RESUMO
BACKGROUND: Remifentanil presents good intubation conditions and blunting adverse hemodynamic responses following intubation. So, we evaluated to determine optimal dosage of remifentanil for intubation which consider ideal body weight. METHODS: 160 ASA class 1-2 patients were selected and divided 4 groups, which were composed of 40 patients. Group 1 and 2 were administrated dosage calculated by TBW (total body weight). Each group was administrated intravenous continuous infusion dose of 1.0 ug/kg/min of remifentanil during 2 minutes followed by intravenous bolus dose of 2 mg/kg of propofol (Group 1) and 2.0 ug/kg/min of remifentanil followed by same dose of propofol (Group 2). Group 3 and 4 were administerated same dosage of Group 1 and 2 but administrated dosage calculated by IBW (ideal body weight). We didn't use any muscle relaxant. Intubation conditions and postintubation hemodynamic responses were assessed by 5 items based on GCRP (good clinical research practice), MAP (mean arterial pressure) and HR (heart rate). RESULTS: We have done intubation safely 60, 75, 55 and 98% of Group 1, 2, 3 and 4 respectively. Group 1, 3 have 'technically unacceptable' cases, but group 2, 4 have 'clinically unacceptable' cases. Hemodynamic responses of Group 4 were more stable than Group 2, especially obese patients. Obese patients present a problem for the appropriate dosing of remifentanil and profound hypotension and/or bradycardia developed more frequently when administerated agent calculated by total body weight. CONCLUSIONS: The optimal dosage which produce best intubation conditions and least side effects has to be determined according to IBW.