TRANSTHORACIC BIOIMPEDANCE CAN MEASURE EXTRAVASCULAR LUNG WATER IN ACUTE LUNG INJURY

We used a porcine endotoxemic model of acute lung injury to compare ex travascular lung water (EVLW) measured by right transthoracic bioimped ance to postmortem gravimetric EVLW measurements. Adult pigs were rand omized into control (N = 5) or endotoxin groups [150 mu g/kg Escherich ia coli lipopolysaccharide B for 1 hr followed by 3 hr of resuscitatio n for a thermodilution cardiac output less than 90% of baseline using either isotonic saline (N = 5) or isooncotic albumin (N = 5)]. Right l ung resistance was measured using a novel electrode array and a highly sensitive analyzer and was used to calculate right lung resistivity. At the end of the experiment, animals in the endotoxin-albumin group h ad higher gravimetric EVLWs than those in the endotoxin-saline or cont rol groups (P < 0.05). Right lung resistivity corrected for body weigh t significantly correlated with gravimetric EVLW (r(2) = 0.49; SEE = 0 .96; P = 0.0038). Using multiple regression analysis, a predictive equ ation for EVLW based on right lung resistivity, body weight, and mean pulmonary artery pressure was generated (r(2) = 0.81; SEE = 0.60; P < 0.0001). These results demonstrate that right lung resistivity measure ments can provide a noninvasive estimate of EVLW. In addition, crystal loid may be preferable to colloid for fluid resuscitation in noncardio genic pulmonary edema. (C) 1996 Academic Press, Inc.