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Joseph A, Petit M, Vieillard-Baron A. Hemodynamic effects of positive end-expiratory pressure. Curr Opin Crit Care 2024; 30:10-19. [PMID: 38085886 DOI: 10.1097/mcc.0000000000001124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
PURPOSE OF REVIEW Positive end-expiratory pressure (PEEP) is required in the Berlin definition of acute respiratory distress syndrome and is a cornerstone of its treatment. Application of PEEP increases airway pressure and modifies pleural and transpulmonary pressures according to respiratory mechanics, resulting in blood volume alteration into the pulmonary circulation. This can in turn affect right ventricular preload, afterload and function. At the opposite, PEEP may improve left ventricular function, providing no deleterious effect occurs on the right ventricle. RECENT FINDINGS This review examines the impact of PEEP on cardiac function with regards to heart-lung interactions, and describes its consequences on organs perfusion and function, including the kidney, gut, liver and the brain. PEEP in itself is not beneficious nor detrimental on end-organ hemodynamics, but its hemodynamic effects vary according to both respiratory mechanics and association with other hemodynamic variables such as central venous or mean arterial pressure. There are parallels in the means of preventing deleterious impact of PEEP on the lungs, heart, kidney, liver and central nervous system. SUMMARY The quest for optimal PEEP settings has been a prominent goal in ARDS research for the last decades. Intensive care physician must maintain a high degree of vigilance towards hemodynamic effects of PEEP on cardiac function and end-organs circulation.
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Affiliation(s)
- Adrien Joseph
- Medical Intensive Care Unit, Ambroise Paré Hospital, Assistance Publique-Hôpitaux de Paris, Boulogne-Billancourt
| | - Matthieu Petit
- Medical Intensive Care Unit, Ambroise Paré Hospital, Assistance Publique-Hôpitaux de Paris, Boulogne-Billancourt
- Inserm, CESP, Paris-Saclay University, Université de Versailles Saint-Quentin-en-Yvelines, Villejuif, France
| | - Antoine Vieillard-Baron
- Medical Intensive Care Unit, Ambroise Paré Hospital, Assistance Publique-Hôpitaux de Paris, Boulogne-Billancourt
- Inserm, CESP, Paris-Saclay University, Université de Versailles Saint-Quentin-en-Yvelines, Villejuif, France
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2
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Mojoli F, Pozzi M, Arisi E. Setting positive end-expiratory pressure: using the pressure-volume curve. Curr Opin Crit Care 2024; 30:35-42. [PMID: 38085871 DOI: 10.1097/mcc.0000000000001127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
PURPOSE OF REVIEW To discuss the role of pressure-volume curve (PV curve) in exploring elastic properties of the respiratory system and setting mechanical ventilator to reduce ventilator-induced lung injury. RECENT FINDINGS Nowadays, quasi-static PV curves and loops can be easily obtained and analyzed at the bedside without disconnection of the patient from the ventilator. It is shown that this tool can provide useful information to optimize ventilator setting. For example, PV curves can assess for patient's individual potential for lung recruitability and also evaluate the risk for lung injury of the ongoing mechanical ventilation setting. SUMMARY In conclusion, PV curve is an easily available bedside tool: its correct interpretation can be extremely valuable to enlighten potential for lung recruitability and select a high or low positive end-expiratory pressure (PEEP) strategy. Furthermore, recent studies have shown that PV curve can play a significant role in PEEP and driving pressure fine tuning: clinical studies are needed to prove whether this technique will improve outcome.
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Affiliation(s)
- Francesco Mojoli
- Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, Unit of Anesthesia and Intensive Care, University of Pavia, Pavia, Italy
- Anesthesia and Intensive Care, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy
| | - Marco Pozzi
- Anesthesia and Intensive Care, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy
| | - Eric Arisi
- Anesthesia and Intensive Care, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy
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3
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Krohn F, Novello M, van der Giessen RS, De Zeeuw CI, Pel JJM, Bosman LWJ. The integrated brain network that controls respiration. eLife 2023; 12:83654. [PMID: 36884287 PMCID: PMC9995121 DOI: 10.7554/elife.83654] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 01/29/2023] [Indexed: 03/09/2023] Open
Abstract
Respiration is a brain function on which our lives essentially depend. Control of respiration ensures that the frequency and depth of breathing adapt continuously to metabolic needs. In addition, the respiratory control network of the brain has to organize muscular synergies that integrate ventilation with posture and body movement. Finally, respiration is coupled to cardiovascular function and emotion. Here, we argue that the brain can handle this all by integrating a brainstem central pattern generator circuit in a larger network that also comprises the cerebellum. Although currently not generally recognized as a respiratory control center, the cerebellum is well known for its coordinating and modulating role in motor behavior, as well as for its role in the autonomic nervous system. In this review, we discuss the role of brain regions involved in the control of respiration, and their anatomical and functional interactions. We discuss how sensory feedback can result in adaptation of respiration, and how these mechanisms can be compromised by various neurological and psychological disorders. Finally, we demonstrate how the respiratory pattern generators are part of a larger and integrated network of respiratory brain regions.
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Affiliation(s)
- Friedrich Krohn
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
| | - Manuele Novello
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
| | | | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands.,Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, Amsterdam, Netherlands
| | - Johan J M Pel
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
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Abstract
Mechanical ventilation can be life-saving for the premature infant, but is often injurious to immature and underdeveloped lungs. Lung injury is caused by atelectrauma, oxygen toxicity, and volutrauma. Lung protection must include appropriate lung recruitment starting in the delivery suite and throughout mechanical ventilation. Strategies include open lung ventilation, positive end-expiratory pressure, and volume-targeted ventilation. Respiratory function monitoring, such as capnography and ventilator graphics, provides clinicians with continuous real-time information and an adjunct to optimize lung-protective ventilatory strategies. Further research is needed to assess which lung-protective strategies result in a decrease in long-term respiratory morbidity.
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Chen Z, Zhong M, Jiang L, Chen N, Tu S, Wei Y, Sang L, Zheng X, Zhang C, Tao J, Deng L, Song Y. Effects of the Lower Airway Secretions on Airway Opening Pressures and Suction Pressures in Critically Ill COVID-19 Patients: A Computational Simulation. Ann Biomed Eng 2020; 48:3003-3013. [PMID: 33078367 PMCID: PMC7571532 DOI: 10.1007/s10439-020-02648-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/03/2020] [Indexed: 02/06/2023]
Abstract
In patients with critically ill COVID-19 pneumonia, lower airways are filled with plenty of highly viscous exudates or mucus, leading to airway occlusion. The estimation of airway opening pressures and effective mucus clearance are therefore two issues that clinicians are most concerned about during mechanical ventilation. In this study we retrospectively analyzed respiratory data from 24 critically ill patients with COVID-19 who received invasive mechanical ventilation and recruitment maneuver at Jinyintan Hospital in Wuhan, China. Among 24 patients, the mean inspiratory plateau pressure was 52.4 ± 4.4 cmH2O (mean ± [SD]). Particularly, the capnograms presented an upward slope during the expiratory plateau, indicting the existence of airway obstruction. A computational model of airway opening was subsequently introduced to investigate possible fluid dynamic mechanisms for the extraordinarily high inspiratory plateau pressures among these patients. Our simulation results showed that the predicted airway opening pressures could be as high as 40-50 cmH2O and the suction pressure could exceed 20 kPa as the surface tension and viscosity of secretion simulants markedly increased, likely causing the closures of the distal airways. We concluded that, in some critically ill patients with COVID-19, limiting plateau pressure to 30 cmH2O may not guarantee the opening of airways due to the presence of highly viscous lower airway secretions, not to mention spontaneous inspiratory efforts. Active airway humidification and effective expectorant drugs are therefore strongly recommended during airway management.
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Affiliation(s)
- Zhenglong Chen
- School of Medical Instrumentation, Shanghai University of Medicine & Health Sciences, 257 Tianxiong Road, Shanghai, 201318, China
| | - Ming Zhong
- Department of Intensive Care Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
| | - Li Jiang
- Department of Critical Care Medicine, Xuanwu Hospital, Capital Medical University, 45 Changchun Street, Xicheng District, Beijing, 100053, China
| | - Nanshan Chen
- Department of Respiratory and Critical Care Medicine, Wuhan Jinyintan Hospital, 1 Yintan Road, Dongxihu District, Wuhan, 430023, China
| | - Shengjin Tu
- Department of Respiratory and Critical Care Medicine, Wuhan Jinyintan Hospital, 1 Yintan Road, Dongxihu District, Wuhan, 430023, China
| | - Yuan Wei
- Department of Respiratory and Critical Care Medicine, Wuhan Jinyintan Hospital, 1 Yintan Road, Dongxihu District, Wuhan, 430023, China
| | - Ling Sang
- Department of Critical Care Medicine, GuangZhou Institute of Respiratory Health, The First Affiliated Hospital of GuangZhou Medical University, 151 Yanjiangxi Road, Guangzhou, 510120, China
| | - Xia Zheng
- Department of Critical Care Medicine, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, Zhejiang, China
| | - Chunyuan Zhang
- NMPA Key Laboratory for Respiratory and Anaesthetic Equipment, 1 Jinyinhua Road, Shanghai, 201321, China
| | - Jiale Tao
- Department of Intensive Care Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Linhong Deng
- Changzhou Key Laboratory of Respiratory Medical Engineering, Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Yuanlin Song
- Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Xuhui District, Shanghai, 200032, China
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6
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Driving Pressure During General Anesthesia for Open Abdominal Surgery (DESIGNATION): study protocol of a randomized clinical trial. Trials 2020; 21:198. [PMID: 32070400 PMCID: PMC7029544 DOI: 10.1186/s13063-020-4075-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/13/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Intraoperative driving pressure (ΔP) is associated with development of postoperative pulmonary complications (PPC). When tidal volume (VT) is kept constant, ΔP may change according to positive end-expiratory pressure (PEEP)-induced changes in lung aeration. ΔP may decrease if PEEP leads to a recruitment of collapsed lung tissue but will increase if PEEP mainly causes pulmonary overdistension. This study tests the hypothesis that individualized high PEEP, when compared to fixed low PEEP, protects against PPC in patients undergoing open abdominal surgery. METHODS The "Driving prESsure durIng GeNeral AnesThesIa for Open abdomiNal surgery trial" (DESIGNATION) is an international, multicenter, two-group, double-blind randomized clinical superiority trial. A total of 1468 patients will be randomly assigned to one of the two intraoperative ventilation strategies. Investigators screen patients aged ≥ 18 years and with a body mass index ≤ 40 kg/m2, scheduled for open abdominal surgery and at risk for PPC. Patients either receive an intraoperative ventilation strategy with individualized high PEEP with recruitment maneuvers (RM) ("individualized high PEEP") or one in which PEEP of 5 cm H2O without RM is used ("low PEEP"). In the "individualized high PEEP" group, PEEP is set at the level at which ΔP is lowest. In both groups of the trial, VT is kept at 8 mL/kg predicted body weight. The primary endpoint is the occurrence of PPC, recorded as a collapsed composite of adverse pulmonary events. DISCUSSION DESIGNATION will be the first randomized clinical trial that is adequately powered to compare the effects of individualized high PEEP with RM versus fixed low PEEP without RM on the occurrence of PPC after open abdominal surgery. The results of DESIGNATION will support anesthesiologists in their decisions regarding PEEP settings during open abdominal surgery. TRIAL REGISTRATION Clinicaltrials.gov, NCT03884543. Registered on 21 March 2019.
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Khemani RG, Parvathaneni K, Yehya N, Bhalla AK, Thomas NJ, Newth CJL. Positive End-Expiratory Pressure Lower Than the ARDS Network Protocol Is Associated with Higher Pediatric Acute Respiratory Distress Syndrome Mortality. Am J Respir Crit Care Med 2019; 198:77-89. [PMID: 29373802 DOI: 10.1164/rccm.201707-1404oc] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
RATIONALE The ARDS Network (ARDSNet) used a positive end-expiratory pressure (PEEP)/FiO2 model in many studies. In general, pediatric intensivists use less PEEP and higher FiO2 than this model. OBJECTIVES To evaluate whether children managed with PEEP lower than recommended by the ARDSNet PEEP/FiO2 model had higher mortality. METHODS This was a multicenter, retrospective analysis of patients with pediatric acute respiratory distress syndrome (PARDS) managed without a formal PEEP/FiO2 protocol. Four distinct datasets were combined for analysis. We extracted time-matched PEEP/FiO2 values, calculating the difference between PEEP level and the ARDSNet-recommended PEEP level for a given FiO2. We analyzed the median difference over the first 24 hours of PARDS diagnosis against ICU mortality and adjusted for confounding variables, effect modifiers, or factors that may have affected the propensity to use lower PEEP. MEASUREMENTS AND MAIN RESULTS Of the 1,134 patients with PARDS, 26.6% were managed with lower PEEP relative to the amount of FiO2 recommended by the ARDSNet protocol. Patients managed with lower PEEP experienced higher mortality than those who were managed with PEEP levels in line with or higher than recommended by the protocol (P < 0.001). After adjustment for hypoxemia, inotropes, comorbidities, severity of illness, ventilator settings, nitric oxide, and dataset, PEEP lower than recommended by the protocol remained independently associated with higher mortality (odds ratio, 2.05; 95% confidence interval, 1.32-3.17). Findings were similar after propensity-based covariate adjustment (odds ratio, 2.00; 95% confidence interval, 1.24-3.22). CONCLUSIONS Patients with PARDS managed with lower PEEP relative to FiO2 than recommended by the ARDSNet model had higher mortality. Clinical trials targeting PEEP management in PARDS are needed.
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Affiliation(s)
- Robinder G Khemani
- 1 Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, California.,2 Department of Pediatrics, Keck School of Medicine, and
| | - Kaushik Parvathaneni
- 1 Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, California.,3 Department of Biological Sciences, Dana and David Dornsife College of Letters Arts and Sciences, University of Southern California, Los Angeles, California
| | - Nadir Yehya
- 4 Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Anoopindar K Bhalla
- 1 Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, California.,2 Department of Pediatrics, Keck School of Medicine, and
| | - Neal J Thomas
- 5 Division of Pediatric Critical Care Medicine, Department of Pediatrics and Public Health Science, Penn State Hershey Children's Hospital, Hershey, Pennsylvania
| | - Christopher J L Newth
- 1 Department of Anesthesiology and Critical Care Medicine, Children's Hospital Los Angeles, Los Angeles, California.,2 Department of Pediatrics, Keck School of Medicine, and
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8
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Kung SC, Hung YL, Chen WL, Wang CM, Chang HC, Liu WL. Effects of Stepwise Lung Recruitment Maneuvers in Patients with Early Acute Respiratory Distress Syndrome: A Prospective, Randomized, Controlled Trial. J Clin Med 2019; 8:jcm8020231. [PMID: 30744214 PMCID: PMC6406466 DOI: 10.3390/jcm8020231] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 01/31/2019] [Accepted: 02/06/2019] [Indexed: 12/16/2022] Open
Abstract
Since the clinical benefit of lung recruitment maneuvers (LRMs) is still conflicting, we performed this prospective, randomized, controlled study to investigate whether LRMs should be used in the routine management of acute respiratory distress syndrome (ARDS). This trial was conducted in four intensive care units (ICUs) to compare application of a modified stepwise LRMs with solely lung-protective ventilation in patients with moderate to severe ARDS within 72 h from the onset. The primary outcome was 28-day mortality, and the secondary outcomes were ventilator-free days and ICU-free days. We collected data on 120 ARDS patients from 2009 to 2012, and there was no difference in 28-day mortality between the two groups (28.3% vs. 30.0%, p = 0.84). However, among survivors, patients in the LRM group had a significant longer median duration of ventilator-free days (18 vs. 13 days; p = 0.04) and ICU-free days (16 vs. 11 days; p = 0.03) at 28 days than in the control group. The respiratory system compliance was significantly higher in the LRM group from day 1 to day 7. The occurrence rate of barotrauma was similar in both groups. We concluded that LRMs combined with lung-protective ventilation in early ARDS may improve patient outcomes.
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Affiliation(s)
- Shu-Chen Kung
- Department of Respiratory Therapy, Chi Mei Medical Center, Liouying, Tainan 73657, Taiwan.
| | - Yi-Li Hung
- Department of Pediatrics, Cathay General Hospital, Taipei, Taiwan.
- School of Medicine, College of Medicine, Fu Jen Catholic University, Xinzhuang Dist., New Taipei City 24205, Taiwan (R.O.C).
| | - Wan-Ling Chen
- Department of Respiratory Therapy, Chi Mei Medical Center, Liouying, Tainan 73657, Taiwan.
| | - Ching-Min Wang
- Department of Internal Medicine, Chi Mei Medical Center, Liouying, Tainan 73657, Taiwan.
| | - Hui-Chun Chang
- Department of Respiratory Therapy, Chi Mei Medical Center, Liouying, Tainan 73657, Taiwan.
| | - Wei-Lun Liu
- School of Medicine, College of Medicine, Fu Jen Catholic University, Xinzhuang Dist., New Taipei City 24205, Taiwan (R.O.C).
- Division of Critical Care Medicine, Department of Emergency and Critical Care Medicine, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City 24352, Taiwan (R.O.C.).
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9
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Nabian M, Narusawa U. Quasi-static pulmonary P–V curves of patients with ARDS, Part I: Characterization. Respir Physiol Neurobiol 2018; 248:36-42. [DOI: 10.1016/j.resp.2017.10.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 10/23/2017] [Accepted: 10/28/2017] [Indexed: 01/07/2023]
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Nabian M, Narusawa U. Patient-specific optimization of mechanical ventilation for patients with acute respiratory distress syndrome using quasi-static pulmonary P-V data. INFORMATICS IN MEDICINE UNLOCKED 2018; 12:44-55. [PMID: 35036518 PMCID: PMC8740849 DOI: 10.1016/j.imu.2018.06.003] [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: 04/28/2018] [Revised: 06/05/2018] [Accepted: 06/06/2018] [Indexed: 11/13/2022] Open
Abstract
Quasi-static, pulmonary pressure-volume (P-V) curves were combined with a respiratory system model to analyze tidal pressure cycles, simulating mechanical ventilation of patients with acute respiratory distress syndrome (ARDS). Two important quantities including 1) tidal recruited volume and 2) tidal hyperinflated volume were analytically computed by integrating the distribution of alveolar elements over the affected pop-open pressure range. We analytically predicted the tidal recruited volume of four canine subjects and compared our results with similar experimental measurements on canine models for the validation. We then applied our mathematical model to the P-V data of ARDS populations in four stages of Early ARDS, Deep Knee, Advanced ARDS and Baby Lung to quantify the tidal recruited volume and tidal hyperinflated volume as an indicator of ventilator-induced lung injury (VILI). These quantitative predictions based on patient-specific P-V data suggest that the optimum parameters of mechanical ventilation including PEEP and Tidal Pressure (Volume) are largely varying among ARDS population and are primarily influenced by the degree in the severity of ARDS.
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Affiliation(s)
- Mohsen Nabian
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA, USA
| | - Uichiro Narusawa
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA, USA
- Department of Bio-engineering, Northeastern University, Boston, MA, USA
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11
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Impact of Recruitment on Static and Dynamic Lung Strain in Acute Respiratory Distress Syndrome. Anesthesiology 2016; 124:443-52. [PMID: 26569171 DOI: 10.1097/aln.0000000000000946] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Lung strain, defined as the ratio between end-inspiratory volume and functional residual capacity, is a marker of the mechanical load during ventilation. However, changes in lung volumes in response to pressures may occur in injured lungs and modify strain values. The objective of this study was to clarify the role of recruitment in strain measurements. METHODS Six oleic acid-injured pigs were ventilated at positive end-expiratory pressure (PEEP) 0 and 10 cm H2O before and after a recruitment maneuver (PEEP = 20 cm H2O). Lung volumes were measured by helium dilution and inductance plethysmography. In addition, six patients with moderate-to-severe acute respiratory distress syndrome were ventilated with three strategies (peak inspiratory pressure/PEEP: 20/8, 32/8, and 32/20 cm H2O). Lung volumes were measured in computed tomography slices acquired at end-expiration and end-inspiration. From both series, recruited volume and lung strain (total, dynamic, and static) were computed. RESULTS In the animal model, recruitment caused a significant decrease in dynamic strain (from [mean ± SD] 0.4 ± 0.12 to 0.25 ± 0.07, P < 0.01), while increasing the static component. In patients, total strain remained constant for the three ventilatory settings (0.35 ± 0.1, 0.37 ± 0.11, and 0.32 ± 0.1, respectively). Increases in tidal volume had no significant effects. Increasing PEEP constantly decreased dynamic strain (0.35 ± 0.1, 0.32 ± 0.1, and 0.04+0.03, P < 0.05) and increased static strain (0, 0.06 ± 0.06, and 0.28 ± 0.11, P < 0.05). The changes in dynamic and total strain among patients were correlated to the amount of recruited volume. An analysis restricted to the changes in normally aerated lung yielded similar results. CONCLUSION Recruitment causes a shift from dynamic to static strain in early acute respiratory distress syndrome.
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12
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Donoso A, Arriagada D, Contreras D, Ulloa D, Neumann M. [Respiratory monitoring of pediatric patients in the Intensive Care Unit]. BOLETIN MEDICO DEL HOSPITAL INFANTIL DE MEXICO 2016; 73:149-165. [PMID: 29421202 DOI: 10.1016/j.bmhimx.2016.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/29/2016] [Accepted: 02/02/2016] [Indexed: 06/08/2023] Open
Abstract
Respiratory monitoring plays an important role in the care of children with acute respiratory failure. Therefore, its proper use and correct interpretation (recognizing which signals and variables should be prioritized) should help to a better understanding of the pathophysiology of the disease and the effects of therapeutic interventions. In addition, ventilated patient monitoring, among other determinations, allows to evaluate various parameters of respiratory mechanics, know the status of the different components of the respiratory system and guide the adjustments of ventilatory therapy. In this update, the usefulness of several techniques of respiratory monitoring including conventional respiratory monitoring and more recent methods are described. Moreover, basic concepts of mechanical ventilation, their interpretation and how the appropriate analysis of the information obtained can cause an impact on the clinical management of the patient are defined.
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Affiliation(s)
| | | | - Dina Contreras
- Hospital Clínico Metropolitano La Florida, Santiago, Chile
| | - Daniela Ulloa
- Hospital Clínico Metropolitano La Florida, Santiago, Chile
| | - Megan Neumann
- Hospital Clínico Metropolitano La Florida, Santiago, Chile
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13
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Open Lung Approach for the Acute Respiratory Distress Syndrome: A Pilot, Randomized Controlled Trial. Crit Care Med 2016; 44:32-42. [PMID: 26672923 DOI: 10.1097/ccm.0000000000001383] [Citation(s) in RCA: 172] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The open lung approach is a mechanical ventilation strategy involving lung recruitment and a decremental positive end-expiratory pressure trial. We compared the Acute Respiratory Distress Syndrome network protocol using low levels of positive end-expiratory pressure with open lung approach resulting in moderate to high levels of positive end-expiratory pressure for the management of established moderate/severe acute respiratory distress syndrome. DESIGN A prospective, multicenter, pilot, randomized controlled trial. SETTING A network of 20 multidisciplinary ICUs. PATIENTS Patients meeting the American-European Consensus Conference definition for acute respiratory distress syndrome were considered for the study. INTERVENTIONS At 12-36 hours after acute respiratory distress syndrome onset, patients were assessed under standardized ventilator settings (FIO2≥0.5, positive end-expiratory pressure ≥10 cm H2O). If Pao2/FIO2 ratio remained less than or equal to 200 mm Hg, patients were randomized to open lung approach or Acute Respiratory Distress Syndrome network protocol. All patients were ventilated with a tidal volume of 4 to 8 ml/kg predicted body weight. MEASUREMENTS AND MAIN RESULTS From 1,874 screened patients with acute respiratory distress syndrome, 200 were randomized: 99 to open lung approach and 101 to Acute Respiratory Distress Syndrome network protocol. Main outcome measures were 60-day and ICU mortalities, and ventilator-free days. Mortality at day-60 (29% open lung approach vs. 33% Acute Respiratory Distress Syndrome Network protocol, p = 0.18, log rank test), ICU mortality (25% open lung approach vs. 30% Acute Respiratory Distress Syndrome network protocol, p = 0.53 Fisher's exact test), and ventilator-free days (8 [0-20] open lung approach vs. 7 [0-20] d Acute Respiratory Distress Syndrome network protocol, p = 0.53 Wilcoxon rank test) were not significantly different. Airway driving pressure (plateau pressure - positive end-expiratory pressure) and PaO2/FIO2 improved significantly at 24, 48 and 72 hours in patients in open lung approach compared with patients in Acute Respiratory Distress Syndrome network protocol. Barotrauma rate was similar in both groups. CONCLUSIONS In patients with established acute respiratory distress syndrome, open lung approach improved oxygenation and driving pressure, without detrimental effects on mortality, ventilator-free days, or barotrauma. This pilot study supports the need for a large, multicenter trial using recruitment maneuvers and a decremental positive end-expiratory pressure trial in persistent acute respiratory distress syndrome.
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14
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Setting the Ventilator in the NICU. PEDIATRIC AND NEONATAL MECHANICAL VENTILATION 2015. [PMCID: PMC7122498 DOI: 10.1007/978-3-642-01219-8_42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Success in providing respiratory support to the neonate requires a clear understanding of the context in which it is being applied. Perhaps more than for any other age group, the array of different situations in which ventilation is applied to the newborn infant is extremely broad, with in each case different pathophysiological disturbances and often the need to use a specific approach to apply ventilation optimally. Table 42.1 provides a list of the more common situations in which conventional ventilation is used in the neonate and includes some considerations regarding ventilator settings for each situation. For each situation, a suggested mode of ventilation is indicated, along with target ranges for positive end-expiratory pressure (PEEP) and tidal volume (VT). Further discussion of the physiological rationale and available evidence for ventilator settings is set out below.
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15
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García-Prieto E, Amado-Rodríguez L, Albaiceta GM. [Monitorization of respiratory mechanics in the ventilated patient]. Med Intensiva 2013; 38:49-55. [PMID: 24199991 DOI: 10.1016/j.medin.2013.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 09/16/2013] [Indexed: 10/26/2022]
Abstract
Monitoring during mechanical ventilation allows the measurement of different parameters of respiratory mechanics. Accurate interpretation of these data can be useful for characterizing the situation of the different components of the respiratory system, and for guiding ventilator settings. In this review, we describe the basic concepts of respiratory mechanics, their interpretation, and their potential use in fine-tuning mechanical ventilation.
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Affiliation(s)
- E García-Prieto
- Servicio de Medicina Intensiva, Hospital Universitario Central de Asturias, Oviedo, España
| | - L Amado-Rodríguez
- Servicio de Medicina Intensiva, Hospital Universitario Central de Asturias, Oviedo, España; Departamento de Biología Funcional, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, Oviedo, España
| | - G M Albaiceta
- Servicio de Medicina Intensiva, Hospital Universitario Central de Asturias, Oviedo, España; Departamento de Biología Funcional, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, Oviedo, España; Centro de Investigación Biomédica en Red-Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, España.
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Assessment of Dynamic Mechanical Properties of the Respiratory System During High-Frequency Oscillatory Ventilation*. Crit Care Med 2013; 41:2502-11. [DOI: 10.1097/ccm.0b013e31828cf3ea] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Pressure Support in Acute Respiratory Distress Syndrome. Crit Care Med 2013; 41:1811-2. [DOI: 10.1097/ccm.0b013e31828c261a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Dechert RE, Haas CF, Ostwani W. Current knowledge of acute lung injury and acute respiratory distress syndrome. Crit Care Nurs Clin North Am 2013; 24:377-401. [PMID: 22920464 DOI: 10.1016/j.ccell.2012.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) continues to be a major cause of mortality in adult and pediatric critical care medicine. This article discusses the pulmonary sequelae associated with ALI and ARDS, the support of ARDS with mechanical ventilation, available adjunctive therapies, and experimental therapies currently being tested. It is hoped that further understanding of the fundamental biology, improved identification of the patient's inflammatory state, and application of therapies directed at multiple sites of action may ultimately prove beneficial for patients suffering from ALI/ARDS.
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Affiliation(s)
- Ronald E Dechert
- Department of Respiratory Care, University of Michigan Health System, 8-720 Mott Hospital, 1540 East Hospital Drive, SPC 4208, Ann Arbor, MI 48109, USA.
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Abstract
The lungs of an extremely preterm infant ≤28 weeks gestation are structurally and biochemically immature and vulnerable to injury from positive pressure ventilation. A lung protective approach to respiratory support is vital, aiming to ventilate an open lung, using the lowest pressure settings that maintain recruitment and oxygenation and avoiding hyperinflation with each tidal breath. For infants with severe respiratory distress syndrome and persistent atelectasis, lung protective ventilation requires recruitment using stepwise pressure increments, followed by reduction in ventilator pressures in search of an optimal point at which to maintain ventilation. Several studies, including a single randomised controlled trial, have found this lung protective strategy to be more effectively administered using high-frequency oscillatory ventilation rather than conventional ventilation. Many extremely preterm infants have minimal atelectasis and low oxygen requirements in the first days of life, and the ventilatory approach in this case should be one of avoidance of factors including overdistension that are known to contribute to later pulmonary deterioration. From a practical perspective, this means setting positive end-expiratory pressure at the lowest value that maintains oxygenation and restricting tidal volume using a volume-targeted mode of ventilation.
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Affiliation(s)
- Peter A Dargaville
- Department of Paediatrics, Royal Hobart Hospital and University of Tasmania, Hobart, Tasmania, Australia.
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Bruells CS, Dembinski R. [Positive end-expiratory pressure : adjustment in acute lung injury]. Anaesthesist 2012; 61:336-43. [PMID: 22526744 DOI: 10.1007/s00101-012-2003-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Treatment of patients suffering from acute lung injury is a challenge for the treating physician. In recent years ventilation of patients with acute hypoxic lung injury has changed fundamentally. Besides the use of low tidal volumes, the most beneficial setting of positive end-expiratory pressure (PEEP) has been in the focus of researchers. The findings allow adaption of treatment to milder forms of acute lung injury and severe forms. Additionally computed tomography techniques to assess the pulmonary situation and recruitment potential as well as bed-side techniques to adjust PEEP on the ward have been modified and improved. This review gives an outline of recent developments in PEEP adjustment for patients suffering from acute hypoxic and hypercapnic lung injury and explains the fundamental pathophysiology necessary as a basis for correct treatment.
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Affiliation(s)
- C S Bruells
- Klinik für Anästhesiologie, Universitätsklinikum Aachen, Aachen, Deutschland.
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Tusman G, Böhm SH, Warner DO, Sprung J. Atelectasis and perioperative pulmonary complications in high-risk patients. Curr Opin Anaesthesiol 2012; 25:1-10. [DOI: 10.1097/aco.0b013e32834dd1eb] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Abstract
PURPOSE OF REVIEW Electrical impedance tomography (EIT) is an attractive method of monitoring patients during mechanical ventilation because it can provide a noninvasive continuous image of pulmonary impedance, which indicates the distribution of ventilation. This article will discuss ongoing research on EIT, with a focus on methodological aspects and limitations and novel approaches in terms of pathophysiology, diagnosis and therapeutic advancements. RECENT FINDINGS EIT enables the detection of regional distribution of alveolar ventilation and, thus, the quantification of local inhomogeneities in lung mechanics. By detecting recruitment and derecruitment, a positive end-expiratory pressure level at which tidal ventilation is relatively homogeneous in all lung regions can be defined. Additionally, different approaches to characterize the temporal local behaviour of lung tissue during ventilation have been proposed, which adds important information. SUMMARY There is growing evidence that supports EIT usage as a bedside measure to individually optimize ventilator settings in critically ill patients in order to prevent ventilator-induced lung injury. A standardization of current approaches to analyse and interpret EIT data is required in order to facilitate the clinical implementation.
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González-López A, Astudillo A, García-Prieto E, Fernández-García MS, López-Vázquez A, Batalla-Solís E, Taboada F, Fueyo A, Albaiceta GM. Inflammation and matrix remodeling during repair of ventilator-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2011; 301:L500-9. [PMID: 21743031 DOI: 10.1152/ajplung.00010.2011] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
High-pressure ventilation triggers different inflammatory and matrix remodeling responses within the lung. Although some of them may cause injury, the involvement of these mediators in repair is largely unknown. To identify mechanisms of repair after ventilator-induced lung injury (VILI), mice were randomly assigned to baseline conditions (no ventilation), injury [90 min of high-pressure ventilation without positive end-expiratory pressure (PEEP)], repair (injury followed by 4 h of low-pressure ventilation with PEEP), and ventilated controls (low-pressure ventilation with PEEP for 90 and 330 min). Histological injury and lung permeability increased during injury, but were partially reverted in the repair group. This was accompanied by a proinflammatory response, together with increases in TNF-α and IFN-γ, which returned to baseline during repair, and a decrease in IL-10. However, macrophage inflammatory protein-2 (MIP-2) and matrix metalloproteinases (MMP)-2 and -9 increased after injury and persisted in being elevated during repair. Mortality in the repair phase was 50%. Survivors showed increased cell proliferation, lower levels of collagen, and higher levels of MIP-2 and MMP-2. Pan-MMP or specific MMP-2 inhibition (but not MIP-2, TNF-α, or IL-4 inhibition) delayed epithelial repair in an in vitro wound model using murine or human alveolar cells cultured in the presence of bronchoalveolar lavage fluid from mice during the repair phase or from patients with acute respiratory distress syndrome, respectively. Similarly, MMP inhibition with doxycycline impaired lung repair after VILI in vivo. In conclusion, VILI can be reverted by normalizing ventilation pressures. An adequate inflammatory response and extracellular matrix remodeling are essential for recovery. MMP-2 could play a key role in epithelial repair after VILI and acute respiratory distress syndrome.
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Abstract
Ventilator-induced lung injury (VILI) consists of tissue damage and a biological response resulting from the application of inappropriate mechanical forces to the lung parenchyma. The current paradigm attributes VILI to overstretching due to very high-volume ventilation (volutrauma) and cyclic changes in aeration due to very low-volume ventilation (atelectrauma); however, this model cannot explain some research findings. In the present review, we discuss the relevance of cyclic deformation of lung tissue as the main determinant of VILI. Parenchymal stability resulting from the interplay of respiratory parameters such as tidal volume, positive end-expiratory pressure or respiratory rate can explain the results of different clinical trials and experimental studies that do not fit with the classic volutrauma/atelectrauma model. Focusing on tissue deformation could lead to new bedside monitoring and ventilatory strategies.
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Affiliation(s)
- Guillermo M Albaiceta
- Intensive Care Unit, Hospital Universitario Central de Asturias, Departamento de Biología Funcional, Universidad de Oviedo, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Celestino Villamil s/n, 33006 Oviedo, Spain
- CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Spain
| | - Lluis Blanch
- CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Spain
- Critical Care Center, Hospital de Sabadell, Corporació Parc Taulí, Insitut Universitari Fundació Parc Tauli, Universitat Autònoma de Barcelona, Parc Taulí s/n, 08208 Sabadell, Spain
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Hata JS, Simmons JS, Kumar AB, Rickelman JH, Nickel EJ, Simmons ST, Torner J. The acute effectiveness and safety of the constant-flow, pressure-volume curve to improve hypoxemia in acute lung injury. J Intensive Care Med 2011; 27:119-27. [PMID: 21220269 DOI: 10.1177/0885066610394390] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To investigate the effectiveness of the constant-flow, pressure-volume curve (PVC) to prescribe positive end-expiratory pressure (PEEP) in acute lung injury (ALI) and risk of cardiopulmonary deterioration during the PVC process. DESIGN A retrospective, cohort study. SETTING A surgical intensive care unit (ICU) of a tertiary, university hospital. PATIENTS Fifty consecutive ventilated patients diagnosed with ALI undergoing the PVC maneuver from 1999 to 2003. INTERVENTIONS Titration of PEEP based on the lower inflection point of the constant-flow, pressure-volume curve. MEASUREMENTS AND MAIN RESULTS Patients were divided into 2 groups based on PVC-guided PEEP changes of <3 cm H2O (PVC-NC or "no change") or ≥3 cm H2O (PVC-CHG or "change") from the initial empiric prescription. There was a greater increase in partial pressure of arterial oxygen (PaO2)/fractional concentration of inspired oxygen (FiO2) in the PVC-CHG group, with a mean change of 80 ± 50 (95% confidence interval [CI] 61, 98) versus 42 ± 54 (95% CI 17, 67) in the PVC-NC group. Eighty-two percent of patients (41/50) showed an increase in ratio of partial pressure of arterial oxygen to fraction of inspired oxygen (PaO2/FiO2) by 20% within 6 to 24 hours after the PVC test-greater in the PVC-CHG group (OR 1.44, 95% CI 1.02, 2.01). Thirteen percent (4/30) within the PVC-CHG group and none within the PVC-NC group (0/20) required a 25% increase in vasoactive infusion rates (P = .089) in relation to the procedure. Univariate logistic regression showed that PVC-CHG was significantly associated with a 20% change in PaO2/FiO2 (OR 7.54, 95% CI 1.37, 41.41). Multivariate logistic modeling showed that PVC-guided PEEP changes of ≥3 cm H2O, age ≤65 years, and pre-PVC FiO2 ≥ .85 were significantly associated with a 20% increase in PaO2/FiO2 (receiver operator area under the curve = .86). CONCLUSIONS In the setting of acute lung injury, use of the constant-flow, pressure-volume curve to prescribe PEEP appears associated with improvement in oxygenation with limited risk of acute, process-related, cardiopulmonary deterioration.
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Affiliation(s)
- J Steven Hata
- Center for Critical Care, Departments of General Anesthesiology and Outcomes Research, Cleveland Clinic Foundation, Cleveland, OH 44122, USA.
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Albaiceta GM, Gutierrez-Fernández A, García-Prieto E, Puente XS, Parra D, Astudillo A, Campestre C, Cabrera S, Gonzalez-Lopez A, Fueyo A, Taboada F, López-Otin C. Absence or Inhibition of Matrix Metalloproteinase–8 Decreases Ventilator-Induced Lung Injury. Am J Respir Cell Mol Biol 2010; 43:555-63. [DOI: 10.1165/rcmb.2009-0034oc] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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Abstract
Prevention of iatrogenic injury due to ventilation of a heterogeneous lung requires knowledge of dynamic regional events occurring within the tidal cycle. Quantitative bedside imaging techniques that are sensitive to regional mechanics and tidal events hold potential for information delivery that cannot be realized by pressure-volume monitoring alone.
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Affiliation(s)
- John J Marini
- Regions Hospital MS 11203B, University of Minnesota, 640 Jackson Street, St Paul, MN 55101-2595, USA.
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Khemani RG, Newth CJL. The design of future pediatric mechanical ventilation trials for acute lung injury. Am J Respir Crit Care Med 2010; 182:1465-74. [PMID: 20732987 DOI: 10.1164/rccm.201004-0606ci] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Pediatric practitioners face unique challenges when attempting to translate or adapt adult-derived evidence regarding ventilation practices for acute lung injury or acute respiratory distress syndrome into pediatric practice. Fortunately or unfortunately, there appears to be selective adoption of adult practices for pediatric mechanical ventilation, many of which pose considerable challenges or uncertainty when translated to pediatrics. These differences, combined with heterogeneous management strategies within pediatric critical care, can complicate clinical practice and make designing robust clinical trials in pediatric acute respiratory failure particularly difficult. These issues surround the lack of explicit ventilator protocols in pediatrics, either computer or paper based; differences in modes of conventional ventilation and perceived marked differences in the approach to high-frequency oscillatory ventilation; challenges with patient recruitment; the shortcomings of the definition of acute lung injury and acute respiratory distress syndrome; the more reliable yet still somewhat unpredictable relationship between lung injury severity and outcome; and the reliance on potentially biased surrogate outcome measures, such as ventilator-free days, for all pediatric trials. The purpose of this review is to highlight these challenges, discuss pertinent work that has begun to address them, and propose potential solutions or future investigations that may help facilitate comprehensive trials on pediatric mechanical ventilation and define clinical practice standards.
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Affiliation(s)
- Robinder G Khemani
- University of Southern California, Children's Hospital Los Angeles, CA 90027, USA.
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Abstract
PURPOSE OF REVIEW In the last 2 years, several reports have dealt with recruitment/positive end-expiratory pressure (PEEP) selection. Most of them confirm previous results and few add new information. RECENT FINDINGS It has been definitely confirmed that opening pressures are different throughout the acute respiratory distress syndrome lung parenchyma, ranging from 5-10 up to 30-40 cmH2O. The highest opening pressures are required to open the most dependent lung regions. It has been found that in 2 s, most of the recruitable lung regions may be open when a proper pressure is applied. The best way to assess recruitment is computed tomography scanning, whereas lung mechanics are a reasonable bedside surrogate. Impedance tomography has been increasingly tested, whereas gas exchange is the less reliable indicator of recruitment. A large outcome study showed that higher PEEP might provide survival benefit in a subgroup of more severe patients as compared with lower PEEP. To set PEEP in each individual patient, the use of the expiratory limb of the pressure-volume curve has been suggested. Setting PEEP according to transpulmonary pressure has a robust physiological background, although it requires confirmatory study. SUMMARY Indiscriminate application of recruitment maneuver in unselected acute respiratory distress syndrome population does not provide benefits. However, in the most severe patients, recruitment maneuver has to be considered and higher PEEP applied. To individualize PEEP, the expiratory phase has to be considered, and the esophageal pressure measurement to compute the transpulmonary pressure should be progressively introduced in clinical practice.
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Blanch L, Albaiceta GM. Sildenafil for pulmonary hypertension in ARDS: a new pleasant effect? Intensive Care Med 2010; 36:729-31. [DOI: 10.1007/s00134-010-1771-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Accepted: 01/15/2010] [Indexed: 10/19/2022]
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Comparison of four methods of lung volume recruitment during high frequency oscillatory ventilation. Intensive Care Med 2009; 35:1990-8. [DOI: 10.1007/s00134-009-1628-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Accepted: 08/18/2009] [Indexed: 10/20/2022]
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Koefoed-Nielsen J, Hansen LK, Larsson A. Does a solitary lobar collapse give pressure-lung volume relationship similar to that found in acute respiratory distress syndrome? A porcine experimental study. Clin Physiol Funct Imaging 2008; 28:391-7. [DOI: 10.1111/j.1475-097x.2008.00819.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Piacentini E, Wysocki M, Blanch L. A new automated method versus continuous positive airway pressure method for measuring pressure-volume curves in patients with acute lung injury. Intensive Care Med 2008; 35:565-70. [PMID: 18853137 DOI: 10.1007/s00134-008-1322-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Accepted: 09/20/2008] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare pressure-volume (P-V) curves obtained with the Galileo ventilator with those obtained with the CPAP method in patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). DESIGN Prospective, observational study. SETTING General critical care center. PATIENTS AND PARTICIPANTS Patients with ALI/ARDS and receiving mechanical ventilation. INTERVENTIONS Pressure-volume curves were obtained in random order with the CPAP technique and with the software PV Tool-2 (Galileo ventilator). MEASUREMENTS AND RESULTS In ten consecutive patients, airway pressure was measured by a pressure transducer and changes in lung volume were measured by respiratory inductive plethysmography. P-V curves were fitted to a sigmoidal equation with a mean R (2) of 0.994 +/- 0.003. Intraclass correlation coefficients were all >0.75 (P < 0.001 at all pressure levels). Lower (LIP) and upper inflection (UIP), and deflation maximum curvature (PMC) points calculated from the fitted variables showed a good correlation between methods with intraclass correlation coefficients of 0.98 (0.92, 0.99), 0.92 (0.69, 0.98), and 0.97 (0.86, 0.98), respectively (P < 0.001 in all cases). Bias and limits of agreement for LIP (0.51 +/- 0.95 cmH(2)O; -1.36 to 2.38 cmH(2)O), UIP (0.53 +/- 1.52 cmH(2)O; -2.44 to 3.50 cmH(2)O), and PMC (-0.62 +/- 0.89 cmH(2)O; -2.35 to 1.12 cmH(2)O) obtained with the two methods in the same patient were clinically acceptable. No adverse effects were observed. CONCLUSION The PV Tool-2 built into the Galileo ventilator is equivalent to the CPAP method for tracing static P-V curves of the respiratory system in critically ill patients receiving mechanical ventilation.
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Affiliation(s)
- Enrique Piacentini
- Doctorando UAB, Intensive Care Unit, Hospital Mútua de Terrassa, Terrassa, Spain
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Owens RL, Stigler WS, Hess DR. Do newer monitors of exhaled gases, mechanics, and esophageal pressure add value? Clin Chest Med 2008; 29:297-312, vi-vii. [PMID: 18440438 DOI: 10.1016/j.ccm.2008.02.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The current understanding of lung mechanics and ventilator-induced lung injury suggests that patients who have acute respiratory distress syndrome should be ventilated in such a way as to minimize alveolar over-distension and repeated alveolar collapse. Clinical trials have used such lung protective strategies and shown a reduction in mortality; however, there is data that these "one-size fits all" strategies do not work equally well in all patients. This article reviews other methods that may prove useful in monitoring for potential lung injury: exhaled breath condensate, pressure-volume curves, and esophageal manometry. The authors explore the concepts, benefits, difficulties, and relevant clinical trials of each.
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Affiliation(s)
- Robert L Owens
- Department of Medicine, Pulmonary and Critical Care Unit, Cox 2, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
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Gordo-Vidal F, Gómez-Tello V, Palencia-Herrejón E, Latour-Pérez J, Sánchez-Artola B, Díaz-Alersi R. [High PEEP vs. conventional PEEP in the acute respiratory distress syndrome: a systematic review and meta-analysis]. Med Intensiva 2008; 31:491-501. [PMID: 18039449 DOI: 10.1016/s0210-5691(07)74856-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To perform a systematic review and meta-analysis of the literature to evaluate the effects of high PEEP versus conventional PEEP on mortality and on the risk of barotrauma in patients with the acute respiratory distress syndrome (ARDS). SOURCE OF DATA Computer search of Medline, Embase, CINAHL, CANCERLIT, Pascal-Biomed, ACP Journal Club, Cochrane library (CDSR, DARE, CCTR), ISI Proceedings, Current Contents, and Web of Science, as well as manual search of selected references. SELECTION OF STUDIES Controlled random clinical trials published after NAECC (1994) that evaluated the effect of two levels of PEEP and that reported the mortality and incidence of barotrauma in the series. DATA EXTRACTION By two investigators working independently, with discrepancies resolved by group consensus. Contingency tables were elaborated and the RRs with corresponding confidence intervals were obtained for each study. RESULTS Four articles were selected for the meta-analysis of mortality and three for the meta-analysis of barotrauma. No effects of PEEP level on mortality were found (RR 0.73, 95% CI: 0.49 to 1.10) or on the incidence of barotrauma (RR 0.50, 95% CI: 0.14 to 1.73). However, an analysis of the studies in which PEEP was individualized in function of Pflex showed a significant decrease in mortality (RR 0.59, 95% CI: 0.43 to 0.82) (p=0.001) CONCLUSIONS The use of high or conventional PEEP in function of oxygenation does not affect mortality or the incidence of barotrauma in patients with ARDS. However, there might be a decrease in mortality associated to high PEEP individualized in function of the pulmonary mechanics of each patient.
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Affiliation(s)
- F Gordo-Vidal
- Unidad de Cuidados Intensivos, Fundación Hospital Alcorcón, Madrid, España.
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Koefoed-Nielsen J, Andersen G, Barklin A, Bach A, Lunde S, Tønnesen E, Larsson A. Maximal hysteresis: a new method to set positive end-expiratory pressure in acute lung injury? Acta Anaesthesiol Scand 2008; 52:641-9. [PMID: 18419718 DOI: 10.1111/j.1399-6576.2008.01600.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND No methods are superior when setting positive end-expiratory pressure (PEEP) in acute lung injury (ALI). In ALI, the vertical distance (hysteresis) between the inspiratory and expiratory limbs of a static pressure-volume (PV) loop mainly indicates lung recruitment. We hypothesized that PEEP set at the pressure where hysteresis is 90% of its maximum (90%MH) would give similar oxygenation, but less cardiovascular depression than PEEP set at the pressure at lower inflection point (LIP) on the inspiratory limb or at the point of maximal curvature (PMC) on the expiratory limb in ALI. METHODS In 12 mechanically ventilated pigs, ALI was induced in a randomized fashion by lung lavage, lung lavage plus injurious ventilation, or by oleic acid. From a static PV loop obtained by an interrupted low-flow method, the pressures at LIP [25 (25, 25) cmH(2)O, mean and 25, 75 percentiles], at PMC [24 (20, 24) cmH(2)O], and at 90% MH [19 (18, 19) cmH(2)O] were determined and used for the PEEP-settings. We measured lung inflation (by computed tomography), end-expiratory lung volume (EELV), airway pressures, compliance of the respiratory system (Crs), blood gases, cardiac output and arterial blood pressure. RESULTS There were no differences between the PEEP settings in EELV or oxygenation, but the 90%MH setting gave lower end-inspiratory pause pressure (P<0.025), higher Crs (P<0.025), less hyper-aeration (P<0.025) and better maintained hemodynamics. CONCLUSION In this porcine lung injury model, PEEP set at 90% MH gave better lung mechanics and hemodynamics, than PEEP set at PMC or LIP.
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Hua YM, Lien SH, Liu TY, Lee CM, Yuh YS. A decremental PEEP trial for determining open-lung PEEP in a rabbit model of acute lung injury. Pediatr Pulmonol 2008; 43:371-80. [PMID: 18293413 DOI: 10.1002/ppul.20780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A positive end-expiratory pressure (PEEP) above the lower inflection point (LIP) of the pressure-volume curve has been thought necessary to maintain recruited lung volume in acute lung injury (ALI). We used a strategy to identify the level of open-lung PEEP (OLP) by detecting the maximum tidal compliance during a decremental PEEP trial (DPT). We performed a randomized controlled study to compare the effect of the OLP to PEEP above LIP and zero PEEP on pulmonary mechanics, gas exchange, hemodynamic change, and lung injury in 26 rabbits with ALI. After recruitment maneuver, the lavage-injured rabbits received DPTs to identify the OLP. Animals were randomized to receive volume controlled ventilation with either: (a) PEEP = 0 cm H2O (ZEEP); (b) PEEP = 2 cm H2O above OLP (OLP + 2); or (c) PEEP = 2 cm H2O above LIP (LIP + 2). Peak inspiratory pressure and mean airway pressure were recorded and arterial blood gases were analyzed every 30 min. Mean blood pressure and heart rate were monitored continuously. Lung injury severity was assessed by lung wet/dry weight ratio. Animals in OLP + 2 group had less lung injury as well as relatively better compliance, more stable pH, and less hypercapnia compared to the LIP + 2 and ZEEP groups. We concluded that setting PEEP according to the OLP identified by DPTs is an effective method to attenuate lung injury. This strategy could be used as an indicator for optimal PEEP. The approach is simple and noninvasive and may be of clinical interest.
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Affiliation(s)
- Yi-Ming Hua
- Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
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Albaiceta GM, Gutiérrez-Fernández A, Parra D, Astudillo A, García-Prieto E, Taboada F, Fueyo A. Lack of matrix metalloproteinase-9 worsens ventilator-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2008; 294:L535-43. [DOI: 10.1152/ajplung.00334.2007] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Matrix metalloproteinase-9 (MMP-9) is released by neutrophils at the sites of acute inflammation. This enzyme modulates matrix turnover and inflammatory response, and its activity has been found to be increased after ventilator-induced lung injury. To clarify the role of MMP-9, mice lacking this enzyme and their wild-type counterparts were ventilated for 2 h with high- or low-peak inspiratory pressures (25 and 15 cmH2O, respectively). Lung injury was evaluated by gas exchange, respiratory mechanics, wet-to-dry weight ratio, and histological analysis. The activity of MMP-9 and levels of IL-1β, IL-4, and macrophage inflammatory protein (MIP-2) were measured in lung tissue and bronchoalveolar lavage fluid (BALF). Cell count and myeloperoxidase activity were measured in BALF. There were no differences between wild-type and Mmp9−/− animals after low-pressure ventilation. After high-pressure ventilation, wild-type mice exhibited an increase in MMP-9 in tissue and BALF. Mice lacking MMP-9 developed more severe lung injury than wild-type mice, in terms of impaired oxygenation and lung mechanics, and higher damage in the histological study. These effects correlated with an increase in both cell count and myeloperoxidase activity in the BALF, suggesting an increased neutrophilic influx in response to ventilation. An increase in IL-1β and IL-4 in the BALF only in knockout mice could be responsible for the differences. There were no differences between genotypes in MMP-2, MMP-8, or tissue inhibitors of metalloproteinases. These results show that MMP-9 protects against ventilator-induced lung injury by decreasing alveolar neutrophilic infiltration, probably by modulation of the cytokine response in the air spaces.
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Albaiceta GM, Blanch L, Lucangelo U. Static pressure–volume curves of the respiratory system: were they just a passing fad? Curr Opin Crit Care 2008; 14:80-6. [DOI: 10.1097/mcc.0b013e3282f2b8f4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Seymour CW, Frazer M, Reilly PM, Fuchs BD. Airway pressure release and biphasic intermittent positive airway pressure ventilation: are they ready for prime time? ACTA ACUST UNITED AC 2007; 62:1298-308; discussion 1308-9. [PMID: 17495742 DOI: 10.1097/ta.0b013e31803c562f] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Airway pressure release ventilation and biphasic positive airway pressure ventilation are being used increasingly as alternative strategies to conventional assist control ventilation for patients with acute respiratory distress syndrome (ARDS) and acute lung injury. By permitting spontaneous breathing throughout the ventilatory cycle, these modes offer several advantages over conventional strategies to improve the pathophysiology in these patients, including gas exchange, cardiovascular function, and reducing or eliminating the need for heavy sedation and paralysis. Whether these surrogate outcomes will translate into better patient outcomes remains to be determined. The purpose of this review is to summarize the rationale behind the use of these ventilatory strategies in ARDS, the clinical experience with the use of these modes, and their future applications in trauma patients.
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Affiliation(s)
- Christopher W Seymour
- Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia 19104-4283, USA
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Jeon K, Jeon IS, Suh GY, Chung MP, Koh WJ, Kim H, Kwon OJ, Han DH, Chung MJ, Lee KS. Two methods of setting positive end-expiratory pressure in acute lung injury: an experimental computed tomography volumetric study. J Korean Med Sci 2007; 22:476-83. [PMID: 17596657 PMCID: PMC2693641 DOI: 10.3346/jkms.2007.22.3.476] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study was conducted to observe effects of two methods of setting positive end-expiratory pressure (PEEP) based on the pressure-volume (PV) curve. After lung injury was induced by oleic acid in six mongrel adult dogs, the inflation PV curve was traced and the lower inflection point (LIP) was measured. The 'PEEP(INF)' was defined as LIP+2 cmH(2)O. After recruitment maneuver to move the lung physiology to the deflation limb of PV curve, decremental PEEP was applied. The lowest level of PEEP that did not result in a significant drop in PaO(2) was defined as the 'PEEP(DEF)'. Arterial blood gases, lung mechanics, hemodynamics, and lung volumes (measured on computed tomography during end-expiratory pause) were measured at PEEP of 0 cmH(2)O, PEEP(INF) and PEEP(DEF) sequentially. The median PEEP(INF) was 13.4 cm H(2)O (interquartile range, 12.5-14.3) and median PEEP(DEF) was 12.0 cm H(2)O (10.0-16.5) (p=0.813). PEEP(DEF) was associated with significantly higher PaO(2) and lung volumes, and significantly lower shunt fraction and cardiac index when compared to PEEP(INF) (p<0.05). Setting the PEEP based on the deflation limb of the PV curve was useful in improving oxygenation and lung volumes in a canine lung injury model.
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Affiliation(s)
- Kyeongman Jeon
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Ik Soo Jeon
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Gee Young Suh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Man Pyo Chung
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Won-Jung Koh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hojoong Kim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - O Jung Kwon
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Dai-Hee Han
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Myung Jin Chung
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kyung Soo Lee
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Albaiceta GM, Garcia E, Taboada F. Comparative study of four sigmoid models of pressure-volume curve in acute lung injury. Biomed Eng Online 2007; 6:7. [PMID: 17300715 PMCID: PMC1802870 DOI: 10.1186/1475-925x-6-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 02/14/2007] [Indexed: 11/25/2022] Open
Abstract
Background The pressure-volume curve of the respiratory system is a tool to monitor and set mechanical ventilation in acute lung injury. Mathematical models of the static pressure-volume curve of the respiratory system have been proposed to overcome the inter- and intra-observer variability derived from eye-fitting. However, different models have not been compared. Methods The goodness-of-fit and the values of derived parameters (upper asymptote, maximum compliance and points of maximum curvature) in four sigmoid models were compared, using pressure-volume data from 30 mechanically ventilated patients during the early phase of acute lung injury. Results All models showed an excellent goodness-of-fit (R2 always above 0.92). There were significant differences between the models in the parameters derived from the inspiratory limb, but not in those derived from the expiratory limb of the curve. The within-case standard deviations of the pressures at the points of maximum curvature ranged from 2.33 to 6.08 cmH2O. Conclusion There are substantial variabilities in relevant parameters obtained from the four different models of the static pressure-volume curve of the respiratory system.
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Affiliation(s)
- Guillermo M Albaiceta
- Intensive Care Unit, Hospital Universitario Central de Asturias, Oviedo, Spain
- Department of Functional Biology, University of Oviedo, Oviedo, Spain
| | - Esteban Garcia
- Intensive Care Unit, Hospital Universitario Central de Asturias, Oviedo, Spain
| | - Francisco Taboada
- Intensive Care Unit, Hospital Universitario Central de Asturias, Oviedo, Spain
- Department of Medicine, University of Oviedo, Oviedo, Spain
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Current World Literature. Curr Opin Anaesthesiol 2006; 19:660-5. [PMID: 17093372 DOI: 10.1097/aco.0b013e3280122f5d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
PURPOSE OF REVIEW To address lung recruitment according to pressure/volume curves, along with regional recruitment versus hyperinflation evidence from computed tomography and electrical impedance tomography. RECENT FINDINGS Cyclical tidal volume recruitment of atelectatic lung regions causes acute lung injury, as do large breaths during pneumonectomy. Using the lower inflection point on the static pressure/volume inflation curve plus 2 cmH2O as a positive end-expiratory pressure setting limits hyperinflation in acute lung injury, but may not provide enough positive end-expiratory pressure to avoid cyclical recruitment/derecruitment injury in more severe acute lung injury regions. Both computed tomography and electrical impedance tomography can help titrate positive end-expiratory pressure in these regions, thereby assuring an 'open lung' ventilatory pattern. Regional pressure/volume curves show that adequate positive end-expiratory pressure for severe acute lung injury regions may not be reliably determined from whole lung pressure/volume curves. Balancing positive end-expiratory pressure requires both arterial PO2 and PCO2 values to determine at what level hyperinflated regions become seriously underperfused (develop very high ventilation-perfusion ratios), adding to the hypercarbia from increased deadspace. SUMMARY Positive end-expiratory pressure levels must be high enough to minimize recruitment/derecruitment cycling. Balancing recruitment versus overdistension may require thoracic tomography, to assure sufficient improvement in oxygenation while limiting hypercarbia.
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Affiliation(s)
- Ron Dueck
- Department of Anesthesiology, University of California, San Diego, California, USA.
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Saner FH, Pavlaković G, Gu Y, Fruhauf NR, Paul A, Radtke A, Nadalin S, Malagó M, Broelsch CE. Does PEEP impair the hepatic outflow in patients following liver transplantation? Intensive Care Med 2006; 32:1584-90. [PMID: 16941166 DOI: 10.1007/s00134-006-0357-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2006] [Accepted: 07/27/2006] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Evaluation of the impact of end-expiratory pressure (PEEP) ventilation on venous liver outflow, portal vein, and hepatic artery flows as well as systemic hemodynamics in patients following liver transplantation (LT). DESIGN Prospective, interventional patient study. SETTING University hospital intensive care unit. PATIENTS 65 consecutive patients after LT. INTERVENTIONS All patients were intubated and mechanically ventilated with biphasic positive airway pressure (BIPAP). The effects of three levels of PEEP (0, 5, and 10 mbar) applied at random order on hepatic inflow and outflow were studied in the immediate postoperative period. MEASUREMENT AND RESULTS Central venous-, arterial pressure, and cardiac index was recorded from every patient at three different PEEP levels (0, 5, and 10 mbar). Simultaneously, flow velocities in the hepatic-, portal vein, and hepatic artery were determined by Doppler ultrasound. PEEP of 10 mbar significantly increased central venous pressure in comparison with zero PEEP. Mean arterial pressure and cardiac index was not influenced. Hepatic inflow and outflow of the transplanted livers were not impaired by any of the used PEEP levels. CONCLUSIONS BIPAP ventilation with PEEP levels up to 10 mbar does not affect systemic hemodynamics. Furthermore, neither venous outflow nor portal venous or hepatic artery inflow of the liver are impaired at PEEP levels up to 10 mbar immediately following liver transplantation. Although these results suggest that PEEP ventilation up to 10 mbar does not affect liver hemodynamics, further studies are needed to determine whether these findings could be confirmed for a longer ventilation period with PEEP.
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Affiliation(s)
- Fuat H Saner
- University Clinic Essen, Department of General-, Visceral-, and Transplant Surgery, Hufelandstrasse 55, 45122 Essen, Germany.
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Andrews P, Azoulay E, Antonelli M, Brochard L, Brun-Buisson C, de Backer D, Dobb G, Fagon JY, Gerlach H, Groeneveld J, Mancebo J, Metnitz P, Nava S, Pugin J, Pinsky M, Radermacher P, Richard C, Tasker R. Year in review in intensive care medicine. 2005. I. Acute respiratory failure and acute lung injury, ventilation, hemodynamics, education, renal failure. Intensive Care Med 2006; 32:207-216. [PMID: 16450098 DOI: 10.1007/s00134-005-0027-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Accepted: 12/08/2005] [Indexed: 01/20/2023]
Affiliation(s)
- Peter Andrews
- Intensive Care Medicine Unit, Western General Hospital, Edinburgh, UK
| | - Elie Azoulay
- Intensive Care Medicine Unit, Saint Louis Hospital, Paris, France
| | - Massimo Antonelli
- Department of Intensive Care and Anesthesiology, Universita Cattolica del Sacro Cuore, Rome, Italy
| | - Laurent Brochard
- Réanimation Médicale, AP-HP, Hôpital Henri Mondor, INSERM U 615, Université, Paris 12, France.
| | - Christian Brun-Buisson
- Medical Intensive Care Unit, University Hospital Henri Mondor, 51 avenue du Marechal de Lattre de Tassigny, 94000, Creteil, France
| | - Daniel de Backer
- Service des Soins Intensifs, Hôpital Erasme, 808 route de Lennick, 1070, Bruxelles, Belgium
| | - Geoffrey Dobb
- Intensive Care Medicine Unit, Royal Perth Hospital, Perth, Australia
| | - Jean-Yves Fagon
- Intensive Care Medicine Unit, European Georges Pompidou Hospital, Paris, France
| | - Herwig Gerlach
- Department of Anesthesiology, Vivantes-Klinikum Neukoelln, Berlin, Germany
| | | | - Jordi Mancebo
- Intensive Care Medicine Unit, Hospital Sant Pau, Barcelona, Spain
| | - Philipp Metnitz
- Department of Anesthesia and General Intensive Care Medicine, University Hospital of Vienna, Vienna, Austria
| | - Stefano Nava
- Intensive Care Medicine Unit, Fondazione S. Maugeri, Pavia, Italy
| | - Jerome Pugin
- Intensive Care Medicine Unit, University Hospital of Geneva, Geneva, Switzerland
| | - Michael Pinsky
- Intensive Care Medicine Unit, University of Pittsburgh Medical Center, Pittsburgh, Pa., USA
| | - Peter Radermacher
- Department of Anesthesia, University Medical School of Ulm, Ulm, Germany
| | - Christian Richard
- Intensive Care Medicine Unit, University Hospital of Le Kremlin-Bicetre, Le Kremlin Bicetre, France
| | - Robert Tasker
- Pediatric Intensive Care Unit, Addenbrooke's Hospital, Cambridge, UK
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