Smooth emergence is important for patient safety and satisfaction. Coughing during emergence is associated with detrimental effects like laryngospasm, sore throat, hoarseness, negative pressure pulmonary edema and bleeding at surgical site 1. Especially sore throat and hoarseness are most common complications after extubation 2,3 and closely related to patient satisfaction 4. Using double lumen tube (DLT) increase the incidence of hoarseness and airway injury than using single lumen tube for it has large size5,6. Various technique and drugs have been proposed for reducing coughing during extubation including smooth emergence 1,7-11 and this is closely correlate with reducing sore throat and hoarseness 12. One of the proposed technique, the use of short acting opioids are prefered13-15 because it can be maintained during emergence with less respiratory depression. Remifentanil is a potent short acting opioid and several studies choose remifentanil combined with other anesthetic agents 1,15,16. There is a study about the EC50 and EC95 of remifentanil in effect site Target controlled infusion(TCI) for preventing cough during emergence after thyroidectomy with propofol-remifentanil anesthesia 15 but no study about the proper dose of remifentanil for smooth DLT extubation.

The purpose of this study was to evaluate the EC50 and EC95 of remifentanil in effect-site TCI for preventing cough during extubation of DLT in total TIVA with propofol and remifentanil.

Inclusion Criteria:

• ASA I-II,
• Undergoing general anesthesia with DLT for lung wedge resection

Exclusion Criteria:

• Anticipated difficult airway
• Surgical duration of > 120 min,
• Patient with gastroesophageal reflux or asthma, chronic obstructive disease and upper respiratory infection were excluded from the study.