Optimal dose of ropivacaine for relieving cough-pain after video-assisted thoracoscopic lobectomy by single intrapleural injection: A randomized, double-blind, controlled study.

BACKGROUND

Pain due to coughing after thoracoscopic surgery remains a clinical problem, and its relief by intrapleural analgesia has not been extensively studied. This study attempts to determine the suitable volume of 0.75% ropivacaine needed for intrapleural analgesia after thoracoscopic surgery.

METHODS

A double-blind, randomized, controlled trial was performed. Forty-five patients were randomly divided into three groups: R20, R15, and R10 (n = 15); 20 ml, 15 ml, or 10 ml of 0.75% ropivacaine was injected into the pleural cavity of each patient in the 3 groups, respectively, when the pain score from postoperative coughing was ≥4. The primary outcome was pain score upon coughing (C-NRS), and the secondary outcomes were pain score at rest (R-NRS), morphine consumption, time of onset, and duration of intrapleural analgesia.

RESULTS

All patients in the R20 and R15 groups reported effective pain relief after intrapleural injection when postoperative coughing occurred. However, only 7 patients in the R10 group reported effective relief of pain. Compared with the patients in the R10 group, patients in the R20 and R15 groups had lower C-NRS scores, less morphine consumption at 8 h and 24 h, a shorter time to pain relief, and a longer duration of analgesia. There was no significant difference of R-NRS among the three groups.

CONCLUSION

Intrapleural analgesia with 0.75% ropivacaine at a volume of 15 ml or 20 ml effectively relieved pain due to coughing after thoracoscopic surgery.

TRIAL REGISTRATION: ChiCTR1800017515.