The Effect of Preoperative Serratus Anterior Muscle Plane Block on Persistent Postsurgical Pain After Video-assisted Thoracic Surgery: A Retrospective Cohort Study.

OBJECTIVES Acute pain intensity is a strong indicator for the occurrence of persistent postsurgical pain (PPP) after video-assisted thoracic surgery (VATS). The effect of preoperative serratus anterior muscle plane block (SAPB) on PPP was investigated. MATERIALS AND METHODS In this retrospective cohort study, data of 148 patients who underwent VATS for lung nodules in 2019 were collected. Seventy-four patients received a single-shot of SAPB with 0.33% ropivacaine 30 mL after anesthesia induction and another 74 patients received intercostal blocks using 1% ropivacaine 10 mL at the fifth to seventh intercostal spaces after surgery. Postoperative analgesia was accomplished by continuous infusion of flurbiprofen (8 mg/h), and intravenous oxycodone rescue (1 mg) given on demand. Pain intensity was recorded at 24 and 48 hours after surgery and all patients were followed up 3 months after surgery investigating the occurrence of PPP. RESULTS Intraoperative sufentanil in the SAPB group was significantly decreased in comparison with Control group (0.34±0.09 vs. 0.43±0.14 ug/kg, P<0.001). The incidence of PPP was comparable between 2 groups (20.2% [15/74] vs. 14.8% [11/74], P=0.078). All patients who experienced PPP rated their PPP as mild, except 1 patient in Control group rated her pain as moderate. Multivariate logistic regression showed that pain score at 24 hours (odds ratio 1.646, 95% confidence interval [1.058, 2.560], P=0.027) and female (odds ratio 3.711, 95% confidence interval [1.274, 10.810], P=0.026) were independent risk factors for the development of PPP. DISCUSSION When SAPB was combined with continuous infusion of nonsteroidal anti-inflammatory drugs, no patient had moderate chronic pain. Pain score at 24 hours after surgery and female were risk factors for PPP after VATS.