Energy metabolism in dogs during anesthesia, curarization, or acute arterial hypotension

¹ Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil

Forty-two determinations of metabolism (O₂ consumption measured by air analysis of the expired air) were made in 14 dogs anesthetized with Dial or Nembutal-morphine (shown not to alter the dog's basal metabolism). Fifty determinations in 14 other dogs (under the same anesthesia) were made before (with spontaneous respiration) and after gallamine curarization (under artificial respiration). The metabolic level after many hours was not significantly altered, either by the anesthesia used or after the gallamine curarization (fair constancy of the arterial pressure was observed in both series of experiments). Therefore, tonus of skeletal muscle and activity of respiratory muscles do not contribute significantly to the total energy metabolism of dogs at rest. The influence of arterial hypotension on metabolism was studied in 18 anesthetized dogs, before (with spontaneous respiration) and several hours after transection of the cervical spinal cord (under artificial respiration and curarization). In all, 71 determinations of heat production were made. The fall in blood pressure, about 50–60% from normal, had no immediate or delayed influence upon the metabolism level.