Comparison of analgesic efficacy of ultrasound-guided thoracic paravertebral block versus surgeon-guided serratus anterior plane block for acute postoperative pain in patients undergoing thoracotomy for lung surgery-A prospective randomized study

Context: Inadequate pain relief after thoracotomy may lead to postoperative respiratory complications. Aims: We have compared total morphine consumption in 24 hours following thoracotomy. Settings and Design: This prospective randomized pilot study involved 50 patients undergoing elective thoracotomy for lung surgery at AIIMS, New Delhi. Patients and Methods: Fifty patients undergoing elective thoracotomy were randomly allocated into two groups. In Group I patients, ultrasound (USG)-guided paravertebral catheter was inserted preoperatively and in Group II patients, serratus anterior plane (SAP) catheter was inserted by the surgeon before closure. Ropivacaine bolus (group I: 0.2% 0.1 ml/kg and group II: 0.375% 0.4 ml/kg) was given before extubation, followed by its continuous infusion for 24 hours. If the numerical rating scale (NRS) was >3, then patients were given intravenous (i.v.) morphine 3 mg. Total 24-hour morphine consumption, duration of effective analgesia, hemodynamic parameters, side effects, and overall patient satisfaction were recorded. Statistical Analysis Used: T-test was used to compare the parametric values in both the groups, whereas the Mann-Whitney U-test was performed to compare the nonparametric values. Results: Postoperative morphine requirement in the ParaVertebral Block (PVB) group (8.65 ± 4.27 mg) was less as compared to the SAP group (11.87 ± 6.22 mg) but that was not statistically significant (p 0.052). Postoperative pain scores at rest and on movement, patient satisfaction, and incidence of chronic post-thoracotomy pain were comparable in both the groups. Conclusion: SAP block with continuous catheter technique seems to be a safe and effective modality for the management of acute postoperative pain after thoracotomy.