Background: The aim of this study was to evaluate the effect of serratus anterior plane block in addition to intrathecal morphine for early postoperative period after video-assisted thoracoscopic surgery on the amount of morphine consumption and the Visual Analog Scale scores.

Methods: This single-blind, randomized-controlled study included a total of 64 patients (39 males, 25 females; mean age: 53.6±17.0 years; range, 20 to 89 years) who were scheduled for video-assisted thoracoscopic surgery in a tertiary hospital between September 2019 and March 2020. Postoperative pain control was achieved with intrathecal morphine 0.6 mg addition to serratus anterior plane block (Group ITM+SAPB) or with only intrathecal morphine (Group ITM) after an induction of anesthesia. The serratus anterior plane block was performed with a single injection of 0.4 mL/kg of 0.25% bupivacaine at the level of fifth rib with ultrasound guidance. Morphine consumption, pain scores, and side effects were recorded in the postoperative period.

Results: The mean morphine consumption was significantly lower in the ITM+SAPB group at all time points. Compared to the control group, the Visual Analog Scale-resting and coughing scores were significantly lower in the first 12 h after surgery. Pain scores were significantly higher in the ITM+SAPB group in patients where the trocar was inserted at upper level of the fifth rib than the lower level (3-5 vs. 5-8) during the first 6 h after surgery.

Conclusion: The use of serratus anterior plane block in addition to intrathecal morphine is a safe and effective way to improve pain control for early postoperative period after video-assisted thoracoscopic surgery. The serratus anterior plane block ensures better analgesia until the peak effect of spinal morphine occurs.

Keywords : Intrathecal injections, nerve block, opioid analgesics, video-assisted thoracoscopic surgery, ultrasonography