Efficacy of ultrasound-guided second serratus anterior plane block on postoperative quality of recovery and analgesia after video-assisted thoracic surgery: a randomized, triple-blind, placebo-controlled study.

Abstract

Background: Despite widespread application of minimally invasive video-assisted thoracic surgery (VATS), postoperative pain following this procedure is still a constant clinical challenge. Serratus anterior plane (SAP) block is one of the regional analgesic techniques with promising outcomes. However, due to the limited duration of action, optimal analgesia is often not achieved with a single injection. We tested whether in patients who have been subjected to routine SAP block under preoperative anesthesia, the addition of a second SAP block 24 hours after surgery, improves quality of recovery, lowers postoperative opioid consumption, and reduces the prevalence of chronic pain.

Methods: The present study is a single institutional, prospective, randomized, triple-blinded, placebo-controlled study. Ninety patients undergoing VATS from January 2022 to April 2022 were randomized at 1:1 ratio to receive ultrasound-guided second SAP block with 15 mL 0.375% ropivacaine (SAP block group) or 15 mL normal saline (control group) 24 hours after both groups received routine SAP block with 15 mL 0.375% ropivacaine. The primary outcome was quality of patient recovery, measured using 40-item quality of recovery questionnaire (QoR-40) at postoperative day 2 (POD 2). Secondary outcomes included: postoperative pain scores at rest, postoperative opioid consumptions, number of times that patient controlled analgesia (PCA) pump button was pressed, perioperative complications and adverse effects, prevalence of chronic pain at 2^nd and 3^rd month postoperatively, and length of hospital stay (LOS).

Results: A total of 83 patients completed the study: 43 patients in SAP block group and 40 patients in the control group. The global QoR-40 scores on POD 2 and POD 3 were significantly higher among SAP block group patients (180.07±11.34, 182.09±8.20) compared with the control group (172.18±6.15, 177.50±6.94) (P=0.01, P=0.008) respectively. Postoperative pain scores, opioid consumptions and incidence of postoperative nausea and vomiting were significantly lower among patients in SAP block group versus control group. There were no statistically significant differences in perioperative complications and LOS between the two groups. The prevalence of chronic pain at the 2^nd and 3^rd month postoperatively for patients in SAP block group and control group was 16.3%, 14%, and 32.5%, 27.5% respectively.

Conclusions: In patients undergoing VATS, application of ultrasound-guided second SAP block 24 hours after surgery improved postoperative quality of life, reduced opioid consumption and related side effects, and lowered the prevalence of chronic pain.