Abstract:

Objective　To determine the median effective volume (EV₅₀) of 0.375% ropivacaine for serratus anterior plane block (SAPB) in postoperative analgesia after lobectomy by sequential method, and to provide a reference for clinical application. Methods　A total of 24 adult patients who underwent unilateral thoracoscopic lobectomy from January 2024 to January 2025 were selected. Their ages ranged from 18 to 64 years, body mass index (BMI) was between 18 and 30 kg/m², height was from 155 to 175 cm, and American Society of Anesthesiologists (ASA) classification was grade I to III. For the first patient, 30 ml of 0.375% ropivacaine was selected as the volume of local anesthetic. The volume of the block was adjusted based on the postoperative analgesic effect: if the block effect of the previous patient was complete, the volume of local anesthetic for the next patient was reduced by 2 ml.If the block effect is unsatisfactory, add 2 ml. The inclusion of cases will end after obtaining 7 turning points.Record the block plane at 5, 10, 15, 20 and 30 minutes after the completion of the block. Record the Visual Analogue Scale (VAS) scores of patients at rest and during movement at 2, 6, 12, 24 and 48 hours after surgery. Record the total number of times the patients pressed the patient-controlled intravenous analgesia (PCIA) button from 0 to 12 hours and from 13 to 48 hours after surgery. The Probit regression model was used to determine the EV₅₀ and its 95% confidence interval (CI) of 0.375% ropivacaine serratus anterior plane block for postoperative analgesia in patients undergoing thoracoscopic lobectomy. The occurrence of adverse reactions such as postoperative nausea and vomiting (PONV), skin itching, local anesthetic toxicity, local hematoma, respiratory depression and infection at the puncture site was recorded,Statistical analysis was conducted using t-tests and Fisher's exact probability method. Results　Twenty-four patients successfully underwent serratus anterior plane block and were included in the analysis. Among them, 13 patients (54%) achieved complete analgesia. The EV₅₀ of ultrasound-guided 0.375% ropivacaine SAPB for postoperative analgesia after thoracoscopic lobectomy was 24.97 ml (95%CI 23.81 - 26.10 ml), and the 95% effective capacity(EV₉₅) was 27.10 ml (95%CI 25.99 - 33.51 ml).Three patients experienced postoperative nausea and vomiting (PONV), and one patient had skin itching. None of the patients had any adverse reactions related to the block operation. Conclusion　The EV₅₀ of 0.375% ropivacaine for single-shot paravertebral block under ultrasound guidance in postoperative analgesia after thoracoscopic lobectomy was 24.97 ml (95%CI 23.81 - 26.10 ml).

Key words:

Serratus anterior plane block, Postoperative analgesia, Thoracoscopic surgery, Ropivacaine

摘要：

目的　采用序贯法测定0.375％罗哌卡因前锯肌平面阻滞（serratus anterior plane block， SAPB）用于肺叶切除术术后镇痛的半数有效容量（EV₅₀），为临床应用提供参考。方法　选择2024年1月至2025年1月行单侧胸腔镜肺叶切除术的24例成年患者，年龄18 ~ 64岁，体重指数（BMI）18 ~ 30 kg/m²，身高155 ~ 175 cm，美国麻醉医师协会（american society of anesthesiology， ASA）Ⅰ ~ Ⅲ级。选取0.375%罗哌卡因30 ml为第一例患者的局麻药容量，根据术后镇痛效果调整阻滞容量：若前一例患者阻滞效果完全，则下一例患者的局麻药容量减少2 ml；若阻滞效果欠佳则增加2 ml，获得7个转折点后结束纳入病例。记录阻滞完成后第 5、10、15、20、30 min的阻滞平面，术后第2 h、6 h、12 h、24 h、48 h患者静息和运动时的视觉模拟量表（VAS）评分，术后0 ~ 12 h和13 ~ 48 h的患者静脉自控镇痛（PCIA）按压总次数。采用Probit回归模型测定0.375%罗哌卡因前锯肌平面阻滞用于胸腔镜肺叶切除术患者术后镇痛的EV₅₀及其95%置信区间（CI）。记录术后恶心呕吐（PONV）、皮肤瘙痒、局麻药中毒、局部血肿、呼吸抑制及穿刺部位感染等不良反应的发生情况，采用t检验，Fisher确切概率法进行统计分析。结果　24例患者成功完成前锯肌平面阻滞并纳入分析，其中13例（54%）镇痛效果完全。超声引导下0.375%罗哌卡因SAPB用于胸腔镜肺叶切术术后镇痛的EV₅₀为24.97 ml（95%CI 23.81 ~ 26.10 ml），95%有效容量（EV₉₅）为27.10 ml（95%CI 25.99 ~ 33.51 ml）。有3例患者发生了PONV，1例患者发生了皮肤瘙痒，所有患者均未发生阻滞操作相关不良反应。结论　超声引导下0.375%罗哌卡因SAPB用于胸腔镜肺叶切除术术后镇痛的EV₅₀为24.97 ml（95% CI 23.81 ~ 26.10 ml）。

关键词:

前锯肌平面阻滞, 术后镇痛, 胸腔镜手术, 罗哌卡因