A comparison of ketamine and lidocaine spray with propofol for the insertion of laryngeal mask airway in children: a double-blinded randomized trial

Abstract

The laryngeal mask airway (LMA) has been used successfully as both a ventilatory device and a conduit for tracheal intubation. In this double-blinded, randomized study, we examined whether pretreatment with lidocaine spray, ketamine anesthesia, and LMA insertion could be used as airway management that could maintain spontaneous breathing in children. After IV premedication with midazolam 0.05 mg/kg and glycopyrrolate 0.005 mg/kg, 90 patients were randomly allocated to 1 of 2 main groups for the administration of either propofol or ketamine: 40 patients received 2.5, 3.0, 3.5, or 4.0 mg/kg of propofol IV (n = 10 each), whereas 50 patients received 2.0, 2.5, 3.0, 3.5, or 4.0 mg/kg of ketamine IV (n = 10 each). Only in the ketamine group was lidocaine spray applied to the oropharynx 1 min before anesthesia induction. After injection of the designated drug, self-respiration, airway obstruction, and jaw relaxation were checked. Self-respiration, laryngospasm coughing, gagging, swallowing, biting or tongue movements, secretions, and head or limb movements after LMA insertion were graded. All variables were graded as satisfactory, acceptable, or unsatisfactory. The overall result was considered satisfactory if all criteria were satisfactory; acceptable if all were better than acceptable, but at least one acceptable criterion was included; and unsatisfactory if at least one criterion was unsatisfactory. Overall satisfactory or acceptable results in every patient were achieved only in the ketamine 3.0 or 3.5 mg/kg subgroups. No propofol dose was completely satisfactory; most cases involved apnea or airway obstruction. Ketamine and lidocaine spray were appropriate for LMA insertion, which may be a safe method for management of difficult airway in children.

Implications: Ketamine and lidocaine spray appear to be appropriate for laryngeal mask airway (LMA) insertion in children. Thus, apnea and airway obstruction, the two most serious and frequent complications of propofol, can be avoided during LMA insertion.