Effect-site concentration of remifentanil to prevent cough after laryngomicrosurgery.

OBJECTIVES/HYPOTHESIS The aim of this study was to discover the optimal effect-site concentration of remifentanil for cough prevention that does not delay awakening or cause respiratory depression during emergence from anesthesia with propofol and remifentanil in laryngomicrosurgery patients. STUDY DESIGN Prospective, randomized, controlled trial. METHODS One hundred five patients were randomly assigned to maintain an effect-site concentration (Ce) of remifentanil at a predetermined value of 1 (R1), 1.5 (R1.5), and 2 (R2) ng/mL during emergence. The incidence and grade (0, no coughing; 1, single cough; 2, more than one episode of nonsustained coughing; 3, sustained and repetitive coughing with head lift) of cough, emergence time, blood pressure (MAP), heart rate (HR), spontaneous respiratory rate, oxygen saturation, and postoperative nausea and vomiting (PONV) were recorded during emergence and recovery. RESULTS The total number of patients with coughing during emergence was lower in groups R1.5 and R2 than in group R1. The cough grade during tracheal extubation was lower in groups R1.5 and R2 than in group R1. In group R2, emergence time was longer and postanesthesia care unit score was lower than in groups R1 and R1.5. Also in group R2, transient hypoventilation and PONV were more frequent compared to group R1. There were no differences in MAP and HR among the three groups during emergence and recovery. CONCLUSIONS Maintenance of remifentanil at Ce 1.5 and 2 ng/mL suppressed coughing without serious adverse events during emergence from anesthesia with propofol and remifentanil in patients undergoing laryngomicrosurgery.