THE USE OF DOPEXAMINE HYDROCHLORIDE TO INCREASE OXYGEN DELIVERY PERIOPERATIVELY

Perioperative increases in oxygen delivery may reduce morbidity and mo rtality in certain groups of surgical patients. However positive inotr opic drugs, such as dobutamine and epinephrine themselves, may increas e oxygen demand. Dopexamine hydrochloride is a new dopamine analogue w ith action at beta2-adrenoceptors and DA1 receptors, but it possesses no direct alpha-adrenoceptor activity. We assessed the suitability of dopexamine to increase oxygen delivery perioperatively in eight patien ts having vascular surgery and studied its effects on oxygen demand. O xygen delivery was increased toward 600 mL.min-1.m-2 by intravenous (I V) fluid infusion and IV titration of dopexamine hydrochloride. Oxygen delivery could be increased preoperatively (375 +/- 43 to 552 +/- 50 mL.min-1.m-2, P < 0.05) with >600 mL.min-1.m-2 being achieved in five patients. This increase was achieved without significant increase in t otal body oxygen consumption (114 +/- 10 to 123 +/- 7 mL.min-1.m-2 P > 0.05) or rate pressure product (13.7 +/- 2.8 X 10(3) to 13.5 +/- 2.1 X 10(3) mm Hg.beats/min, P > 0.05). Postoperatively oxygen delivery wa s increased again without an increase in oxygen consumption (126 +/- 1 0 mL.min-1.m-2, P > 0.05) or rate pressure product (14.2 +/- 0.9 X 10( 3) mm Hg.beats/min, P > 0.05). Dopexamine hydrochloride may provide a method for increasing oxygen delivery perioperatively with only limite d increase in total body or myocardial oxygen demand.