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

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.