[Anesthesia induction for laryngeal mask insertion--comparison of propofol with midazolam and propofol with thiopental].

We compared the patient's response to laryngeal mask (LM) insertion and hemodynamics among three anesthesia induction methods; P group using 2.5 mg.kg-1 propofol with 0.2 microgram.kg-1 fentanyl, M group using 0.2 mg.kg-1 midazolam with 0.2 microgram. kg-1 fentanyl, B group using 5 mg.kg-1 thiopental with 0.2 microgram.kg-1 fentanyl. Each 30 patients, 35 to 65 years, for elective mastectomy were entered in three groups. Preanesthetic medication was i.m. injection of 0.5 mg atropine and 5 mg midazolam 30 min before the induction. Anesthesia was induced with intravenous injection of each dose of P, M or B in 20 sec followed by fentanyl. When verbal response disappeared, a laryngeal mask was inserted. The number of patients with difficult insertion or showing body movement or gagging were larger in the order of M group > B group > P group. Blood pressure and heart rate in the P group were significantly lower than those in the other two groups. It was concluded that P allowed the most smooth insertion of LM among the three groups, but it also induced hypotension and bradycardia.