Effects of Dosages of Remifentanil Calculated by Total Body Weight and Ideal Body Weight to Intubation Circumstances and Adverse Hemodynamic Responses

Kim, Shin Sung; Kim, Young Taek; Park, Byung Soon; Lee, Byung Jun

Abstract

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.