Canadian Journal of Anesthesia, Vol 16, 525-537, Copyright © 1969 by Canadian Anesthesiologists' Society

Whole-Body Metabolism During and after Abdominal Surgery

¹ Mayo Clinic and Mayo Foundation: Section of Anesthesiology and Mayo Graduate School of Medicine (University of Minnesota), Rochester

Oxygen, acid-base components, electrolytes, and energy-producing metabolites were measured in arterial and mixed venous blood before, during, and for three days after abdominal operations in 11 patients. A respiratory alkalosis without a metabolic component was present throughout most of the study interval. Predictably, arteriovenous differences were not found for any electrolyte or metabolite. Arterial and venous oxygen tensions were satisfactory throughout anaesthesia, but the postoperative Pa_oo2 indicated considerable persisting atelectasis. Arterial concentrations of non-esterified fatty acids and ketone bodies were increased before anaesthesia and throughout the operation. Blood sugar increased during the operation and remained above normal postoperatively, probably from intravenous solutions. Mean concentrations of immunoreactive insulin remained in the normal range in spite of this increase in blood sugar. Fat metabolism appeared to predominate, and ketosis occurred in the presence of increased blood sugar. Lactate and pyruvate levels increased steadily throughout the operation and decreased postoperatively.

Careful maintenance of arterial oxygen tension and of the circulation during and after anaesthesia for general surgery results in little change in acid-base balance and electrolytes. The changes in blood levels of energy-producing metabo lites are moderate and usually reverse themselves. Duration of operation or type of surgery had little influence on the variables studied.

Note:

Read at the meeting of the Canadian Anaesthetists' Society, Toronto, June 15 to 19, 1969. This investigation was supported in part by research grant gm-14919 from the US National Institutes of Health, Public Health Service.