Extravascular lung water index and Halperin score to predict outcome in critically ill patients

The aim of this study was to describe real world extravascular lung water index (EVLWI) measurements obtained by pulse index continuous cardiac output (PiCCO) on the day of admission. These were then related to a radiologic score for lung edema, Halperin score and both the Halperin score and EVLWI were assessed for prediction of in-hospital mortality in critically ill patients.

A total of 311 patients admitted to a tertiary medical university hospital between February 2004 and December 2010 were included in this retrospective analysis and of these 177 patients were intubated. In-hospital mortality was assessed by logistic regression. In the overall cohort, EVLWI and the Halperin score correlated poorly (r = 0.17; p = 0.02). In intubated patients, EVLWI and Halperin score did not correlate (r = 0.09; p = 0.39), whereas in patients who were not intubated there was a moderate association (r = 0.30; p = 0.007).

In the overall cohort, (a) EVLWI (hazard ratio [HR] 1.10, 95% confidence interval [CI] 1.02–1.19; p = 0.01; area under the curve [AUC] 0.63, 95% CI 0.54–0.71) but not (b) Halperin score (HR 1.00, 95% CI 0.996–1.004; p = 0.94; AUC 0.52, 95% CI 0.45–0.58) was associated with in-hospital mortality There was a robust association of EVLWI (HR 1.12, 95% CI 1.01–1.25; p = 0.03) but not Halperin score (HR 1.003, 95% CI 0.997–1.009; p = 0.30) with mortality in non-intubated patients. In intubated patients, neither EVLWI (HR 0.997 95% CI 0.990–1.003; p = 0.33) nor Halperin score (HR 1.08; 95% CI 0.88–1.32; p = 0.47) was associated with mortality.

The EVLWI correlated moderately with a radiologic score for lung edema, the Halperin score, in non-intubated but not in intubated patients. The EVLWI at admission was associated with in-hospital mortality in our patient collective of critically ill patients and might constitute not only a tool for risk stratification but most importantly a valuable treatment goal.