Optimal Effect-Site Concentration of Remifentanil for Inhibiting Response to Laryngeal Mask Airway Removal during Emergence

Purpose: This randomized, controlled, double-blind study was designed to determine the optimal dose of remifentanil for preventing complications associated with the removal of a laryngeal mask airway (LMA) without delaying emergence. Materials and Methods: This study randomly assigned 128 patients to remifentanil effect-site concentrations (Ce) of 0 ng/mL (group R0), 0.5 ng/mL (group R0.5), 1.0 ng/mL (group R1.0), and 1.5 ng/mL (group R1.5) during emergence. The emergence and recovery profiles were recorded. Adverse events such as coughing, air way obstruction, breath-holding, agitation, desaturation, nausea, and vomiting were also evaluated. Results: The number of patients with respiratory complications such as coughing and breath-holding was significantly lower in the R1.0 and R1.5 groups than in the R0 group (p<0.05). Emergence agitation also decreased in the R1.0 and R1.5 groups (p<0.0083). The time to LMA removal was significantly longer in the R1.5 group than in the other groups (p<0.05). Conclusion: Maintaining a remifentanil Ce of 1.0 ng/mL during emergence may suppress adverse events such as coughing, breath-holding, and agitation following the removal of LMA without delayed awakening.