Comparison of butorphanol and thiopentone vs fentanyl and thiopentone for laryngeal mask airway insertion

Study Objective: To compare laryngeal mask airway (LMA) insertion conditions using a combination of butorphanol and thiopentone vs fentanyl and thiopentone. Design: Prospective, randomized, and double-blind study. Setting: Operating theater. Patients: One hundred four females, with American Society of Anesthesiologists grades I and II, diagnosed with carcinoma cervix scheduled for intracavitary implant placement, were recruited into the study. The patients were randomly divided into 2 groups of 52 each. Intervention: Anesthesia was induced with butorphanol (30 mu g kg(-1)) and thiopentone in group B and fentanyl (1.5 mu g kg(-1)) and thiopentone in group F, followed by LMA insertion. Anesthesia was maintained with O-2, N2O, and isoflurane with spontaneous ventilation. Measurements: Six variables were noted oil a 3-point scale: jaw relaxation (nil/slight/gross), ease of insertion (easy/difficult/impossible), swallowing (nil/slight/gross), coughing/gagging (nil/slight/gross), limb/head movement (nil/slight/gross), and laryngospasm (nil/slight/gross). Postoperatively, sedation score was assessed on a 4-point scale at 1/2 hour, 1 hour, and 2 hours. Main Results: The 2 groups were demographically similar. Incidence of full jaw relaxation at first attempt was significantly higher in group B vs F (48 vs 35 patients, P = 0.003). Insertion was easy in 48 vs 37 patients in group B and F, respectively (P = 0.017). The incidence of swallowing, patient movements, and laryngospasm was comparable among the groups. Coughing/gagging was significantly lower in group B (P = 0.008). Significantly more patients were sedated in group B at 1/2 hour ( P = 0.010) and 1 hour (P = 0.000). None of the patients were deeply sedated at 1 hour. At 2 hours, all patients were awake. Conclusion: The use of butorphanol and thiopentone as induction agents produced excellent LMA insertion conditions compared to fentanyl and thiopentone (98% vs 86% success rate with 92% vs 71 % easy insertion). (c) 2006 Elsevier Inc. All rights reserved.