A prospective study of lung water measurements during patient management in an intensive care unit

Abstract

We prospectively evaluated a protocol that included extravascular thermal volume (ETV) as a measure of extravascular lung water (EVLW) instead of pulmonary artery wedge pressure (Ppaw) measurements to guide the hemodynamic management of 48 critically ill patients. Patients were randomized to either a protocol management (PM), or to a routine management (RM) group. In the RM group, EVLW measurements were unknown to the primary care physicians. The 2 groups were similar with respect to age, gender, and severity of illness. In patients with initially high EVLW, EVLW fell to a greater extent in PM than in RM patients (18 +/- 5 versus 4 +/- 8% decrease, p less than 0.05). This difference was even greater in patients with heart failure. No adverse effects on oxygenation or renal function occurred in following the protocol. Mortality for the groups as a whole was similar, but was significantly better (p less than 0.05) for PM patients with initially high EVLW and normal Ppaw (predominantly patients with sepsis or the adult respiratory distress syndrome). For both groups, patients with an initial EVLW greater than 14 ml/kg had a significantly greater mortality than did those with a lesser amount of EVLW: 13 of 15 (87%) versus 13 of 32 (41%), p less than 0.05. We conclude that management based on a protocol using EVLW measurements is safe, may hasten the resolution of pulmonary edema, and may lead to improved outcome in some critically ill patients.