Plasma lipids during extracorporeal circulation.

Total lipids, lipid classes, and per cent composition of fatty acids were investigated in plasma and stored subcutaneous fats of 19 subjects undergoing extracorporeal circulation (ECC). The tests were made before and 3, 20, 40, and 60 minutes after ECC was started. Hemodilution caused a general fall in total lipids and lipid classes. Evaluation of the lipid classes as percentages of the total lipids assumed to be 100 per cent allow the lipid variation due to hemodilution to be disregarded. A linear correlation between an increase in free fatty acids (FFA) and a decrease in triglycerides can thus be observed. This has been attributed to action of the lipase lipoproteic (LLP) activity stimulated by heparin, which is usually employed in ECC hemodilution. The hypothesis that FFA's are mobilized from stored subcutaneous fats was discounted.