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Grune J, Tabuchi A, Kuebler WM. Alveolar dynamics during mechanical ventilation in the healthy and injured lung. Intensive Care Med Exp 2019; 7:34. [PMID: 31346797 PMCID: PMC6658629 DOI: 10.1186/s40635-019-0226-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 02/13/2019] [Indexed: 02/12/2023] Open
Abstract
Mechanical ventilation is a life-saving therapy in patients with acute respiratory distress syndrome (ARDS). However, mechanical ventilation itself causes severe co-morbidities in that it can trigger ventilator-associated lung injury (VALI) in humans or ventilator-induced lung injury (VILI) in experimental animal models. Therefore, optimization of ventilation strategies is paramount for the effective therapy of critical care patients. A major problem in the stratification of critical care patients for personalized ventilation settings, but even more so for our overall understanding of VILI, lies in our limited insight into the effects of mechanical ventilation at the actual site of injury, i.e., the alveolar unit. Unfortunately, global lung mechanics provide for a poor surrogate of alveolar dynamics and methods for the in-depth analysis of alveolar dynamics on the level of individual alveoli are sparse and afflicted by important limitations. With alveolar dynamics in the intact lung remaining largely a "black box," our insight into the mechanisms of VALI and VILI and the effectiveness of optimized ventilation strategies is confined to indirect parameters and endpoints of lung injury and mortality.In the present review, we discuss emerging concepts of alveolar dynamics including alveolar expansion/contraction, stability/instability, and opening/collapse. Many of these concepts remain still controversial, in part due to limitations of the different methodologies applied. We therefore preface our review with an overview of existing technologies and approaches for the analysis of alveolar dynamics, highlighting their individual strengths and limitations which may provide for a better appreciation of the sometimes diverging findings and interpretations. Joint efforts combining key technologies in identical models to overcome the limitations inherent to individual methodologies are needed not only to provide conclusive insights into lung physiology and alveolar dynamics, but ultimately to guide critical care patient therapy.
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Affiliation(s)
- Jana Grune
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Berlin, 10117 Berlin, Germany
| | - Arata Tabuchi
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Wolfgang M. Kuebler
- Institute of Physiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Berlin, 10117 Berlin, Germany
- The Keenan Research Centre for Biomedical Science at St. Michael’s, Toronto, Canada
- Departments of Surgery and Physiology, University of Toronto, Toronto, Canada
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Sasko B, Thiem U, Christ M, Trappe HJ, Ritter O, Pagonas N. Size matters: An observational study investigating estimated height as a reference size for calculating tidal volumes if low tidal volume ventilation is required. PLoS One 2018; 13:e0199917. [PMID: 29958278 PMCID: PMC6025863 DOI: 10.1371/journal.pone.0199917] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 06/15/2018] [Indexed: 11/19/2022] Open
Abstract
Purpose Acute lung injury is a life threatening condition often requiring mechanical ventilation. Lung-protective ventilation with tidal volumes of 6 mL/kg predicted body weight (PBW, calculated on the basis of a patient’s sex and height), is part of current recommended ventilation strategy. Hence, an exact height is necessary to provide optimal mechanical ventilation. However, it is a common practice to visually estimate the body height of mechanically ventilated patients and use these estimates as a reference size for ventilator settings. We aimed to determine if the common practice of estimating visual height to define tidal volume reduces the possibility of receiving lung-protective ventilation. Methods In this prospective observational study, 28 mechanically ventilated patients had their heights visually estimated by 20 nurses and 20 physicians. All medical professionals calculated the PBW and a corresponding tidal volume with 6 ml/kg/PBW on the basis of their visual estimation. The patients’ true heights were measured and the true PBW with a corresponding tidal volume was calculated. Finally, estimates and measurements were compared. Results 1033 estimations were undertaken by 153 medical professionals. The majority of the estimates were imprecise and resulting data comprised taller body heights, higher PBW and higher tidal volumes (all p≤0.01). When estimates of patients´ heights are used as a reference for tidal-volume definition, patients are exposed to mean tidal volumes of 6.5 ± 0.4 ml/kg/PBW. 526 estimation-based tidal volumes (51.1%) did not provide lung-protective ventilation. Shorter subjects (<175cm) were a specific risk group with an increased risk of not receiving lung protective ventilation (OR 6.6; 95%CI 1.2–35.4; p = 0.02), while taller subjects had a smaller risk of being exposed to inadequately high tidal volumes (OR 0.15; 95%CI 0.02–0.8; p = 0.02). Furthermore, we found an increased risk of overestimating if the assessor was a female (OR 1.74; 95%CI 1.14–2.65; p = 0.01). Conclusion The common practice of visually estimating body height and using these estimates for ventilator settings is imprecise and potentially harmful because it reduces the chance of receiving lung-protective ventilation. Avoiding this practice increases the patient safety. Instead, height should be measured as a standard procedure.
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Affiliation(s)
- Benjamin Sasko
- Department of Cardiology, Brandenburg Medical School, University Hospital Brandenburg, Germany
- Department of Cardiology, Marienhospital Herne, Ruhr-University Bochum, Herne, North Rhine-Westphalia, Germany
- * E-mail:
| | - Ulrich Thiem
- Department of Medical Informatics, Biometry and Epidemiology, Ruhr-University Bochum, Bochum, North Rhine-Westphalia, Germany
| | - Martin Christ
- Department of Cardiology, Marienhospital Herne, Ruhr-University Bochum, Herne, North Rhine-Westphalia, Germany
| | - Hans-Joachim Trappe
- Department of Cardiology, Marienhospital Herne, Ruhr-University Bochum, Herne, North Rhine-Westphalia, Germany
| | - Oliver Ritter
- Department of Cardiology, Brandenburg Medical School, University Hospital Brandenburg, Germany
| | - Nikolaos Pagonas
- Department of Cardiology, Brandenburg Medical School, University Hospital Brandenburg, Germany
- Department of Nephrology, Marienhospital Herne, Ruhr-University Bochum, Herne, North Rhine-Westphalia, Germany
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Raymondos K, Dirks T, Quintel M, Molitoris U, Ahrens J, Dieck T, Johanning K, Henzler D, Rossaint R, Putensen C, Wrigge H, Wittich R, Ragaller M, Bein T, Beiderlinden M, Sanmann M, Rabe C, Schlechtweg J, Holler M, Frutos-Vivar F, Esteban A, Hecker H, Rosseau S, von Dossow V, Spies C, Welte T, Piepenbrock S, Weber-Carstens S. Outcome of acute respiratory distress syndrome in university and non-university hospitals in Germany. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2017; 21:122. [PMID: 28554331 PMCID: PMC5448143 DOI: 10.1186/s13054-017-1687-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Accepted: 05/02/2017] [Indexed: 01/06/2023]
Abstract
Background This study investigates differences in treatment and outcome of ventilated patients with acute respiratory distress syndrome (ARDS) between university and non-university hospitals in Germany. Methods This subanalysis of a prospective, observational cohort study was performed to identify independent risk factors for mortality by examining: baseline factors, ventilator settings (e.g., driving pressure), complications, and care settings—for example, case volume of ventilated patients, size/type of intensive care unit (ICU), and type of hospital (university/non-university hospital). To control for potentially confounding factors at ARDS onset and to verify differences in mortality, ARDS patients in university vs non-university hospitals were compared using additional multivariable analysis. Results Of the 7540 patients admitted to 95 ICUs from 18 university and 62 non-university hospitals in May 2004, 1028 received mechanical ventilation and 198 developed ARDS. Although the characteristics of ARDS patients were very similar, hospital mortality was considerably lower in university compared with non-university hospitals (39.3% vs 57.5%; p = 0.012). Treatment in non-university hospitals was independently associated with increased mortality (OR (95% CI): 2.89 (1.31–6.38); p = 0.008). This was confirmed by additional independent comparisons between the two patient groups when controlling for confounding factors at ARDS onset. Higher driving pressures (OR 1.10; 1 cmH2O increments) were also independently associated with higher mortality. Compared with non-university hospitals, higher positive end-expiratory pressure (PEEP) (mean ± SD: 11.7 ± 4.7 vs 9.7 ± 3.7 cmH2O; p = 0.005) and lower driving pressures (15.1 ± 4.4 vs 17.0 ± 5.0 cmH2O; p = 0.02) were applied during therapeutic ventilation in university hospitals, and ventilation lasted twice as long (median (IQR): 16 (9–29) vs 8 (3–16) days; p < 0.001). Conclusions Mortality risk of ARDS patients was considerably higher in non-university compared with university hospitals. Differences in ventilatory care between hospitals might explain this finding and may at least partially imply regionalization of care and the export of ventilatory strategies to non-university hospitals. Electronic supplementary material The online version of this article (doi:10.1186/s13054-017-1687-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Konstantinos Raymondos
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Tamme Dirks
- Department of Cardiology, KRH Klinikum Robert Koch Gehrden, Gehrden, Germany
| | - Michael Quintel
- Department of Anaesthesiology, Emergency and Intensive Care Medicine, Göttingen University Hospital, Göttingen, Germany
| | - Ulrich Molitoris
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Jörg Ahrens
- Department of Anaesthesiology and Intensive Care Medicine, Klinikum Links der Weser, Bremen, Germany
| | - Thorben Dieck
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Kai Johanning
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Dietrich Henzler
- Department of Anaesthesiology, Herford Hospital, Herford, Germany
| | - Rolf Rossaint
- Department of Anaesthesiology, RWTH Aachen University Hospital, Aachen, Germany
| | - Christian Putensen
- Department of Anaesthesiology and Surgical Intensive Care Medicine, Bonn University Hospital, Bonn, Germany
| | - Hermann Wrigge
- Department of Anaesthesiology and Intensive Care Medicine, Leipzig University Hospital, Leipzig, Germany
| | - Ralph Wittich
- Department of Anaesthesiology and Intensive Care Medicine, Carl Thieme Hospital, Cottbus, Germany
| | - Maximilian Ragaller
- Department of Anaesthesiology and Intensive Care Medicine, Carl Gustav Carus University Hospital, Dresden, Germany
| | - Thomas Bein
- Department of Anaesthesiology, Regensburg University Hospital, Regensburg, Germany
| | - Martin Beiderlinden
- Department of Anaesthesiology and Intensive Care Medicine, Essen University Hospital, Essen, Germany
| | - Maxi Sanmann
- Department of Anaesthesiology, Dietrich-Bonhoeffer Hospital, Neubrandenburg, Germany
| | - Christian Rabe
- Department of Internal Medicine, Bonn University Hospital, Bonn, Germany
| | - Jörn Schlechtweg
- Department of Anaesthesiology, Klinikum Bad Salzungen, Bad Salzungen, Germany
| | - Monika Holler
- Department of Anaesthesiology and Intensive Care Medicine, Municipal Hospital Martha-Maria Halle-Dölau, Halle, Germany
| | - Fernando Frutos-Vivar
- Department of Intensive Care Unit, Hospital Universitario de Getafe, CIBER de Enfermedades Respiratorias, Madrid, Spain
| | - Andres Esteban
- Department of Intensive Care Unit, Hospital Universitario de Getafe, CIBER de Enfermedades Respiratorias, Madrid, Spain
| | - Hartmut Hecker
- Department of Biometry, Hannover Medical School, Hannover, Germany
| | - Simone Rosseau
- Department of Internal Medicine, Division Infectiology and Pulmonology, Charité University Hospital, Berlin, Germany
| | - Vera von Dossow
- Department of Anesthesiology and Intensive Care, Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539, München, Germany.
| | - Claudia Spies
- Department of Anaesthesiology and Intensive Care Medicine, Charité University Hospital, Berlin, Germany
| | - Tobias Welte
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
| | - Siegfried Piepenbrock
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, Carl-Neuberg-Straße 1, 30625, Hannover, Germany
| | - Steffen Weber-Carstens
- Department of Anaesthesiology and Intensive Care Medicine, Charité University Hospital, Berlin, Germany
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Dodoo-Schittko F, Brandstetter S, Brandl M, Blecha S, Quintel M, Weber-Carstens S, Kluge S, Meybohm P, Rolfes C, Ellger B, Bach F, Welte T, Muders T, Thomann-Hackner K, Bein T, Apfelbacher C. Characteristics and provision of care of patients with the acute respiratory distress syndrome: descriptive findings from the DACAPO cohort baseline and comparison with international findings. J Thorac Dis 2017; 9:818-830. [PMID: 28449491 DOI: 10.21037/jtd.2017.03.120] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Little is known about the characteristics and real world life circumstances of ARDS (acute respiratory distress syndrome) patient populations. This knowledge is essential for transferring evidence-based therapy into routine healthcare. The aim of this study was to report socio-demographic and clinical characteristics in an unselected population of ARDS patients and to compare these results to findings from other large ARDS cohorts. METHODS A German based cross-sectional observational study was carried out. A total of 700 ARDS patients were recruited in 59 study sites between September 2014 and January 2016. Socio-demographic, disease and care related variables were recorded. Additionally, characteristics of other large ARDS cohorts identified by a systematic literature search were extracted into evidence tables. RESULTS Median age of ARDS patients was 58 years, 69% were male. Sixty percent had no employment, predominantly due to retirement. Seventy-one percent lived with a partner. The main cause of ARDS was a pulmonary 'direct' origin (79%). The distribution of severity was as follows: mild (14%), moderate (48%), severe (38%). Overall ICU mortality was calculated to be 34%. The observed prevalence of critical events (hypoxemia, hypoglycemia, re-intubation) was 47%. Supportive measures during ICU-treatment were applied to 60% of the patients. Other ARDS cohorts revealed a high heterogeneity in reported concomitant diseases, but sepsis and pneumonia were most frequently reported. Mean age ranged from 54 to 71 years and most patients were male. Other socio-demographic factors have been almost neglected. CONCLUSIONS The proportion of patients suffering of mild ARDS was lower compared to the only study identified, which also applied the Berlin definition. The frequency of critical events during ICU treatment was high and the implementation of evidence-based therapy (prone positioning, neuro-muscular blockers) was limited. More evidence on socio-demographic characteristics and further studies applying the current diagnostic criteria are desirable.
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Affiliation(s)
- Frank Dodoo-Schittko
- Medical Sociology, Institute of Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany
| | - Susanne Brandstetter
- Medical Sociology, Institute of Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany
| | - Magdalena Brandl
- Medical Sociology, Institute of Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany
| | - Sebastian Blecha
- Department of Anesthesia, Operative Intensive Care, University Hospital Regensburg, Regensburg, Germany
| | - Michael Quintel
- Department of Anesthesiology, Emergency and Intensive Care Medicine, University Medicine, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Steffen Weber-Carstens
- Department of Anesthesia and Operative Intensive Care, Charitè Universitätsmedizin Berlin, Campus Virchow Klinikum and Campus Charitè Mitte, Berlin, Germany
| | - Stefan Kluge
- Department of Intensive Care Medicine, University Medical Centre, Hamburg-Eppendorf, Hamburg, Germany
| | - Patrick Meybohm
- Department of Anesthesiology, Intensive Care Medicine, and Pain Therapy, University Hospital Frankfurt, Frankfurt, Germany
| | - Caroline Rolfes
- Department of Anesthesiology and Operative Intensive Care, University Hospital Marburg, Marburg, Germany
| | - Björn Ellger
- Department of Anesthesiology and Operative Intensive Care, University Hospital Münster, Münster, Germany
| | - Friedhelm Bach
- Department of Anesthesiology and Intensive Care, Evangelisches Krankenhaus, Bielefeld, Germany
| | - Tobias Welte
- Department of Respiratory Medicine, Medizinische Hochschule Hannover, Hannover, Germany
| | - Thomas Muders
- Department of Anesthesiology and Operative Intensive Care, University Hospital Bonn, Bonn, Germany
| | - Kathrin Thomann-Hackner
- Department of Anesthesia, Operative Intensive Care, University Hospital Regensburg, Regensburg, Germany
| | - Thomas Bein
- Department of Anesthesia, Operative Intensive Care, University Hospital Regensburg, Regensburg, Germany
| | - Christian Apfelbacher
- Medical Sociology, Institute of Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany
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5
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Underuse versus equipoise for low tidal volume ventilation in acute respiratory distress syndrome: is this the right question?*. Crit Care Med 2014; 42:2310-1. [PMID: 25226131 DOI: 10.1097/ccm.0000000000000564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tidal volume and plateau pressure use for acute lung injury from 2000 to present: a systematic literature review. Crit Care Med 2014; 42:2278-89. [PMID: 25098333 DOI: 10.1097/ccm.0000000000000504] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE Since publication of the Respiratory Management of Acute Lung Injury and Acute Respiratory Distress Syndrome (ARMA) trial in 2000, use of tidal volume (VT) less than or equal to 6 mL/kg predicted body weight with corresponding plateau airway pressures (PPlat) less than or equal to 30 cm H2O has been advocated for acute lung injury. However, compliance with these recommendations is unknown. We therefore investigated VT (mL/kg predicted body weight) and PPlat (cm H2O) practices reported in studies of acute lung injury since ARMA using a systematic literature review (i.e., not a meta-analysis). DATA SOURCES PubMed, Scopus, and EMBASE. STUDY SELECTION Randomized controlled trials and nonrandomized studies enrolling patients with acute lung injury from May 2000 to June 2013 and reporting VT. DATA EXTRACTION Whether the study was a randomized controlled trial or a nonrandomized study and performed or not at an Acute Respiratory Distress Syndrome Network center; in randomized controlled trials, the pre- and postrandomization VT (mL/kg predicted body weight) and PPlat (cm H2O) and whether a VT protocol was used postrandomization; in nonrandomized studies, baseline VT and PPlat. DATA SYNTHESIS Twenty-two randomized controlled trials and 71 nonrandomized studies were included. Since 2000 at acute respiratory distress syndrome Network centers, routine VT was similar comparing randomized controlled trials and nonrandomized studies (p = 0.25) and unchanged over time (p = 0.75) with a mean value of 6.81 (95% CI, 6.45, 7.18). At non-acute respiratory distress syndrome Network centers, routine VT was also similar when comparing randomized controlled trials and nonrandomized studies (p = 0.71), but decreased (p = 0.001); the most recent estimate for it was 6.77 (6.22, 7.32). All VT estimates were significantly greater than 6 (p ≤ 0.02). In randomized controlled trials employing VT protocols, routine VT was reduced in both acute respiratory distress syndrome Network (n = 4) and non-acute respiratory distress syndrome Network (n = 11) trials (p ≤ 0.01 for both), but even postrandomization was greater than 6 (6.47 [6.29, 6.65] and 6.80 [6.42, 7.17], respectively; p ≤ 0.0001 for both). In 59 studies providing data, routine PPlat, averaged across acute respiratory distress syndrome Network or non-acute respiratory distress syndrome Network centers, was significantly less than 30 (p ≤ 0.02). CONCLUSIONS For clinicians treating acute lung injury since 2000, achieving VT less than or equal to 6 mL/kg predicted body weight may not have been as attainable or important as PPlat less than or equal to 30 cm H2O. If so, there may be equipoise to test if VT less than or equal to 6 mL/kg predicted body weight are necessary to improve acute lung injury outcome.
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Oda S, Aibiki M, Ikeda T, Imaizumi H, Endo S, Ochiai R, Kotani J, Shime N, Nishida O, Noguchi T, Matsuda N, Hirasawa H. The Japanese guidelines for the management of sepsis. J Intensive Care 2014; 2:55. [PMID: 25705413 PMCID: PMC4336273 DOI: 10.1186/s40560-014-0055-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 09/16/2014] [Indexed: 02/08/2023] Open
Abstract
This is a guideline for the management of sepsis, developed by the Sepsis Registry Committee of The Japanese Society of Intensive Care Medicine (JSICM) launched in March 2007. This guideline was developed on the basis of evidence-based medicine and focuses on unique treatments in Japan that have not been included in the Surviving Sepsis Campaign guidelines (SSCG), as well as treatments that are viewed differently in Japan and in Western countries. Although the methods in this guideline conform to the 2008 SSCG, the Japanese literature and the results of the Sepsis Registry Survey, which was performed twice by the Sepsis Registry Committee in intensive care units (ICUs) registered with JSICM, are also referred. This is the first and original guideline for sepsis in Japan and is expected to be properly used in daily clinical practice. This article is translated from Japanese, originally published as “The Japanese Guidelines for the Management of Sepsis” in the Journal of the Japanese Society of Intensive Care Medicine (J Jpn Soc Intensive Care Med), 2013; 20:124–73. The original work is at http://dx.doi.org/10.3918/jsicm.20.124.
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Affiliation(s)
- Shigeto Oda
- Department of Emergency and Critical Care Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-Ku, Chiba 260-8677 Japan
| | - Mayuki Aibiki
- Department of Emergency Medicine, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295 Japan
| | - Toshiaki Ikeda
- Division of Critical Care and Emergency Medicine, Tokyo Medical University Hachioji Medical Center, 1163 Tatemachi, Hachioji, Tokyo 193-0998 Japan
| | - Hitoshi Imaizumi
- Department of Intensive Care Medicine, Sapporo Medical University School of Medicine, S1 W17, Chuo-ku, Sapporo, 060-8556 Japan
| | - Shigeatsu Endo
- Department of Emergency Medicine, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate 020-0023 Japan
| | - Ryoichi Ochiai
- First Department of Anesthesia, Toho University School of Medicine, 6-11-1 Omori-nishi, Ota-ku, Tokyo 143-8541 Japan
| | - Joji Kotani
- Department of Emergency, Disaster and Critical Care Medicine, Hyogo College of Medicine, 1-1 Mukogawacho, Nishinomiya, Hyogo 663-8131 Japan
| | - Nobuaki Shime
- Division of Intensive Care Unit, University Hospital, Kyoto Prefectural University of Medicine, Kajii-cho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566 Japan
| | - Osamu Nishida
- Department of Anesthesiology and Critical Care Medicine, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192 Japan
| | - Takayuki Noguchi
- Department of Anesthesiology and Intensive Care Medicine, Oita University School of Medicine, 1-1 Idaigaoka, Hazamacho, Yufu, Oita 879-5593 Japan
| | - Naoyuki Matsuda
- Emergency and Critical Care Medicine, Graduate School of Medicine Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 Japan
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Chang SY, Dabbagh O, Gajic O, Patrawalla A, Elie MC, Talmor DS, Malhotra A, Adesanya A, Anderson HL, Blum JM, Park PK, Gong MN. Contemporary ventilator management in patients with and at risk of ALI/ARDS. Respir Care 2014; 58:578-88. [PMID: 22906363 DOI: 10.4187/respcare.01755] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Ventilator practices in patients at risk for acute lung injury (ALI) and ARDS are unclear. We examined factors associated with choice of set tidal volumes (VT), and whether VT < 8 mL/kg predicted body weight (PBW) relates to the development of ALI/ARDS. METHODS We performed a secondary analysis of a multicenter cohort of adult subjects at risk of lung injury with and without ALI/ARDS at onset of invasive ventilation. Descriptive statistics were used to describe ventilator practices in specific settings and ALI/ARDS risk groups. Logistic regression analysis was used to determine the factors associated with the use of VT < 8 mL/kg PBW and the relationship of VT to ALI/ARDS development and outcome. RESULTS Of 829 mechanically ventilated patients, 107 met the criteria for ALI/ARDS at time of intubation, and 161 developed ALI/ARDS after intubation (post-intubation ALI/ARDS). There was significant intercenter variability in initial ventilator settings, and in the incidence of ALI/ARDS and post-intubation ALI/ARDS. The median VT was 7.96 (IQR 7.14-8.94) mL/kg PBW in ALI/ARDS subjects, and 8.45 (IQR 7.50-9.55) mL/kg PBW in subjects without ALI/ARDS (P = .004). VT decreased from 8.40 (IQR 7.38-9.37) mL/kg PBW to 7.97 (IQR 6.90-9.23) mL/kg PBW (P < .001) in those developing post-intubation ALI/ARDS. Among subjects without ALI/ARDS, VT ≥ 8 mL/kg PBW was associated with shorter height and higher body mass index, while subjects with pneumonia were less likely to get ≥ 8 mL/kg PBW. Initial VT ≥ 8 mL/kg PBW was not associated with the post-intubation ALI/ARDS (adjusted odds ratio 1.30, 95% CI 0.74-2.29) or worse outcomes. Post-intubation ALI/ARDS subjects had mortality similar to subjects intubated with ALI/ARDS. CONCLUSIONS Clinicians seem to respond to ALI/ARDS with lower initial VT. Initial VT, however, was not associated with the development of post-intubation ALI/ARDS or other outcomes.
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Affiliation(s)
- Steven Y Chang
- Division of Pulmonary and Critical Care Medicine, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey 07103, USA.
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9
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Pintado MC, de Pablo R. Individualized positive end-expiratory pressure application in patients with acute respiratory distress syndrome. Med Intensiva 2014; 38:498-501. [PMID: 24485531 DOI: 10.1016/j.medin.2013.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 10/30/2013] [Accepted: 11/04/2013] [Indexed: 01/21/2023]
Abstract
Current treatment of acute respiratory distress syndrome is based on ventilatory support with a lung protective strategy, avoiding the development of iatrogenic injury, including ventilator-induced lung injury. One of the mechanisms underlying such injury is atelectrauma, and positive end-expiratory pressure (PEEP) is advocated in order to avoid it. The indicated PEEP level has not been defined, and in many cases is based on the patient oxygen requirements for maintaining adequate oxygenation. However, this strategy does not consider the mechanics of the respiratory system, which varies in each patient and depends on many factors-including particularly the duration of acute respiratory distress syndrome. A review is therefore made of the different methods for adjusting PEEP, focusing on the benefits of individualized application.
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Affiliation(s)
- M C Pintado
- Unidad de Cuidados Intensivos, Hospital Universitario Príncipe de Asturias, Alcalá de Henares, Madrid, España.
| | - R de Pablo
- Unidad de Cuidados Intensivos, Hospital Universitario Príncipe de Asturias, Alcalá de Henares, Madrid, España
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Fioretto JR, Carvalho WB. Temporal evolution of acute respiratory distress syndrome definitions. J Pediatr (Rio J) 2013; 89:523-30. [PMID: 24035871 DOI: 10.1016/j.jped.2013.02.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 02/14/2013] [Indexed: 10/26/2022] Open
Abstract
OBJECTIVE to review the evolution of acute respiratory distress syndrome (ARDS) definitions and present the current definition for the syndrome. DATA SOURCE a literature review and selection of the most relevant articles on ARDS definitions was performed using the MEDLINE®/PubMed® Resource Guide database (last ten years), in addition to including the most important articles (classic articles) that described the disease evolution. DATA SYNTHESIS the review included the following subjects: introduction; importance of definition; description of the first diagnostic criterion and subsequently used definitions, such as acute lung injury score; definition by the American-European Consensus Conference, and its limitations; description of the definition by Delphi, and its problems; accuracy of the aforementioned definitions; description of most recent definition (the Berlin definition), and its limitations; and practical importance of the new definition. CONCLUSIONS ARDS is a serious disease that remains an ongoing diagnostic and therapeutic challenge. The evolution of definitions used to describe the disease shows that studies are needed to validate the current definition, especially in pediatrics, where the data are very scarce.
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Affiliation(s)
- José R Fioretto
- Pediatrics Department, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, São Paulo, SP, Brazil; Sociedade Paulista de Terapia Intensiva, São Paulo, SP, Brazil.
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11
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Temporal evolution of acute respiratory distress syndrome definitions. JORNAL DE PEDIATRIA (VERSÃO EM PORTUGUÊS) 2013. [DOI: 10.1016/j.jpedp.2013.02.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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Shekar K, Davies AR, Mullany DV, Tiruvoipati R, Fraser JF. To ventilate, oscillate, or cannulate? J Crit Care 2013; 28:655-62. [PMID: 23827735 DOI: 10.1016/j.jcrc.2013.04.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 03/09/2013] [Accepted: 04/17/2013] [Indexed: 02/05/2023]
Abstract
Ventilatory management of acute respiratory distress syndrome has evolved significantly in the last few decades. The aims have shifted from optimal gas transfer without concern for iatrogenic risks to adequate gas transfer while minimizing lung injury. This change in focus, along with improved ventilator and multiorgan system management, has resulted in a significant improvement in patient outcomes. Despite this, a number of patients develop hypoxemic respiratory failure refractory to lung-protective ventilation (LPV). The intensivist then faces the dilemma of either persisting with LPV using adjuncts (neuromuscular blocking agents, prone positioning, recruitment maneuvers, inhaled nitric oxide, inhaled prostacyclin, steroids, and surfactant) or making a transition to rescue therapies such as high-frequency oscillatory ventilation (HFOV) and/or extracorporeal membrane oxygenation (ECMO) when both these modalities are at their disposal. The lack of quality evidence and potential harm reported in recent studies question the use of HFOV as a routine rescue option. Based on current literature, the role for venovenous (VV) ECMO is probably sequential as a salvage therapy to ensure ultraprotective ventilation in selected young patients with potentially reversible respiratory failure who fail LPV despite neuromuscular paralysis and prone ventilation. Given the risk profile and the economic impact, future research should identify the patients who benefit most from VV ECMO. These choices may be further influenced by the emerging novel extracorporeal carbon dioxide removal devices that can compliment LPV. Given the heterogeneity of acute respiratory distress syndrome, each of these modalities may play a role in an individual patient. Future studies comparing LPV, HFOV, and VV ECMO should not only focus on defining the patients who benefit most from each of these therapies but also consider long-term functional outcomes.
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Affiliation(s)
- Kiran Shekar
- Critical Care Research Group, Adult Intensive Care Services, The Prince Charles Hospital, The University of Queensland, Brisbane, Queensland, Australia.
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Esteban A, Frutos-Vivar F, Muriel A, Ferguson ND, Peñuelas O, Abraira V, Raymondos K, Rios F, Nin N, Apezteguía C, Violi DA, Thille AW, Brochard L, González M, Villagomez AJ, Hurtado J, Davies AR, Du B, Maggiore SM, Pelosi P, Soto L, Tomicic V, D'Empaire G, Matamis D, Abroug F, Moreno RP, Soares MA, Arabi Y, Sandi F, Jibaja M, Amin P, Koh Y, Kuiper MA, Bülow HH, Zeggwagh AA, Anzueto A. Evolution of mortality over time in patients receiving mechanical ventilation. Am J Respir Crit Care Med 2013; 188:220-30. [PMID: 23631814 DOI: 10.1164/rccm.201212-2169oc] [Citation(s) in RCA: 417] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Baseline characteristics and management have changed over time in patients requiring mechanical ventilation; however, the impact of these changes on patient outcomes is unclear. OBJECTIVES To estimate whether mortality in mechanically ventilated patients has changed over time. METHODS Prospective cohort studies conducted in 1998, 2004, and 2010, including patients receiving mechanical ventilation for more than 12 hours in a 1-month period, from 927 units in 40 countries. To examine effects over time on mortality in intensive care units, we performed generalized estimating equation models. MEASUREMENTS AND MAIN RESULTS We included 18,302 patients. The reasons for initiating mechanical ventilation varied significantly among cohorts. Ventilatory management changed over time (P < 0.001), with increased use of noninvasive positive-pressure ventilation (5% in 1998 to 14% in 2010), a decrease in tidal volume (mean 8.8 ml/kg actual body weight [SD = 2.1] in 1998 to 6.9 ml/kg [SD = 1.9] in 2010), and an increase in applied positive end-expiratory pressure (mean 4.2 cm H2O [SD = 3.8] in 1998 to 7.0 cm of H2O [SD = 3.0] in 2010). Crude mortality in the intensive care unit decreased in 2010 compared with 1998 (28 versus 31%; odds ratio, 0.87; 95% confidence interval, 0.80-0.94), despite a similar complication rate. Hospital mortality decreased similarly. After adjusting for baseline and management variables, this difference remained significant (odds ratio, 0.78; 95% confidence interval, 0.67-0.92). CONCLUSIONS Patient characteristics and ventilation practices have changed over time, and outcomes of mechanically ventilated patients have improved. Clinical trials registered with www.clinicaltrials.gov (NCT01093482).
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Affiliation(s)
- Andrés Esteban
- Hospital Universitario de Getafe & Centro de Investigación Biomédica en red de Enfermedades Respiratorias, Spain.
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14
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Türkog˘lu M, Erdem GU, Suyanı E, Sancar ME, Yalçın MM, Aygencel G, Akı Z, Sucak G. Acute respiratory distress syndrome in patients with hematological malignancies. Hematology 2013; 18:123-130. [DOI: 10.1179/1607845412y.0000000038] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
Affiliation(s)
- Melda Türkog˘lu
- Department of Medical Intensive Care UnitSchool of Medicine, Gazi University Besevler, Ankara, Turkey
| | - Gökmen Umut Erdem
- Department of Medical Intensive Care UnitSchool of Medicine, Gazi University Besevler, Ankara, Turkey
| | - Elif Suyanı
- Department of HematologySchool of Medicine, Gaza University Besevler, Ankara, Turkey
| | - Muhammed Erkam Sancar
- Department of Medical Intensive Care UnitSchool of Medicine, Gazi University Besevler, Ankara, Turkey
| | | | - Gülbin Aygencel
- Department of Medical Intensive Care UnitSchool of Medicine, Gazi University Besevler, Ankara, Turkey
| | - Zeynep Akı
- Department of HematologySchool of Medicine, Gaza University Besevler, Ankara, Turkey
| | - Gülsan Sucak
- Department of HematologySchool of Medicine, Gaza University Besevler, Ankara, Turkey
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Silversides JA, Ferguson ND. Clinical review: Acute respiratory distress syndrome - clinical ventilator management and adjunct therapy. Crit Care 2013; 17:225. [PMID: 23672857 PMCID: PMC3672489 DOI: 10.1186/cc11867] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is a potentially devastating form of acute inflammatory lung injury with a high short-term mortality rate and significant long-term consequences among survivors. Supportive care, principally with mechanical ventilation, remains the cornerstone of therapy - although the goals of this support have changed in recent years - from maintaining normal physiological parameters to avoiding ventilator-induced lung injury while providing adequate gas exchange. In this article we discuss the current evidence base for ventilatory support and adjunctive therapies in patients with ARDS. Key components of such a strategy include avoiding lung overdistension by limiting tidal volumes and airway pressures, and the use of positive end-expiratory pressure with or without lung recruitment manoeuvres in patients with severe ARDS. Adjunctive therapies discussed include pharmacologic techniques (for example, vasodilators, diuretics, neuromuscular blockade) and nonpharmacologic techniques (for example, prone position, alternative modes of ventilation).
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Affiliation(s)
- Jonathan A Silversides
- Interdepartmental Division of Critical Care, University of Toronto, 600 University Avenue, Suite 18-206, Toronto, ON, Canada M5G 1X5
| | - Niall D Ferguson
- Interdepartmental Division of Critical Care, University of Toronto, 600 University Avenue, Suite 18-206, Toronto, ON, Canada M5G 1X5
- Department of Medicine, Division of Respirology, University Health Network and Mount Sinai Hospital, University of Toronto, Mount Sinai Hospital, 600 University Avenue, Suite 18-206, Toronto, ON, Canada M5G 1X5
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Müller T, Bein T, Philipp A, Graf B, Schmid C, Riegger G. Extracorporeal pulmonary support in severe pulmonary failure in adults: a treatment rediscovered. DEUTSCHES ARZTEBLATT INTERNATIONAL 2013; 110:159-66. [PMID: 23533547 DOI: 10.3238/arztebl.2013.0159] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 12/20/2012] [Indexed: 12/18/2022]
Abstract
BACKGROUND Severe, acute respiratory failure in adults still carries a high mortality. In recent years, improved pulmonary support techniques have been used increasingly alongside conventional treatment. About 1000 such treatments are performed in Germany annually, and the number is rising rapidly. The two types of systems currently in use involve venovenous extracorporeal membrane oxygenation (ECMO) and extracorporeal carbon dioxide elimination. METHODS The underlying principles, technical implementation, efficacy, and adverse effects of the new techniques are summarized in the light of a selective review of the literature, supplemented by the authors' personal experience. Recommendations are given for clinical use. RESULTS Currently, only limited high-quality data (from prospective randomized trials) are available to support the use of either of these techniques in adults. Veno-venous ECMO systems can effectively secure gas exchange in patients with severe respiratory failure, with experienced centers reporting survival rates from 63% to 75%. Either pump-free arteriovenous systems or low-flow ECMO systems can be used for extracorporeal carbon dioxide elimination. Complications can be serious or life-threatening and must, therefore, be rapidly recognized and treated: these include vascular injury during cannulation, venous thrombosis in a cannulated vessel, an increased hemorrhagic tendency, and thrombocytopenia. CONCLUSION Modern miniaturized pulmonary support systems enable protective mechanical ventilation with low tidal volumes, reduce ventilator-associated lung injury, and can improve survival rates in critically ill patients with a manageable adverse effect profile.
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Affiliation(s)
- Thomas Müller
- Department of Internal Medicine II, University Medical Center Regensburg, Franz-Josef-Strauss Allee 11, 93053 Regensburg, Germany.
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Hess DR, Kondili D, Burns E, Bittner EA, Schmidt UH. A 5-year observational study of lung-protective ventilation in the operating room: a single-center experience. J Crit Care 2013; 28:533.e9-15. [PMID: 23369521 DOI: 10.1016/j.jcrc.2012.11.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 11/19/2012] [Accepted: 11/20/2012] [Indexed: 11/25/2022]
Abstract
PURPOSE We assessed the evolution of lung-protective ventilation strategies during anesthesia and identified factors associated with the selection of a nonprotective ventilation strategy. METHODS This retrospective observational study covered a 5-year period from March 2006 to March 2011. It included 45575 adult patients who underwent intubation de novo in the operating room. We considered a tidal volume (VT) greater than 10 mL/kg of ideal body weight (IBW) and/or positive end-expiratory pressure (PEEP) less than 5 cm H2O as not lung protective. We evaluated the use of nonprotective ventilation strategies over time in men and women, by American Society of Anesthesiologists classification, and for elective vs emergent surgery. RESULTS Over the duration of the study, there was a significant reduction in the percentage of patients receiving a VT greater than 10 mL/kg IBW (28.5%-16.3%, P < .001), zero PEEP (27.5%-18.2%, P < .001), and VT greater than 10 mL/kg IBW with PEEP less than 5 cm H2O (13.4%-8.0%, P < .001). The odds of receiving nonprotective ventilation were greater for women than for men, in the first year compared with the last year, and for elective compared with emergent surgery. CONCLUSION Although use of nonprotective ventilation decreased over time, an important percentage of patients continue to receive nonprotective ventilation.
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Affiliation(s)
- Dean R Hess
- Respiratory Care, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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18
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The need for and feasibility of a pediatric ventilation trial: reflections on a survey among pediatric intensivists*. Pediatr Crit Care Med 2012; 13:632-8. [PMID: 22791089 DOI: 10.1097/pcc.0b013e31824fbc37] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To explore what design would be reasonable, acceptable, and feasible for a pediatric trial investigating the effect of low tidal volume ventilation. DESIGN A two-round modified Delphi approach among pediatric intensivists with a visible special interest in mechanical ventilation. SETTINGS None. SUBJECTS Pediatric intensivists. INTERVENTIONS None. MEASUREMENTS AND RESULTS In the first questionnaire "experts" classified 64 items as "important," "not so important" or "not important" (June 2010). The second questionnaire included the 29 items having been classified by more than 50% of the experts as being "important" in the first questionnaire that needed to be ranked in order of importance (August 2010). Twenty-nine of 50 (64%) experts responded to the first questionnaire, and 28 of the 29 initial responders (96.6%) to the second questionnaire. Actual expert opinion favored the following: age of study population 0 yrs to 2 yrs, expected duration of ventilation ≥ 48 hrs, and stratification by the severity of hypoxemia (cutoff PaO(2)/FIO(2) < 200). The two study arms should compare the effect of 6 mL/kg vs. 10 mL/kg on mortality. However, these views of the experts face two major issues. First, 10 mL/kg does not represent standard of care. Second, numerous uncertainties render mortality unsuitable as primary measure of outcome including a large sample size (>1500). CONCLUSIONS Actual expert opinion favored investigating the effect of 6 mL/kg vs.10 mL/kg on mortality. Such a design suffers from various serious criticisms. Therefore, and in our opinion, a pediatric Acute Respiratory Distress Syndrome Network trial is not realistic.
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Dick TE, Molkov YI, Nieman G, Hsieh YH, Jacono FJ, Doyle J, Scheff JD, Calvano SE, Androulakis IP, An G, Vodovotz Y. Linking Inflammation, Cardiorespiratory Variability, and Neural Control in Acute Inflammation via Computational Modeling. Front Physiol 2012; 3:222. [PMID: 22783197 PMCID: PMC3387781 DOI: 10.3389/fphys.2012.00222] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 06/03/2012] [Indexed: 01/10/2023] Open
Abstract
Acute inflammation leads to organ failure by engaging catastrophic feedback loops in which stressed tissue evokes an inflammatory response and, in turn, inflammation damages tissue. Manifestations of this maladaptive inflammatory response include cardio-respiratory dysfunction that may be reflected in reduced heart rate and ventilatory pattern variabilities. We have developed signal-processing algorithms that quantify non-linear deterministic characteristics of variability in biologic signals. Now, coalescing under the aegis of the NIH Computational Biology Program and the Society for Complexity in Acute Illness, two research teams performed iterative experiments and computational modeling on inflammation and cardio-pulmonary dysfunction in sepsis as well as on neural control of respiration and ventilatory pattern variability. These teams, with additional collaborators, have recently formed a multi-institutional, interdisciplinary consortium, whose goal is to delineate the fundamental interrelationship between the inflammatory response and physiologic variability. Multi-scale mathematical modeling and complementary physiological experiments will provide insight into autonomic neural mechanisms that may modulate the inflammatory response to sepsis and simultaneously reduce heart rate and ventilatory pattern variabilities associated with sepsis. This approach integrates computational models of neural control of breathing and cardio-respiratory coupling with models that combine inflammation, cardiovascular function, and heart rate variability. The resulting integrated model will provide mechanistic explanations for the phenomena of respiratory sinus-arrhythmia and cardio-ventilatory coupling observed under normal conditions, and the loss of these properties during sepsis. This approach holds the potential of modeling cross-scale physiological interactions to improve both basic knowledge and clinical management of acute inflammatory diseases such as sepsis and trauma.
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Affiliation(s)
- Thomas E Dick
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Case Western Reserve University Cleveland, OH, USA
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An G, Nieman G, Vodovotz Y. Toward computational identification of multiscale "tipping points" in acute inflammation and multiple organ failure. Ann Biomed Eng 2012; 40:2414-24. [PMID: 22527009 DOI: 10.1007/s10439-012-0565-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 04/02/2012] [Indexed: 12/25/2022]
Abstract
Sepsis accounts annually for nearly 10% of total U.S. deaths, costing nearly $17 billion/year. Sepsis is a manifestation of disordered systemic inflammation. Properly regulated inflammation allows for timely recognition and effective reaction to injury or infection, but inadequate or overly robust inflammation can lead to Multiple Organ Dysfunction Syndrome (MODS). There is an incongruity between the systemic nature of disordered inflammation (as the target of inflammation-modulating therapies), and the regional manifestation of organ-specific failure (as the subject of organ support), that presents a therapeutic dilemma: systemic interventions can interfere with an individual organ system's appropriate response, yet organ-specific interventions may not help the overall system reorient itself. Based on a decade of systems and computational approaches to deciphering acute inflammation, along with translationally-motivated experimental studies in both small and large animals, we propose that MODS evolves due to the feed-forward cycle of inflammation → damage → inflammation. We hypothesize that inflammation proceeds at a given, "nested" level or scale until positive feedback exceeds a "tipping point." Below this tipping point, inflammation is contained and manageable; when this threshold is crossed, inflammation becomes disordered, and dysfunction propagates to a higher biological scale (e.g., progressing from cellular, to tissue/organ, to multiple organs, to the organism). Finally, we suggest that a combination of computational biology approaches involving data-driven and mechanistic mathematical modeling, in close association with studies in clinically relevant paradigms of sepsis/MODS, are necessary in order to define scale-specific "tipping points" and to suggest novel therapies for sepsis.
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Affiliation(s)
- Gary An
- Department of Surgery, University of Chicago, Chicago, IL 60637, USA
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21
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Positive end expiratory pressure in patients with acute respiratory distress syndrome – The past, present and future. Biomed Signal Process Control 2012. [DOI: 10.1016/j.bspc.2011.03.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Vadász I, Hubmayr RD, Nin N, Sporn PHS, Sznajder JI. Hypercapnia: a nonpermissive environment for the lung. Am J Respir Cell Mol Biol 2012; 46:417-21. [PMID: 22246860 DOI: 10.1165/rcmb.2011-0395ps] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Patients with severe acute and chronic lung diseases develop derangements in gas exchange that may result in increased levels of CO(2) (hypercapnia), the effects of which on human health are incompletely understood. It has been proposed that hypercapnia may have beneficial effects in patients with acute lung injury, and the concepts of "permissive" and even "therapeutic" hypercapnia have emerged. However, recent work suggests that CO(2) can act as a signaling molecule via pH-independent mechanisms, resulting in deleterious effects in the lung. Here we review recent research on how elevated CO(2) is sensed by cells in the lung and the potential harmful effects of hypercapnia on epithelial and endothelial barrier, lung edema clearance, innate immunity, and host defense. In view of these findings, we raise concerns about the potentially deleterious effects hypercapnia may have in patients with acute and chronic lung diseases.
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Affiliation(s)
- István Vadász
- Department of Internal Medicine, University of Giessen Lung Center, Justus Liebig University, Germany.
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Chiumello D, Taccone P, Berto V, Marino A, Migliara G, Lazzerini M, Gattinoni L. Long-term outcomes in survivors of acute respiratory distress syndrome ventilated in supine or prone position. Intensive Care Med 2011; 38:221-9. [PMID: 22187085 DOI: 10.1007/s00134-011-2445-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 10/25/2011] [Indexed: 12/29/2022]
Abstract
PURPOSE The aim of this study is to examine long-term pulmonary function and quality of life in survivors of acute respiratory distress syndrome (ARDS) previously enrolled in a randomized multicenter trial testing prone compared with supine positioning (PSII study) at five Italian centers. DESIGN Observational prospective study. SUBJECTS AND MEASUREMENTS Pulmonary function [spirometric test, gas exchange, carbon monoxide diffusion capacity (DLCO)], high-resolution computed tomography (CT) scan, and health-related quality of life [Short Form-36 (SF-36) and St. George's Respiratory Questionnaire] were evaluated at 12 months. RESULTS Twenty-six patients (13 in each group, mean age 54.1 ± 2.8 years, body mass index 24.5 ± 1.4 kg/m(2), PaO(2)/FiO(2) 117 ± 49 mmHg) were evaluated. There were no significant differences in demographic data, illness severity, or outcome between the prone and supine groups. The overall survival rate was 40%. Pulmonary function was in the normal range without any differences between the two groups. Quantitative lung CT scan analysis showed similar amounts for not aerated (8.1 ± 3.2% versus 7.3 ± 3.4%), poorly aerated (15.3 ± 3.6% versus 17.1 ± 4.9%), and well-aerated (64.0% ± 8.4 versus 70.2 ± 8.4%) lung regions, while overaerated lung region was slightly higher in the prone compared with the supine group (12.5 ± 6.5% versus 5.3 ± 5.5%). Health-related quality of life was similar to in healthy population. However, these patients showed reduction in daily activity specifically due to pulmonary disease as measured by the St. George's Respiratory Questionnaire. CONCLUSIONS No differences in pulmonary function or quality of life were observed in this small group of ARDS survivor patients treated in prone versus supine position.
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Affiliation(s)
- D Chiumello
- Dipartimento di Anestesia, Rianimazione (Intensiva e Subintensiva) e Terapia del Dolore, Fondazione IRCCS Ca' Granda-Ospedale Maggiore Policlinico, Via Francesco Sforza 35, Milan, Italy.
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Del Sorbo L, Goffi A, Ranieri VM. Mechanical ventilation during acute lung injury: current recommendations and new concepts. Presse Med 2011; 40:e569-83. [PMID: 22104487 DOI: 10.1016/j.lpm.2011.05.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 05/05/2011] [Accepted: 05/13/2011] [Indexed: 01/08/2023] Open
Abstract
Despite a very large body of investigations, no effective pharmacological therapies have been found to cure acute lung injury. Hence, supportive care with mechanical ventilation remains the cornerstone of treatment. However, several experimental and clinical studies showed that mechanical ventilation, especially at high tidal volumes and pressures, can cause or aggravate ALI. Therefore, current clinical recommendations are developed with the aim of avoiding ventilator-induced lung injury (VILI) by limiting tidal volume and distending ventilatory pressure according to the results of the ARDS Network trial, which has been to date the only intervention that has showed success in decreasing mortality in patients with ALI/ARDS. In the past decade, a very large body of investigations has determined significant achievements on the pathophysiological knowledge of VILI. Therefore, new perspectives, which will be reviewed in this article, have been defined in terms of the efficiency and efficacy of recognizing, monitoring and treating VILI, which will eventually lead to further significant improvement of outcome in patients with ARDS.
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Affiliation(s)
- Lorenzo Del Sorbo
- Università di Torino, Dipartimento di Anestesiologia e Medicina degli Stati Critici, Ospedale S. Giovanni Battista-Molinette, 10126 Torino, Italy
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Abstract
PURPOSE OF REVIEW Despite improvements in outcome due to lung protective ventilation strategies using low tidal volumes, the mortality rate from acute respiratory distress syndrome (ARDS) remains unacceptably high, ranging from 34 to 64%. The predominant cause of death in ARDS is not severe hypoxemia, which is one of the defining criteria of ARDS, but multiple organ failure (MOF). RECENT FINDINGS In view of the relationship between ARDS and MOF, two different but complementary pathophysiological perspectives will be developed in this article: ARDS as a consequence of MOF, and ARDS as the cause of MOF. This framework may be useful in guiding the development of novel therapeutic strategies that ultimately improve the outcome of ARDS and sepsis patients. SUMMARY ARDS is a severe lung disease characterized by a very complex pathophysiology, involving not only the respiratory system but also nonpulmonary distal organs. Elucidation of the pathophysiological mechanisms bi-directionally linking MOF to ARDS appears to be a promising area of research that hopefully will lead to improved outcomes for these devastating conditions.
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Acute Lung Injury in the ICU: Focus on Prevention. ANNUAL UPDATE IN INTENSIVE CARE AND EMERGENCY MEDICINE 2011 2011. [DOI: 10.1007/978-3-642-18081-1_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Acute lung injury in children: therapeutic practice and feasibility of international clinical trials. Pediatr Crit Care Med 2010; 11:681-9. [PMID: 20228688 DOI: 10.1097/pcc.0b013e3181d904c0] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To describe mechanical ventilation strategies in acute lung injury and to estimate the number of eligible patients for clinical trials on mechanical ventilation management. In contrast to adult medicine, there are few clinical trials to guide mechanical ventilation management in children with acute lung injury. DESIGN A cross-sectional study for six 24-hr periods from June to November 2007. SETTING Fifty-nine pediatric intensive care units in 12 countries in North America and Europe. PATIENTS We identified children meeting acute lung injury criteria and collected detailed information on illness severity, mechanical ventilatory support, and use of adjunctive therapies. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Of 3823 patients screened, 414 (10.8%) were diagnosed with acute lung injury by their treating physician, but only 165 (4.3%) patients met prestablished inclusion/exclusion criteria to this trial and, therefore, would have been eligible for a clinical trial. Of these, 124 (75.2%) received conventional mechanical ventilation, 27 (16.4%) received high-frequency oscillatory ventilation, and 14 (8.5%) received noninvasive mechanical ventilation. In the conventional mechanical ventilation group, 43.5% were ventilated in a pressure control mode with a mean tidal volume of 8.3 ± 3.3 mL/kg; and there was no clear relationship between positive end-expiratory pressure and Fio2 delivery in the conventional mechanical ventilation group. Use of adjunctive treatments, including nitric oxide, prone positioning, surfactant, hemofiltration, recruitment maneuvers, steroids, bronchodilators, and fluid restriction, was highly variable. CONCLUSIONS Our study reveals inconsistent mechanical ventilation practice and use of adjunctive therapies in children with acute lung injury. Pediatric clinical trials assessing mechanical ventilation management are needed to generate evidence to optimize outcomes. We estimate that a large number of centers (∼60) are needed to conduct such trials; it is imperative, therefore, to bring about international collaboration.
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Eissa D, Carton EG, Buggy DJ. Anaesthetic management of patients with severe sepsis. Br J Anaesth 2010; 105:734-43. [PMID: 21030391 DOI: 10.1093/bja/aeq305] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Severe sepsis, a syndrome characterized by systemic inflammation and acute organ dysfunction in response to infection, is a major healthcare problem affecting all age groups throughout the world. Anaesthetists play a central role in the multidisciplinary management of patients with severe sepsis from their initial deterioration at ward level, transfer to the diagnostic imaging suite, and intraoperative management for emergency surgery. The timely administration of appropriate i.v. antimicrobial therapy is a crucial step in the care of patients with severe sepsis who may require surgery to control the source of sepsis. Preoperative resuscitation, aimed at optimizing major organ perfusion, is based on judicious use of fluids, vasopressors, and inotropes. Intraoperative anaesthesia management requires careful induction and maintenance of anaesthesia, optimizing intravascular volume status, avoidance of lung injury during mechanical ventilation, and ongoing monitoring of arterial blood gases, lactate concentration, haematological and renal indices, and electrolyte levels. Postoperative care overlaps with ongoing management of the severe sepsis syndrome patient in the intensive care unit. These patients are by definition, high risk, already requiring multiple supports, and require experienced and skilful decision-making to optimize their chances of a favourable outcome. Similar to acute myocardial infarction, stroke, or acute trauma, the initial hours (golden hours) of clinical management of severe sepsis represent an important opportunity to reduce morbidity and mortality. Rapid clinical assessment, resuscitation and surgical management by a focused multidisciplinary team, and early effective antimicrobial therapy are the key components to improved patient outcome.
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Affiliation(s)
- D Eissa
- Division of Anaesthesia, Mater Misericordiae University Hospital, Eccles Street, Dublin 7, Ireland
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Rose L. Clinical application of ventilator modes: Ventilatory strategies for lung protection. Aust Crit Care 2010; 23:71-80. [PMID: 20378369 DOI: 10.1016/j.aucc.2010.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 03/09/2010] [Accepted: 03/12/2010] [Indexed: 10/19/2022] Open
Abstract
INTRODUCTION Identification of the mortality reducing effect of lung protective ventilation using low tidal volumes and pressure limitation is one of the biggest advances in the application of mechanical ventilation. Yet studies continue to demonstrate low adoption of this style of ventilation. Critical care nurses in Australia and New Zealand have a high level of responsibility and autonomy for mechanical ventilation and weaning practices and therefore require in-depth knowledge of ventilator technology, its clinical application and the current evidence for effective ventilation strategies. AIM To present an overview of current knowledge and research relating to lung protective ventilation. METHOD A multidatabase literature search using the terms protective ventilation, open lung, high frequency oscillatory ventilation, airway pressure release ventilation, and weaning. RESULTS Based on clinical trials and physiological evidence lung protective strategies using low tidal volumes and moderate levels of PEEP have been recommended as strategies to prevent tidal alveolar collapse and overdistension in patients with ALI/ARDS. Evidence now suggests these strategies may also be beneficial in patients with normal lungs. Lung protective ventilation may be applied with either volume or pressure-controlled ventilation. Pressure-controlled ventilation allows regulation over injurious peak inspiratory pressures; however no study has identified the superiority of pressure-controlled ventilation over low tidal volume strategies using volume-control. Other lung protective ventilation strategies include moderate to high positive-end expiratory pressure, recruitment manoeuvres, high frequency oscillatory ventilation, and airway pressure release ventilation though definitive trials identifying consistently improved patient outcomes are still needed. No ventilation strategy can be more lung protective than the timely discontinuation of mechanical ventilation. Despite the above recommendations, evidence suggests the decision to commence weaning and attempt extubation continue to be delayed. Critical care nurses play a vital role in the recognition of patients capable of spontaneous breathing and ready for extubation. Organisational interventions such as weaning protocols as well as computerised weaning systems may have less effect when nurses are able to manage weaning processes effectively. CONCLUSIONS Lung protective ventilatory strategies are not consistently applied and weaning and extubation continue to be delayed. Critical care nurses need to establish a strong knowledge base to promote effective and appropriate management of patients requiring mechanical ventilation.
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Affiliation(s)
- Louise Rose
- Lawrence S. Bloomberg Limited Term Professor in Critical Care Nursing, Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, Toronto, Ontario, Canada.
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Brochard LJ. Tidal volume during acute lung injury: let the patient choose? Intensive Care Med 2010; 35:1830-2. [PMID: 19760207 DOI: 10.1007/s00134-009-1632-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Accepted: 08/17/2009] [Indexed: 11/24/2022]
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Jauncey-Cooke JI, Bogossian F, East CE. Lung protective ventilation strategies in paediatrics-A review. Aust Crit Care 2010; 23:81-8. [PMID: 20047842 DOI: 10.1016/j.aucc.2009.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 11/03/2009] [Accepted: 11/10/2009] [Indexed: 10/20/2022] Open
Abstract
Ventilator Associated Lung Injury (VALI) is an iatrogenic phenomena that significantly impacts on the morbidity and mortality of critically ill patients. The hazards associated with mechanical ventilation are becoming increasingly understood courtesy of a large body of research. Barotrauma, volutrauma and biotrauma all play a role in VALI. Concomitant to this growth in understanding is the development of strategies to reduce the deleterious impact of mechanical ventilation. The majority of the research is based upon adult populations but with careful extrapolation this review will focus on paediatrics. This review article describes the physiological basis of VALI and discusses the various lung protective strategies that clinicians can employ to minimise its incidence and optimise outcomes for paediatric patients.
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Affiliation(s)
- Jacqui I Jauncey-Cooke
- The University of Queensland, School of Nursing and Midwifery, Herston, Australia; Clinical Nurse, PICU, Mater Children's Hospital, South Brisbane, Queensland, Australia.
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Loring SH, O'Donnell CR, Behazin N, Malhotra A, Sarge T, Ritz R, Novack V, Talmor D. Esophageal pressures in acute lung injury: do they represent artifact or useful information about transpulmonary pressure, chest wall mechanics, and lung stress? J Appl Physiol (1985) 2009; 108:515-22. [PMID: 20019160 DOI: 10.1152/japplphysiol.00835.2009] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Acute lung injury can be worsened by inappropriate mechanical ventilation, and numerous experimental studies suggest that ventilator-induced lung injury is increased by excessive lung inflation at end inspiration or inadequate lung inflation at end expiration. Lung inflation depends not only on airway pressures from the ventilator but, also, pleural pressure within the chest wall. Although esophageal pressure (Pes) measurements are often used to estimate pleural pressures in healthy subjects and patients, they are widely mistrusted and rarely used in critical illness. To assess the credibility of Pes as an estimate of pleural pressure in critically ill patients, we compared Pes measurements in 48 patients with acute lung injury with simultaneously measured gastric and bladder pressures (Pga and P(blad)). End-expiratory Pes, Pga, and P(blad) were high and varied widely among patients, averaging 18.6 +/- 4.7, 18.4 +/- 5.6, and 19.3 +/- 7.8 cmH(2)O, respectively (mean +/- SD). End-expiratory Pes was correlated with Pga (P = 0.0004) and P(blad) (P = 0.0104) and unrelated to chest wall compliance. Pes-Pga differences were consistent with expected gravitational pressure gradients and transdiaphragmatic pressures. Transpulmonary pressure (airway pressure - Pes) was -2.8 +/- 4.9 cmH(2)O at end exhalation and 8.3 +/- 6.2 cmH(2)O at end inflation, values consistent with effects of mediastinal weight, gravitational gradients in pleural pressure, and airway closure at end exhalation. Lung parenchymal stress measured directly as end-inspiratory transpulmonary pressure was much less than stress inferred from the plateau airway pressures and lung and chest wall compliances. We suggest that Pes can be used to estimate transpulmonary pressures that are consistent with known physiology and can provide meaningful information, otherwise unavailable, in critically ill patients.
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Affiliation(s)
- Stephen H Loring
- Department of Anesthesia, Critical Care, and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
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Vlaar APJ, Honselaar WB, Binnekade JM, Groeneveld AB, Spronk PE, Schultz MJ, Juffermans NP. Diagnosing acute lung injury in the critically ill: a national survey among critical care physicians. Acta Anaesthesiol Scand 2009; 53:1293-9. [PMID: 19719815 DOI: 10.1111/j.1399-6576.2009.02102.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Incidence reports on acute lung injury (ALI) vary widely. An insight into the diagnostic preferences of critical care physicians when diagnosing ALI may improve identification of the ALI patient population. METHODS Critical care physicians in the Netherlands were surveyed using vignettes involving hypothetical patients and a questionnaire. The vignettes varied in seven diagnostic determinants based on the North American European Consensus Conference and the lung injury score. Preferences were analyzed using a mixed-effects logistic regression model and presented as an odds ratio (OR) with a 95% confidence interval. RESULTS From 243 surveys sent to 30 hospitals, 101 were returned (42%). ORs were as follows: chest X-ray consistent with ALI: OR 1.7 (1.3-2.3), high positive end-expiratory pressure (PEEP) (15 cmH(2)O): OR 5.0 (3.9-6.6), low pulmonary artery occlusion pressures (PAOP) (<18 mmHg): OR 4.7 (3.6-6.1), low compliance (30 ml/cmH(2)O): OR 0.7 (0.5-0.9), low PaO(2)/FiO(2) (<250 mmHg): OR 9.2 (6.9-12.3), absence of heart failure: OR 1.2 (0.9-1.5), presence of a risk factor for ALI (sepsis): OR 1.0 (0.8-1.3). The questionnaire revealed that critical care physicians with an anesthesiology background differed from physicians with an internal medicine background with regard to hemodynamic variables when considering an ALI diagnosis (P<0.05). CONCLUSIONS Dutch critical care physicians consider the PEEP level, but not the presence of a risk factor for ALI, as an important factor to diagnose ALI. Background specialty of critical care physicians influences diagnostic preferences and may account for variance in the reported incidence of ALI.
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Affiliation(s)
- A P J Vlaar
- Department of Intensive Care Medicine, Laboratory of Experimental Intensive Care and Anesthesiology, Academic Medical Centre, Meibergdreef 9, Amsterdam, The Netherlands.
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Chetan G, Rathisharmila R, Narayanan P, Mahadevan S. Acute respiratory distress syndrome in pediatric intensive care unit. Indian J Pediatr 2009; 76:1013-6. [PMID: 19907932 DOI: 10.1007/s12098-009-0215-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Accepted: 02/25/2009] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To report causes, clinical feature and outcome of children with Acute Respiratory Distress Syndrome (ARDS). METHODS The case records of children admitted with ARDS from June 2003 to June 2006 were retrospectively reviewed and the data collected was analyzed. RESULTS A total of 17 children were diagnosed as ARDS during study period giving an incidence of 22.7/1,000 admissions. The mean (SD) age was 74.5 (56.32) mo [range 6-144 mo]. Primary lung pathology contributed to a (53%) cases of ARDS while the rest (47%) had non pulmonary causes. There was not any significant different in mortality between these two groups. Similarly when infections and non infections conditions were considered separately there was no difference in survival. All children were ventilated using Pressure Controlled Ventilation. The mean (SD) duration of ventilation was 5.0 days [range 1-10 days]. The maximum PEEP (SD) used during the course of ventilation was 10 (3.37) cm H2O [range 7-18], while the maximum PIP (SD) used was 31 (3.75) cm H2O (range 25-36). The overall mortality was 70%; highest in children less than 2 years of age. Majority of the children had shock as the most common comorbid factor and had a high mortality (73.3%). CONCLUSION The high incidence and mortality of ARDS and the presence of a large proportion of potentially preventable accidents and poisoning cases in the study group underline the need for health education measures addressing preventive strategies among the rural population.
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Affiliation(s)
- G Chetan
- Department of Pediatrics, Jawaharlal Institute of Post Graduate Medical Education and Research, Pondicherry, India
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Singh JM, Ferguson ND, MacDonald RD, Stewart TE, Schull MJ. Ventilation practices and critical events during transport of ventilated patients outside of hospital: a retrospective cohort study. PREHOSP EMERG CARE 2009; 13:316-23. [PMID: 19499467 DOI: 10.1080/10903120902935264] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Little is known about mechanical ventilation practices during patient transport outside of hospital in the civilian setting, although these practices may have clinical impact. Objective. We set out to describe ventilation practice, the use of lung-protective ventilation strategies, administration of sedation and neuromuscular blockade, and related critical events during out-of-hospital transport of ventilated patients. METHODS We conducted a population-based retrospective cohort study. Ventilator, pharmacy, and clinical data were extracted from the database of the provincial transport medicine agency in Ontario, Canada. Patients at risk for acute lung injury were identified by explicit screening criteria and lung-protective ventilation was assessed according to evidence-based thresholds. Critical events occurring during transport consisting of clinical deterioration or resuscitative procedures were recorded. RESULTS. We identified 1,735 mechanically ventilated adults who received out-of-hospital transport. Volume control and pressure control were the most commonly used ventilation modes. The median tidal volume delivered during transport was 500 mL (interquartile range 450-600) with positive end-expiratory pressure (PEEP) of 5 cmH(2)O (5-7) and peak inspiratory pressure of 24 cmH(2)O (20-29). Most patients (92%) were ventilated with peak pressures < or = 35 cmH(2)O; 22% of patients were ventilated with PEEP < 5 cmH(2)O. Ventilation in patients at risk of acute lung injury was not significantly different, and 68% of this subgroup was ventilated within lung-protective thresholds. Sedation was administered in 1,235 transports (71.2%) with frequent repeat administration. Neuromuscular blockade was administered in 385 transports (22.2%). Critical events occurred during 297 (17.1%) transports, due primarily to new-onset hypotension (n = 208). New in-transit hypotension was independently associated with sedative administration. CONCLUSIONS In-transit mechanical ventilation practices are variable, although patient exposure to potentially injurious pressures and volumes is uncommon. The application of PEEP is modest. In-transit hypotension is common and associated with sedative administration. The extent to which these practices impact patient outcome is unclear.
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Affiliation(s)
- Jeffrey M Singh
- Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Ontario, Canada.
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Sundaresan A, Yuta T, Hann CE, Chase JG, Shaw GM. A minimal model of lung mechanics and model-based markers for optimizing ventilator treatment in ARDS patients. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2009; 95:166-180. [PMID: 19327863 DOI: 10.1016/j.cmpb.2009.02.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 12/22/2008] [Accepted: 02/20/2009] [Indexed: 05/27/2023]
Abstract
A majority of patients admitted to the Intensive Care Unit (ICU) require some form of respiratory support. In the case of Acute Respiratory Distress Syndrome (ARDS), the patient often requires full intervention from a mechanical ventilator. ARDS is also associated with mortality rate as high as 70%. Despite many recent studies on ventilator treatment of the disease, there are no well established methods to determine the optimal Positive End-Expiratory Pressure (PEEP) or other critical ventilator settings for individual patients. A model of fundamental lung mechanics is developed based on capturing the recruitment status of lung units. The main objective of this research is to develop a minimal model that is clinically effective in determining PEEP. The model was identified for a variety of different ventilator settings using clinical data. The fitting error was between 0.1% and 4% over the inflation limb and between 0.3% and 13% over the deflation limb at different PEEP settings. The model produces good correlation with clinical data, and is clinically applicable due to the minimal number of patient specific parameters to identify. The ability to use this identified patient specific model to optimize ventilator management is demonstrated by its ability to predict the patient specific response of PEEP changes before clinically applying them. Predictions of recruited lung volume change with change in PEEP have a median absolute error of 1.87% (IQR: 0.93-4.80%; 90% CI: 0.16-11.98%) for inflation and a median of 5.76% (IQR: 2.71-10.50%; 90% CI: 0.43-17.04%) for deflation, across all data sets and PEEP values (N=34predictions). This minimal model thus provides a clinically useful and relatively simple platform for continuous patient specific monitoring of lung unit recruitment for a patient.
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Affiliation(s)
- Ashwath Sundaresan
- Center for BioEngineering, Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, New Zealand.
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Advanced closed loops during mechanical ventilation (PAV, NAVA, ASV, SmartCare). Best Pract Res Clin Anaesthesiol 2009; 23:81-93. [PMID: 19449618 DOI: 10.1016/j.bpa.2008.08.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
New modes of mechanical ventilation with advanced closed loops are now available, and in the future these could assume a greater role in supporting critically ill patients in intensive care units (ICUs) for several reasons. Two modes of ventilation--proportional assist ventilation and neurally adjusted ventilatory assist--deliver assisted ventilation proportional to the patient's effort, improving patient-ventilator synchrony. Also, a few systems that automate the medical reasoning with advanced closed-loops, such as SmartCare and adaptive support ventilation, have the potential to improve knowledge transfer by continuously implementing automated protocols. Moreover, they may improve patient-ventilator interactions and outcomes, and provide a partial solution to the forecast clinician shortages by reducing ICU-related costs, time spent on mechanical ventilation, and staff workload. Preliminary studies are promising, and initial systems are currently being refined with increasing clinical experience. A new era of mechanical ventilation should emerge with these systems.
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History of mechanical ventilation may affect respiratory mechanics evolution in acute respiratory distress syndrome. J Crit Care 2009; 24:626.e1-6. [PMID: 19427758 DOI: 10.1016/j.jcrc.2009.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 02/03/2009] [Accepted: 02/16/2009] [Indexed: 12/17/2022]
Abstract
PURPOSE The aim of this study was to investigate the effect of mechanical ventilation (MV) before acute respiratory distress syndrome (ARDS) on subsequent evolution of respiratory mechanics and blood gases in protectively ventilated patients with ARDS. METHODS Nineteen patients with ARDS were stratified into 2 groups according to ARDS onset relative to the onset of MV: In group A (n = 11), MV was applied at the onset of ARDS; in group B (n = 8), MV had been initiated before ARDS. Respiratory mechanics and arterial blood gas were assessed in early (<or=3 days) and late (8-11 days) ARDS, on zero positive end-expiratory pressure and positive end-expiratory pressure of 10 cm H(2)O. RESULTS In group A, Pao(2)/fractional inspired oxygen concentration increased (121 +/- 43 vs 161 +/- 60 mm Hg) and minimal resistance of respiratory system decreased (8.3 +/- 1.8 vs 6.0 +/- 2.1 cm H(2)O L(-1) s(-1)) from early to late ARDS. In group B, static elastance of respiratory system increased in the late stage (30.4 +/- 7.8 vs 36.4 +/- 9.9 cm H(2)O/L). In both groups, positive end-expiratory pressure application resulted in Pao(2)/fractional inspired oxygen concentration improvement and minimal resistance of respiratory system decreases in both stages. CONCLUSION In protectively ventilated patients with ARDS, late alteration of respiratory mechanics occurs more commonly in patients who have been ventilated before ARDS onset, suggesting that the history of MV affects the subsequent progress of ARDS even when using protective ventilation.
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Abstract
PURPOSE OF REVIEW To describe the trends in the results of epidemiological studies of mechanical ventilation. RECENT FINDINGS Changes in population demographics have increased the incidence of mechanical ventilation. Higher age and comorbidity rates portend poorer outcomes of mechanical ventilation. The most common indication for initiation of mechanical ventilation is acute respiratory failure, including postoperative respiratory failure, pneumonia, sepsis, and acute respiratory distress syndrome. Patients with sepsis and acute respiratory distress syndrome have a much higher mortality risk than the rest of this population. Changes over time in the selection of modes of ventilation, tidal volumes, positive end-expiratory pressure levels, weaning strategies, and tracheostomy timing appear to accord with data from randomized controlled trials in the literature. However, despite these changes, observational studies have not detected a statistically significant change in adjusted mortality over time. SUMMARY The burden of critical illness will likely continue to increase in the future. Evidence from randomized trials appears to have affected the management of mechanical ventilation, but adherence to evidence-based practices may not be ideal.
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Frutos-Vivar F, Ferguson ND, Esteban A. Mechanical ventilation: quo vadis? Intensive Care Med 2009; 35:775-8. [DOI: 10.1007/s00134-009-1450-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Accepted: 02/19/2009] [Indexed: 10/21/2022]
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Metnitz PGH, Metnitz B, Moreno RP, Bauer P, Del Sorbo L, Hoermann C, de Carvalho SA, Ranieri VM. Epidemiology of mechanical ventilation: analysis of the SAPS 3 database. Intensive Care Med 2009; 35:816-25. [PMID: 19288079 DOI: 10.1007/s00134-009-1449-9] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Accepted: 12/30/2008] [Indexed: 12/21/2022]
Abstract
OBJECTIVE To evaluate current practice of mechanical ventilation in the ICU and the characteristics and outcomes of patients receiving it. DESIGN Pre-planned sub-study of a multicenter, multinational cohort study (SAPS 3). PATIENTS 13,322 patients admitted to 299 intensive care units (ICUs) from 35 countries. INTERVENTIONS None. MAIN MEASUREMENTS AND RESULTS Patients were divided into three groups: no mechanical ventilation (MV), noninvasive MV (NIV), and invasive MV. More than half of the patients (53% [CI: 52.2-53.9%]) were mechanically ventilated at ICU admission. FIO2, VT and PEEP used during invasive MV were on average 50% (40-80%), 8 mL/kg actual body weight (6.9-9.4 mL/kg) and 5 cmH2O (3-6 cmH2O), respectively. Several invMV patients (17.3% (CI:16.4-18.3%)) were ventilated with zero PEEP (ZEEP). These patients exhibited a significantly increased risk-adjusted hospital mortality, compared with patients ventilated with higher PEEP (O/E ratio 1.12 [1.05-1.18]). NIV was used in 4.2% (CI: 3.8-4.5%) of all patients and was associated with an improved risk-adjusted outcome (OR 0.79, [0.69-0.90]). CONCLUSION Ventilation mode and parameter settings for MV varied significantly across ICUs. Our results provide evidence that some ventilatory modes and settings could still be used against current evidence and recommendations. This includes ventilation with tidal volumes >8mL/kg body weight in patients with a low PaO2/FiO2 ratio and ZEEP in invMV patients. Invasive mechanical ventilation with ZEEP was associated with a worse outcome, even after controlling for severity of disease. Since our study did not document indications for MV, the association between MV settings and outcome must be viewed with caution.
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Affiliation(s)
- Philipp G H Metnitz
- ICU 13I1, Dept. of Anesthesiology and General Intensive Care, Medical University of Vienna, Vienna, Austria
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Oba Y, Thameem DM, Zaza T. High levels of PEEP may improve survival in acute respiratory distress syndrome: A meta-analysis. Respir Med 2009; 103:1174-81. [PMID: 19269800 DOI: 10.1016/j.rmed.2009.02.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 02/12/2009] [Accepted: 02/12/2009] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Positive end-expiratory pressure (PEEP) has been viewed as an essential component of mechanical ventilation in acute respiratory distress syndrome (ARDS) and acute lung injury (ALI). However, clinical trials have not yet convincingly demonstrated that high PEEP levels improve survival. The object of this study was to test a priori hypotheses that a small but clinically important mortality benefit of high PEEP did exist, especially in patients with greater overall severity of illness and differences in PEEP protocols might have affected the study results. METHODS Meta-analysis of randomized controlled trials comparing high versus low PEEP in ARDS/ALI. Studies were identified by search of MEDLINE (1950-2008) and other sources. MEASUREMENTS AND MAIN RESULTS Five studies including 2447 patients were identified. A pooled analysis showed a significant reduction in hospital mortality in favor of high PEEP (RR=0.89; 95% CI, 0.80-0.99; p=0.03). However, significant statistical and clinical heterogeneities such as differences in disease severity and ventilator protocols were found. The differences in PEEP protocols were not associated with differences in mortality rates. A logistic analysis suggested that the beneficial effect of high PEEP was greater in patients with higher ICU severity scores. CONCLUSIONS The statistical and clinical heterogeneities make proper interpretation of the results difficult. However, a small, but significant mortality benefit of high PEEP may exist. In addition, our analysis suggests the effects of high PEEP are greater in patients with higher ICU severity scores.
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Affiliation(s)
- Yuji Oba
- University of Missouri-Columbia, Division of Pulmonary, Critical Care and Environmental Medicine, Five Hospital Drive, CE 412, Columbia, MO 65212, USA.
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Phua J, Badia JR, Adhikari NKJ, Friedrich JO, Fowler RA, Singh JM, Scales DC, Stather DR, Li A, Jones A, Gattas DJ, Hallett D, Tomlinson G, Stewart TE, Ferguson ND. Has Mortality from Acute Respiratory Distress Syndrome Decreased over Time? Am J Respir Crit Care Med 2009; 179:220-7. [DOI: 10.1164/rccm.200805-722oc] [Citation(s) in RCA: 552] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Brochard L, Rouby JJ. Changing Mortality in Acute Respiratory Distress Syndrome? Yes, We Can! Am J Respir Crit Care Med 2009; 179:177-8. [DOI: 10.1164/rccm.200811-1712ed] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Hypercapnia in late-phase ALI/ARDS: providing spontaneous breathing using pumpless extracorporeal lung assist. Intensive Care Med 2009; 35:1100-5. [DOI: 10.1007/s00134-009-1426-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 01/10/2009] [Indexed: 10/21/2022]
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Hajjar LA, Schout D, Galas FRBG, Uip DE, Levin ASS, Filho HHC, Sakane PT, Suslik CA, de Camargo Teixeira JM, Bonfa E, Barone AA, de Arruda Martins M, Boulos M, Auler JOC. Guidelines on management of human infection with the novel virus influenza A (H1N1)--a report from the Hospital das Clínicas of the University of São Paulo. Clinics (Sao Paulo) 2009; 64:1015-24. [PMID: 19841710 PMCID: PMC2763061 DOI: 10.1590/s1807-59322009001000013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 09/29/2009] [Indexed: 12/13/2022] Open
Abstract
The pandemic novel influenza A (H1N1) infection was considered widespread in Brazil on July, 2009. Since then, 9.249 cases were confirmed in Brazil, most of them concentrated in São Paulo. The Hospital das Clínicas of the University of São Paulo is a reference center for H1N1 cases in São Paulo. The purpose of this review is to analyze the evidence concerning diagnosis, prevention, and treatment of novel influenza A (H1N1) infection. In addition, we propose guidelines for the management of this pandemic emphasizing Hospital das Clínicas "bundles" for the control of the pandemic novel influenza A (H1N1).
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Affiliation(s)
- Ludhmila Abrahao Hajjar
- Department of Anesthesiology, InCor-Heart Institute and Instituto do Câncer do Estado de São Paulo - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - Denise Schout
- Department of Preventive Medicine, Epidemiology Service - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - Filomena Regina Barbosa Gomes Galas
- Department of Anesthesiology, InCor-Heart Institute and Instituto do Câncer do Estado de São Paulo - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - David Everson Uip
- Hospital Emilio Ribas - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - Anna Sara Shafferman Levin
- Department of Infectious Diseases - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - Helio Hehl Caiaffa Filho
- Department of Pathology - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - Pedro Takanori Sakane
- Instituto da Criança - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - Carlos Alberto Suslik
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | | | - Eloisa Bonfa
- Department of Internal Medicine - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - Antonio Alci Barone
- Department of Infectious Diseases - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - Milton de Arruda Martins
- Department of Internal Medicine - Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - Marcos Boulos
- Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil
| | - Jose Otavio Costa Auler
- Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - São Paulo/SP, Brazil., , Tel.: 55 11 3069.6431
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Abstract
PURPOSE OF REVIEW To critically examine the mortality rates of septic shock over the last 25 years to determine if significant improvements have been accomplished. RECENT FINDINGS A gradual and progressive improvement in mortality rates associated with septic shock has been realized over the few decades. These improvements in outcome are quantitatively small but significant and they primarily represent improvements in supportive care, and the recognition that well meaning and seemingly logical treatments have been overused and probably contributed to excess mortality rates in the past. SUMMARY Survival rates for patients in septic shock have gradually improved in critical care units worldwide over the last 25 years. Further improvement will be predicated on the discovery of new therapies to disrupt the underlying pathophysiology of sepsis and the development of improved rapid, diagnostic testing and immune monitoring of individual patients.
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Abstract
OBJECTIVE Acute respiratory distress syndrome is a common disorder associated with significant mortality and morbidity. The aim of this article is to critically evaluate the definition of acute respiratory distress syndrome and examine the impact the definition has on clinical practice and research. DATA SOURCES Articles from a MEDLINE search (1950 to August 2007) using the Medical Subject Heading respiratory distress syndrome, adult, diagnosis, limited to the English language and human subjects, their relevant bibliographies, and personal collections, were reviewed. DATA SYNTHESIS The definition of acute respiratory distress syndrome is important to researchers, clinicians, and administrators alike. It has evolved significantly over the last 40 years, culminating in the American-European Consensus Conference definition, which was published in 1994. Although the American-European Consensus Conference definition is widely used, it has some important limitations that may impact on the conduct of clinical research, on resource allocation, and ultimately on the bedside management of such patients. These limitations stem partially from the fact that as defined, acute respiratory distress syndrome is a heterogeneous entity and also involve the reliability and validity of the criteria used in the definition. This article critically evaluates the American-European Consensus Conference definition and its limitations. Importantly, it highlights how these limitations may contribute to clinical trials that have failed to detect a potential true treatment effect. Finally, recommendations are made that could be considered in future definition modifications with an emphasis on the significance of accurately identifying the target population in future trials and subsequently in clinical care. CONCLUSION How acute respiratory distress syndrome is defined has a significant impact on the results of randomized, controlled trials and epidemiologic studies. Changes to the current American-European Consensus Conference definition are likely to have an important role in advancing the understanding and management of acute respiratory distress syndrome.
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Affiliation(s)
- John J Marini
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA.
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