Impaired utilization of exogenous amino acids after surgery for subarachnoid haemorrhage

Summary We studied the metabolic response to acute aneurysm surgery and its modification by parenteral nutrition. Forty-eight patients receiving perioperative corticosteroid treatment were randomly assigned to receive glucose alone (7.2 kcal/day, D5W+C), glucose and a conventional amino acid solution (7.2 kcal/day and 0.15gN/ day, CAA+C) or glucose and branched chain amino acid enriched solution (7.2 kcal/day and 0.14 gN/day, BCAA+C). Twenty patients without corticosteroid treatment received either glucose alone (7.2 kcal/day, D5W) or glucose and a conventional amino acid solution (7.2 kcal/day and 0.14gN/day, CAA). Poor nitrogen utilization was indicated by strongly negative nitrogen balance in all groups and a failure of the infused amino acids to improve nitrogen balance. (Day0; D5W+C: –9.3±3.6g/day and CAA+C: – 8.2±9.7g/ day vs CAA: –2.6±4.9g/day, p<0.05,Day 1; D5W+C: –14.9 ±9g/day vs CAA:–7.7±6.5g/day, p<0.05, MANOVA). We conclude that subarachnoid haemorrhage and its surgical treatment induce a catabolic response and impaired utilization of exogenous nitrogen, further amplified by perioperative corticosteroids, which is in sharp contrast to the response to surgery not involving the central nervous system.