Opioids are used as a treatment for coughing. Recent studies have reported an antitussive effect of remifentanil during recovery from general anesthesia by suppressed coughing. The coughing reflex may differ throughout the respiratory tract from the larynx to the bronchi. But the proper dose of remifentanil to prevent cough during double-lumen tube (DLT) extubation is unknown.Twenty-five ASA physical status 1 and 2 patients, 20 to 65 years of age who were undergoing video-assisted thoracoscopic lung surgery requiring 1-lung ventilation were enrolled. The effective effect-site concentration (Ce) of remifentanil for 50% and 95% of patients (EC50 and EC95) for preventing cough was determined using the isotonic regression method with a bootstrapping approach, following the Dixon up-and-down method. Recovery profiles and hemodynamic values after anesthesia were compared between patients with cough and patients without cough.EC50 and EC95 of remifentanil was 1.670 ng/mL [95% confidence interval (95% CI) 1.393–1.806] and 2.275 ng/mL (95% CI 1.950–2.263), respectively. There were no differences in recovery profiles and hemodynamic values after anesthesia between patients with/without cough. No patients suffered respiratory complications during the emergence period.Remifentanil can be a safe and reliable method of cough prevention during emergence from sevoflurane anesthesia after thoracic surgery requiring DLT. EC50 and EC95 of remifentanil that suppresses coughing is 1.670 and 2.275 ng/mL, respectively.

Objective: There is a growing demand for cuffless blood pressure (BP) measurement as an easy alternative to cuff-occlusion-based BP measurement. We assessed the accuracy of a new cuffless, watch-style BP monitor with a magnetoplethysmography (MPG) sensor compared to two standard auscultatory and oscillatory BP monitors. Subjects and Methods: A total of 34 patients with uncontrolled hypertension (systolic BP ≥150 mm Hg or diastolic BP ≥95 mm Hg) were enrolled in the study. BP was measured by two conventional monitors and the new device during the pre-exercise phase, during isometric handgrip exercise, and during the recovery phase (5 min after exercise). The correlation between monitors was assessed using intraclass correlation coefficient (ICC) and Bland-Altman plots. Results: Although two reference monitors produced highly correlated BP measurements, each was differentially correlated with BP measurements obtained by the new MPG monitor. During exercise, the mean difference between systolic BP obtained by the MPG and oscillatory monitors was >7 mm Hg with an ICC of 0.549 (95% CI 0.264-0.746) in systole and 0.737 (95% CI 0.534-0.859) in diastole. The ICC between the auscultatory monitor and the MPG monitor was 0.753 (95% CI 0.559-0.868) in systole and 0.841 (95% CI 0.706-0.918) in diastole after exercise. Bland-Altman plots also indicated that the performance of the new MPG device was very similar to that of the auscultatory monitor. Conclusion: Although the performance of the new MPG monitor was comparable to that of the reference monitors used in this study, improved stability and accuracy are necessary for accurate BP evaluation during dynamic activity.