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

Abstract

The predictors of mortality in patients with acute lung injury are similar to those predictive of mortality in the general intensive care unit population, indicating disease heterogeneity within this cohort. Accordingly, APACHE III predicts mortality in acute lung injury as well as a model using variables selected specifically for patients with acute lung injury.

The Siren Song of Simple Tools That Predict Mortality

“…Several studies previously identified these variables as independently associated with death. 15,17,18 What, then, does this study 12 add to the literature? Villar and colleagues deviate from most, but not all, 16 prior studies by developing and validating an extremely simple prediction tool that retains excellent performance.…”

“…In fact, at least a dozen prior studies aimed to fully characterize the predictors of mortality among patients with acute lung injury (ALI) or ARDS or to integrate predictors of death into a prognostic index specific to this disease. [13][14][15][16] Villar et al are also not the first to identify age, airway plateau pressure, and oxygenation as predictors of mortality in ARDS. Several studies previously identified these variables as independently associated with death.…”

“…Because prediction tools such as the APACHE model and most ARDS models rely on dozens of variable inputs to predict mortality, a calculator or computer is needed to estimate the risk of death. 15 The need for a computer is trivial when these models are used in the research context for risk-adjustment or for benchmarking ICU performance, but can be impractical when employed clinically. Only the simplest tools stand a chance at being used at the bedside, given the time constraints placed on critical care practitioners.…”

On the complexity of scoring acute respiratory distress syndrome: do not forget hemodynamics!

“…They also proposed a score combining arterial pH (protective per 0.1 more alkalotic), minute ventilation (protective when <9 L/min), PaCO 2 (protective per 5 mmHg increase), and PaO 2 /FiO 2 (associated with mortality when decreasing) (2). The overall in-hospital mortality in their study was 38.5% and the predictive value of the score was better than the acute physiology and chronic health evaluation (APACHE) III in their development cohort, although not different in their validation cohort (2). Later, the same group validated a simpler clinical predictive score (3).…”

“…In ARDS, a lot of studies have reported many predictors of prognosis (2)(3)(4)(5)(6). Very recently, Villar et al proposed a new score called the "APPS" which is very simply based on age, PaO 2 /FiO 2 and plateau pressure (Pplat) (7).…”