LOAD-INDEPENDENT LEFT-VENTRICULAR FUNCTION IN A HEMORRHAGIC-SHOCK MODEL

Load-independent left ventricular (LV) function has been recently show n to be reversibly depressed in septic shock, The peak systolic pressu re to end systolic volume ratio (PSP/ESV) is a load independent measur e of LV function. We evaluated PSP/ESV in a porcine model of hemorrhag ic shock, Hemorrhagic shock was induced in five adult swine by arteria l bleeding to a mean arterial pressure of 45-65 mmHg. This hypotension was maintained for 30 min, and then each animal was resuscitated to b aseline mean arterial pressure using shed blood and crystalloid soluti on. Data (echocardiographically derived ejection fraction and oxygen t ransport parameters) were collected at baseline, after 30 min of hypot ension and postresuscitation. Although the cardiac index, a marker for systolic function, and the mean arterial pressure, as well as oxygen delivery and consumption returned to baseline levels, the PSP/ESV rati o remained low despite adequate fluid resuscitation. This model provid es a reproducible hemodynamically stable cardiac dysfunction associate d with hemorrhagic shock. (C) 1996 Academic Press, Inc.