Median Effective Dose Of Remifentanil For Proseal Laryngeal Mask Airway Insertion And Tolerance In Adult

OBJECTIVES:1,To determine median effective dose of remifentanil combination with 2.5mg/kg propofol,when inserting Proseal laryngeal mask airway in adult;2,To determine median effective dose of remifentanil for maintaining the tolerance to Proseal laryngeal mask airway in awake and spontaneously breathing patients.METHODS:Sixty ASAⅠ～Ⅱpatients aged 20～55yrs were recruited.This experiment has two parts.PartⅠ:twenty patients were chosen from sixty patients.Patients were induced with propofol and remifentanil.Remifentanil was given at 60s after intravenous infusion of 2.5mg/kg propofol,and laryngeal mask airway was inserted at 150s after anesthesia induction.Remifentanil was given by "up and down" method. Initial dose was 0.5μg/kg,and the ratio between two close dose was 1.2. Assessed the response after inserting the Proseal laryngeal mask airway. Positive reaction was defined when patient response was "bad".The samples were recruited from anterior positive reaction case and amount to 20 patients.PartⅡ:Sixty patients was assigned into six groups(n=10 in each group)in a randomized,double-blind manner.The dose of remifentanil 0.061,0.048,0.039,0.03,0.025 and 0.02μg/kg/min was given respectively.Remifentanil was given after 5 minutes of inserting PLMA.Single dose of remifentanil(0.25μg/kg)was given before continuous intravenous infusion.Respiratory response subscore of comfort scale(CSRR)and Ramsay sedation scale(RSS)Were recorded after 25 minutes.Calculated the ED50 respectively.RESULTS:1,The ED50 of remifentanil was 0.19μg/kg(95% confidence interval ranged from 0.17μg/kg to 0.20μg/kg)for inserting Proseal laryngeal mask airway.2,The ED50 of remifentanil for Proseal laryngeal mask airway tolerance was 0.027μg/kg/min(95%confidence interval ranged from 0.023μg/kg/min to 0.030μg/kg/min)in awake and spontaneously breathing patients.CONCLUSIONS:1,The stimulus response of inserting Proseal laryngeal mask airway can be inhibit by a low dose remifentanil combined with propofol.2,The patients tolerated stimulus of laryngeal mask with a low dose continuous intravenous infusion of remifentanil in awake,and can maintain the hemodynamic stability.