Abstract: Background and purpose: Perioperative hypothermia will affect the prognosis of cancer patients. Amino acid infusion can increase the core temperature by endogenous thermogenesis. And the forced-air warming system has gained high acceptance as a measure for rewarming. This study aimed to find out whether amino acid infusion was effective to treat postoperative hypothermia and how well the treatment effect was when compared with the forced-air warming system. Methods: Fifty-seven ASA Ⅰ or Ⅱ patients aged 18-60 years undergoing elective esophageal or gastric cancer operation under epidural-general anesthesia and whose core temperature were below 36 ℃. When admitted to the recovery room were randomly divided into 3 groups (n=19): Group Ⅰ received intravenous infusion of mixed amino acid at a rate of 2 mL·kg^-1·h^-1 (A); Group Ⅱ received a forced-air system (B); group Ⅲ received no therapy (C). Rectal temperature and thermal comfort were recorded per 5 min during the first 1 h and oral temperature and thermal comfort were recorded at the 2, 6 and 24 h. ABG was recorded when patients were admitted to the recovery room and at the first hour. Results: At the first hour, the rectal temperature and thermal comfort of groups A and B were higher when compared with group C (P<0.05), and there was no difference between groups A and B (P>0.05). At the second and sixth hour, the temperature and thermal comfort of group A were higher when compared with group B and C (P<0.05), and there was no difference between groups B and C (P>0.05). At the 24th hour, there were no statistically significant differences in the temperature and thermal comfort among the three groups (P>0.05). Conclusion: The rewarming effect of infusion of mixed amino acid is better than that of the forced-air warming system. It is the more effective and convenient method to rewarm the postoperative hypothermia.

Key words: Mixed amino acid, Forced-air warming system, Postoperative hypothermia, Tumor metastasis