Effects of extravascular lung water on severity of illness and survival of patients with acute respiratory distress syndrome

Abstract

Objective To evaluate the relationship between the extravascular lung water (EVLW) and other markers of lung injury and determine whether or not EVLW predicts survival in patients with acute respiratory distress syndrome (ARDS) and examine if indexing EVLW with predicted body weight (EVLWp) strengthens its discriminative power. Methods EVLW and other markers of lung injury [including: PaO2/FiO2 (P/F), oxygenation index (OI) = mean pressure (Pm) ×FiO2×100/PaO2, static compliance (Cst) and lung injury score (LIS)] were measured prospectively for 3 days in 27 patients with early ARDS between January 2011 and December 2011 at intensive care units (ICU) of Subei People's Hospital. The relationship between indexing EVLW with actual body weight (EVLWa), EVLWp and other markers of lung injury, the 28-day mortality were evaluated. Results Acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ), fluid balance in first 3 days, days of mechanical ventilation and ICU stay were significantly higher on admission in nonsurvivors compared with survivors (P 0.05). ROC curve analysis indicated that EVLWp (0.759, P 0.05) discriminated between survivors and nonsurvivors. Three-day average EVLWp ≥12.5 ml/kg predicted the 28-day mortality with 62.5% specificity and 80% sensitivity. Conclusion Increased extravascular lung water is a feature of early ARDS and predicts survival. EVLWp, instead of EVLWa, improves the predictive value of extravascular lung water for survival and it is correlated with markers of disease severity. Key words: Pulmonary edema; Respiratory distress syndrome, adult; Prognosis