Amino Acid Infusion:a New Method To Cure Postoperative Shivering With Hypothermia

Objection:To study the therapeutic effect of intravenous amino acid infusion in the period of anesthesia recovery on postoperative shivering in the patients undergoing gastrointestinal surgery under general anesthesia combined with epidural block.Methods:Using randomized double-blind controlled study, sixty Patients who showed shivering ≥grade 2 for >3 min, and tympanic temperature <36℃ were randomly allocated by computer-coded envelopes into three groups (n=20) to receive either intravenous AAs (Group AA), pethidine (Group P), or tramadol (Group T). Drug administration was separated into two steps:2 ml normal saline was given to the AA group, followed by Novamin(?) 18AA-Ⅱ infusion at a rate of 2 ml·kg-1·h-1 (approximately 4 kJ·kg-1·h-1) for 1 h. Two milliliters of normal saline containing either 0.5 mg·kg-1 pethidine or 1 mg·kg-1 tramadol was administered to the respective pethidine or tramadol group, followed by normal saline infusion at the same rate of 2 ml·kg-1·-1 for 1 h. Shivering grade、tympanic temperature and thermal comfort were assessed every 5 min for 1 h. Blood glucose and lactic acid concentrations were measured before and after treatment. Postoperative nausea、vomiting and re-shivering were also recorded.Findings:Shivering grades at T5minand T10min point in Group AA were significantly higher than that of Group P and Group T. There were five cases of re-shivering in Group T versus none in Group AA or Group P. Tympanic temperature increased significantly faster in Group AA versus the Group P and Group T, beginning 10 min after treatment. Thermal comfort improved significantly faster in Group AA (within 5 min) versus the other two groups (10 min). In Group AA, the thermal comfort index reached [(50±1.41)mm], or perceived thermoneutrality. Blood glucose concentration in AA group increased from[(6.83±0.34) mmol·L-1]to [(7.51±0.51)mmol·L-1]. There were some cases of nausea and vomiting in pethidine and tramadol groups, but none in the AA group.Interpretation:Amino acid infusion is a new method to cure postoperative shivering with hypothermia. Amino acid infusion alleviates hypothermia and improves thermal comfort more effectively than pethidine and tramadol, with less nausea and vomiting and no re-shivering episodes.