Effect of amino acid solutions on intraoperative hypothermia and postoperative shivering. Comparison of two anesthetic regimens.

BACKGROUND

Intraoperative hypothermia is a major adverse effect of general anesthesia. The different anesthetics may influence thermoregulation differently. Proteins or amino acids have been postulated to stimulate heat production. The purpose of this study is to compare the effects of intraoperative administration of amino acid solutions on intraoperative hypothermia and postoperative shivering in two different anesthetic regimens.

METHODS

Forty ASA I-III craniotomy patients were assigned to four groups of 10 patients in a randomized prospective study, as follows: ISO - isoflurane-based anesthesia; PRO - propofol-based anesthesia; ISO + AA - Isoflurane-based anesthesia with supplementation of amino acid infusion; PRO + AA - Isoflurane-based anesthesia with supplementation of amino acid infusion. Hemodynamic parameters, esophageal temperature and postoperative shivering scores were recorded.

RESULTS

Core temperatures were higher during emergence in amino acid-treated propofol group, compared with the other groups. The core temperature decreased significantly in three groups throughout the operation, except the in amino acid-treated propofol group. The shivering intensity was less in the amino acid-treated groups.

CONCLUSION

The anesthetic method may influence the thermic effect of amino acids under general anesthesia. Propofol anesthesia has more thermogenic effect than isoflurane when combined with amino acid solutions.