Optimal conditions for Laryngeal Mask Airway insertion in children can be determined by the trapezius squeezing test

Abstract

Study Objective To evaluate the trapezius squeezing test as a criterion of adequate anesthetic depth for Laryngeal Mask Airway (LMA) insertion in children without neuromuscular blocking agents. Design Prospective, randomized clinical trial. Setting Operating room of a university hospital. Patients 45 ASA physical status I and II children, aged one to 6 years, undergoing minor surgical procedures. Interventions An LMA was inserted in each child after the trapezius squeezing test turned to be negative. Measurements Presence of coughing, gagging, gross purposeful movements, breath holding, laryngospasm, or desaturation during or within one minute of LMA insertion were recorded. Elapsed time of LMA insertion, end-tidal sevoflurane concentration, blood pressure, and heart rate values were also noted. Main Results LMA insertion was successful in 41 patients. Elapsed time to complete insertion was 5.7 ± 1.9 minutes, and end-tidal sevoflurane concentration was 3.6 ± 1.1 vol%. No marked hemodynamic changes occurred in any child. Conclusions The trapezius squeezing test is a reliable clinical indicator to assess adequate anesthetic depth for LMA insertion in children without neuromuscular blocking agents.