Oxygen consumption is increased in the postanesthesia period after burn excision

We studied the intraoperative and postoperative effects of anesthesia and wound excision on oxygen delivery and oxygen consumption after burn injury. Twenty adult sheep were studied: six had halothane anesthesia alone and 14 had anesthesia and third-degree burns over 15% of the total body surface. Body temperatures were maintained within 1 degree C of baseline value during the operations. The burns on six sheep were totally excised and hide from donor sheep was grafted 3 hours after injury; in eight sheep, excision and grafting were done 5 days after injury. We found that 3 hours of anesthesia in controls decreased oxygen delivery (DO2) by 22% +/- 6% and oxygen consumption (VO2) by 30% +/- 7% from waking baseline values primarily because of a decrease in cardiac output as oxygen (O2) extraction from hemoglobin also decreased. However, no base deficit developed. DO2 and (VO2) transiently increased to 9% +/- 3% above baseline value on the sheeps' return to the waking state. Anesthesia and wound excision, which began 3 hours after the burns were formed, decreased DO2 and VO2 by 25% +/- 4% and 32% +/- 4%, respectively, despite baseline filling pressures. However, a base deficit of -3 +/- 1 mEq/L developed during the two-hour operations, which began with the administration of anesthesia alone. Oxygen consumption increased to 25% +/- 6% above the waking baseline value upon each subject's return to the waking state. In the sheep treated 5 days after burn injury, DO2 decreased by 35% +/- 6% and VO2 decreased by 42% +/- 6% below the value during the waking hypermetabolic state when the sheep were under anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)