DIASPIRIN CROSS-LINKED HEMOGLOBIN (DCLHB(TM)) DOES NOT AFFECT THE ANESTHETIC POTENCY OF ISOFLURANE IN RATS

Hemoglobin solutions are being developed as oxygen carrying fluids for multiple clinical indications. Despite an early report of accentuatio n of ether anesthesia, the effect of hemoglobin on anesthetic potency has not been assessed. We assessed the effect of alpha-alpha diaspirin crosslinked hemoglobin (DCLHb) on the anesthetic requirement of isofl urane necessary to keep rats unresponsive to noxious stimuli (1.0 MAC [minimum alveolar concentration]). During isoflurane administration, e ach rat received one of the following fluid regimens: 44Hct/N-normal h ematocrit and volume; 34Hct/H-8.0 ml of donor blood given as a hypervo lemic bolus; 30Hct/H-5.0 ml of DCLHb given as an exchange transfusion and 8.0 ml as a hypervolemic bolus; or 16Hct/H-15.0 mi of DCLHb given as an exchange transfusion and 8,0 ml as a hypervolemic bolus. MAC was determined using a standard tail clamp technique. The isoflurane requ irement to achieve 1.0 MAC was not different between the four groups. These results are consistent with a hypothesis that DCLHb does not cha nge the anesthetic state.