Single and double injection paravertebral block comparison in reduction mammaplasty cases: a randomized controlled study

Background: This study compares the analgesic effects and dermatomal blockade distributions of single and double injection bilateral thoracic paravertebral block (TPVB) techniques in patients undergoing reduction mammaplasty. Methods: After obtaining ethics committee approval, 60 patients scheduled for bilateral reduction mammaplasty were included in the study. Preoperatively, the patients received one of single (Group S: T3-T4) or double (Group D: T2-T3 & T4-T5) injection bilateral TPVBs using bupivacaine 0.375% 20 ml per side. All patients were operated under general anesthesia. The T3-T6 dermatomal blockade distributions on the midclavicular line were followed by pin-prick test for 30 min preoperatively and 48 h postoperatively. All patients received paracetamol 1 g when numeric rating scale (NRS) pain score was >= 4, and also tramadol 1 mg/kg when NRS was >= 4 again after 1 h. The primary endpoint was NRS pain scores at postoperative 12th h. The secondary endpoints were dermatomal blockade distributions and NRS scores through the postoperative first 48 h, time until first pain and the analgesic consumption on days 1 and 2. Results: Fifty-two patients completed the study. The NRS pain scores at 12th h were similar (right side: P = 0.100, left side: P = 0.096). The remaining NRS scores and other parameters were also comparable within the groups (P >= 0.05). Only single injection TPVB application time was shorter (P < 0.001). Conclusions: The single injection TPVB technique provided sufficient dermatomal distribution and analgesic efficacy with the advantages of being faster and less invasive.