Impaired utilization of exogenous amino acids after surgery for subarachnoid haemorrhage

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 0.15 gN/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 0.14 gN/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. (Day 0; D5W + C: -9.3 +/- 3.6 g/day and CAA + C: -8.2 +/- 9.7 g/day vs CAA: -2.6 +/- 4.9 g/day, p less than 0.05, Day 1; D5W + C: -14.9 +/- 9 g/day vs CAA: -7.7 +/- 6.5 g/day, p less than 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.