Metabolic and hemodynamic aspects of the hypothermia of early burn shock

Guinea pigs briefly anesthetized with Halothane were burned over 70% of their body surface area. Core temperature progressively decreased over an 8 hour period reaching its lowest level just before death. Heart rate, cardiac output, and oxygen consumption also diminished over this period. The fractional distribution of the cardiac output to the pancreas, adipose tissue, burned and unburned skin and muscles fell sharply. Actual volume flow to the heart and brain also decreased while plasma FFA concentration exhibited little change. However, hyperglycemia was noted due in part to peripheral insulin resistance. Although plasma catecholamines increased during this trauma, their effect was muted by a low plasma pH and a rising lactic acid concentration. It is postulated that the destroyed peripheral temperature receptors, hypoxic areas of the brain, decreased blood flow through high metabolic areas and low oxygen and substrate utilization in the periphery brought about the hypometabolism.