LAUSR

Background: This study aimed to estimate the optimal dose of sufentanil, coadministered with 2.5 mg/kg propofol, for satisfactory laryngeal mask airway (LMA) insertion conditions in Chinese children and to determine the optimal bolus dose. Methods: Seventy-five Chinese children aged 2 to 6 years with the American Society of Anesthesiologists physical status I or II, undergoing elective minor surgery were recruited. They were randomly divided into 5 different dosage groups (0, 0.05, 0.1, 0.15, 0.2 &mgr;g/kg). A predetermined sufentanil diluted with 5 mL saline was injected 30 s, 200 s later, followed by 2.5 mg/kg propofol over 10 s. After that the insertion conditions were assessed, using a 6-category score. The duration of apnea was recorded. A Probit analysis was performed to determine the ED50 and ED95 with 95% confidence interval for optimal conditions. Results: There were less hemodynamic changes in all sufentanil groups than propofol-only group, with 0.2 &mgr;g/kg patients showing the most stable cardiovascular responses and best insertion conditions. However, the duration of apnea increased with the increasing dosage of sufentanil. From Probit analysis, the ED50 and ED95 of sufentanil for optimum score were 0.064 &mgr;g/kg and 0.177 &mgr;g/kg, respectively. Conclusion: In combination with propofol for anesthesia induction in Chinese children, sufentanil 0.2 &mgr;g/kg could prevent patients from dramatic hemodynamic change, providing satisfactory LMA insertion conditions.