Thoracic epidural local anesthetics are ineffective in alleviating post-thoracotomy ipsilateral shoulder pain

Abstract

Objective: This study was conducted to estimate the incidence and clinical predictors of post-thoracotomy shoulder pain and to determine the effectiveness of thoracic epidural block in alleviating this pain. Design: A prospective clinical trial. Setting: University teaching hospital. Participants and Interventions: Thirty-two adult patients undergoing elective thoracic surgery consented to participate in the study. All operations were open thoracotomies done by the same team of surgeons and anesthesiologists. A thoracic (T6) epidural catheter was placed before induction of general anesthesia. Each patient received 7 mL of lidocaine 2% epidurally and repeated doses of 5 mL of lidocaine 2% every half hour during the operation. Postoperatively, the occurrence of incision or ipsilateral shoulder pain was observed and treated with a maximal dose of 5 mL of lidocaine 2%. If ineffective, indomethacin suppository (nonsteroidal anti-inflammatory drug [NSAID]) was given. Variables such as patient’s age, sex, American Society of Anesthesiologists physical status, type, site and duration of surgery, duration of anesthesia, the resection of main bronchus, and the use of thoracostomy tubes were recorded. Measurements and Main Results: Postoperatively, 10 patients (31%) had shoulder pain, 4 patients (12.5%) complained of incision pain, and 2 (6.3%) complained of both incision and shoulder pain. A bolus of 5 mL of lidocaine 2% in the epidural catheter relieved incision pain in all the patients, but was ineffective for shoulder pain. Indomethacin suppository was effective in these patients. No correlation was found between any variable and the occurrence of shoulder pain. Conclusions: It is concluded that post-thoracotomy shoulder pain is a common problem, and the previously mentioned variables did not predict its appearance. Thoracic epidural block is effective in the treatment of incision but not shoulder pain. The NSAID indomethacin suppository was found to be effective for that problem.