Studies of lipid and carbohydrate metabolism during surface-induced deep hypothermia with circulatory arrest for open-heart surgery

Abstract

Plasma lipids, blood glucose, plasma insulin (IRI) and serum dopamine-beta-hydroxylase (DBH) were measured in 30 subjects undergoing surface-induced deep hypothermia with circulatory arrest for open-heart surgery. Non-esterified fatty acid (NEFA) in the plasma rapidly increased at the lowest temperature (23 degrees C) reached and other lipids in the plasma decreased during the cooling period. An increase of NEFA and a decrease of triglyceride have been attributed to the action of lipoprotein lipase activity stimulated by heparin. It is also likely that the decrease of other lipids and beta-lipoprotein in the plasma results from the transient hypofunction of the liver due to hypothermia. Blood glucose increased during the cooling period, while plasma insulin showed no significant change. Serum DBH reflecting catecholamine also showed no significant change during the cooling or rewarming periods. Therefore, hyperglycemia in hypothermic open-heart surgery may result from the decrease of peripheral utilization of glucose and from the inhibition of insulin secretion due to the transient pancreatic hypofunction.

Histopathological, histochemical and biochemical postmortem changes in induced fatal hypothermia in rats

“…The non-significant changes in serum total protein levels in the hypothermia groups compared with those of the NC group were attributed to the sparing effects of lipids and carbohydrates, which are considered the primary fuel for energy production, followed by proteins. Therefore, the intensity and duration of the cold exposure, as well as the duration of survival before death, are important factors affecting protein catabolism and hence total protein levels in the blood [ 54 , 55 ].…”