[Basic study on the mechanism of postanesthetic recovery acceleration caused by infusion of bicarbonated Ringer's solution].

BACKGROUND: Effect of bicarbonated Ringer's solution (BRS) on the liver function of rats with metabolic acidosis was compared with that of lactated Ringer's solution (LRS) and Ringer's solutions (RS). Furthermore, the effect of acidosis on the plasma protein binding ratio of propofol was examined. METHODS: Partial hepatectomized rats were divided into three groups, and BRS, LRS or RS was intravenously administered at 20 ml x kg(-1) x hr(-1) with propofol (45 mg x kg(-1) hr(-1)) for 90 min. Immediately after the administration, indocyanine-green (ICG) was infused. Blood sampling was done at 30, 60, 90 and 120 min after the ICG infusion, and the ICG concentration in plasma was measured. Propofol was added to plasma of rats with ketoacidosis or normal rats (final conc. 5 microg x ml(-1)), and incubated for 30 min at 37 degrees C. After incubation, plasma propofol concentrations were measured. RESULTS: The reduction of ICG in plasma of BRS group was the fastest among the three groups. Plasma protein binding ratio of propofol in plasma samples of rats with ketoacidosis tended to be lower than those of normal rats samples. CONCLUSIONS: These results suggest that metabolic acidosis induced the delay of awakening from anesthesia, suggesting that BRS accelerates recovery from anesthesia through amelioration of acidosis.