TRACHEAL INTUBATION IN AMBULATORY SURGERY PATIENTS - USING REMIFENTANIL AND PROPOFOL WITHOUT MUSCLE-RELAXANTS

Using alfentanil followed by an anesthetic induction dose of propofol provides adequate conditions for tracheal intubation without neuromusc ular relaxants. Remifentanil, which has a clinical onset similar to th at of alfentanil, has not been investigated for this indication. Accor dingly, 80 ASA physical status I and II premedicated outpatients were randomly assigned to one of four groups (n = 20/group). Remifentanil 1 , 2, 3, or 4 mu g/kg (Groups I-IV, respectively) was infused intraveno usly over 90 s. Sixty seconds after beginning the remifentanil infusio n, propofol 2 mg/kg was infused over 5 s. Ninety seconds after the adm inistration of propofol, laryngoscopy and tracheal intubation were att empted and graded. Clinically acceptable intubating conditions (i.e., jaw relaxed, Vocal cords open, and fewer than two coughs in response t o intubation) were observed in 35%, 75%, 100%, and 95% of patients in Groups I-IV, respectively. Clinically acceptable intubating conditions were significantly (P < 0.05) less likely to occur in Group I compare d with all other groups. Excellent intubating conditions (i.e., vocal cords open, no movement in response to intubation) were observed in 30 %, 50%, 80%, 80% of patients in Groups I-IV, respectively. Overall con ditions at intubation were significantly (P < 0.05) better in Groups I II and IV compared with Groups I and II. The mean time to resumption o f spontaneous ventilation after induction was <5 min in all groups. No patient manifested clinically significant muscle rigidity. The mean a rterial pressure decreased 16%, 20%, 2&%, 26% immediately before trach eal intubation in Groups I-TV, respectively. No patient was treated fo r hypotension or bradycardia. In conclusion, healthy, premedicated pat ients with favorable airway anatomy can be reliably intubated with goo d or excellent conditions 90 s after the administration of remifentani l 3-4 mu g/kg and propofol 2 mg/kg. Implications: Remifentanil 3 mu g/ kg and propofol. 2 mg/kg co-administered intravenously may reliably pr ovide adequate conditions for tracheal intubation in healthy patients without neuromuscular relaxants. This combination of drugs may allow t he rapid return of spontaneous ventilation.