Rehabilitation and Prevention, USL Toscana Sudest, Arezzo, Italy
| | - Simon Oczkowski
- Department of Medicine, Division of Critical Care, McMaster University, Hamilton, ON, Canada
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - Raffaele Scala
- CardioThoraco-Neuro-Vascular Department, Pulmonology and RICU, S Donato Hospital USL Toscana Sudest, Arezzo, Italy
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8
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Hopkins SR, Stickland MK. The Pulmonary Vasculature. Semin Respir Crit Care Med 2023; 44:538-554. [PMID: 37816344 PMCID: PMC11192587 DOI: 10.1055/s-0043-1770059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/12/2023]
Abstract
The pulmonary circulation is a low-pressure, low-resistance circuit whose primary function is to deliver deoxygenated blood to, and oxygenated blood from, the pulmonary capillary bed enabling gas exchange. The distribution of pulmonary blood flow is regulated by several factors including effects of vascular branching structure, large-scale forces related to gravity, and finer scale factors related to local control. Hypoxic pulmonary vasoconstriction is one such important regulatory mechanism. In the face of local hypoxia, vascular smooth muscle constriction of precapillary arterioles increases local resistance by up to 250%. This has the effect of diverting blood toward better oxygenated regions of the lung and optimizing ventilation-perfusion matching. However, in the face of global hypoxia, the net effect is an increase in pulmonary arterial pressure and vascular resistance. Pulmonary vascular resistance describes the flow-resistive properties of the pulmonary circulation and arises from both precapillary and postcapillary resistances. The pulmonary circulation is also distensible in response to an increase in transmural pressure and this distention, in addition to recruitment, moderates pulmonary arterial pressure and vascular resistance. This article reviews the physiology of the pulmonary vasculature and briefly discusses how this physiology is altered by common circumstances.
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Affiliation(s)
- Susan R. Hopkins
- Department of Radiology, University of California, San Diego, California
| | - Michael K. Stickland
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta
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9
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Kenny JES. A framework for heart-lung interaction and its application to prone position in the acute respiratory distress syndrome. Front Physiol 2023; 14:1230654. [PMID: 37614757 PMCID: PMC10443730 DOI: 10.3389/fphys.2023.1230654] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 07/24/2023] [Indexed: 08/25/2023] Open
Abstract
While both cardiac output (Qcirculatory) and right atrial pressure (PRA) are important measures in the intensive care unit (ICU), they are outputs of the system and not determinants. That is to say, in a model of the circulation wherein venous return and cardiac function find equilibrium at an 'operating point' (OP, defined by the PRA on the x-axis and Qcirculatory on the y-axis) both the PRA and Qcirculatory are, necessarily, dependent variables. A simplified geometrical approximation of Guyton's model is put forth to illustrate that the independent variables of the system are: 1) the mean systemic filling pressure (PMSF), 2) the pressure within the pericardium (PPC), 3) cardiac function and 4) the resistance to venous return. Classifying independent and dependent variables is clinically-important for therapeutic control of the circulation. Recent investigations in patients with acute respiratory distress syndrome (ARDS) have illuminated how PMSF, cardiac function and the resistance to venous return change when placing a patient in prone. Moreover, the location of the OP at baseline and the intimate physiological link between the heart and the lungs also mediate how the PRA and Qcirculatory respond to prone position. Whereas turning a patient from supine to prone is the focus of this discussion, the principles described within the framework apply equally-well to other more common ICU interventions including, but not limited to, ventilator management, initiating vasoactive medications and providing intravenous fluids.
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Affiliation(s)
- Jon-Emile S. Kenny
- Health Sciences North Research Institute, Sudbury, ON, Canada
- Flosonics Medical, Toronto, ON, Canada
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10
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Grotberg JC, Reynolds D, Kraft BD. Management of severe acute respiratory distress syndrome: a primer. Crit Care 2023; 27:289. [PMID: 37464381 DOI: 10.1186/s13054-023-04572-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 07/10/2023] [Indexed: 07/20/2023] Open
Abstract
This narrative review explores the physiology and evidence-based management of patients with severe acute respiratory distress syndrome (ARDS) and refractory hypoxemia, with a focus on mechanical ventilation, adjunctive therapies, and veno-venous extracorporeal membrane oxygenation (V-V ECMO). Severe ARDS cases increased dramatically worldwide during the Covid-19 pandemic and carry a high mortality. The mainstay of treatment to improve survival and ventilator-free days is proning, conservative fluid management, and lung protective ventilation. Ventilator settings should be individualized when possible to improve patient-ventilator synchrony and reduce ventilator-induced lung injury (VILI). Positive end-expiratory pressure can be individualized by titrating to best respiratory system compliance, or by using advanced methods, such as electrical impedance tomography or esophageal manometry. Adjustments to mitigate high driving pressure and mechanical power, two possible drivers of VILI, may be further beneficial. In patients with refractory hypoxemia, salvage modes of ventilation such as high frequency oscillatory ventilation and airway pressure release ventilation are additional options that may be appropriate in select patients. Adjunctive therapies also may be applied judiciously, such as recruitment maneuvers, inhaled pulmonary vasodilators, neuromuscular blockers, or glucocorticoids, and may improve oxygenation, but do not clearly reduce mortality. In select, refractory cases, the addition of V-V ECMO improves gas exchange and modestly improves survival by allowing for lung rest. In addition to VILI, patients with severe ARDS are at risk for complications including acute cor pulmonale, physical debility, and neurocognitive deficits. Even among the most severe cases, ARDS is a heterogeneous disease, and future studies are needed to identify ARDS subgroups to individualize therapies and advance care.
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Affiliation(s)
- John C Grotberg
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO, 63110, USA.
| | - Daniel Reynolds
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO, 63110, USA
| | - Bryan D Kraft
- Division of Pulmonary and Critical Care Medicine, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO, 63110, USA
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11
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McNicholas BA, Ibarra-Estrada M, Perez Y, Li J, Pavlov I, Kharat A, Vines DL, Roca O, Cosgrave D, Guerin C, Ehrmann S, Laffey JG. Awake prone positioning in acute hypoxaemic respiratory failure. Eur Respir Rev 2023; 32:32/168/220245. [PMID: 37137508 PMCID: PMC10155045 DOI: 10.1183/16000617.0245-2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/22/2023] [Indexed: 05/05/2023] Open
Abstract
Awake prone positioning (APP) of patients with acute hypoxaemic respiratory failure gained considerable attention during the early phases of the coronavirus disease 2019 (COVID-19) pandemic. Prior to the pandemic, reports of APP were limited to case series in patients with influenza and in immunocompromised patients, with encouraging results in terms of tolerance and oxygenation improvement. Prone positioning of awake patients with acute hypoxaemic respiratory failure appears to result in many of the same physiological changes improving oxygenation seen in invasively ventilated patients with moderate-severe acute respiratory distress syndrome. A number of randomised controlled studies published on patients with varying severity of COVID-19 have reported apparently contrasting outcomes. However, there is consistent evidence that more hypoxaemic patients requiring advanced respiratory support, who are managed in higher care environments and who can be prone for several hours, benefit most from APP use. We review the physiological basis by which prone positioning results in changes in lung mechanics and gas exchange and summarise the latest evidence base for APP primarily in COVID-19. We examine the key factors that influence the success of APP, the optimal target populations for APP and the key unknowns that will shape future research.
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Affiliation(s)
- Bairbre A McNicholas
- Department of Anaesthesia and Intensive Care Medicine, Galway University Hospital, Saolta Hospital Group, Galway, Ireland
- School of Medicine, University of Galway, Galway, Ireland
| | - Miguel Ibarra-Estrada
- Unidad de Terapia Intensiva, Hospital Civil Fray Antonio Alcalde, Guadalajara, Jalisco, Mexico
| | - Yonatan Perez
- Clinical Investigation Center, INSERM 1415, CHRU Tours, Tours, France
- Médecine Intensive Réanimation, CHRU Tours, Tours, France
- Médecine Intensive Réanimation, Hôpital de Hautepierre, Hôpitaux universitaires de Strasbourg, Strasbourg, France
| | - Jie Li
- Department of Cardiopulmonary Sciences, Division of Respiratory Care, Rush University, Chicago, IL, USA
| | - Ivan Pavlov
- Department of Emergency Medicine, Hôpital de Verdun, Montréal, QC, Canada
| | - Aileen Kharat
- Department of Respiratory Medicine, Geneva University Hospital, Geneva, Switzerland
| | - David L Vines
- Department of Cardiopulmonary Sciences, Division of Respiratory Care, Rush University, Chicago, IL, USA
| | - Oriol Roca
- Servei de Medicina Intensiva, Parc Taulí Hospital Universitari, Sabadell, Spain
- Departament de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - David Cosgrave
- Department of Anaesthesia and Intensive Care Medicine, Galway University Hospital, Saolta Hospital Group, Galway, Ireland
- School of Medicine, University of Galway, Galway, Ireland
| | - Claude Guerin
- University of Lyon, Lyon and INSERM 955, Créteil, France
| | - Stephan Ehrmann
- Clinical Investigation Center, INSERM 1415, CHRU Tours, Tours, France
- Médecine Intensive Réanimation, CHRU Tours, Tours, France
| | - John G Laffey
- Department of Anaesthesia and Intensive Care Medicine, Galway University Hospital, Saolta Hospital Group, Galway, Ireland
- School of Medicine, University of Galway, Galway, Ireland
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12
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Ergün B, Yakar MN, Küçük M, Baghiyeva N, Emecen AN, Yaka E, Ergan B, Gökmen AN. Combined Effects of Prone Positioning and Airway Pressure Release Ventilation on Oxygenation in Patients with COVID-19 ARDS. Turk J Anaesthesiol Reanim 2023; 51:188-198. [PMID: 37455436 DOI: 10.4274/tjar.2022.22783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Abstract
Objective Coronavirus disease 2019 (COVID-19) can cause acute respiratory distress syndrome (ARDS). Invasive mechanical ventilation (IMV) support and prone positioning are essential treatments for severe COVID-19 ARDS. We aimed to determine the combined effect of prone position and airway pressure release ventilation (APRV) modes on oxygen improvement in mechanically-ventilated patients with COVID-19. Methods This prospective observational study included 40 eligible patients (13 female, 27 male). Of 40 patients, 23 (57.5%) were ventilated with APRV and 17 (42.5%) were ventilated with controlled modes. A prone position was applied when the PaO2/FiO2 ratio <150 mmHg despite IMV in COVID-19 ARDS. The numbers of patients who completed the first, second, and third prone were 40, 25, and 15, respectively. Incident barotrauma events were diagnosed by both clinical findings and radiological images. Results After the second prone, the PaO2/FiO2 ratio of the APRV group was higher compared to the PaO2/FiO2 ratio of the control group [189 (150-237)] vs. 127 (100-146) mmHg, respectively, (P=0.025). Similarly, after the third prone, the PaO2/FiO2 ratio of the APRV group was higher compared to the PaO2/FiO2 ratio of the control group [194 (132-263)] vs. 83 (71-136) mmHg, respectively, (P=0.021). Barotrauma events were detected in 13.0% of the patients in the APRV group and 11.8% of the patients in the control group (P=1000). The 28-day mortality was not different in the APRV group than in the control group (73.9% vs. 70.6%, respectively, P=1000). Conclusion Using the APRV mode during prone positioning improves oxygenation, especially in the second and third prone positions, without increasing the risk of barotrauma. However, no benefit on mortality was detected.
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Affiliation(s)
- Bişar Ergün
- Department of Internal Medicine and Critical Care, Dokuz Eylül University Faculty of Medicine, İzmir, Turkey
| | - Mehmet Nuri Yakar
- Department of Anaesthesiology and Critical Care, Dokuz Eylül University Faculty of Medicine, İzmir, Turkey
| | - Murat Küçük
- Department of Internal Medicine and Critical Care, Dokuz Eylül University Faculty of Medicine, İzmir, Turkey
| | - Narmin Baghiyeva
- Department of Anaesthesiology and Critical Care, Dokuz Eylül University Faculty of Medicine, İzmir, Turkey
| | - Ahmet Naci Emecen
- Department of Public Health, Epidemiology Subsection, Dokuz Eylül University Faculty of Medicine, İzmir, Turkey
| | - Erdem Yaka
- Department of Neurology and Critical Care, Dokuz Eylül University Faculty of Medicine, İzmir, Turkey
| | - Begüm Ergan
- Department of Pulmonary and Critical Care, Dokuz Eylül University Faculty of Medicine, İzmir, Turkey
| | - Ali Necati Gökmen
- Department of Anaesthesiology and Critical Care, Dokuz Eylül University Faculty of Medicine, İzmir, Turkey
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13
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Taenaka H, Yoshida T, Hashimoto H, Firstiogusran AMF, Ishigaki S, Iwata H, Enokidani Y, Ebishima H, Kubo N, Koide M, Koyama Y, Sakaguchi R, Tokuhira N, Horiguchi Y, Uchiyama A, Fujino Y. Personalized ventilatory strategy based on lung recruitablity in COVID-19-associated acute respiratory distress syndrome: a prospective clinical study. Crit Care 2023; 27:152. [PMID: 37076900 PMCID: PMC10116825 DOI: 10.1186/s13054-023-04360-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 02/14/2023] [Indexed: 04/21/2023] Open
Abstract
BACKGROUND Heterogeneity is an inherent nature of ARDS. Recruitment-to-inflation ratio has been developed to identify the patients who has lung recruitablity. This technique might be useful to identify the patients that match specific interventions, such as higher positive end-expiratory pressure (PEEP) or prone position or both. We aimed to evaluate the physiological effects of PEEP and body position on lung mechanics and regional lung inflation in COVID-19-associated ARDS and to propose the optimal ventilatory strategy based on recruitment-to-inflation ratio. METHODS Patients with COVID-19-associated ARDS were consecutively enrolled. Lung recruitablity (recruitment-to-inflation ratio) and regional lung inflation (electrical impedance tomography [EIT]) were measured with a combination of body position (supine or prone) and PEEP (low 5 cmH2O or high 15 cmH2O). The utility of recruitment-to-inflation ratio to predict responses to PEEP were examined with EIT. RESULTS Forty-three patients were included. Recruitment-to-inflation ratio was 0.68 (IQR 0.52-0.84), separating high recruiter versus low recruiter. Oxygenation was the same between two groups. In high recruiter, a combination of high PEEP with prone position achieved the highest oxygenation and less dependent silent spaces in EIT (vs. low PEEP in both positions) without increasing non-dependent silent spaces in EIT. In low recruiter, low PEEP in prone position resulted in better oxygenation (vs. both PEEPs in supine position), less dependent silent spaces (vs. low PEEP in supine position) and less non-dependent silent spaces (vs. high PEEP in both positions). Recruitment-to-inflation ratio was positively correlated with the improvement in oxygenation and respiratory system compliance, the decrease in dependent silent spaces, and was inversely correlated with the increase in non-dependent silent spaces, when applying high PEEP. CONCLUSIONS Recruitment-to-inflation ratio may be useful to personalize PEEP in COVID-19-associated ARDS. Higher PEEP in prone position and lower PEEP in prone position decreased the amount of dependent silent spaces (suggesting lung collapse) without increasing the amount of non-dependent silent spaces (suggesting overinflation) in high recruiter and in low recruiter, respectively.
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Affiliation(s)
- Hiroki Taenaka
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takeshi Yoshida
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Haruka Hashimoto
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Andi Muhammad Fadlillah Firstiogusran
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Suguru Ishigaki
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hirofumi Iwata
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yusuke Enokidani
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hironori Ebishima
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Naoko Kubo
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Moe Koide
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yukiko Koyama
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Ryota Sakaguchi
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Natsuko Tokuhira
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yu Horiguchi
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Akinori Uchiyama
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yuji Fujino
- The Department of Anesthesiology and Intensive Care Medicine, Osaka University Graduate School of Medicine, 2-15 Yamadaoka, Suita, Osaka, 565-0871, Japan
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14
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Rampon GL, Simpson SQ, Agrawal R. Prone Positioning for Acute Hypoxemic Respiratory Failure and ARDS: A Review. Chest 2023; 163:332-340. [PMID: 36162482 DOI: 10.1016/j.chest.2022.09.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 09/11/2022] [Accepted: 09/12/2022] [Indexed: 01/14/2023] Open
Abstract
Prone positioning is an immediately accessible, readily implementable intervention that was proposed initially as a method for improvement in gas exchange > 50 years ago. Initially implemented clinically as an empiric therapy for refractory hypoxemia, multiple clinical trials were performed on the use of prone positioning in various respiratory conditions, cumulating in the landmark Proning Severe ARDS Patients trial, which demonstrated mortality benefit in patients with severe ARDS. After this trial and the corresponding meta-analysis, expert consensus and societal guidelines recommended the use of prone positioning for the management of severe ARDS. The ongoing COVID-19 pandemic has brought prone positioning to the forefront of medicine, including widespread implementation of prone positioning in awake, spontaneously breathing, nonintubated patients with acute hypoxemic respiratory failure. Multiple clinical trials now have been performed to investigate the safety and effectiveness of prone positioning in these patients and have enhanced our understanding of the effects of the prone position in respiratory failure. In this review, we discuss the physiologic features, clinical outcome data, practical considerations, and lingering questions of prone positioning.
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Affiliation(s)
- Garrett L Rampon
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS
| | - Steven Q Simpson
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Kansas Medical Center, Kansas City, KS.
| | - Ritwick Agrawal
- Pulmonary Critical Care and Sleep Medicine Section, Medical Care Line, Michael E. DeBakey Veteran Affairs Medical Center, Houston, TX; Pulmonary Critical Care and Sleep Medicine Section, Department of Medicine, Baylor College of Medicine, Houston, TX
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15
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Hsia CCW, Bates JHT, Driehuys B, Fain SB, Goldin JG, Hoffman EA, Hogg JC, Levin DL, Lynch DA, Ochs M, Parraga G, Prisk GK, Smith BM, Tawhai M, Vidal Melo MF, Woods JC, Hopkins SR. Quantitative Imaging Metrics for the Assessment of Pulmonary Pathophysiology: An Official American Thoracic Society and Fleischner Society Joint Workshop Report. Ann Am Thorac Soc 2023; 20:161-195. [PMID: 36723475 PMCID: PMC9989862 DOI: 10.1513/annalsats.202211-915st] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Multiple thoracic imaging modalities have been developed to link structure to function in the diagnosis and monitoring of lung disease. Volumetric computed tomography (CT) renders three-dimensional maps of lung structures and may be combined with positron emission tomography (PET) to obtain dynamic physiological data. Magnetic resonance imaging (MRI) using ultrashort-echo time (UTE) sequences has improved signal detection from lung parenchyma; contrast agents are used to deduce airway function, ventilation-perfusion-diffusion, and mechanics. Proton MRI can measure regional ventilation-perfusion ratio. Quantitative imaging (QI)-derived endpoints have been developed to identify structure-function phenotypes, including air-blood-tissue volume partition, bronchovascular remodeling, emphysema, fibrosis, and textural patterns indicating architectural alteration. Coregistered landmarks on paired images obtained at different lung volumes are used to infer airway caliber, air trapping, gas and blood transport, compliance, and deformation. This document summarizes fundamental "good practice" stereological principles in QI study design and analysis; evaluates technical capabilities and limitations of common imaging modalities; and assesses major QI endpoints regarding underlying assumptions and limitations, ability to detect and stratify heterogeneous, overlapping pathophysiology, and monitor disease progression and therapeutic response, correlated with and complementary to, functional indices. The goal is to promote unbiased quantification and interpretation of in vivo imaging data, compare metrics obtained using different QI modalities to ensure accurate and reproducible metric derivation, and avoid misrepresentation of inferred physiological processes. The role of imaging-based computational modeling in advancing these goals is emphasized. Fundamental principles outlined herein are critical for all forms of QI irrespective of acquisition modality or disease entity.
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16
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Peng Q, Yang S, Zhang Y, Zhao W, Hu M, Meng B, Ni H, Min L, Yu J, Wang Y, Zhang L. Effects of awake prone position vs. usual care on acute hypoxemic respiratory failure in patients with COVID-19: A systematic review and meta-analysis of randomized controlled trials. Front Med (Lausanne) 2023; 10:1120837. [PMID: 37081841 PMCID: PMC10111056 DOI: 10.3389/fmed.2023.1120837] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 03/06/2023] [Indexed: 04/22/2023] Open
Abstract
Background Previous studies have shown that an awake prone position may be beneficial for the treatment of acute respiratory distress syndrome (ARDS) or acute hypoxic respiratory failure (AHRF) in patients with COVID-19, but the results are not consistent, especially in terms of oxygenation outcomes and intubation rate. This systematic review and meta-analysis assessed the effects of the awake prone position on AHRF in patients with COVID-19 with all randomized controlled trials (RCTs). Methods An extensive search of online databases, including MEDLINE, Embase, Web of Science, and Cochrane Central Register of Controlled Trials from 1 December 2019 to 30 October 2022, with no language restrictions was performed. This systematic review and meta-analysis are based on the PRISMA statement. We only included RCTs and used the Cochrane risk assessment tool for quality assessment. Results Fourteen RCTs fulfilled the selection criteria, and 3,290 patients were included. A meta-analysis found that patients in the awake prone position group had more significant improvement in the SpO2/FiO2 ratio [mean difference (MD): 29.76; 95% confidence interval (CI): 1.39-48.13; P = 0.001] compared with the usual care. The prone position also reduced the need for intubation [odd ratio (OR): 0.72; 95% CI: 0.61 to 0.84; P < 0.0001; I 2 = 0%]. There was no significant difference in mortality, hospital length of stay, incidence of intensive care unit (ICU) admission, and adverse events between the two groups. Conclusion The awake prone position was a promising intervention method, which is beneficial to improve the oxygenation of patients with ARDS or AHRF caused by COVID-19 and reduce the need for intubation. However, the awake prone position showed no obvious advantage in mortality, hospital length of stay, incidence of ICU admission, and adverse events. Systematic review registration International Prospective Register of Systematic Reviews (PROSPERO), identifier: CRD42022367885.
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Affiliation(s)
- Qing Peng
- Department of Orthopedics, Clinical Medical College of Yangzhou University, Yangzhou, China
| | - Sheng Yang
- Department of Orthopedics, Graduate School of Dalian Medical University, Dalian, China
| | - Yu Zhang
- Department of Orthopedics, Clinical Medical College of Yangzhou University, Yangzhou, China
| | - Wenjie Zhao
- Department of Orthopedics, Graduate School of Dalian Medical University, Dalian, China
| | - Man Hu
- Department of Orthopedics, Graduate School of Dalian Medical University, Dalian, China
| | - Bo Meng
- Department of Orthopedics, Graduate School of Dalian Medical University, Dalian, China
| | - Huanhuan Ni
- Department of Anesthesiology, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Lingfeng Min
- Department of Respiratory, Clinical Medical College of Yangzhou University, Yangzhou, China
| | - Jiangquan Yu
- Department of Critical Care Medicine, Clinical Medical College of Yangzhou University, Yangzhou, China
- *Correspondence: Jiangquan Yu
| | - Yongxiang Wang
- Department of Orthopedics, Clinical Medical College of Yangzhou University, Yangzhou, China
- Yongxiang Wang
| | - Liang Zhang
- Department of Orthopedics, Regenerative Medicine Engineering Technology Research Center of Yangzhou, Yangzhou, China
- Liang Zhang
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17
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Huang YH, Ren G, Xiao H, Yang D, Kong FMS, Ho WY, Cai J. Volumetric multiphase ventilation imaging based on four-dimensional computed tomography for functional lung avoidance radiotherapy. Med Phys 2022; 49:7237-7246. [PMID: 35841346 DOI: 10.1002/mp.15847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 04/20/2022] [Accepted: 06/23/2022] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Current computed tomography (CT)-based lung ventilation imaging (CTVI) techniques derive a static ventilation image without temporal information. This research aims to develop a four-dimensional CT (4DCT)-based multiphase dynamic ventilation imaging framework capable of recovering the entire ventilation process throughout the breathing cycle for functional lung avoidance radiotherapy (FLART). METHODS A total of 15 free-breathing thoracic 4DCT scans of lung or esophageal cancer patients were collected from the public datasets. The lung region of each phase image was first delineated, and then the mask-free isotropic total variation image registration algorithm was used to derive the deformation vector fields between the end-expiration (EE) phase and other phases. As a surrogate of ventilation, the voxel-wise local expansion ratio of each phase relative to the EE phase was estimated using the parameterized Integrated Jacobian Formulation method in the EE phase coordinate. Lastly, the dynamic ventilation images were generated by warping these phase-specific local expansion distributions with a same geometry into their respective breathing phases. Quantitative analysis, including interphase Spearman correlation coefficients, voxel-wise, and regional-wise expansion/contraction tracking, were performed to indirectly validate the proposed method. RESULTS The proposed method maintains the physiological meaning of ventilation on each phase and enables to recover the dynamic lung ventilation process. The mean interphase Spearman correlations ranged between 0.23 ± 0.20 and 0.93 ± 0.04 and decreased near the EE phase. Only 26.2% (2.59E + 6 out of 9.89E + 6) of lung voxels exhibited the same expansion/contraction pattern as the global lung. Qualitative and quantitative evaluations of the interphase ventilation distribution difference show that ventilation spatiotemporal heterogeneities generally exist during respiration. CONCLUSIONS In contrast to conventional CTVI metrics, our method enables to extract additional phase-resolved respiration-correlated information and reflects the generally existed ventilation spatiotemporal heterogeneities. Subsequent studies with quantitative phase-by-phase cross-modality evaluations will further explore its potential to deepen our understanding of lung function and respiration mechanics and also to facilitate more accurate implementation of FLART.
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Affiliation(s)
- Yu-Hua Huang
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR
| | - Ge Ren
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR
| | - Haonan Xiao
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR
| | - Dongrong Yang
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR
| | - Feng-Ming Spring Kong
- Department of Clinical Oncology, The University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Wai Yin Ho
- Department of Nuclear Medicine, Queen Mary Hospital, Hong Kong, Hong Kong SAR
| | - Jing Cai
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR
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18
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Raimondi F, Cazzaniga S, Annibali S, Novelli L, Brivio M, Pappacena S, Malandrino L, Bonaffini PA, Bianco I, Liggeri N, Gritti P, Lorini FL, Sironi S, Di Marco F. Extent and Distribution of Parenchymal Abnormalities in Baseline CT-Scans Do Not Predict Awake Prone Positioning Response in COVID-19 Related ARDS. Diagnostics (Basel) 2022; 12:diagnostics12081848. [PMID: 36010199 PMCID: PMC9406535 DOI: 10.3390/diagnostics12081848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/24/2022] [Accepted: 07/24/2022] [Indexed: 12/15/2022] Open
Abstract
Prone positioning is frequently used for non-intubated hypoxemic patients with COVID-19, although conclusive evidence is still lacking. The aim of the present study was to investigate whether baseline CT-scans could predict the improvement in oxygenation in COVID-19 related Acute respira-tory syndrome (ARDS) patients when pronated. Methods: A retrospective study of COVID-19 patients who underwent non-invasive ventilation (NIV) and prone positioning was conducted. Results: Forty-five patients were included. On average, 50% of the overall lung volume was affected by the disease, as observed in the CT-scans, with ground glass opacities (GGOs) and consolidations accounting for 44% and 4%, respectively. The abnormalities were mainly posterior, as demonstrated by posterior/anterior distribution ratios of 1.5 and 4.4 for GGO and consolidation, respectively. The median PaO2/FiO2 ratio during NIV in a supine position (SP1) was 140 [IQR 108–169], which improved by 67% (+98) during prone positioning, on average. Once supine positioning was resumed (SP2), the improvement in oxygenation was maintained in 28 patients (62% of the overall population, categorized as “responders”). We found no significant differences between responders and non-responders in terms of the extent (p = 0.92) and the distribution of parenchymal abnormalities seen in the baseline CT (p = 0.526). Conclusion: Despite the lack of a priori estimation of the sample size, considering the absence of any trends in the differences and correlations, we can reasonably conclude that the baseline chest CT-scan does not predict a gas-exchange response in awake prone-positioned patients with COVID-19 related ARDS. Physicians dealing with this category of patients should not rely on the imaging at presentation when evaluating whether to pronate patients.
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Affiliation(s)
- Federico Raimondi
- Pulmonary Medicine Unit, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (F.R.); (L.N.); (S.P.); (L.M.)
| | - Sara Cazzaniga
- Department of Intensive Critical Care, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (S.C.); (M.B.); (P.G.); (F.L.L.)
| | - Simona Annibali
- Department of Diagnostic Radiology, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (S.A.); (P.A.B.); (I.B.); (N.L.); (S.S.)
- Department of Medicine and Surgery, University of Milano-Bicocca, 20126 Milan, Italy
| | - Luca Novelli
- Pulmonary Medicine Unit, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (F.R.); (L.N.); (S.P.); (L.M.)
| | - Matteo Brivio
- Department of Intensive Critical Care, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (S.C.); (M.B.); (P.G.); (F.L.L.)
| | - Simone Pappacena
- Pulmonary Medicine Unit, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (F.R.); (L.N.); (S.P.); (L.M.)
- Department of Health Sciences, University of Milan, 20122 Milan, Italy
| | - Luca Malandrino
- Pulmonary Medicine Unit, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (F.R.); (L.N.); (S.P.); (L.M.)
- Department of Health Sciences, University of Milan, 20122 Milan, Italy
| | - Pietro Andrea Bonaffini
- Department of Diagnostic Radiology, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (S.A.); (P.A.B.); (I.B.); (N.L.); (S.S.)
- Department of Medicine and Surgery, University of Milano-Bicocca, 20126 Milan, Italy
| | - Ilaria Bianco
- Department of Diagnostic Radiology, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (S.A.); (P.A.B.); (I.B.); (N.L.); (S.S.)
- Department of Medicine and Surgery, University of Milano-Bicocca, 20126 Milan, Italy
| | - Noemi Liggeri
- Department of Diagnostic Radiology, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (S.A.); (P.A.B.); (I.B.); (N.L.); (S.S.)
- Department of Medicine and Surgery, University of Milano-Bicocca, 20126 Milan, Italy
| | - Paolo Gritti
- Department of Intensive Critical Care, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (S.C.); (M.B.); (P.G.); (F.L.L.)
| | - Ferdinando Luca Lorini
- Department of Intensive Critical Care, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (S.C.); (M.B.); (P.G.); (F.L.L.)
- Department of Medicine and Surgery, University of Milano-Bicocca, 20126 Milan, Italy
| | - Sandro Sironi
- Department of Diagnostic Radiology, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (S.A.); (P.A.B.); (I.B.); (N.L.); (S.S.)
- Department of Medicine and Surgery, University of Milano-Bicocca, 20126 Milan, Italy
| | - Fabiano Di Marco
- Pulmonary Medicine Unit, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (F.R.); (L.N.); (S.P.); (L.M.)
- Department of Health Sciences, University of Milan, 20122 Milan, Italy
- Correspondence: ; Tel.: +39-035-2673456
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19
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Le Terrier C, Sigaud F, Lebbah S, Desmedt L, Hajage D, Guérin C, Pugin J, Primmaz S, Terzi N. Early prone positioning in acute respiratory distress syndrome related to COVID-19: a propensity score analysis from the multicentric cohort COVID-ICU network-the ProneCOVID study. Crit Care 2022; 26:71. [PMID: 35331332 PMCID: PMC8944409 DOI: 10.1186/s13054-022-03949-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 03/14/2022] [Indexed: 12/02/2022] Open
Abstract
Background Delaying time to prone positioning (PP) may be associated with higher mortality in acute respiratory distress syndrome (ARDS) due to coronavirus disease 2019 (COVID-19). We evaluated the use and the impact of early PP on clinical outcomes in intubated patients hospitalized in intensive care units (ICUs) for COVID-19. Methods All intubated patients with ARDS due to COVID-19 were involved in a secondary analysis from a prospective multicenter cohort study of COVID-ICU network including 149 ICUs across France, Belgium and Switzerland. Patients were followed-up until Day-90. The primary outcome was survival at Day-60. Analysis used a Cox proportional hazard model including a propensity score. Results Among 2137 intubated patients, 1504 (70.4%) were placed in PP during their ICU stay and 491 (23%) during the first 24 h following ICU admission. One hundred and eighty-one patients (36.9%) of the early PP group had a PaO2/FiO2 ratio > 150 mmHg when prone positioning was initiated. Among non-early PP group patients, 1013 (47.4%) patients had finally been placed in PP within a median delay of 3 days after ICU admission. Day-60 mortality in non-early PP group was 34.2% versus 39.3% in the early PP group (p = 0.038). Day-28 and Day-90 mortality as well as the need for adjunctive therapies was more important in patients with early PP. After propensity score adjustment, no significant difference in survival at Day-60 was found between the two study groups (HR 1.34 [0.96–1.68], p = 0.09 and HR 1.19 [0.998–1.412], p = 0.053 in complete case analysis or in multiple imputation analysis, respectively).
Conclusions In a large multicentric international cohort of intubated ICU patients with ARDS due to COVID-19, PP has been used frequently as a main treatment. In this study, our data failed to show a survival benefit associated with early PP started within 24 h after ICU admission compared to PP after day-1 for all COVID-19 patients requiring invasive mechanical ventilation regardless of their severity.
Supplementary Information The online version contains supplementary material available at 10.1186/s13054-022-03949-7.
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Affiliation(s)
- Christophe Le Terrier
- Division of Intensive Care, Geneva University Hospitals and the University of Geneva Faculty of Medicine, Geneva, Switzerland
| | - Florian Sigaud
- Medical Intensive Care Unit, Grenoble Alpes University Hospital, Grenoble, France
| | - Said Lebbah
- AP-HP, Département de Santé Publique, Centre de Pharmaco-épidémiologie, Paris, France
| | - Luc Desmedt
- Medical Intensive Care Unit, Nantes Hôtel-Dieu University Hospital, Nantes, France
| | - David Hajage
- AP-HP, Département de Santé Publique, Centre de Pharmaco-épidémiologie, Paris, France
| | - Claude Guérin
- Division of Intensive Care, Edouard Herriot University Hospital, Lyon, France
| | - Jérôme Pugin
- Division of Intensive Care, Geneva University Hospitals and the University of Geneva Faculty of Medicine, Geneva, Switzerland
| | - Steve Primmaz
- Division of Intensive Care, Geneva University Hospitals and the University of Geneva Faculty of Medicine, Geneva, Switzerland
| | - Nicolas Terzi
- Medical Intensive Care Unit, Grenoble Alpes University Hospital, Grenoble, France. .,Medical Intensive Care Unit, Grenoble Alpes University Hospital, Avenue Maquis du Grésivaudan, 38700, La Tronche, France.
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20
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Prognostic value of computed tomographic findings in acute respiratory distress syndrome and the response to prone positioning. BMC Pulm Med 2022; 22:71. [PMID: 35216579 PMCID: PMC8874746 DOI: 10.1186/s12890-022-01864-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 02/15/2022] [Indexed: 01/06/2023] Open
Abstract
Background Prone positioning enables the redistribution of lung weight, leading to the improvement of gas exchange and respiratory mechanics. We aimed to evaluate whether the initial findings of acute respiratory distress syndrome (ARDS) on computed tomography (CT) are associated with the subsequent response to prone positioning in terms of oxygenation and 60-day mortality. Methods We retrospectively included patients who underwent prone positioning for moderate to severe ARDS from October 2014 to November 2020 at a medical center in Taiwan. A semiquantitative CT rating scale was used to quantify the extent of consolidation and ground-glass opacification (GGO) in the sternal, central and vertebral regions at three levels (apex, hilum and base) of the lungs. A prone responder was identified by a 20% increase in the ratio of arterial oxygen pressure (PaO2) to the fraction of oxygen (FiO2) or a 20 mmHg increase in PaO2. Results Ninety-six patients were included, of whom 68 (70.8%) were responders. Compared with nonresponders, responders had a significantly greater median dorsal–ventral difference in CT-consolidation scores (10 vs. 7, p = 0.046) but not in CT-GGO scores (− 1 vs. − 1, p = 0.974). Although dorsal–ventral differences in neither CT-consolidation scores nor CT-GGO scores were associated with 60-day mortality, high total CT-GGO scores (≥ 15) were an independent factor associated with 60-day mortality (odds ratio = 4.07, 95% confidence interval, 1.39–11.89, p = 0.010). Conclusions In patients with moderate to severe ARDS, a greater difference in the extent of consolidation along the dependent-independent axis on CT scan is associated with subsequent prone positioning oxygenation response, but not clinical outcome regarding survival. High total CT-GGO scores were independently associated with 60-day mortality. Supplementary Information The online version contains supplementary material available at 10.1186/s12890-022-01864-9.
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21
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Kawakami A, Yamakawa K, Nishioka D, Ota K, Kusaka Y, Umegaki O, Ito Y, Takasu A.
PaO
2
/
FiO
2
ratio responsiveness to prone positioning in intubated patients with severe
COVID
‐19: a retrospective observational study. Acute Med Surg 2022; 9:e765. [PMID: 35677680 PMCID: PMC9167425 DOI: 10.1002/ams2.765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 05/15/2022] [Indexed: 12/15/2022] Open
Abstract
Aim Prone positioning of coronavirus disease 2019 (COVID‐19) patients could improve oxygenation. However, clinical data on prone positioning of intubated COVID‐19 patients are limited. We investigated trends of PaO2 / FiO2 ratio values in patients during prone positioning to identify a predictive factor for early detection of patients requiring advanced therapeutic intervention such as extracorporeal membrane oxygenation (ECMO). Methods This retrospective, observational cohort study was undertaken between April 2020 and May 2021 in a tertiary referral hospital for COVID‐19 in Osaka, Japan. We included intubated adult COVID‐19 patients treated with prone positioning within the first 72 h of admission to the intensive care unit and followed them until hospital discharge or death. Primary outcomes were in‐hospital mortality and escalation of care to ECMO. We used unsupervised k‐means clustering modeling to categorize COVID‐19 patients by PaO2 / FiO2 ratio responsiveness to prone positioning. Results The final study cohort comprised 54 of 155 consecutive severe COVID‐19 patients. Three clusters were generated according to trends in PaO2 / FiO2 ratios during prone positioning (cluster A, n = 16; cluster B, n = 24; cluster C, n = 14). Baseline characteristics of all clusters were almost similar. Cluster A (no increase in PaO2 / FiO2 ratio during prone positioning) had a significantly higher proportion of patients placed on ECMO or who died (6/16, 37.5%). Numbers of patients with ECMO and with in‐hospital death were significantly different between the three groups (p = 0.017). Conclusion In Japanese patients intubated due to COVID‐19, clinicians should consider earlier escalation of treatment, such as facility transfer or ECMO, if the PaO2 / FiO2 ratio does not increase during initial prone positioning.
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Affiliation(s)
- Akiko Kawakami
- Department of Emergency and Critical Care Medicine Osaka Medical and Pharmaceutical University Takatsuki Japan
| | - Kazuma Yamakawa
- Department of Emergency and Critical Care Medicine Osaka Medical and Pharmaceutical University Takatsuki Japan
| | - Daisuke Nishioka
- Department of Medical Statistics, Research and Development Center Osaka Medical and Pharmaceutical University Takatsuki Japan
| | - Koshi Ota
- Department of Emergency and Critical Care Medicine Osaka Medical and Pharmaceutical University Takatsuki Japan
| | - Yusuke Kusaka
- Department of Anesthesiology Osaka Medical and Pharmaceutical University Takatsuki Japan
| | - Osamu Umegaki
- Intensive Care Unit Osaka Medical and Pharmaceutical University Hospital Takatsuki Japan
| | - Yuri Ito
- Department of Medical Statistics, Research and Development Center Osaka Medical and Pharmaceutical University Takatsuki Japan
| | - Akira Takasu
- Department of Emergency and Critical Care Medicine Osaka Medical and Pharmaceutical University Takatsuki Japan
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22
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Winkler T, Kohli P, Kelly VJ, Kehl EG, Witkin AS, Rodriguez-Lopez JM, Hibbert KA, Kone MT, Systrom DM, Waxman AB, Venegas JG, Channick RN, Harris RS. Perfusion imaging heterogeneity during NO inhalation distinguishes pulmonary arterial hypertension (PAH) from healthy subjects and has potential as an imaging biomarker. Respir Res 2022; 23:325. [PMID: 36457013 PMCID: PMC9714016 DOI: 10.1186/s12931-022-02239-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 11/03/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Without aggressive treatment, pulmonary arterial hypertension (PAH) has a 5-year mortality of approximately 40%. A patient's response to vasodilators at diagnosis impacts the therapeutic options and prognosis. We hypothesized that analyzing perfusion images acquired before and during vasodilation could identify characteristic differences between PAH and control subjects. METHODS We studied 5 controls and 4 subjects with PAH using HRCT and 13NN PET imaging of pulmonary perfusion and ventilation. The total spatial heterogeneity of perfusion (CV2Qtotal) and its components in the vertical (CV2Qvgrad) and cranio-caudal (CV2Qzgrad) directions, and the residual heterogeneity (CV2Qr), were assessed at baseline and while breathing oxygen and nitric oxide (O2 + iNO). The length scale spectrum of CV2Qr was determined from 10 to 110 mm, and the response of regional perfusion to O2 + iNO was calculated as the mean of absolute differences. Vertical gradients in perfusion (Qvgrad) were derived from perfusion images, and ventilation-perfusion distributions from images of 13NN washout kinetics. RESULTS O2 + iNO significantly enhanced perfusion distribution differences between PAH and controls, allowing differentiation of PAH subjects from controls. During O2 + iNO, CV2Qvgrad was significantly higher in controls than in PAH (0.08 (0.055-0.10) vs. 6.7 × 10-3 (2 × 10-4-0.02), p < 0.001) with a considerable gap between groups. Qvgrad and CV2Qtotal showed smaller differences: - 7.3 vs. - 2.5, p = 0.002, and 0.12 vs. 0.06, p = 0.01. CV2Qvgrad had the largest effect size among the primary parameters during O2 + iNO. CV2Qr, and its length scale spectrum were similar in PAH and controls. Ventilation-perfusion distributions showed a trend towards a difference between PAH and controls at baseline, but it was not statistically significant. CONCLUSIONS Perfusion imaging during O2 + iNO showed a significant difference in the heterogeneity associated with the vertical gradient in perfusion, distinguishing in this small cohort study PAH subjects from controls.
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Affiliation(s)
- Tilo Winkler
- grid.38142.3c000000041936754XDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114 USA
| | - Puja Kohli
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA USA
| | - Vanessa J. Kelly
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA USA
| | - Ekaterina G. Kehl
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA USA
| | - Alison S. Witkin
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA USA
| | - Josanna M. Rodriguez-Lopez
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA USA
| | - Kathryn A. Hibbert
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA USA
| | - Mamary T. Kone
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA USA
| | - David M. Systrom
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA USA
| | - Aaron B. Waxman
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA USA
| | - Jose G. Venegas
- grid.38142.3c000000041936754XDepartment of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114 USA
| | - Richard N. Channick
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA USA
| | - R. Scott Harris
- grid.38142.3c000000041936754XDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA USA
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23
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Lagier D, Zeng C, Fernandez-Bustamante A, Melo MFV. Perioperative Pulmonary Atelectasis: Part II. Clinical Implications. Anesthesiology 2022; 136:206-236. [PMID: 34710217 PMCID: PMC9885487 DOI: 10.1097/aln.0000000000004009] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The development of pulmonary atelectasis is common in the surgical patient. Pulmonary atelectasis can cause various degrees of gas exchange and respiratory mechanics impairment during and after surgery. In its most serious presentations, lung collapse could contribute to postoperative respiratory insufficiency, pneumonia, and worse overall clinical outcomes. A specific risk assessment is critical to allow clinicians to optimally choose the anesthetic technique, prepare appropriate monitoring, adapt the perioperative plan, and ensure the patient's safety. Bedside diagnosis and management have benefited from recent imaging advancements such as lung ultrasound and electrical impedance tomography, and monitoring such as esophageal manometry. Therapeutic management includes a broad range of interventions aimed at promoting lung recruitment. During general anesthesia, these strategies have consistently demonstrated their effectiveness in improving intraoperative oxygenation and respiratory compliance. Yet these same intraoperative strategies may fail to affect additional postoperative pulmonary outcomes. Specific attention to the postoperative period may be key for such outcome impact of lung expansion. Interventions such as noninvasive positive pressure ventilatory support may be beneficial in specific patients at high risk for pulmonary atelectasis (e.g., obese) or those with clinical presentations consistent with lung collapse (e.g., postoperative hypoxemia after abdominal and cardiothoracic surgeries). Preoperative interventions may open new opportunities to minimize perioperative lung collapse and prevent pulmonary complications. Knowledge of pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should provide the basis for current practice and help to stratify and match the intensity of selected interventions to clinical conditions.
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Affiliation(s)
- David Lagier
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Congli Zeng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Marcos F. Vidal Melo
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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24
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Pollock RD, Hodkinson PD, Smith TG. Oh G: The x, y and z of human physiological responses to acceleration. Exp Physiol 2021; 106:2367-2384. [PMID: 34730860 DOI: 10.1113/ep089712] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 10/18/2021] [Indexed: 01/06/2023]
Abstract
NEW FINDINGS What is the topic of this review? This review focuses on the main physiological challenges associated with exposure to acceleration in the Gx, Gy and Gz directions and to microgravity. What advances does it highlight? Our current understanding of the physiology of these environments and latest strategies to protect against them are discussed in light of the limited knowledge we have in some of these areas. ABSTRACT The desire to go higher, faster and further has taken us to environments where the accelerations placed on our bodies far exceed or are much lower than that attributable to Earth's gravity. While on the ground, racing drivers of the fastest cars are exposed to high degrees of lateral acceleration (Gy) during cornering. In the air, while within the confines of the lower reaches of Earth's atmosphere, fast jet pilots are routinely exposed to high levels of acceleration in the head-foot direction (Gz). During launch and re-entry of suborbital and orbital spacecraft, astronauts and spaceflight participants are exposed to high levels of chest-back acceleration (Gx), whereas once in space the effects of gravity are all but removed (termed microgravity, μG). Each of these environments has profound effects on the homeostatic mechanisms within the body and can have a serious impact, not only for those with underlying pathology but also for healthy individuals. This review provides an overview of the main challenges associated with these environments and our current understanding of the physiological and pathophysiological adaptations to them. Where relevant, protection strategies are discussed, with the implications of our future exposure to these environments also being considered.
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Affiliation(s)
- Ross D Pollock
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK
| | - Peter D Hodkinson
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK
| | - Thomas G Smith
- Centre for Human and Applied Physiological Sciences, King's College London, London, UK.,Department of Anaesthesia, Guy's and St Thomas' NHS Foundation Trust, London, UK
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Chang KW, Hu HC, Chiu LC, Chan MC, Liang SJ, Yang KY, Chen WC, Fang WF, Chen YM, Sheu CC, Chang WA, Wang HC, Chien YC, Peng CK, Wu CL, Kao KC. Comparison of prone positioning and extracorporeal membrane oxygenation in acute respiratory distress syndrome: A multicenter cohort study and propensity-matched analysis. J Formos Med Assoc 2021; 121:1149-1158. [PMID: 34740489 PMCID: PMC8519810 DOI: 10.1016/j.jfma.2021.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 10/06/2021] [Accepted: 10/09/2021] [Indexed: 01/17/2023] Open
Abstract
Background/Purpose Both prone positioning and extracorporeal membrane oxygenation (ECMO) are used as rescue therapies for severe hypoxemia in patients with acute respiratory distress syndrome (ARDS). This study compared outcomes between patients with severe influenza pneumonia-related ARDS who received prone positioning and those who received ECMO. Methods This retrospective cohort study included eight tertiary referral centers in Taiwan. All patients who were diagnosed as having influenza pneumonia-related severe ARDS were enrolled between January and March 2016. We collected their demographic data and prone positioning and ECMO outcomes from medical records. Results In total, 263 patients diagnosed as having ARDS were included, and 65 and 53 of them received prone positioning and ECMO, respectively. The baseline PaO2/FiO2 ratio, Acute Physiology and Chronic Health Evaluation II score and Sequential Organ Failure Assessment score did not significantly differ between the two groups. The 60-day mortality rate was significantly higher in the ECMO group than in the prone positioning group (60% vs. 28%, p = 0.001). A significantly higher mortality rate was still observed in the ECMO group after propensity score matching (59% vs. 36%, p = 0.033). In the multivariate Cox regression analysis, usage of prone positioning or ECMO was the single independent predictor for 60-day mortality (hazard ratio: 2.177, p = 0.034). Conclusion While the patients receiving prone positioning had better outcome, the causality between prone positioning and the prognosis is unknown. However, the current data suggested that patients with influenza-related ARDS may receive prone positioning before ECMO support.
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Affiliation(s)
- Ko-Wei Chang
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Han-Chung Hu
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang-Gung University College of Medicine, Taoyuan, Taiwan
| | - Li-Chung Chiu
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Ming-Cheng Chan
- Division of Critical Care and Respiratory Therapy, Department of Internal Medicine, Taichung Veterans General Hospital, Taiwan; College of Science, Tunghai University, Taiwan
| | - Shinn-Jye Liang
- Division of Pulmonary and Critical Care, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Kuang-Yao Yang
- Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Emergency and Critical Care Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Wei-Chih Chen
- Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Emergency and Critical Care Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Wen-Feng Fang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; Department of Respiratory Care, Chang Gung University of Science and Technology, Chiayi, Taiwan
| | - Yu-Mu Chen
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
| | - Chau-Chyun Sheu
- Division of Pulmonary and Critical Care Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Wei-An Chang
- Division of Pulmonary and Critical Care Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hao-Chien Wang
- Division of Chest Medicine, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Ying-Chun Chien
- Division of Chest Medicine, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Chung-Kan Peng
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chieh-Liang Wu
- Center for Quality Management, Taichung Veterans General Hospital, Taichung, Taiwan; Office of Medical Administration, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Kuo-Chin Kao
- Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang-Gung University College of Medicine, Taoyuan, Taiwan.
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Awake Prone Positioning Strategy for Nonintubated Hypoxic Patients with COVID-19: A Pilot Trial with Embedded Implementation Evaluation. Ann Am Thorac Soc 2021; 18:1360-1368. [PMID: 33356977 PMCID: PMC8513648 DOI: 10.1513/annalsats.202009-1164oc] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Rationale: Prone positioning is an appealing therapeutic strategy for nonintubated hypoxic patients with coronavirus disease (COVID-19), but its effectiveness remains to be established in randomized controlled trials. Objectives: To identify contextual factors relevant to the conduct of a definitive clinical trial evaluating a prone positioning strategy for nonintubated hypoxic patients with COVID-19. Methods: We conducted a cluster randomized pilot trial at a quaternary care teaching hospital. Five inpatient medical service teams were randomly allocated to two treatment arms: 1) usual care (UC), consisting of current, standard management of hypoxia and COVID-19; or 2) the Awake Prone Positioning Strategy (APPS) plus UC. Included patients had positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing or suspected COVID-19 pneumonia and oxygen saturation less than 93% or new oxygen requirement of 3 L per minute or greater and no contraindications to prone positioning. Oxygenation measures were collected within 48 hours of eligibility and included nadir oxygen saturation to fraction of inspired oxygen (S/F) ratio and time spent with S/F ratio less than 315. Concurrently, we conducted an embedded implementation evaluation using semistructured interviews with clinician and patient participants to determine contextual factors relevant to the successful conduct of a future clinical trial. The primary outcomes were drawn from an implementation science framework including acceptability, adoption, appropriateness, effectiveness, equity, feasibility, fidelity, and penetration. Results: Forty patients were included in the cluster randomized trial. Patients in the UC group (n = 13) had a median nadir S/F ratio over the 48-hour study period of 216 (95% confidence interval [95% CI], 95–303) versus 253 (95% CI, 197–267) in the APPS group (n = 27). Patients in the UC group spent 42 hours (95% CI, 13–47) of the 48-hour study period with an S/F ratio below 315 versus 20 hours (95% CI, 6–39) for patients in the APPS group. Mixed-methods analyses uncovered several barriers relevant to the conduct of a successful definitive randomized controlled trial, including low adherence to prone positioning, large differences between physician-recommended and patient-tolerated prone durations, and diffusion of prone positioning into usual care. Conclusions: A definitive trial evaluating the effect of prone positioning in nonintubated patients with COVID-19 is warranted, but several barriers must be addressed to ensure that the results of such a trial are informative and readily translated into practice.
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Berg RMG, Hartmann JP, Iepsen UW, Christensen RH, Ronit A, Andreasen AS, Bailey DM, Mortensen J, Moseley PL, Plovsing RR. Therapeutic benefits of proning to improve pulmonary gas exchange in severe respiratory failure: focus on fundamentals of physiology. Exp Physiol 2021; 107:759-770. [PMID: 34242438 PMCID: PMC9290689 DOI: 10.1113/ep089405] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/06/2021] [Indexed: 12/27/2022]
Abstract
New Findings What is the topic of this review? The use of proning for improving pulmonary gas exchange in critically ill patients. What advances does it highlight? Proning places the lung in its ‘natural’ posture, and thus optimises the ventilation‐perfusion distribution, which enables lung protective ventilation and the alleviation of potentially life‐threatening hypoxaemia in COVID‐19 and other types of critical illness with respiratory failure.
Abstract The survival benefit of proning patients with acute respiratory distress syndrome (ARDS) is well established and has recently been found to improve pulmonary gas exchange in patients with COVID‐19‐associated ARDS (CARDS). This review outlines the physiological implications of transitioning from supine to prone on alveolar ventilation‐perfusion (V˙A--Q˙) relationships during spontaneous breathing and during general anaesthesia in the healthy state, as well as during invasive mechanical ventilation in patients with ARDS and CARDS. Spontaneously breathing, awake healthy individuals maintain a small vertical (ventral‐to‐dorsal) V˙A/Q˙ ratio gradient in the supine position, which is largely neutralised in the prone position, mainly through redistribution of perfusion. In anaesthetised and mechanically ventilated healthy individuals, a vertical V˙A/Q˙ ratio gradient is present in both postures, but with better V˙A--Q˙ matching in the prone position. In ARDS and CARDS, the vertical V˙A/Q˙ ratio gradient in the supine position becomes larger, with intrapulmonary shunting in gravitationally dependent lung regions due to compression atelectasis of the dorsal lung. This is counteracted by proning, mainly through a more homogeneous distribution of ventilation combined with a largely unaffected high perfusion dorsally, and a consequent substantial improvement in arterial oxygenation. The data regarding proning as a therapy in patients with CARDS is still limited and whether the associated improvement in arterial oxygenation translates to a survival benefit remains unknown. Proning is nonetheless an attractive and lung protective manoeuvre with the potential benefit of improving life‐threatening hypoxaemia in patients with ARDS and CARDS.
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Affiliation(s)
- Ronan M G Berg
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark.,Centre for Physical Activity Research, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark.,Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK
| | - Jacob Peter Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Centre for Physical Activity Research, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark.,Department of Emergency Medicine, North Zealand Hospital, Hillerød, Denmark
| | - Ulrik Winning Iepsen
- Centre for Physical Activity Research, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark.,Department of Anaesthesia and Intensive Care, Copenhagen University Hospital - Hvidovre Hospital, Hvidovre, Denmark
| | | | - Andreas Ronit
- Department of Infectious Diseases, Copenhagen University Hospital - Hvidovre Hospital, Hvidovre, Denmark
| | - Anne Sofie Andreasen
- Department of Anaesthesia and Intensive Care, Copenhagen University Hospital - Herlev Hospital, Herlev, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK
| | - Jann Mortensen
- Department of Clinical Physiology, Nuclear Medicine & PET, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Pope L Moseley
- Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ronni R Plovsing
- Department of Anaesthesia and Intensive Care, Copenhagen University Hospital - Hvidovre Hospital, Hvidovre, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Rosén J, von Oelreich E, Fors D, Jonsson Fagerlund M, Taxbro K, Skorup P, Eby L, Campoccia Jalde F, Johansson N, Bergström G, Frykholm P. Awake prone positioning in patients with hypoxemic respiratory failure due to COVID-19: the PROFLO multicenter randomized clinical trial. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2021; 25:209. [PMID: 34127046 PMCID: PMC8200797 DOI: 10.1186/s13054-021-03602-9] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 05/11/2021] [Indexed: 02/07/2023]
Abstract
Background The effect of awake prone positioning on intubation rates is not established.
The aim of this trial was to investigate if a protocol for awake prone positioning reduces the rate of endotracheal intubation compared with standard care among patients with moderate to severe hypoxemic respiratory failure due to COVID-19. Methods We conducted a multicenter randomized clinical trial. Adult patients with confirmed COVID-19, high-flow nasal oxygen or noninvasive ventilation for respiratory support and a PaO2/FiO2 ratio ≤ 20 kPa were randomly assigned to a protocol targeting 16 h prone positioning per day or standard care. The primary endpoint was intubation within 30 days. Secondary endpoints included duration of awake prone positioning, 30-day mortality, ventilator-free days, hospital and intensive care unit length of stay, use of noninvasive ventilation, organ support and adverse events. The trial was terminated early due to futility. Results Of 141 patients assessed for eligibility, 75 were randomized of whom 39 were allocated to the control group and 36 to the prone group. Within 30 days after enrollment, 13 patients (33%) were intubated in the control group versus 12 patients (33%) in the prone group (HR 1.01 (95% CI 0.46–2.21), P = 0.99). Median prone duration was 3.4 h [IQR 1.8–8.4] in the control group compared with 9.0 h per day [IQR 4.4–10.6] in the prone group (P = 0.014). Nine patients (23%) in the control group had pressure sores compared with two patients (6%) in the prone group (difference − 18% (95% CI − 2 to − 33%); P = 0.032). There were no other differences in secondary outcomes between groups. Conclusions The implemented protocol for awake prone positioning increased duration of prone positioning, but did not reduce the rate of intubation in patients with hypoxemic respiratory failure due to COVID-19 compared to standard care. Trial registration ISRCTN54917435. Registered 15 June 2020 (https://doi.org/10.1186/ISRCTN54917435). Supplementary Information The online version contains supplementary material available at 10.1186/s13054-021-03602-9.
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Affiliation(s)
- Jacob Rosén
- Department of Surgical Sciences, Section of Anaesthesiology and Intensive Care Medicine, Uppsala University, Entrance 78, 1 floor, 751 85, Uppsala, Sweden.
| | - Erik von Oelreich
- Perioperative Medicine and Intensive Care, Karolinska University Hospital, Solna, Sweden.,Department of Physiology and Pharmacology, Section of Anesthesiology and Intensive Care Medicine, Karolinska Institutet, Solna, Sweden
| | - Diddi Fors
- Department of Surgical Sciences, Section of Anaesthesiology and Intensive Care Medicine, Uppsala University, Entrance 78, 1 floor, 751 85, Uppsala, Sweden
| | - Malin Jonsson Fagerlund
- Perioperative Medicine and Intensive Care, Karolinska University Hospital, Solna, Sweden.,Department of Physiology and Pharmacology, Section of Anesthesiology and Intensive Care Medicine, Karolinska Institutet, Solna, Sweden
| | - Knut Taxbro
- Department of Anaesthesiology and Intensive Care Medicine, Ryhov County Hospital, Jönköping, Sweden
| | - Paul Skorup
- Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden
| | - Ludvig Eby
- Acute and Reparative Medicine, Karolinska University Hospital, Solna, Sweden
| | - Francesca Campoccia Jalde
- Perioperative Medicine and Intensive Care, Karolinska University Hospital, Solna, Sweden.,Department of Molecular Medicine and Surgery, Section of Thoracic Anesthesiology and Intensive Care, Karolinska Institutet, Solna, Sweden
| | - Niclas Johansson
- Department of Infectious Diseases, Karolinska University Hospital, Solna, Sweden.,Infectious Diseases Unit, Department of Medicine, Karolinska Institutet, Solna, Sweden
| | - Gustav Bergström
- Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden
| | - Peter Frykholm
- Department of Surgical Sciences, Section of Anaesthesiology and Intensive Care Medicine, Uppsala University, Entrance 78, 1 floor, 751 85, Uppsala, Sweden
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Hypoxic pulmonary vasoconstriction as a regulator of alveolar-capillary oxygen flux: A computational model of ventilation-perfusion matching. PLoS Comput Biol 2021; 17:e1008861. [PMID: 33956786 PMCID: PMC8130924 DOI: 10.1371/journal.pcbi.1008861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 05/18/2021] [Accepted: 03/04/2021] [Indexed: 11/19/2022] Open
Abstract
The relationship between regional variabilities in airflow (ventilation) and blood flow (perfusion) is a critical determinant of gas exchange efficiency in the lungs. Hypoxic pulmonary vasoconstriction is understood to be the primary active regulator of ventilation-perfusion matching, where upstream arterioles constrict to direct blood flow away from areas that have low oxygen supply. However, it is not understood how the integrated action of hypoxic pulmonary vasoconstriction affects oxygen transport at the system level. In this study we develop, and make functional predictions with a multi-scale multi-physics model of ventilation-perfusion matching governed by the mechanism of hypoxic pulmonary vasoconstriction. Our model consists of (a) morphometrically realistic 2D pulmonary vascular networks to the level of large arterioles and venules; (b) a tileable lumped-parameter model of vascular fluid and wall mechanics that accounts for the influence of alveolar pressure; (c) oxygen transport accounting for oxygen bound to hemoglobin and dissolved in plasma; and (d) a novel empirical model of hypoxic pulmonary vasoconstriction. Our model simulations predict that under the artificial test condition of a uniform ventilation distribution (1) hypoxic pulmonary vasoconstriction matches perfusion to ventilation; (2) hypoxic pulmonary vasoconstriction homogenizes regional alveolar-capillary oxygen flux; and (3) hypoxic pulmonary vasoconstriction increases whole-lobe oxygen uptake by improving ventilation-perfusion matching. The relationship between regional ventilation (airflow) and perfusion (blood flow) is a major determinant of gas exchange efficiency. Atelactasis and pulmonary vascular occlusive diseases, such as acute pulmonary embolism, are characterized by ventilation-perfusion mismatching and decreased oxygen in the bloodstream. Despite the physiological and medical importance of ventilation-perfusion matching, there are gaps in our knowledge of the regulatory mechanisms that maintain adequate gas exchange under pathological and normal conditions. Hypoxic pulmonary vasoconstriction is understood to be the primary regulator of ventilation-perfusion matching, where upstream arterioles constrict to direct blood flow away from areas that have low oxygen supply, yet it is not understood how this mechanism affects oxygen transport at the system level. In this study we present a computational model of the ventilation-perfusion matching and hypoxic pulmonary vasoconstriction to better understand how physiological regulation at the regional level scales to affect oxygen transport at the system level. Our model simulations predict that this regulatory mechanism improves the spatial overlap of airflow and blood flow, which serves to increase the uptake of oxygen into the bloodstream. This improved understanding of ventilation-perfusion matching may offer insights into the etiology of, and therapeutic interventions for diseases characterized by ventilation-perfusion mismatching.
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West CM, Wearing OH, Rhem RG, Scott GR. Pulmonary hypertension is attenuated and ventilation-perfusion matching is maintained during chronic hypoxia in deer mice native to high altitude. Am J Physiol Regul Integr Comp Physiol 2021; 320:R800-R811. [PMID: 33826424 DOI: 10.1152/ajpregu.00282.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hypoxia at high altitude can constrain metabolism and performance and can elicit physiological adjustments that are deleterious to health and fitness. Hypoxic pulmonary hypertension is a particularly serious and maladaptive response to chronic hypoxia, which results from vasoconstriction and pathological remodeling of pulmonary arteries, and can lead to pulmonary edema and right ventricle hypertrophy. We investigated whether deer mice (Peromyscus maniculatus) native to high altitude have attenuated this maladaptive response to chronic hypoxia and whether evolved changes or hypoxia-induced plasticity in pulmonary vasculature might impact ventilation-perfusion (V-Q) matching in chronic hypoxia. Deer mouse populations from both high and low altitudes were born and raised to adulthood in captivity at sea level, and various aspects of lung function were measured before and after exposure to chronic hypoxia (12 kPa O2, simulating the O2 pressure at 4,300 m) for 6-8 wk. In lowlanders, chronic hypoxia increased right ventricle systolic pressure (RVSP) from 14 to 19 mmHg (P = 0.001), in association with thickening of smooth muscle in pulmonary arteries and right ventricle hypertrophy. Chronic hypoxia also impaired V-Q matching in lowlanders (measured at rest using SPECT-CT imaging), as reflected by increased log SD of the perfusion distribution (log SDQ) from 0.55 to 0.86 (P = 0.031). In highlanders, chronic hypoxia had attenuated effects on RVSP and no effects on smooth muscle thickness, right ventricle mass, or V-Q matching. Therefore, evolved changes in lung function help attenuate maladaptive plasticity and contribute to hypoxia tolerance in high-altitude deer mice.
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Affiliation(s)
- Claire M West
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Oliver H Wearing
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Rod G Rhem
- Division of Respirology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Graham R Scott
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
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Langer T, Brioni M, Guzzardella A, Carlesso E, Cabrini L, Castelli G, Dalla Corte F, De Robertis E, Favarato M, Forastieri A, Forlini C, Girardis M, Grieco DL, Mirabella L, Noseda V, Previtali P, Protti A, Rona R, Tardini F, Tonetti T, Zannoni F, Antonelli M, Foti G, Ranieri M, Pesenti A, Fumagalli R, Grasselli G. Prone position in intubated, mechanically ventilated patients with COVID-19: a multi-centric study of more than 1000 patients. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2021; 25:128. [PMID: 33823862 PMCID: PMC8022297 DOI: 10.1186/s13054-021-03552-2] [Citation(s) in RCA: 150] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/26/2021] [Indexed: 02/06/2023]
Abstract
Background Limited data are available on the use of prone position in intubated, invasively ventilated patients with Coronavirus disease-19 (COVID-19). Aim of this study is to investigate the use and effect of prone position in this population during the first 2020 pandemic wave. Methods Retrospective, multicentre, national cohort study conducted between February 24 and June 14, 2020, in 24 Italian Intensive Care Units (ICU) on adult patients needing invasive mechanical ventilation for respiratory failure caused by COVID-19. Clinical data were collected on the day of ICU admission. Information regarding the use of prone position was collected daily. Follow-up for patient outcomes was performed on July 15, 2020. The respiratory effects of the first prone position were studied in a subset of 78 patients. Patients were classified as Oxygen Responders if the PaO2/FiO2 ratio increased ≥ 20 mmHg during prone position and as Carbon Dioxide Responders if the ventilatory ratio was reduced during prone position. Results Of 1057 included patients, mild, moderate and severe ARDS was present in 15, 50 and 35% of patients, respectively, and had a resulting mortality of 25, 33 and 41%. Prone position was applied in 61% of the patients. Patients placed prone had a more severe disease and died significantly more (45% vs. 33%, p < 0.001). Overall, prone position induced a significant increase in PaO2/FiO2 ratio, while no change in respiratory system compliance or ventilatory ratio was observed. Seventy-eight % of the subset of 78 patients were Oxygen Responders. Non-Responders had a more severe respiratory failure and died more often in the ICU (65% vs. 38%, p = 0.047). Forty-seven % of patients were defined as Carbon Dioxide Responders. These patients were older and had more comorbidities;
however, no difference in terms of ICU mortality was observed (51% vs. 37%, p = 0.189 for Carbon Dioxide Responders and Non-Responders, respectively). Conclusions During the COVID-19 pandemic, prone position has been widely adopted to treat mechanically ventilated patients with respiratory failure. The majority of patients improved their oxygenation during prone position, most likely due to a better ventilation perfusion matching. Trial registration: clinicaltrials.gov number: NCT04388670 Supplementary Information The online version contains supplementary material available at 10.1186/s13054-021-03552-2.
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Affiliation(s)
- Thomas Langer
- Department of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy.,Department of Anesthesia and Intensive Care Medicine, Niguarda Ca' Granda, Milan, Italy
| | - Matteo Brioni
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Amedeo Guzzardella
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Eleonora Carlesso
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Luca Cabrini
- Ospedale di Circolo e Fondazione Macchi, Università degli studi dell'Insubria, Varese, Italy
| | - Gianpaolo Castelli
- Department of Anesthesiology and Intensive Care, ASST Mantova-Ospedale Carlo Poma, Mantova, Italy
| | | | - Edoardo De Robertis
- Division of Anaesthesia, Analgesia and Intensive Care, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Martina Favarato
- Department of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy
| | - Andrea Forastieri
- Department of Anesthesia and Intensive Care, A. Manzoni Hospital, ASST Lecco, Lecco, Italy
| | - Clarissa Forlini
- Department of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy.,Department of Anesthesia and Intensive Care Medicine, Niguarda Ca' Granda, Milan, Italy
| | - Massimo Girardis
- Department of Anesthesia and Intensive Care, University Hospital of Modena, Modena, Italy
| | - Domenico Luca Grieco
- Department of Anesthesiology, Intensive Care and Emergency Medicine, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Sacred Heart Catholic University, Rome, Italy
| | - Lucia Mirabella
- Department of Medical and Surgical Sciences, Intensive Care Unit, University of Foggia, Foggia, Italy
| | - Valentina Noseda
- Department of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy
| | - Paola Previtali
- Department of Anesthesia and Intensive Care Medicine, Niguarda Ca' Granda, Milan, Italy
| | - Alessandro Protti
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, MI, Italy.,Department of Anaesthesia and Intensive Care, Humanitas Clinical and Research Center-IRCCS, Rozzano, MI, Italy
| | - Roberto Rona
- Department of Anesthesia and Intensive Care Medicine, San Gerardo Hospital ASST Monza, Monza, Italy
| | - Francesca Tardini
- Department of Anesthesia and Intensive Care Medicine, Niguarda Ca' Granda, Milan, Italy
| | - Tommaso Tonetti
- Anesthesia and Intensive Care Medicine, Policlinico di Sant'Orsola, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Fabio Zannoni
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Massimo Antonelli
- Department of Anesthesiology, Intensive Care and Emergency Medicine, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Sacred Heart Catholic University, Rome, Italy
| | - Giuseppe Foti
- Department of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy.,Department of Anesthesia and Intensive Care Medicine, San Gerardo Hospital ASST Monza, Monza, Italy
| | - Marco Ranieri
- Anesthesia and Intensive Care Medicine, Policlinico di Sant'Orsola, Alma Mater Studiorum University of Bologna, Bologna, Italy
| | - Antonio Pesenti
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Roberto Fumagalli
- Department of Medicine and Surgery, University of Milan-Bicocca, Monza, Italy.,Department of Anesthesia and Intensive Care Medicine, Niguarda Ca' Granda, Milan, Italy
| | - Giacomo Grasselli
- Department of Anesthesia, Critical Care and Emergency, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy. .,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
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Clark AR, Burrowes KS, Tawhai MH. Integrative Computational Models of Lung Structure-Function Interactions. Compr Physiol 2021; 11:1501-1530. [PMID: 33577123 DOI: 10.1002/cphy.c200011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Anatomically based integrative models of the lung and their interaction with other key components of the respiratory system provide unique capabilities for investigating both normal and abnormal lung function. There is substantial regional variability in both structure and function within the normal lung, yet it remains capable of relatively efficient gas exchange by providing close matching of air delivery (ventilation) and blood delivery (perfusion) to regions of gas exchange tissue from the scale of the whole organ to the smallest continuous gas exchange units. This is despite remarkably different mechanisms of air and blood delivery, different fluid properties, and unique scale-dependent anatomical structures through which the blood and air are transported. This inherent heterogeneity can be exacerbated in the presence of disease or when the body is under stress. Current computational power and data availability allow for the construction of sophisticated data-driven integrative models that can mimic respiratory system structure, function, and response to intervention. Computational models do not have the same technical and ethical issues that can limit experimental studies and biomedical imaging, and if they are solidly grounded in physiology and physics they facilitate investigation of the underlying interaction between mechanisms that determine respiratory function and dysfunction, and to estimate otherwise difficult-to-access measures. © 2021 American Physiological Society. Compr Physiol 11:1501-1530, 2021.
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Affiliation(s)
- Alys R Clark
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Kelly S Burrowes
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Merryn H Tawhai
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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Prone Ventilation for Patients with Mild or Moderate Acute Respiratory Distress Syndrome. Ann Am Thorac Soc 2021; 17:24-29. [PMID: 31532692 DOI: 10.1513/annalsats.201906-456ip] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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Kizhakke Puliyakote AS, Elliott AR, Sá RC, Anderson KM, Crotty Alexander LE, Hopkins SR. Vaping disrupts ventilation-perfusion matching in asymptomatic users. J Appl Physiol (1985) 2020; 130:308-317. [PMID: 33180648 DOI: 10.1152/japplphysiol.00709.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Inhalation of e-cigarette's aerosols (vaping) has the potential to disrupt pulmonary gas exchange, but the effects in asymptomatic users are unknown. We assessed ventilation-perfusion (V̇A/Q̇) mismatch in asymptomatic e-cigarette users, using magnetic resonance imaging (MRI). We hypothesized that vaping induces V̇A/Q̇ mismatch through alterations in both ventilation and perfusion distributions. Nine young, asymptomatic "Vapers" with >1-yr vaping history, and no history of cardiopulmonary disease, were imaged supine using proton MRI, to assess the right lung at baseline and immediately after vaping. Seven young "Controls" were imaged at baseline only. Relative dispersion (SD/means) was used to quantify the heterogeneity of the individual ventilation and perfusion distributions. V̇A/Q̇ mismatch was quantified using the second moments of the ventilation and perfusion versus V̇A/Q̇ ratio distributions, log scale, LogSDV̇, and LogSDQ̇, respectively, analogous to the multiple inert gas elimination technique. Spirometry was normal in both groups. Ventilation heterogeneity was similar between groups at baseline (Vapers, 0.43 ± 0.13; Controls, 0.51 ± 0.11; P = 0.13) but increased after vaping (to 0.57 ± 0.17; P = 0.03). Perfusion heterogeneity was greater (P = 0.04) in Vapers at baseline (0.53 ± 0.06) compared with Controls (0.44 ± 0.10) but decreased after vaping (to 0.42 ± 0.07; P = 0.005). Vapers had greater (P = 0.01) V̇A/Q̇ mismatch at baseline compared with Controls (LogSDQ̇ = 0.61 ± 0.12 vs. 0.43 ± 0.12), which was increased after vaping (LogSDQ̇ = 0.73 ± 0.16; P = 0.03). V̇A/Q̇ mismatch is greater in Vapers and worsens after vaping. This suggests subclinical alterations in lung function not detected by spirometry.NEW & NOTEWORTHY This research provides evidence of vaping-induced disruptions in ventilation-perfusion matching in young, healthy, asymptomatic adults with normal spirometry who habitually vape. The changes in ventilation and perfusion distributions, both at baseline and acutely after vaping, and the potential implications on hypoxic vasoconstriction are particularly relevant in understanding the pathogenesis of vaping-induced dysfunction. Our imaging-based approach provides evidence of potential subclinical alterations in lung function below thresholds of detection using spirometry.
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Affiliation(s)
- Abhilash S Kizhakke Puliyakote
- Pulmonary Imaging Laboratory, Department of Radiology, UC San Diego Health Sciences, San Diego, California.,Department of Radiology, University of California, San Diego, California
| | - Ann R Elliott
- Pulmonary Imaging Laboratory, Department of Radiology, UC San Diego Health Sciences, San Diego, California.,Department of Medicine, University of California, San Diego, California
| | - Rui C Sá
- Pulmonary Imaging Laboratory, Department of Radiology, UC San Diego Health Sciences, San Diego, California.,Department of Medicine, University of California, San Diego, California
| | - Kevin M Anderson
- Pulmonary Imaging Laboratory, Department of Radiology, UC San Diego Health Sciences, San Diego, California.,Department of Radiology, University of California, San Diego, California
| | | | - Susan R Hopkins
- Pulmonary Imaging Laboratory, Department of Radiology, UC San Diego Health Sciences, San Diego, California.,Department of Radiology, University of California, San Diego, California.,Department of Medicine, University of California, San Diego, California
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Prone position in ARDS patients: why, when, how and for whom. Intensive Care Med 2020; 46:2385-2396. [PMID: 33169218 PMCID: PMC7652705 DOI: 10.1007/s00134-020-06306-w] [Citation(s) in RCA: 234] [Impact Index Per Article: 58.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 10/19/2020] [Indexed: 12/16/2022]
Abstract
In ARDS patients, the change from supine to prone position generates a more even distribution of the gas–tissue ratios along the dependent–nondependent axis and a more homogeneous distribution of lung stress and strain. The change to prone position is generally accompanied by a marked improvement in arterial blood gases, which is mainly due to a better overall ventilation/perfusion matching. Improvement in oxygenation and reduction in mortality are the main reasons to implement prone position in patients with ARDS. The main reason explaining a decreased mortality is less overdistension in non-dependent lung regions and less cyclical opening and closing in dependent lung regions. The only absolute contraindication for implementing prone position is an unstable spinal fracture. The maneuver to change from supine to prone and vice versa requires a skilled team of 4–5 caregivers. The most frequent adverse events are pressure sores and facial edema. Recently, the use of prone position has been extended to non-intubated spontaneously breathing patients affected with COVID-19 ARDS. The effects of this intervention on outcomes are still uncertain.
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Shin KM, Choi J, Chae KJ, Jin GY, Eskandari A, Hoffman EA, Hall C, Castro M, Lee CH. Quantitative CT-based image registration metrics provide different ventilation and lung motion patterns in prone and supine positions in healthy subjects. Respir Res 2020; 21:254. [PMID: 33008396 PMCID: PMC7531138 DOI: 10.1186/s12931-020-01519-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 09/22/2020] [Indexed: 12/22/2022] Open
Abstract
Background Previous studies suggested that the prone position (PP) improves oxygenation and reduces mortality among patients with acute respiratory distress syndrome (ARDS). However, the mechanism of this clinical benefit of PP is not completely understood. The aim of the present study was to quantitatively compare regional characteristics of lung functions in the PP with those in the supine position (SP) using inspiratory and expiratory computed tomography (CT) scans. Methods Ninety subjects with normal pulmonary function and inspiration and expiration CT images were included in the study. Thirty-four subjects were scanned in PP, and 56 subjects were scanned in SP. Non-rigid image registration-based inspiratory-expiratory image matching assessment was used for regional lung function analysis. Tissue fractions (TF) were computed based on the CT density and compared on a lobar basis. Three registration-derived functional variables, relative regional air volume change (RRAVC), volumetric expansion ratio (J), and three-dimensional relative regional displacement (s*) were used to evaluate regional ventilation and deformation characteristics. Results J was greater in PP than in SP in the right middle lobe (P = 0 .025), and RRAVC was increased in the upper and right middle lobes (P < 0.001). The ratio of the TF on inspiratory and expiratory scans, J, and RRAVC at the upper lobes to those at the middle and lower lobes and that ratio at the upper and middle lobes to those at the lower lobes of were all near unity in PP, and significantly higher than those in SP (0.98–1.06 vs 0.61–0.94, P < 0.001). Conclusion We visually and quantitatively observed that PP not only induced more uniform contributions of regional lung ventilation along the ventral-dorsal axis but also minimized the lobar differences of lung functions in comparison with SP. This may help in the clinician’s search for an understanding of the benefits of the application of PP to the patients with ARDS or other gravitationally dependent pathologic lung diseases. Trial registration Retrospectively registered.
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Affiliation(s)
- Kyung Min Shin
- Department of Radiology, School of Medicine, Kyungpook National University, Kyungpook National University Chilgok Hospital, Daegu, South Korea
| | - Jiwoong Choi
- Department of Internal Medicine, School of Medicine, The University of Kansas, Kansas City, Kansas, USA.,Department of Bioengineering, The University of Kansas, Lawrence, Kansas, USA
| | - Kum Ju Chae
- Department of Radiology, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, South Korea
| | - Gong Yong Jin
- Department of Radiology, Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, South Korea
| | - Ali Eskandari
- Department of Radiology, University of Iowa, Iowa City, USA
| | - Eric A Hoffman
- Department of Radiology, University of Iowa, Iowa City, USA.,Internal Medicine, University of Iowa, Iowa City, USA.,Biomedical Engineering, University of Iowa, Iowa City, USA
| | - Chase Hall
- Department of Internal Medicine, School of Medicine, The University of Kansas, Kansas City, Kansas, USA
| | - Mario Castro
- Department of Internal Medicine, School of Medicine, The University of Kansas, Kansas City, Kansas, USA
| | - Chang Hyun Lee
- Department of Radiology, University of Iowa, Iowa City, USA. .,Department of Radiology, Seoul National University College of Medicine, Institute of Radiation Medicine, Seoul National University Hospital, 101 Daehak-ro, Jongnogu, Seoul, 03080, South Korea.
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Chuchalin AG, Gusev EI, Martynov MY, Kim TG, Shogenova LV. [Pulmonary insufficiency in acute stroke: risk factors and mechanisms of development]. Zh Nevrol Psikhiatr Im S S Korsakova 2020; 120:7-16. [PMID: 32790970 DOI: 10.17116/jnevro20201200717] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Various degrees of pulmonary insufficiency (PI) (PaO2 ≤60 mm Hg, SaO2 ≤90%) are diagnosed in most of patients with severe acute stroke (AS). Frequency and severity of PI positively correlates with the severity of AS. PI worsens patient's condition, prolongs the hospitalization period, and increases the probability of fatal outcome. Early clinical signs of PI may be undiagnosed due to the severity of stroke and thus not treated. The initiating pathogenic mechanism of PI is stress-related activation of sympathetic nervous system (SNS) and systemic immunosuppression. In severe stroke with mass effect, the rapid and significant increase in intracranial pressure may additionally activate the SNS. Risk factors of PI include older age, previous pulmonary disease, prolonged supine position, respiratory muscle dysfunction, apnea, and concomitant somatic diseases. Decompensation of somatic diseases leads to multiple stage reactions with facilitation of functional and morphologic changes in the pulmonary system, hypoxemia and hypoxia, promotes infectious complications and multiple organ failure and worsens neurological outcome. Diagnosis and treatment of PI in AS decreases mortality and improves rehabilitation prognosis.
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Affiliation(s)
- A G Chuchalin
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - E I Gusev
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - M Yu Martynov
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - T G Kim
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - L V Shogenova
- Pirogov Russian National Research Medical University, Moscow, Russia
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Paul V, Patel S, Royse M, Odish M, Malhotra A, Koenig S. Proning in Non-Intubated (PINI) in Times of COVID-19: Case Series and a Review. J Intensive Care Med 2020; 35:818-824. [PMID: 32633215 DOI: 10.1177/0885066620934801] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
It has been well known for decades that prone positioning (PP) improves oxygenation. However, it has gained widespread acceptance only in the last few years since studies have shown significant survival benefit. Many centers have established prone ventilation in their treatment algorithm for mechanically ventilated patients with severe acute respiratory distress syndrome (ARDS). Physiologically, PP should also benefit awake, non-intubated patients with acute hypoxemic respiratory failure. However, proning in non-intubated (PINI) patients did not gain any momentum until a few months ago when the Coronavirus disease 2019 (COVID-19) pandemic surged. A large number of sick patients overwhelmed the health care system, and many centers faced a dearth of ventilators. In addition, outcomes of patients placed on mechanical ventilation because of COVID-19 infection have been highly variable and often dismal. Hence, increased focus has shifted to using various strategies to prevent intubation, such as PINI. There is accumulating evidence that PINI is a low-risk intervention that can be performed even outside intensive care unit with minimal assistance and may prevent intubation in certain patients with ARDS. It can also be performed safely at smaller centers and, therefore, may reduce the patient transfer to larger institutions that are overwhelmed in the current crisis. We present a case series of 2 patients with acute hypoxemic respiratory failure who experienced significant improvements in oxygenation with PP. In addition, the physiology of PP is described, and concerns such as proning in obese and patient's anxiety are addressed; an educational pamphlet that may be useful for both patients and health care providers is provided.
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Affiliation(s)
- Vishesh Paul
- Department of Pulmonary & Critical Care Medicine, Carle Foundation Hospital, Urbana, IL, USA
| | - Shawn Patel
- Department of Family Medicine, Carle Foundation Hospital, Urbana, IL, USA
| | - Michelle Royse
- Department of Pulmonary & Critical Care Medicine, Carle Foundation Hospital, Urbana, IL, USA
| | - Mazen Odish
- Department of Pulmonary & Critical Care Medicine, University of California, San Diego, CA, USA
| | - Atul Malhotra
- Department of Pulmonary & Critical Care Medicine, University of California, San Diego, CA, USA
| | - Seth Koenig
- Department of Pulmonary & Critical Care Medicine, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA
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Hopkins SR. Ventilation/Perfusion Relationships and Gas Exchange: Measurement Approaches. Compr Physiol 2020; 10:1155-1205. [PMID: 32941684 DOI: 10.1002/cphy.c180042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ventilation-perfusion ( V ˙ A / Q ˙ ) matching, the regional matching of the flow of fresh gas to flow of deoxygenated capillary blood, is the most important mechanism affecting the efficiency of pulmonary gas exchange. This article discusses the measurement of V ˙ A / Q ˙ matching with three broad classes of techniques: (i) those based in gas exchange, such as the multiple inert gas elimination technique (MIGET); (ii) those derived from imaging techniques such as single-photon emission computed tomography (SPECT), positron emission tomography (PET), magnetic resonance imaging (MRI), computed tomography (CT), and electrical impedance tomography (EIT); and (iii) fluorescent and radiolabeled microspheres. The focus is on the physiological basis of these techniques that provide quantitative information for research purposes rather than qualitative measurements that are used clinically. The fundamental equations of pulmonary gas exchange are first reviewed to lay the foundation for the gas exchange techniques and some of the imaging applications. The physiological considerations for each of the techniques along with advantages and disadvantages are briefly discussed. © 2020 American Physiological Society. Compr Physiol 10:1155-1205, 2020.
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Affiliation(s)
- Susan R Hopkins
- Departments of Medicine and Radiology, University of California, San Diego, California, USA
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41
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Khan S, Choudry E, Mahmood SU, Mulla AY, Mehwish S. Awake Proning: A Necessary Evil During the COVID-19 Pandemic. Cureus 2020; 12:e8989. [PMID: 32775071 PMCID: PMC7402434 DOI: 10.7759/cureus.8989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The spread of COVID-19 has been exponential throughout the globe. Though only a small percentage of infected individuals reach the critical stage of the disease, i.e., acute respiratory distress syndrome (ARDS), this percentage represents a significant number of patients that can overwhelm the healthcare system. Patients presenting with ARDS need mechanical ventilation, as their lungs are unable to oxygenate blood on their own due to fluid accumulation. One way to manage this excess pressure of fluid build-up around the lung tissues is to relieve the dorsal alveoli by prompting the patient to lie face down on the stomach; this is called awake proning. It is a procedure that is directed towards the recruitment of lung parenchyma when infected with pneumonia or when the condition has worsened into ARDS. This helps in relieving the pressure from the dorsal lung surface that has markedly higher perfusion than the ventral surface. Awake proning delays the use of mechanical ventilation and facilitates the patients with severe ARDS or severe pneumonia in maintaining the supply of oxygen to the body tissues. Since medical institutes are overburdened and limited ventilators are available, awake proning can reduce not only the burden on hospitals but also decrease the need for ventilators.
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Affiliation(s)
| | - Erum Choudry
- Dentistry, The Indus Hospital, Indus Hospital Research Center, Karachi, PAK
| | - Syed Uzair Mahmood
- Pediatrics, The Indus Hospital, Indus Hospital Research Center, Karachi, PAK
| | - Aisha Y Mulla
- Dentistry, Karachi Medical and Dental College, Karachi, PAK
| | - Syeda Mehwish
- Dentistry, Karachi Medical and Dental College, Karachi, PAK
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42
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Elliott AR, Kizhakke Puliyakote AS, Tedjasaputra V, Pazár B, Wagner H, Sá RC, Orr JE, Prisk GK, Wagner PD, Hopkins SR. Ventilation-perfusion heterogeneity measured by the multiple inert gas elimination technique is minimally affected by intermittent breathing of 100% O 2. Physiol Rep 2020; 8:e14488. [PMID: 32638530 PMCID: PMC7340847 DOI: 10.14814/phy2.14488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 11/24/2022] Open
Abstract
Proton magnetic resonance (MR) imaging to quantify regional ventilation-perfusion ( V ˙ A / Q ˙ ) ratios combines specific ventilation imaging (SVI) and separate proton density and perfusion measures into a composite map. Specific ventilation imaging exploits the paramagnetic properties of O2 , which alters the local MR signal intensity, in an FI O2 -dependent manner. Specific ventilation imaging data are acquired during five wash-in/wash-out cycles of breathing 21% O2 alternating with 100% O2 over ~20 min. This technique assumes that alternating FI O2 does not affect V ˙ A / Q ˙ heterogeneity, but this is unproven. We tested the hypothesis that alternating FI O2 exposure increases V ˙ A / Q ˙ mismatch in nine patients with abnormal pulmonary gas exchange and increased V ˙ A / Q ˙ mismatch using the multiple inert gas elimination technique (MIGET).The following data were acquired (a) breathing air (baseline), (b) breathing alternating air/100% O2 during an emulated-SVI protocol (eSVI), and (c) 20 min after ambient air breathing (recovery). MIGET heterogeneity indices of shunt, deadspace, ventilation versus V ˙ A / Q ˙ ratio, LogSD V ˙ , and perfusion versus V ˙ A / Q ˙ ratio, LogSD Q ˙ were calculated. LogSD V ˙ was not different between eSVI and baseline (1.04 ± 0.39 baseline, 1.05 ± 0.38 eSVI, p = .84); but was reduced compared to baseline during recovery (0.97 ± 0.39, p = .04). There was no significant difference in LogSD Q ˙ across conditions (0.81 ± 0.30 baseline, 0.79 ± 0.15 eSVI, 0.79 ± 0.20 recovery; p = .54); Deadspace was not significantly different (p = .54) but shunt showed a borderline increase during eSVI (1.0% ± 1.0 baseline, 2.6% ± 2.9 eSVI; p = .052) likely from altered hypoxic pulmonary vasoconstriction and/or absorption atelectasis. Intermittent breathing of 100% O2 does not substantially alter V ˙ A / Q ˙ matching and if SVI measurements are made after perfusion measurements, any potential effects will be minimized.
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Affiliation(s)
- Ann R. Elliott
- Department of MedicineUniversity of California San DiegoLa JollaCAUSA
- The Pulmonary Imaging LaboratoryUniversity of California San DiegoLa JollaCAUSA
| | - Abhilash S. Kizhakke Puliyakote
- The Pulmonary Imaging LaboratoryUniversity of California San DiegoLa JollaCAUSA
- Department of RadiologyUniversity of California San DiegoLa JollaCAUSA
| | - Vincent Tedjasaputra
- Department of MedicineUniversity of California San DiegoLa JollaCAUSA
- The Pulmonary Imaging LaboratoryUniversity of California San DiegoLa JollaCAUSA
| | - Beni Pazár
- The Pulmonary Imaging LaboratoryUniversity of California San DiegoLa JollaCAUSA
- Department of RadiologyUniversity of California San DiegoLa JollaCAUSA
| | - Harrieth Wagner
- Department of MedicineUniversity of California San DiegoLa JollaCAUSA
| | - Rui C. Sá
- Department of MedicineUniversity of California San DiegoLa JollaCAUSA
- The Pulmonary Imaging LaboratoryUniversity of California San DiegoLa JollaCAUSA
| | - Jeremy E. Orr
- Department of MedicineUniversity of California San DiegoLa JollaCAUSA
| | - G. Kim Prisk
- Department of MedicineUniversity of California San DiegoLa JollaCAUSA
- The Pulmonary Imaging LaboratoryUniversity of California San DiegoLa JollaCAUSA
- Department of RadiologyUniversity of California San DiegoLa JollaCAUSA
| | - Peter D. Wagner
- Department of MedicineUniversity of California San DiegoLa JollaCAUSA
| | - Susan R. Hopkins
- Department of MedicineUniversity of California San DiegoLa JollaCAUSA
- The Pulmonary Imaging LaboratoryUniversity of California San DiegoLa JollaCAUSA
- Department of RadiologyUniversity of California San DiegoLa JollaCAUSA
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43
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Boucneau T, Fernandez B, Larson P, Darrasse L, Maître X. 3D Magnetic Resonance Spirometry. Sci Rep 2020; 10:9649. [PMID: 32541799 PMCID: PMC7295793 DOI: 10.1038/s41598-020-66202-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 04/21/2020] [Indexed: 01/23/2023] Open
Abstract
Spirometry is today the gold standard technique for assessing pulmonary ventilatory function in humans. From the shape of a flow-volume loop measured while the patient is performing forced respiratory cycles, the Forced Vital Capacity (FVC) and the Forced Expiratory Volume in one second (FEV1) can be inferred, and the pulmonologist is able to detect and characterize common respiratory afflictions. This technique is non-invasive, simple, widely available, robust, repeatable and reproducible. Yet, its outcomes rely on the patient's cooperation and provide only global information over the lung. With 3D Magnetic Resonance (MR) Spirometry, local ventilation can be assessed by MRI anywhere in the lung while the patient is freely breathing. The larger dimensionality of 3D MR Spirometry advantageously allows the extraction of original metrics that characterize the anisotropic and hysteretic regional mechanical behavior of the lung. Here, we demonstrated the potential of this technique on a healthy human volunteer breathing along different respiratory patterns during the MR acquisition. These new results are discussed with lung physiology and recent pulmonary CT data. As respiratory mechanics inherently support lung ventilation, 3D MR Spirometry may open a new way to non-invasively explore lung function while providing improved diagnosis of localized pulmonary diseases.
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Affiliation(s)
- Tanguy Boucneau
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
| | | | - Peder Larson
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA
| | - Luc Darrasse
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France
| | - Xavier Maître
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Orsay, France.
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44
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McNicholas B, Cosgrave D, Giacomini C, Brennan A, Laffey JG. Prone positioning in COVID-19 acute respiratory failure: just do it? Br J Anaesth 2020; 125:440-443. [PMID: 32571573 PMCID: PMC7280095 DOI: 10.1016/j.bja.2020.06.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 06/03/2020] [Indexed: 01/09/2023] Open
Affiliation(s)
- Bairbre McNicholas
- Department of Anaesthesia and Intensive Care Medicine, Galway University Hospitals, Galway, Ireland; Anaesthesia and Intensive Care Medicine, School of Medicine, National Unversity of Ireland, Galway, Ireland
| | - David Cosgrave
- Department of Anaesthesia and Intensive Care Medicine, Galway University Hospitals, Galway, Ireland; Anaesthesia and Intensive Care Medicine, School of Medicine, National Unversity of Ireland, Galway, Ireland
| | - Camilla Giacomini
- Department of Anaesthesia and Intensive Care Medicine, Galway University Hospitals, Galway, Ireland
| | - Aoife Brennan
- Department of Anaesthesia and Intensive Care Medicine, Galway University Hospitals, Galway, Ireland; Anaesthesia and Intensive Care Medicine, School of Medicine, National Unversity of Ireland, Galway, Ireland
| | - John G Laffey
- Department of Anaesthesia and Intensive Care Medicine, Galway University Hospitals, Galway, Ireland; Anaesthesia and Intensive Care Medicine, School of Medicine, National Unversity of Ireland, Galway, Ireland; Regenerative Medicine Institute at the CURAM Centre for Medical Devices, National University of Ireland, Galway, Ireland.
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45
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Jochmans S, Mazerand S, Chelly J, Pourcine F, Sy O, Thieulot-Rolin N, Ellrodt O, Mercier Des Rochettes E, Michaud G, Serbource-Goguel J, Vinsonneau C, Vong LVP, Monchi M. Duration of prone position sessions: a prospective cohort study. Ann Intensive Care 2020; 10:66. [PMID: 32449068 PMCID: PMC7245995 DOI: 10.1186/s13613-020-00683-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 05/16/2020] [Indexed: 12/16/2022] Open
Abstract
Background Prone position (PP) is highly recommended in moderate-to-severe ARDS. However, the optimal duration of PP sessions remains unclear. We searched to evaluate the time required to obtain the maximum physiological effect, and to search for parameters related to patient survival in PP. Methods and results It was a prospective, monocentric, physiological study. We included in the study all prone-positioned patients in our ICU between June 2016 and January 2018. Pulmonary mechanics, data from volumetric capnography and arterial blood gas were recorded before prone positioning, 2 h after proning, before return to a supine position (SP) and 2 h after return to SP. Dynamic parameters were recorded before proning and every 30 min during the session until 24 h. 103 patients (ARDS 95%) were included performing 231 PP sessions with a mean length of 21.5 ± 5 h per session. They presented a significant increase in pH, static compliance and PaO2/FiO2 with a significant decrease in PaCO2, Pplat, phase 3 slope of the volumetric capnography, PetCO2, VD/VT-phy and ΔP. The beneficial physiological effects continued after 16 h of PP and at least up to 24 h in some patients. The evolution of the respiratory parameters during the first session and also during the pooled sessions did not find any predictor of response to PP, whether before, during or 2 h after the return in SP. Conclusions PP sessions should be prolonged at least 24 h and be extended in the event that the PaO2/FiO2 ratio at 24 h remains below 150, especially since no criteria can predict which patient will benefit or not from it. Trial registration The trial has been registered on 28 June 2016 in ClinicalTrials.gov (NCT 02816190) (https://clinicaltrials.gov/ct2/show/NCT02816190?term=propocap&rank=1).
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Affiliation(s)
- Sebastien Jochmans
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France. .,Unité de Recherche Clinique, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France.
| | - Sandie Mazerand
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France
| | - Jonathan Chelly
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France.,Unité de Recherche Clinique, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France
| | - Franck Pourcine
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France
| | - Oumar Sy
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France
| | - Nathalie Thieulot-Rolin
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France
| | - Olivier Ellrodt
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France
| | - Emmanuelle Mercier Des Rochettes
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France.,Service de Réanimation Médicale, AP-HP, Hôpital Saint-Antoine, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France
| | - Gaël Michaud
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France
| | - Jean Serbource-Goguel
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France
| | - Christophe Vinsonneau
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France.,Unité de Recherche Clinique, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France.,Service de Réanimation, Hôpital de Béthune, 27 rue Delbecque, 62660, Beuvry, France
| | - Ly Van Phach Vong
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France
| | - Mehran Monchi
- Département de Médecine Intensive-Réanimation, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France.,Unité de Recherche Clinique, GH Sud Ile-de-France, Hôpital de Melun, 270 avenue Marc Jacquet, 77000, Melun, France
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Inata Y, Sofue T, Hatachi T, Kyogoku M, Takeuchi M. Prone positioning without neuromuscular blockade during extracorporeal membrane oxygenation in children. Pediatr Int 2020; 62:649-651. [PMID: 32383291 DOI: 10.1111/ped.14151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 12/16/2019] [Accepted: 01/15/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Yu Inata
- Department of Intensive Care Medicine, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Toshiki Sofue
- Department of Intensive Care Medicine, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Takeshi Hatachi
- Department of Intensive Care Medicine, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Miyako Kyogoku
- Department of Intensive Care Medicine, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Muneyuki Takeuchi
- Department of Intensive Care Medicine, Osaka Women's and Children's Hospital, Osaka, Japan
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Voskrebenzev A, Vogel-Claussen J. Proton MRI of the Lung: How to Tame Scarce Protons and Fast Signal Decay. J Magn Reson Imaging 2020; 53:1344-1357. [PMID: 32166832 DOI: 10.1002/jmri.27122] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/20/2020] [Accepted: 02/20/2020] [Indexed: 12/19/2022] Open
Abstract
Pulmonary proton MRI techniques offer the unique possibility of assessing lung function and structure without the requirement for hyperpolarization or dedicated hardware, which is mandatory for multinuclear acquisition. Five popular approaches are presented and discussed in this review: 1) oxygen enhanced (OE)-MRI; 2) arterial spin labeling (ASL); 3) Fourier decomposition (FD) MRI and other related methods including self-gated noncontrast-enhanced functional lung (SENCEFUL) MR and phase-resolved functional lung (PREFUL) imaging; 4) dynamic contrast-enhanced (DCE) MRI; and 5) ultrashort TE (UTE) MRI. While DCE MRI is the most established and well-studied perfusion measurement, FD MRI offers a free-breathing test without any contrast agent and is predestined for application in patients with renal failure or with low compliance. Additionally, FD MRI and related methods like PREFUL and SENCEFUL can act as an ionizing radiation-free V/Q scan, since ventilation and perfusion information is acquired simultaneously during one scan. For OE-MRI, different concentrations of oxygen are applied via a facemask to assess the regional change in T1 , which is caused by the paramagnetic property of oxygen. Since this change is governed by a combination of ventilation, diffusion, and perfusion, a compound functional measurement can be achieved with OE-MRI. The known problem of fast T2 * decay of the lung parenchyma leading to a low signal-to-noise ratio is bypassed by the UTE acquisition strategy. Computed tomography (CT)-like images allow the assessment of lung structure with high spatial resolution without ionizing radiation. Despite these different branches of proton MRI, common trends are evident among pulmonary proton MRI: 1) free-breathing acquisition with self-gating; 2) application of UTE to preserve a stronger parenchymal signal; and 3) transition from 2D to 3D acquisition. On that note, there is a visible convergence of the different methods and it is not difficult to imagine that future methods will combine different aspects of the presented methods.
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Affiliation(s)
- Andreas Voskrebenzev
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
| | - Jens Vogel-Claussen
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany
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48
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Selected discoveries from human research in space that are relevant to human health on Earth. NPJ Microgravity 2020; 6:5. [PMID: 32128361 PMCID: PMC7016134 DOI: 10.1038/s41526-020-0095-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 12/06/2019] [Indexed: 12/14/2022] Open
Abstract
A substantial amount of life-sciences research has been performed in space since the beginning of human spaceflight. Investigations into bone loss, for example, are well known; other areas, such as neurovestibular function, were expected to be problematic even before humans ventured into space. Much of this research has been applied research, with a primary goal of maintaining the health and performance of astronauts in space, as opposed to research to obtain fundamental understanding or to translate to medical care on Earth. Some people—scientists and concerned citizens—have questioned the broader scientific value of this research, with the claim that the only reason to perform human research in space is to keep humans healthy in space. Here, we present examples that demonstrate that, although this research was focused on applied goals for spaceflight participants, the results of these studies are of fundamental scientific and biomedical importance. We will focus on results from bone physiology, cardiovascular and pulmonary systems, and neurovestibular studies. In these cases, findings from spaceflight research have provided a foundation for enhancing healthcare terrestrially and have increased our knowledge of basic physiological processes.
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49
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Clark AR, Burrowes KS, Tawhai MH. Ventilation/Perfusion Matching: Of Myths, Mice, and Men. Physiology (Bethesda) 2019; 34:419-429. [PMID: 31577170 PMCID: PMC7002871 DOI: 10.1152/physiol.00016.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 07/01/2019] [Accepted: 07/08/2019] [Indexed: 11/22/2022] Open
Abstract
Despite a huge range in lung size between species, there is little measured difference in the ability of the lung to provide a well-matched air flow (ventilation) to blood flow (perfusion) at the gas exchange tissue. Here, we consider the remarkable similarities in ventilation/perfusion matching between species through a biophysical lens and consider evidence that matching in large animals is dominated by gravity but in small animals by structure.
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Affiliation(s)
- Alys R Clark
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Kelly S Burrowes
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Merryn H Tawhai
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
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50
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Tedjasaputra V, Sá RC, Anderson KM, Prisk GK, Hopkins SR. Heavy upright exercise increases ventilation-perfusion mismatch in the basal lung: indirect evidence for interstitial pulmonary edema. J Appl Physiol (1985) 2019; 127:473-481. [PMID: 31246558 PMCID: PMC6732434 DOI: 10.1152/japplphysiol.00056.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 06/20/2019] [Accepted: 06/24/2019] [Indexed: 11/22/2022] Open
Abstract
Ventilation-perfusion (V̇a/Q̇) mismatch during exercise may result from interstitial pulmonary edema if increased pulmonary vascular pressure causes fluid efflux into the interstitium. If present, the increased fluid may compress small airways or blood vessels, disrupting V̇a/Q̇ matching, but this is unproven. We hypothesized that V̇a/Q̇ mismatch would be greatest in basal lung following heavy upright exercise, consistent with hydrostatic forces favoring edema accumulation in the gravitationally dependent lung. We applied new tools to reanalyze previously published magnetic resonance imaging data to determine regional V̇a/Q̇ mismatch following 45 min of heavy upright exercise in six athletes (V̇o2max = 61 ± 7 mL·kg-1·min-1). In the supine posture, regional alveolar ventilation and local perfusion were quantified from specific ventilation imaging, proton density, and arterial spin labeling data in a single sagittal slice of the right lung before exercise (PRE), 15 min after exercise (POST), and in recovery 60 min after exercise (REC). Indices of V̇a/Q̇ mismatch [second moments (log scale) of ventilation (LogSDV) and perfusion (LogSDQ) vs. V̇a/Q̇ distributions] were calculated for apical, middle, and basal lung thirds, which represent gravitationally nondependent, middle, and dependent regions, respectively, during upright exercise. LogSDV increased after exercise only in the basal lung (PRE 0.46 ± 0.06, POST 0.57 ± 0.14, REC 0.55 ±0.14, P = 0.01). Similarly, LogSDQ increased only in the basal lung (PRE 0.40 ± 0.06, POST 0.51 ± 0.10, REC 0.44 ± 0.09, P = 0.04). Increased V̇a/Q̇ mismatch in the basal lung after exercise is potentially consistent with interstitial pulmonary edema accumulating in gravitationally dependent lung during exercise.NEW & NOTEWORTHY We reanalyzed previously published MRI data with new tools and found increased ventilation-perfusion mismatch only in the basal lung of athletes following 45 min of cycling exercise. This is consistent with the development of interstitial edema in the gravitationally dependent lung during heavy exercise.
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Affiliation(s)
- Vincent Tedjasaputra
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, California
| | - Rui C Sá
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, California
| | - Kevin M Anderson
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, California
| | - G Kim Prisk
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, California
| | - Susan R Hopkins
- Department of Medicine, University of California, San Diego School of Medicine, La Jolla, California
- Pulmonary Imaging Laboratory, Department of Radiology, University of California, San Diego School of Medicine, La Jolla, California
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