Pulmonary dead-space fraction as a risk factor for death in the acute respiratory distress syndrome.

BACKGROUND No single pulmonary-specific variable, including the severity of hypoxemia, has been found to predict the risk of death independently when measured early in the course of the acute respiratory distress syndrome. Because an increase in the pulmonary dead-space fraction has been described in observational studies of the syndrome, we systematically measured the dead-space fraction early in the course of the illness and evaluated its potential association with the risk of death. METHODS The dead-space fraction was prospectively measured in 179 intubated patients, a mean (+/-SD) of 10.9+/-7.4 hours after the acute respiratory distress syndrome had developed. Additional clinical and physiological variables were analyzed with the use of multiple logistic regression. The study outcome was mortality before hospital discharge. RESULTS The mean dead-space fraction was markedly elevated (0.58+/-0.09) early in the course of the acute respiratory distress syndrome and was higher among patients who died than among those who survived (0.63+/-0.10 vs. 0.54+/-0.09, P<0.001). The dead-space fraction was an independent risk factor for death: for every 0.05 increase, the odds of death increased by 45 percent (odds ratio, 1.45; 95 percent confidence interval, 1.15 to 1.83; P=0.002). The only other independent predictors of an increased risk of death were the Simplified Acute Physiology Score II, an indicator of the severity of illness (odds ratio, 1.06; 95 percent confidence interval, 1.03 to 1.08; P<0.001) and quasistatic respiratory compliance (odds ratio, 1.06; 95 percent confidence interval, 1.01 to 1.10; P=0.01). CONCLUSIONS Increased dead-space fraction is a feature of the early phase of the acute respiratory distress syndrome. Elevated values are associated with an increased risk of death.

[1]  J. Severinghaus,et al.  Alveolar Dead Space as an Index of Distribution of Blood Flow in Pulmonary Capillaries , 1957 .

[2]  J. Tomashefski,et al.  The pulmonary vascular lesions of the adult respiratory distress syndrome. , 1983, The American journal of pathology.

[3]  I. Cheifetz,et al.  Increasing tidal volumes and pulmonary overdistention adversely affect pulmonary vascular mechanics and cardiac output in a pediatric swine model. , 1998, Critical care medicine.

[4]  G. Mcguire,et al.  Validation of the Deltatrac metabolic cart for measurement of dead-space-to-tidal-volume ratio , 1997 .

[5]  R. Albert,et al.  Mechanisms of physiological dead space response to PEEP after acute oleic acid lung injury. , 1983, Journal of applied physiology: respiratory, environmental and exercise physiology.

[6]  M. Lamy,et al.  Pathologic features and mechanisms of hypoxemia in adult respiratory distress syndrome. , 1976, The American review of respiratory disease.

[7]  S. Peters,et al.  A multicenter registry of patients with acute respiratory distress syndrome. Physiology and outcome. , 1992, The American review of respiratory disease.

[8]  G. Rubenfeld,et al.  Interobserver variability in applying a radiographic definition for ARDS. , 1999, Chest.

[9]  G. Bedell.  The Lung: Clinical Physiology and Pulmonary Function Tests. , 1963 .

[10]  P. Parsons,et al.  Establishing the relative accuracy of three new definitions of the adult respiratory distress syndrome. , 1995, Critical care medicine.

[11]  S. Lemeshow,et al.  A new Simplified Acute Physiology Score (SAPS II) based on a European/North American multicenter study , 1993 .

[12]  R. Bone,et al.  An early test of survival in patients with the adult respiratory distress syndrome. The PaO2/FIo2 ratio and its differential response to conventional therapy. Prostaglandin E1 Study Group. , 1989, Chest.

[13]  T. Petty,et al.  The adult respiratory distress syndrome. Clinical features, factors influencing prognosis and principles of management. , 1971, Chest.

[14]  M Lichtwarck-Aschoff,et al.  Compliance is nonlinear over tidal volume irrespective of positive end-expiratory pressure level in surfactant-depleted piglets. , 2000, American journal of respiratory and critical care medicine.

[15]  J F Murray,et al.  An expanded definition of the adult respiratory distress syndrome. , 1988, The American review of respiratory disease.

[16]  D. Green,et al.  Elevated von Willebrand factor antigen is an early plasma predictor of acute lung injury in nonpulmonary sepsis syndrome. , 1990, The Journal of clinical investigation.

[17]  D. Hosmer,et al.  Applied Logistic Regression , 1991 .

[18]  Recovery rate and prognosis in older persons who develop acute lung injury and the acute respiratory distress syndrome. , 2002 .

[19]  E. Ferrannini.  The theoretical bases of indirect calorimetry: a review. , 1988, Metabolism: clinical and experimental.

[20]  K. Steinberg,et al.  Type III Procollagen Peptide in the Adult Respiratory Distress Syndrome: Association of Increased Peptide Levels in Bronchoalveolar Lavage Fluid with Increased Risk for Death , 1995, Annals of Internal Medicine.

[21]  J. H. Comroe.  The Lung. Clinical Physiology and Pulmonary Function Tests , 1956 .

[22]  R J Cook,et al.  Interobserver variation in interpreting chest radiographs for the diagnosis of acute respiratory distress syndrome. , 2000, American journal of respiratory and critical care medicine.

[23]  John B. West.  Ventilation/Blood Flow and Gas Exchange , 1977 .

[24]  P. Bitterman,et al.  Fibrin turnover in lung inflammation and neoplasia. , 2001, American journal of respiratory and critical care medicine.

[25]  A Kari,et al.  Effect of tidal volume on gas exchange and oxygen transport in the adult respiratory distress syndrome. , 1992, The American review of respiratory disease.

[26]  Charles J. Fisher,et al.  Consensus conference definitions for sepsis, septic shock, acute lung injury, and acute respiratory distress syndrome: Time for a reevaluation , 2000, Critical care medicine.

[27]  J. Lynch,et al.  Ventilation-perfusion distributions in the adult respiratory distress syndrome. , 1979, The American review of respiratory disease.

[28]  S. Epstein,et al.  Acute lung injury in the medical ICU: comorbid conditions, age, etiology, and hospital outcome. , 1998, American journal of respiratory and critical care medicine.

[29]  J. Dhainaut,et al.  Early predictive factors of survival in the acute respiratory distress syndrome. A multivariate analysis. , 1998, American journal of respiratory and critical care medicine.

[30]  F. Mosca,et al.  Energy metabolism of surgical patients in the early postoperative period: a reappraisal. , 1988, Critical care medicine.

[31]  M. Lamy,et al.  The American-European Consensus Conference on ARDS. Definitions, mechanisms, relevant outcomes, and clinical trial coordination. , 1994, American journal of respiratory and critical care medicine.

[32]  P. Pelosi,et al.  Lung Structure and Function in Different Stages of Severe Adult Respiratory Distress Syndrome , 1994 .

[33]  D. Schoenfeld,et al.  Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. , 2000, The New England journal of medicine.

[34]  K. Falke,et al.  Ventilation with end-expiratory pressure in acute lung disease. , 1972, The Journal of clinical investigation.

[35]  M. Matthay,et al.  von Willebrand factor antigen is an independent marker of poor outcome in patients with early acute lung injury , 2001, Critical care medicine.

[36]  F. Cheney,et al.  The effects of expiratory positive airway pressure on the resolution of oleic acid-induced lung injury in dogs. , 1982, The American review of respiratory disease.

[37]  E. Weibel,et al.  Alterations of the gas exchange apparatus in adult respiratory insufficiency associated with septicemia. , 2015, The American review of respiratory disease.

[38]  M. Matthay,et al.  Identification of patients with acute lung injury. Predictors of mortality. , 1995, American journal of respiratory and critical care medicine.

[39]  S. Venkataraman,et al.  Accuracy of physiologic deadspace measurement in intubated pediatric patients using a metabolic monitor: comparison with the Douglas bag method. , 1998, Critical care medicine.

[40]  L. J. Weaver,et al.  Distribution of ventilation and perfusion during positive end-expiratory pressure in the adult respiratory distress syndrome. , 2015, The American review of respiratory disease.