The optimal dose of remifentanil for acceptable intubating conditions during propofol induction without neuromuscular blockade
Journal of Clinical Anesthesia, 07/03/2012
Demirkaya M et al. – The optimal bolus dose of remifentanil for acceptable intubating conditions was 2.40µg/kg (95% confidence interval, 1.90–9.0µg/kg) in 95% of patients during induction of anesthesia with propofol 2.0Demirkayamg/kg without neuromuscular blocking agents.Methods
- 50 ASA physical status 1 men, aged between 20 and 40years, who were scheduled for general anesthesia.
- Intubating conditions were evaluated according to the scoring system described by Viby–Mogensen et al.
- Successful intubation was defined as excellent or good.
- For induction of anesthesia, an intravenous (IV) bolus dose of propofol 2.0mg/kg was given over 30seconds followed by the administration of predetermined IV remifentanil over 30seconds; intubation was performed 90seconds after completion of the remifentanil administration.
- The dose of remifentanil used for each patient was determined by the response of the previously tested patients, using the modified Dixon's up–and–down method (using 0.2µg/kg as a step size).
- The first patient was tested with remifentanil 1.0µg/kg.
- If intubation failed, the remifentanil dose was increased by 0.2µg/kg; if intubation was successful, the dose was decreased by 0.2µg/kg.
- Mean arterial pressure (MAP), heart rate (HR), and peripheral oxygen saturation were recorded during the study period.
- According to probit analysis, the effective dose of remifentanil in 50% (ED50) and 95% (ED95) of patients were 1.40µg/kg and 2.40µg/kg, respectively.
- Preintubation and postinduction HR and MAP values were lower than preinduction values (P<0.001).