Metabolic consequences of different perioperative fluid therapies in the neonatal period

Carbohydrate and fat metabolism during and after anaesthesia and surgery was studied in 14 neonates with major congenital non-cardiac anomalies. They were either given a glucose solution until surgery or starved for at least 4 h before surgery. Ringer-acetate alone or Ringer-acetate plus 10% glucose was used for the intraoperative fluid therapy. After anaesthesia all neonates were given a 10% glucose solution. Concentrations of glucose, free fatty acids, triglycerides, lactate, pyruvate, alanine, glycerol and 3-hydroxybutyrate were measured at predetermined intervals pre-, intra- and postoperatively. Blood glucose concentrations rose during surgery both in neonates given glucose before and during surgery (n = 6) and in neonates not given glucose before and during surgery (n = 6). Increased intraoperative levels of free fatty acids and 3-hydroxybutyrate were found in neonates not given glucose before and during surgery. The triglyceride levels were equal in both groups. In two neonates given glucose before surgery and Ringer-acetate during surgery increased levels of 3-hydroxybutyrate were found, particularly in one patient who became hypoglycaemic. In conclusion, starved neonates without intraoperative glucose supply mobilized fat and maintained blood glucose concentrations.