Abstract: Background and purpose: Previous researches have shown that intravenous amino acid infusion during general anaesthesia prevents the decreases in core temperature. This study aimed to investigate the effect of amino acid infusion on postoperative liver and renal function in elderly patients undergoing gastrointestinal surgery. Methods: Forty ASA Ⅰ or Ⅱ patients (33 males, 7 females) aged 65-75 years undergoing elective gastrointestinal cancer operation under epidural block combined with general anesthesia were randomly divided into 2 groups (n=20 each). Group Ⅰ received intravenous infusion of mixed amino acids at a rate of 2 mL·(kg·h) ^-1 from induction of anesthesia to the end of operation (AA group); Group Ⅱ received infusion of equal volume of normal saline (NS group). Snuff temperature was monitored for induction of anesthesia immediately, after 90 min and at closed abdomen. Renal and hepatic function was performed regularly before operation and on the 1st and 7th postoperative day. Results: The nasopharyngeal temperatures at 90 min after the beginning of surgery and the time when the peritoneum was closed in AA group were significantly higher than those in NS group (P<0.05). Hepatic and renal function indices were within the normal range in the AA and NS groups. There were significant increases in TBIL, DBIL, ALT, and AST (P<0.05) after operation, whereas TP, ALB, BUN, Scr and UA decreased significantly (P<0.05). There were no significant differences in hepatic and renal function indices between the AA and NS groups (P>0.05). Conclusion: Intraoperative amino acid infusion has no significant effects on the renal or hepatic function in elderly patients undergoing gastrointestinal surgery.

Key words: Elderly patient, Amino acid, Anesthesia, Renal and hepatic function, Gastrointestinal surgery