Modelling Thirty-day Mortality in the Acute Respiratory Distress Syndrome (ARDS) in an Adult ICU

Abstract

Variables predicting thirty-day outcome from Acute Respiratory Distress Syndrome (ARDS) were analysed using Cox regression structured for time-varying covariates. Over a three-year period, 1996-1998, consecutive patients with ARDS (bilateral chest X-ray opacities, P a O 2 /FiO 2 ratio of <200 and an acute precipitating event) were identified using a prospective computerized data base in a university teaching hospital ICU. The cohort, 106 mechanically ventilated patients, was of mean (SD) age 63.5 (15.5) years and 37% were female. Primary lung injury occurred in 45% and 24% were postoperative. ICU-admission day APACHE II score was 25 (8); ARDS onset time from ICU admission was 1 day (median: range 0-16) and 30 day mortality was 41% (95% CI: 33%-51%). At ARDS onset, P a O 2 /FiO2 ratio was 92 (31), 81% had four-quadrant chest X-ray opacification and lung injury score was 2.75 (0.45). Average mechanical ventilator tidal volume was 10.3 ml/ predicted kg weight. Cox model mortality predictors (hazard ratio, 95% CI

Predictors of hospital mortality in a population-based cohort of patients with acute lung injury*

“…Contrary to some other studies, we did not find that ALI risk factor was an independent predictor of death (10,11,15). This was true regardless of the method that we used to code risk factor (primary risk, any risk, or pulmonary/nonpulmonary risk).…”

“…Consistently identified independent predictors of mortality in previous stud-ies of ALI include age (9, 34), nonpulmonary organ dysfunction (12,14), and liver disease (9,34). Additional predictors of mortality, such as body mass index (33,35), pulmonary deadspace fraction (13), immunosuppression (14), ALI risk factor (10,11,15), and ventilator days before ALI (9), have also been identified, yet many were not isolated as independent predictors in subsequent studies. Previous studies examining predictors of mortality evaluated patients from tertiary care academic centers with few focusing on population-based cohorts (1,34).…”

Modelling survival in acute severe illness: Cox versus accelerated failure time models

“…The peak unadjusted (mortality) hazard was estimated as occurring at days 7–8 (Fig. 3) after onset of ALI/ARDS and showed a similar time‐course to recent independently reported estimates in ARDS [53]. This is of some interest, as noted by Royston and Parmar [54], the medical literature is ‘.…”

Time-dependent changes in pulmonary surfactant function and composition in acute respiratory distress syndrome due to pneumonia or aspiration

“…The aim of the current study was to investigate the time course of surfactant changes in patients with direct ARDS due to pneumonia or aspiration, a patient group that has recently been shown to be different from indirect ARDS patients with respect to imaging analysis, lung elasticity, recruitment capacity and frequency of additional organ failure, compared to ARDS patients with an extrapulmonary trigger event (indirect ARDS) [33,34,17]. As the frequency of additional organ failure has been linked to the outcome of ARDS patients [35], patients with direct ARDS may also have a slightly better prognosis.…”