Effective LMA insertion: Lidocaine and propofol comparison with propofol alone

Abstract

          Propofol is the induction agent used to facilitate the placement of LMA without muscle relaxant. It depressed airway reflexes effectively. We used the efficacy of lidocaine to improve LMA insertion conditions. A propofol dose ranging from 2.5 to 3 mg/kg is recommended for LMA insertion. Among the propofol minimum dose 2.5 mg/kg alone, propofol dose 2 mg/kg and lidocaine iv. and topical lidocaine, which  methods had the best effectiveness and lowest the complications. Methods: This was a prospective double blind control study. We enrolled patients aged 18-65 year undergoing elective surgery, ASA status I-II and anesthesiologist chose the laryngeal mask airway for them. Patients were divided into 3 groups of 50 in each. Group P received propofol 2.5 mg/kg, Group TL-P received 40 mg of topical lidocaine over posterior pharyngeal wall followed 3 min later by propofol 2 mg/kg, and Group IV-P received intravenous lidocaine 1.5 mg/kg 3 min before propofol 2 m g/kg. Jaw opening, coughing, gagging, body movement, laryngospasm and apnea time were recorded. Results: Incidence of gagging, body movement (insertion and after insertion) were found mainly in Group IVL-P (P value < 0.05) and the frequency of optimal insertion condition was lower in Group IVL-P (P value = 0.018).  Conclusions: Topical lidocaine 40 mg followed by propofol 2 mg//kg was effective equally to propofol 2.5 mg/kg for insertion of LMA with the in different complications.