Effects of Blood Resuscitation versus Dextran Resuscitation after Hemorrhage on Intrinsic Myocardial Function

BACKGROUND: Myocardial function is altered by many factors present in hemorrhaged and resuscitated animals. The purpose of this study was to determine whether resuscitation after a short period of hemorrhagic shock, which by itself did not alter intrinsic cardiac function, causes dysfunction. METHODS: Guinea pigs were instrumented to measure blood pressure and cardiac output, and several days later 50% of their blood volume was removed at a rate of 1 mL/min. Some animals were resuscitated with the shed blood and some with 6% dextran. Hearts were studied 1 or 24 hours after resuscitation. RESULTS: Isolated hearts from animals after 1 hour of resuscitation demonstrated dysfunction whether resuscitated with blood or dextran, although dysfunction was more severe with blood resuscitation. By 24 hours, dysfunction was essentially reversed. CONCLUSIONS: Resuscitation after hemorrhagic shock caused injury to the myocardium independent of the hemorrhage. Blood resuscitation resulted in greater dysfunction than did resuscitation with dextran.