M. Manabe

Oral intake of amino acid reduces hypothermia during anesthesia in rats: A-572

Oral intake of amino acid reduces hypothermia during anesthesia in rats T. Yokoyama1, R. Kiyooka1, K. Sluka2, R. Hosoi1, K. Yamashita1, M. Manabe1 1Department of Anesthesiology and Critical Care Medicine, Kochi Medical School; 2Physical Therapy and Rehabilitation Science Graduate Program, University of Iowa Background and Goal of Study: Intravenous amino acid infusion prevents postoperative hypothermia. However, amino acid infusion is usually not appropriate during surgery because of low electrolytes and high osmotic pressure. In this study, we examined the effect of oral intake before anesthesia with or without i.v. infusion of amino acids for prevention of hypothermia in rats. Materials and Methods: Male Wistar rats (250–270 g) were used. Thirty minutes before anesthetic induction, rats were orally administered 10.5 mL of amino acid solution (100 g/L, 400 kcal), AmiparenTM (Otsuka, Japan) or saline. Anesthesia was induced with 5% sevoflurane and maintained by propofol. Rats then received either 3.5 ml/hr i.v. of amino acids or saline (A/A; rats received amino acids intake and infusion, A/S; amino acids intake and saline infusion, S/A; saline intake and amino acid infusion, S/S; saline intake and infusion). Room temperature was kept constant at 24°C, and body temperature was measured rectally every 30 min for 3 h after anesthetic induction. Results and Discussion: Body temperature decreased in all groups during 3 h of anesthesia. However, the body temperature decrease was significantly less in all groups that received amino acids (A/A, A/S, S/A) than the groups that received saline. The body temperature decrease was less in the group that received A/A when compared to the group that received S/A (p 0.003). However, there was no significant difference between A/S and S/A, or A/A and A/S.

Are ultra-short-acting beta-blockers useful to prevent hemodynamic changes during endotracheal intubation?: A-162

Department of Anesthesiology and Critical Care Medicine, Kochi Medical School, Nankoku, Japan Background and Goal of Study: Endotracheal intubation often causes undesirable hemodynamic changes. In this study, we examined the usefulness of ultra-short-acting beta-blockers, esmolol and landiolol, in comparison of fentanyl. Materials and Methods: After institutional approval and written consent, 40 patients classified ASA I–II, 30–70-year-old, were randomly assigned to receive esmolol 1 mg (group E), landiolol 1 mg/kg (group L), fentanyl 3 g/kg (group F) or none (group C) during repeated vital capacity induction with 7% of sevoflurane in oxygen. Blood pressure (BP), heart rate (HR) were recorded during anesthetic induction. Stroke volume (SV) and cardiac output (CO) were also evaluated using BioZTM Impedance Cardiography module (GE Healthcare IT Inc, USA). Serum noradrenaline concentration (NAD) was measured 1 min and 7 min after intubation. Results and Discussions: There were no significant differences in patients’ background between groups. Although BP decreased to about 70% of preinduction value, no significant difference was observed between groups until endotracheal intubation. In all groups, BP was significantly increased after intubation, while BP increase was significantly less in group F (P 0.01); increase of systolic BP to the pre-intubation value: 177 33% in group C, 153 15% in group E, 136 15% in group L and 118 13% in group F. There was no significant difference in CO between groups after intubation. However, increase of NAD after intubation was suppressed to 124% of preintubation value in group F, while NAD increased to more than 300% in other groups. Conclusion(s): Fentanyl significantly suppressed hemodynamic change and noradrenaline secretion during endotracheal intubation, although both esmolol and landiolol showed only tendency to suppress hemodynamic change.