Myocardial Dysfunction Contributes to Irreversible Hemorrhagic Shock

摘要

We have performed a study of the effects of hemorrhagic shock and resuscitation on isolated heart function of guinea pigs. In vivo hemodynamics were monitored during hemorrhage, shock and resuscitation and then intrinsic function of the heart was assessed. Three time periods were studied - 1, 2 or three hours of shock. In some animals shock lasted for 1 hour and then guinea pigs were resuscitated with whole blood or dextran 70,000 MW (same volume as the blood that was removed). The data collected from the isolated heart indicated that hemorrhagic shock lasting 1, 2 or 3 hours by itself did not cause major dysfunction of the heart. The only change in heart function that seems to occur was in the 3 hour shock group in which the left ventricular compliance was slightly depressed. In animals that had been resuscitated with whole blood or with 6% dextran, ventricular performance was depressed compared to control hearts and compared to hearts from animals in hemorrhagic shock suggesting that reperfusion contributed significantly to myocardial dysfunction resulting from hemorrhagic shock. We have also demonstrated that resuscitation with Ringer's lactate improves cardiovascular status to the same extent as does dextran. Giving four times the shed blood volume vs a volume equal to the shed volume, however, it made little difference in the recovery noted. Finally, we have determined that alcohol, given 30 minutes prior to the hemorrhage, impairs the cardiovascular an respiratory compensation for severe blood loss and results in greater mortality.