Recent data have suggested that ventilatory strategy could influence outcome from acute lung injury (ALI) and acute respiratory distress syndrome. We tested the hypothesis that the occurrence of infection/sepsis and violation of the “ARDSNet” protective strategy would worsen outcome.
In a cohort, observational study, all patients admitted to 198 centers from 24 European countries between May 1 and 15, 2002 were followed up until death, hospital discharge, or for 60 days. We studied the predictive factors for mortality in patients with ALI/ARDS, defined according to the American/European consensus conference criteria. “ARDSNet” protective strategy violation was defined as the use of tidal volumes >7.4 ml/kg (predicted body weight), plateau pressure <30 cmH2O, or PEEP higher or lower than proposed by the protocol for a given FiO2.
Of the 3147 adult patients enrolled in the study, 393 (12.5 %) had ALI/ARDS. These patients had higher ICU and hospital mortalities (38.9 vs. 15.6%, 45.5 vs. 21.0%, respectively, p<0.001) than other patients. Nonsurvivors of ALI/ARDS were older (61.6 ± 15.3 vs. 57.5 ± 17.9 years, p=0.36), and more likely to be female (52.9 vs. 34.7%, p=0.016) than survivors. Overall infection rates were similar (74.5 vs. 72.0%, p=0.58); however, septic shock was more prevalent in nonsurvivors (55.6 vs. 32.2%, p<0.001). The average tidal volume was 9.9 ± 2.4 ml/kg, and the PEEP was 4.8 ± 3.9 cmH2O. High tidal volumes were used more in the nonsurvivors compared with survivors (44.4 vs. 33.5%, p=0.019). In a multivariable logistic regression analysis with ICU outcome as the dependent factor, only the presence of cancer, high tidal volume, mean SOFA score, and higher mean fluid balance were independent risk factors for mortality.CONCLUSIONS: In addition to comorbidities and organ dysfunction, high tidal volumes and positive fluid balance are associated with worse outcome from ALI/ARDS.
High tidal volumes are associated with increased mortality and yet are frequently used. More widespread use of lung protective strategies may improve outcome from ALI/ARDS.
J. Vincent, None.