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Jiang L, Chen H, Xie J, Liu L, Yang Y. Prognostic value of time-varying dead space estimates in mechanically ventilated patients with acute respiratory distress syndrome. JOURNAL OF INTENSIVE MEDICINE 2024; 4:187-193. [PMID: 38681797 PMCID: PMC11043632 DOI: 10.1016/j.jointm.2023.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 05/01/2024]
Abstract
Background The dead space fraction (VD/VT) has proven to be a powerful predictor of higher mortality in acute respiratory distress syndrome (ARDS). However, its measurement relies on expired carbon dioxide, limiting its widespread application in clinical practice. Several estimates employing routine variables have been found to be reliable substitutes for direct measurement of VD/VT. In this study, we evaluated the prognostic value of these dead space estimates obtained in the first 7 days following the initiation of ventilation. Methods This retrospective observational study was conducted using data from the Chinese database in intensive care (CDIC). Eligible participants were adult ARDS patients receiving invasive mechanical ventilation while in the intensive care unit between 1st January 2014 and 31st March 2021. We collected data during the first 7 days of ventilation to calculate various dead space estimates, including ventilatory ratio (VR), corrected minute ventilation (V ˙ Ecorr ), VD/VT (Harris-Benedict), VD/VT (Siddiki estimate), and VD/VT (Penn State estimate) longitudinally. A time-dependent Cox model was used to handle these time-varying estimates. Results A total of 392 patients (median age 66 [interquartile range: 55-77] years, median SOFA score 9 [interquartile range: 7-12]) were finally included in our analysis, among whom 132 (33.7%) patients died within 28 days of admission. VR (hazard ratio [HR]=1.04 per 0.1 increase, 95% confidence interval [CI]: 1.01 to 1.06; P=0.013), V ˙ Ecorr (HR=1.08 per 1 increase, 95% CI: 1.04 to 1.12; P < 0.001), VD/VT (Harris-Benedict) (HR=1.25 per 0.1 increase, 95% CI: 1.06 to 1.47; P=0.006), and VD/VT (Penn State estimate) (HR=1.22 per 0.1 increase, 95% CI: 1.04 to 1.44; P=0.017) remained significant after adjustment, while VD/VT (Siddiki estimate) (HR=1.10 per 0.1 increase, 95% CI: 1.00 to 1.20; P=0.058) did not. Given a large number of negative values, VD/VT (Siddiki estimate) and VD/VT (Penn State estimate) were not recommended as reliable substitutes. Long-term exposure to VR >1.3, V ˙ Ecorr >7.53, and VD/VT (Harris-Benedict) >0.59 was independently associated with an increased risk of mortality in ARDS patients. These findings were validated in the fluid and catheter treatment trial (FACTT) database. Conclusions In cases where VD/VT cannot be measured directly, early time-varying estimates of VD/VT such as VR, V ˙ Ecorr , and VD/VT (Harris-Benedict) can be considered for predicting mortality in ARDS patients, offering a rapid bedside application.
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Affiliation(s)
- Lianlian Jiang
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Hui Chen
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
- Department of Critical Care Medicine, The First Affiliated Hospital of Soochow University, Soochow University, Suzhou, Jiangsu, China
| | - Jianfeng Xie
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Ling Liu
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Yi Yang
- Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
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Mueller-Graf F, Frenkel P, Merz J, Reuter S, Vollmar B, Tusman G, Pulletz S, Böhm SH, Zitzmann A, Reuter DA, Adler A. Respiratory gating improves correlation between pulse wave transit time and pulmonary artery pressure in experimental pulmonary hypertension. Physiol Meas 2024; 45:03NT02. [PMID: 38422512 DOI: 10.1088/1361-6579/ad2eb5] [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: 07/17/2023] [Accepted: 02/29/2024] [Indexed: 03/02/2024]
Abstract
Objective. Since pulse wave transit time (PWTT) shortens as pulmonary artery pressure (PAP) increases it was suggested as a potential non-invasive surrogate for PAP. The state of tidal lung filling is also known to affect PWTT independently of PAP. The aim of this retrospective analysis was to test whether respiratory gating improved the correlation coefficient between PWTT and PAP.Approach. In each one of five anesthetized and mechanically ventilated pigs two high-fidelity pressure catheters were placed, one directly behind the pulmonary valve, and the second one in a distal branch of the pulmonary artery. PAP was raised using the thromboxane A2 analogue U46619 and animals were ventilated in a pressure controlled mode (I:E ratio 1:2, respiratory rate 12/min, tidal volume of 6 ml kg-1). All signals were recorded using the multi-channel platform PowerLab®. The arrival of the pulse wave at each catheter tip was determined using a MATLAB-based modified hyperbolic tangent algorithm and PWTT calculated as the time interval between these arrivals.Main results. Correlation coefficient for PWTT and mean PAP wasr= 0.932 for thromboxane. This correlation coefficient increased considerably when heart beats either at end-inspiration (r= 0.978) or at end-expiration (r= 0.985) were selected (=respiratory gating).Significance. The estimation of mean PAP from PWTT improved significantly when taking the respiratory cycle into account. Respiratory gating is suggested to improve for the estimation of PAP by PWTT.
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Affiliation(s)
- Fabian Mueller-Graf
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Medical Center Rostock, Schillingallee 35, D-18057 Rostock, Germany
- Rudolf-Zenker-Institute for Experimental Surgery, University Medical Center Rostock, D-18057 Rostock, Germany
| | - Paul Frenkel
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Medical Center Rostock, Schillingallee 35, D-18057 Rostock, Germany
| | - Jonas Merz
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Medical Center Rostock, Schillingallee 35, D-18057 Rostock, Germany
| | - Susanne Reuter
- Rudolf-Zenker-Institute for Experimental Surgery, University Medical Center Rostock, D-18057 Rostock, Germany
| | - Brigitte Vollmar
- Rudolf-Zenker-Institute for Experimental Surgery, University Medical Center Rostock, D-18057 Rostock, Germany
| | - Gerardo Tusman
- Department of Anesthesiology, Hospital Privado de Comunidad, Mar del Plata, Buenos Aires, Argentina
| | - Sven Pulletz
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Medical Center Rostock, Schillingallee 35, D-18057 Rostock, Germany
| | - Stephan H Böhm
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Medical Center Rostock, Schillingallee 35, D-18057 Rostock, Germany
| | - Amelie Zitzmann
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Medical Center Rostock, Schillingallee 35, D-18057 Rostock, Germany
| | - Daniel A Reuter
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, University Medical Center Rostock, Schillingallee 35, D-18057 Rostock, Germany
| | - Andy Adler
- Systems and Computer Engineering, Carleton University, Ottawa, Canada
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Soares JHN, Raff GW, Fineman JR, Datar SA. Respiratory mechanics and gas exchange in an ovine model of congenital heart disease with increased pulmonary blood flow and pressure. Front Physiol 2023; 14:1188824. [PMID: 37362431 PMCID: PMC10288580 DOI: 10.3389/fphys.2023.1188824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 05/30/2023] [Indexed: 06/28/2023] Open
Abstract
In a model of congenital heart disease (CHD), we evaluated if chronically increased pulmonary blood flow and pressure were associated with altered respiratory mechanics and gas exchange. Respiratory mechanics and gas exchange were evaluated in 6 shunt, 7 SHAM, and 7 control age-matched lambs. Lambs were anesthetized and mechanically ventilated for 15 min with tidal volume of 10 mL/kg, positive end-expiratory pressure of 5 cmH2O, and inspired oxygen fraction of 0.21. Respiratory system, lung and chest wall compliances (Crs, CL and Ccw, respectively) and resistances (Rrs, RL and Rcw, respectively), and the profile of the elastic pressure-volume curve (%E2) were evaluated. Arterial blood gases and volumetric capnography variables were collected. Comparisons between groups were performed by one-way ANOVA followed by Tukey-Kramer test for normally distributed data and with Kruskal-Wallis test followed by Steel-Dwass test for non-normally distributed data. Average Crs and CL in shunt lambs were 30% and 58% lower than in control, and 56% and 68% lower than in SHAM lambs, respectively. Ccw was 52% and 47% higher and Rcw was 53% and 40% lower in shunt lambs compared to controls and SHAMs, respectively. No difference in %E2 was identified between groups. No difference in respiratory mechanics was observed between control and SHAM lambs. In shunt lambs, Rcw, Crs and CL were decreased and Ccw was increased when compared to control and SHAM lambs. Pulmonary gas exchange did not seem to be impaired in shunt lambs when compared to controls and SHAMs.
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Affiliation(s)
- Joao Henrique N. Soares
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Gary W. Raff
- Department of Surgery, School of Medicine, University of California, Davis, Davis, CA, United States
| | - Jeffrey R. Fineman
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States
- Department of Pediatrics, School of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Sanjeev A. Datar
- Department of Pediatrics, School of Medicine, University of California, San Francisco, San Francisco, CA, United States
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Derespina KR, Medar SS, Aydin SI, Kaushik S, Al-Subu A, Ofori-Amanfo G. Volumetric Capnography in Pediatric Extracorporeal Membrane Oxygenation: A Case Series. J Pediatr Intensive Care 2022; 11:109-113. [DOI: 10.1055/s-0040-1718375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 08/30/2020] [Indexed: 10/23/2022] Open
Abstract
AbstractThe kinetics of carbon dioxide elimination (VCO2) may be used as a surrogate for pulmonary blood flow. As such, we can apply a novel use of volumetric capnography to assess hemodynamic stability in patients requiring extracorporeal membrane oxygenation (ECMO). We report our experience of pediatric patients requiring ECMO support who were monitored using volumetric capnography. We describe the use of VCO2 and its association with successful decannulation. This is a prospective observational study of pediatric patients requiring ECMO support at The Children's Hospital at Montefiore from 2017 to 2019. A Respironics NM3 monitor was applied to each patient. Demographics, hemodynamic data, blood gases, and VCO2 (mL/min) data were collected. Data were collected immediately prior to and after decannulation. Over the course of the study period, seven patients were included. Predecannulation VCO2 was higher among patients who were successfully decannulated than nonsurvivors (109 [35, 230] vs. 12.4 [7.6, 17.2] mL/min), though not statistically significant. Four patients (57%) survived without further mechanical support; two (29%) died, and one (14%) was decannulated to Berlin. Predecannulation VCO2 appears to correlate with hemodynamic stability following decannulation. This case series adds to the growing literature describing the use of volumetric capnography in critical care medicine, particularly pediatric patients requiring ECMO. Prospective studies are needed to further elucidate the use of volumetric capnography and optimal timing for ECMO decannulation.
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Affiliation(s)
- Kim R. Derespina
- Division of Pediatric Critical Care Medicine, The Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Shivanand S. Medar
- Division of Pediatric Critical Care Medicine, The Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Scott I. Aydin
- Division of Pediatric Critical Care Medicine, Mount Sinai Kravis Children's Hospital, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Shubhi Kaushik
- Division of Pediatric Critical Care Medicine, Mount Sinai Kravis Children's Hospital, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Awni Al-Subu
- Division of Pediatric Critical Care Medicine, American Family Children's Hospital, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
| | - George Ofori-Amanfo
- Division of Pediatric Critical Care Medicine, Mount Sinai Kravis Children's Hospital, Icahn School of Medicine at Mount Sinai, New York, United States
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Vijayam B, Supriyanto E, Malarvili MB. Digitization and Analysis of Capnography Using Image Processing Technique. Front Digit Health 2021; 3:723204. [PMID: 34778867 PMCID: PMC8585923 DOI: 10.3389/fdgth.2021.723204] [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: 06/10/2021] [Accepted: 09/29/2021] [Indexed: 11/13/2022] Open
Abstract
The study of carbon dioxide expiration is called capnometry. The graphical representation of capnometry is called capnography. There is a growing interest in the usage of capnography as the usage has expanded toward the study of metabolism, circulation, lung perfusion and diffusion, quality of spontaneous respiration, and patency of airways outside of its typical usage in the anesthetic and emergency medicine field. The parameters of the capnograph could be classified as carbon dioxide (CO2) concentration and time points and coordinates, slopes angle, volumetric studies, and functional transformation of wave data. Up to date, there is no gold standard device for the calculation of the capnographic parameters. Capnography digitization using the image processing technique could serve as an option. From the algorithm we developed, eight identical breath waves were tested by four investigators. The values of the parameters chosen showed no significant difference between investigators. Although there were no significant differences between any of the parameters tested, there were a few related parameters that were not calculable. Further testing after refinement of the algorithm could be done. As more capnographic parameters are being derived and rediscovered by clinicians and researchers alike for both lung and non-lung-related diseases, there is a dire need for data analysis and interpretation. Although the proposed algorithm still needs minor refinements and further large-scale testing, we proposed that the digitization of the capnograph via image processing technique could serve as an intellectual option as it is fast, convenient, easy to use, and efficient.
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Affiliation(s)
- Bhuwaneswaran Vijayam
- School of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia
| | - Eko Supriyanto
- School of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia.,Institut Jantung Negara - Universiti Teknologi Malaysia (IJN-UTM) Cardiovascular Engineering Center, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia
| | - M B Malarvili
- School of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia
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6
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Correlation of Pulse Wave Transit Time with Pulmonary Artery Pressure in a Porcine Model of Pulmonary Hypertension. Biomedicines 2021; 9:biomedicines9091212. [PMID: 34572397 PMCID: PMC8467418 DOI: 10.3390/biomedicines9091212] [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: 08/10/2021] [Revised: 08/27/2021] [Accepted: 09/06/2021] [Indexed: 11/17/2022] Open
Abstract
For the non-invasive assessment of pulmonary artery pressure (PAP), surrogates like pulse wave transit time (PWTT) have been proposed. The aim of this study was to invasively validate for which kind of PAP (systolic, mean, or diastolic) PWTT is the best surrogate parameter. To assess both PWTT and PAP in six healthy pigs, two pulmonary artery Mikro-Tip™ catheters were inserted into the pulmonary vasculature at a fixed distance: one in the pulmonary artery trunk, and a second one in a distal segment of the pulmonary artery. PAP was raised using the thromboxane A2 analogue U46619 (TXA) and by hypoxic vasoconstriction. There was a negative linear correlation between PWTT and systolic PAP (r = 0.742), mean PAP (r = 0.712) and diastolic PAP (r = 0.609) under TXA. During hypoxic vasoconstriction, the correlation coefficients for systolic, mean, and diastolic PAP were consistently higher than for TXA-induced pulmonary hypertension (r = 0.809, 0.778 and 0.734, respectively). Estimation of sPAP, mPAP, and dPAP using PWTT is feasible, nevertheless slightly better correlation coefficients were detected for sPAP compared to dPAP. In this study we establish the physiological basis for future methods to obtain PAP by non-invasively measured PWTT.
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7
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Morales-Quinteros L, Neto AS, Artigas A, Blanch L, Botta M, Kaufman DA, Schultz MJ, Tsonas AM, Paulus F, Bos LD. Dead space estimates may not be independently associated with 28-day mortality in COVID-19 ARDS. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2021; 25:171. [PMID: 34001222 PMCID: PMC8127435 DOI: 10.1186/s13054-021-03570-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023]
Abstract
BACKGROUND Estimates for dead space ventilation have been shown to be independently associated with an increased risk of mortality in the acute respiratory distress syndrome and small case series of COVID-19-related ARDS. METHODS Secondary analysis from the PRoVENT-COVID study. The PRoVENT-COVID is a national, multicenter, retrospective observational study done at 22 intensive care units in the Netherlands. Consecutive patients aged at least 18 years were eligible for participation if they had received invasive ventilation for COVID-19 at a participating ICU during the first month of the national outbreak in the Netherlands. The aim was to quantify the dynamics and determine the prognostic value of surrogate markers of wasted ventilation in patients with COVID-19-related ARDS. RESULTS A total of 927 consecutive patients admitted with COVID-19-related ARDS were included in this study. Estimations of wasted ventilation such as the estimated dead space fraction (by Harris-Benedict and direct method) and ventilatory ratio were significantly higher in non-survivors than survivors at baseline and during the following days of mechanical ventilation (p < 0.001). The end-tidal-to-arterial PCO2 ratio was lower in non-survivors than in survivors (p < 0.001). As ARDS severity increased, mortality increased with successive tertiles of dead space fraction by Harris-Benedict and by direct estimation, and with an increase in the VR. The same trend was observed with decreased levels in the tertiles for the end-tidal-to-arterial PCO2 ratio. After adjustment for a base risk model that included chronic comorbidities and ventilation- and oxygenation-parameters, none of the dead space estimates measured at the start of ventilation or the following days were significantly associated with 28-day mortality. CONCLUSIONS There is significant impairment of ventilation in the early course of COVID-19-related ARDS but quantification of this impairment does not add prognostic information when added to a baseline risk model. TRIAL REGISTRATION ISRCTN04346342. Registered 15 April 2020. Retrospectively registered.
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Affiliation(s)
- Luis Morales-Quinteros
- Intensive Care Unit, Hospital Universitari General de Catalunya, Grupo Quironsalud, Carrer Pedro i Pons, 1, 08195, Sant Cugat del Vallès, Barcelona, Spain. .,Universidad Autonoma de Barcelona, Barcelona, Spain. .,Institut D'Investigació, Innovació Parc Taulí I3PT, Sabadell, Spain.
| | - Ary Serpa Neto
- Department of Intensive Care & Laboratory of Experimental Intensive Care and Anaesthesiology (L·E·I·C·A), Amsterdam UMC Location AMC, Amsterdam, The Netherlands.,Department of Critical Care Medicine, Hospital Israelita Albert Einstein, São Paulo, Brazil.,Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), Monash University, Melbourne, Australia.,Data Analytics Research and Evaluation (DARE) Centre, Austin Hospital and University of Melbourne, Melbourne, Australia
| | - Antonio Artigas
- Universidad Autonoma de Barcelona, Barcelona, Spain.,Institut D'Investigació, Innovació Parc Taulí I3PT, Sabadell, Spain.,Critical Care Center, Corporacion Sanitaria Universitaria Parc Taulí, Sabadell, Spain.,CIBER Enfermedades Respiratorias (ISCiii), Madrid, Spain
| | - Lluis Blanch
- Universidad Autonoma de Barcelona, Barcelona, Spain.,Institut D'Investigació, Innovació Parc Taulí I3PT, Sabadell, Spain.,Critical Care Center, Corporacion Sanitaria Universitaria Parc Taulí, Sabadell, Spain.,CIBER Enfermedades Respiratorias (ISCiii), Madrid, Spain
| | - Michela Botta
- Department of Intensive Care & Laboratory of Experimental Intensive Care and Anaesthesiology (L·E·I·C·A), Amsterdam UMC Location AMC, Amsterdam, The Netherlands
| | - David A Kaufman
- Division of Pulmonary, Critical Care, and Sleep Medicine, NYU School of Medicine, New York, NY, USA
| | - Marcus J Schultz
- Department of Intensive Care & Laboratory of Experimental Intensive Care and Anaesthesiology (L·E·I·C·A), Amsterdam UMC Location AMC, Amsterdam, The Netherlands.,Nuffield Department of Medicine, Oxford University, Oxford, UK.,Mahidol-Oxford Tropical Medicine Research Unit (MORU), Mahidol University, Bangkok, Thailand
| | - Anissa M Tsonas
- Department of Intensive Care & Laboratory of Experimental Intensive Care and Anaesthesiology (L·E·I·C·A), Amsterdam UMC Location AMC, Amsterdam, The Netherlands
| | - Frederique Paulus
- Department of Intensive Care & Laboratory of Experimental Intensive Care and Anaesthesiology (L·E·I·C·A), Amsterdam UMC Location AMC, Amsterdam, The Netherlands
| | - Lieuwe D Bos
- Department of Intensive Care & Laboratory of Experimental Intensive Care and Anaesthesiology (L·E·I·C·A), Amsterdam UMC Location AMC, Amsterdam, The Netherlands
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Niveles de capnometría como indicador de evolución de injerto renal de donantes en asistolia no controlada. Med Intensiva 2020; 44:233-238. [DOI: 10.1016/j.medin.2018.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 10/29/2018] [Accepted: 10/30/2018] [Indexed: 11/21/2022]
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9
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Lautz L, Dorne J, Oldenkamp R, Hendriks A, Ragas A. Generic physiologically based kinetic modelling for farm animals: Part I. Data collection of physiological parameters in swine, cattle and sheep. Toxicol Lett 2020; 319:95-101. [DOI: 10.1016/j.toxlet.2019.10.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/09/2019] [Accepted: 10/22/2019] [Indexed: 11/30/2022]
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Sinha P, Calfee CS, Beitler JR, Soni N, Ho K, Matthay MA, Kallet RH. Physiologic Analysis and Clinical Performance of the Ventilatory Ratio in Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med 2019; 199:333-341. [PMID: 30211618 PMCID: PMC6363976 DOI: 10.1164/rccm.201804-0692oc] [Citation(s) in RCA: 188] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 09/10/2018] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Pulmonary dead space fraction (Vd/Vt) is an independent predictor of mortality in acute respiratory distress syndrome (ARDS). Yet, it is seldom used in practice. The ventilatory ratio is a simple bedside index that can be calculated using routinely measured respiratory variables and is a measure of impaired ventilation. Ventilatory ratio is defined as [minute ventilation (ml/min) × PaCO2 (mm Hg)]/(predicted body weight × 100 × 37.5). OBJECTIVES To determine the relation of ventilatory ratio with Vd/Vt in ARDS. METHODS First, in a single-center, prospective observational study of ARDS, we tested the association of Vd/Vt with ventilatory ratio. With in-hospital mortality as the primary outcome and ventilator-free days as the secondary outcome, we tested the role of ventilatory ratio as an outcome predictor. The findings from this study were further verified in secondary analyses of two NHLBI ARDS Network randomized controlled trials. MEASUREMENTS AND MAIN RESULTS Ventilatory ratio positively correlated with Vd/Vt. Ordinal groups of ventilatory ratio had significantly higher Vd/Vt. Ventilatory ratio was independently associated with increased risk of mortality after adjusting for PaO2/FiO2, and positive end-expiratory pressure (odds ratio, 1.51; P = 0.024) and after adjusting for Acute Physiologic Assessment and Chronic Health Evaluation II score (odds ratio, 1.59; P = 0.04). These findings were further replicated in secondary analyses of two separate NHLBI randomized controlled trials. CONCLUSIONS Ventilatory ratio correlates well with Vd/Vt in ARDS, and higher values at baseline are associated with increased risk of adverse outcomes. These results are promising for the use of ventilatory ratio as a simple bedside index of impaired ventilation in ARDS.
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Affiliation(s)
- Pratik Sinha
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Department of Medicine
| | - Carolyn S. Calfee
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Department of Medicine
- Department of Anesthesia, and
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California
| | - Jeremy R. Beitler
- Division of Pulmonary and Critical Care Medicine, University of California, San Diego, San Diego, California
| | - Neil Soni
- Magill Department of Anaesthesia, Intensive Care Medicine and Pain Management, Chelsea and Westminster Hospital, London, United Kingdom; and
| | - Kelly Ho
- Respiratory Care Services, Department of Anesthesia and Perioperative Care, University of California, San Francisco at Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, California
| | - Michael A. Matthay
- Division of Pulmonary, Critical Care, Allergy and Sleep Medicine, Department of Medicine
- Department of Anesthesia, and
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California
| | - Richard H. Kallet
- Respiratory Care Services, Department of Anesthesia and Perioperative Care, University of California, San Francisco at Zuckerberg San Francisco General Hospital and Trauma Center, San Francisco, California
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Al-Subu A, Jooste E, Hornik CP, Fleming GA, Cheifetz IM, Ofori-Amanfo G. Correlation between minute carbon dioxide elimination and pulmonary blood flow in single-ventricle patients after stage 1 palliation and 2-ventricle patients with intracardiac shunts: A pilot study. Paediatr Anaesth 2018; 28:618-624. [PMID: 30133920 PMCID: PMC6485938 DOI: 10.1111/pan.13423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/19/2018] [Indexed: 01/24/2023]
Abstract
BACKGROUND Assessment of pulmonary blood flow and cardiac output is critical in the postoperative management of patients with single-ventricle physiology or 2-ventricle physiology with intracardiac shunting. Currently, such hemodynamic data are only obtainable by invasive procedures, such as cardiac catheterization or the use of a pulmonary artery catheter. Ready availability of such information, especially if attainable noninvasively, could be a valuable addition to postoperative management. AIMS The aim of this study was to assess the correlation between volume of CO2 elimination obtained by volumetric capnography and pulmonary blood flow in pediatric patients with single-ventricle physiology after stage 1 palliation as well as in patients with other cardiac lesions associated with intracardiac shunting. METHODS This prospective cohort study included children with congenital or acquired heart disease who underwent cardiac catheterization as part of clinical care. Cardiac output, pulmonary blood flow, and volume of CO2 elimination were simultaneously collected. Spearman's rank correlation coefficients were used to assess correlation between measurements after controlling for minute ventilation. RESULTS Thirty-five patients were enrolled and divided into 3 groups. Group 1 (n = 8) included single-ventricle patients after stage 1 palliation. Group 2 (n = 10) patients had structural heart disease with 2 ventricles and intracardiac shunting. Group 3 (n = 17) had structurally normal hearts. Among Group 1 patients, the correlation coefficients (R2 ) between volume of CO2 elimination and pulmonary blood flow and volume of CO2 elimination and cardiac output were 0.60 (P = .02) 95% CI [0.01-0.79] and 0.29 (P = .74) 95% CI [-0.91 - 0.86], respectively. In patients with 2 ventricles associated with intracardiac shunts (Group 2), the correlation coefficients between volume of CO2 elimination and pulmonary blood flow and volume of CO2 elimination and cardiac output were 0.86 (P = .001) 95% CI [0.53 - 0.97] and 0.73 (P = .001) 95% CI [0.29 - 0.95], respectively. Among Group 3 patients, the correlation coefficient between volume of CO2 elimination and pulmonary blood flow was 0.66 (P = .038) 95% CI [0.29 - 0.87]. CONCLUSION Volume of CO2 elimination may be a surrogate marker of pulmonary blood flow in single-ventricle patients and patients with biventricular physiology with intracardiac shunting. Also, among patients with normal cardiac anatomy, volume of CO2 elimination may be a marker of cardiac output.
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Affiliation(s)
- Awni Al-Subu
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Edmund Jooste
- Division of Pediatric Anesthesiology, Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Christoph P. Hornik
- Division of Pediatric Critical Care Medicine, Duke University Medical Center, Durham, NC, USA,Duke Clinical Research Institute, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Gregory A. Fleming
- Division of Pediatric Cardiology, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Ira M. Cheifetz
- Division of Pediatric Critical Care Medicine, Duke University Medical Center, Durham, NC, USA
| | - George Ofori-Amanfo
- Division of Pediatric Critical Care, Department of Pediatrics, Kravis Children’s Hospital at Mount Sinai, New York, NY, USA
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Verscheure S, Massion PB, Verschuren F, Damas P, Magder S. Volumetric capnography: lessons from the past and current clinical applications. Crit Care 2016; 20:184. [PMID: 27334879 PMCID: PMC4918076 DOI: 10.1186/s13054-016-1377-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Dead space is an important component of ventilation–perfusion abnormalities. Measurement of dead space has diagnostic, prognostic and therapeutic applications. In the intensive care unit (ICU) dead space measurement can be used to guide therapy for patients with acute respiratory distress syndrome (ARDS); in the emergency department it can guide thrombolytic therapy for pulmonary embolism; in peri-operative patients it can indicate the success of recruitment maneuvers. A newly available technique called volumetric capnography (Vcap) allows measurement of physiological and alveolar dead space on a regular basis at the bedside. We discuss the components of dead space, explain important differences between the Bohr and Enghoff approaches, discuss the clinical significance of arterial to end-tidal CO2 gradient and finally summarize potential clinical indications for Vcap measurements in the emergency room, operating room and ICU.
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Affiliation(s)
- Sara Verscheure
- Department of Critical Care Medicine, University of McGill, Montreal, Quebec, Canada.,Department of General Intensive Care, University Hospital of Liege, Liege, Belgium
| | - Paul B Massion
- Department of General Intensive Care, University Hospital of Liege, Liege, Belgium
| | - Franck Verschuren
- Department of Emergency Medicine, Cliniques universitaire Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Pierre Damas
- Department of General Intensive Care, University Hospital of Liege, Liege, Belgium
| | - Sheldon Magder
- Department of Critical Care Medicine, University of McGill, Montreal, Quebec, Canada.
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Kutter APN, Mosing M, Hartnack S, Raszplewicz J, Renggli M, Mauch JY, Hofer CK. The influence of acute pulmonary hypertension on cardiac output measurements: calibrated pulse contour analysis, transpulmonary and pulmonary artery thermodilution against a modified Fick method in an animal model. Anesth Analg 2015; 121:99-107. [PMID: 25742632 DOI: 10.1213/ane.0000000000000655] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND In critically ill patients with significant pulmonary hypertension (PH), close perioperative cardiovascular monitoring is mandatory, considering the increased morbidity and mortality in this patient group. Although the pulmonary artery catheter is still the standard for the diagnosis of PH, its use to monitor cardiac output (CO) in patients with PH is decreasing as a result of increased morbidity and possible influence of tricuspid regurgitation on the measurements. However, continuous CO measurement methods have never been evaluated under PH regarding their agreement and trending ability. In this study, we evaluated the influence of acute PH and different CO states on transpulmonary thermodilution (TPTD) and calibrated pulse contour analysis (PiCCO; both assessed with PiCCO plus™), intermittent pulmonary artery thermodilution (PATD), and continuous thermodilution (CCO) compared with a modified Fick method (FICK) in an animal model. METHODS Nine healthy pigs were studied under anesthesia. PH of 25 and 40 mm Hg (by administration of the thromboxane analog U46619), CO decreases, and CO increases were induced to test the different CO measurement techniques over a broad range of hemodynamic situations. Before each step, a new baseline data set was collected. CO values were compared using Bland-Altman analysis; trending abilities were assessed via concordance and polar plot analysis. The influence of pulmonary pressure on CO measurements was analyzed using linear mixed models. RESULTS A mean bias of -0.26 L/min with prediction intervals of -0.88 to 1.4 L/min was measured between TPTD and FICK. Their concordance rate was 100% (94%-100% confidence interval), and the mean polar angle -3° with radial limits of agreement of ±28° indicated good trending abilities. PATD compared with FICK also showed good trending ability. Comparisons of PiCCO and CCO versus FICK revealed low agreement and poor trending results with concordance rates of 84% (71%-93%) and 88% (74%-95%), mean polar angles from -17° and -19°, and radial limits of agreement of ±45° and 40°. Pulmonary pressures influenced only the difference between FICK and PiCCO, as assessed by linear mixed models. CONCLUSIONS TPTD compared with FICK was able to track all changes induced during the study period, including those by PH. It yielded better agreement than PATD both compared with FICK. PiCCO and CCO were not mapping all changes correctly, and when used clinically in unstable patients, regular controls with intermittent techniques are required. Acute pharmacologically induced PH did influence the difference between FICK and PiCCO.
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Affiliation(s)
- Annette P N Kutter
- From the Section of Anesthesiology, Equine Department and Section of Epidemiology, Vetsuisse Faculty of the University of Zurich, Zurich, Switzerland; Department of Anesthesiology, Kantonsspital Luzern, Luzern, Switzerland; and Institute of Anesthesiology and Intensive Care Medicine, Triemli City Hospital, Zurich, Switzerland
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Critchley LAH, Zhang J. The Pulmonary Circulation. Anesth Analg 2015; 121:8-10. [DOI: 10.1213/ane.0000000000000657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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