全髋和全膝关节置换术中甲哌卡因脊髓麻醉比布比卡因更可预测运动功能恢复：双盲随机临床试验

背景：对于接受全髋关节置换术(THA)和全膝关节置换术(TKA)的患者而言，脊髓麻醉具有许多优势，但纵观历史，使用长效局部麻醉药有下肢运动功能恢复缓慢且具有不可预测性的缺点。在这项前瞻性、双盲、随机的临床试验中，我们试图确定接受初次THA和TKA的患者中，与小剂量布比卡因脊麻相比，局麻药甲哌卡因是否能更平稳的恢复下肢运动功能。

方法：本试验在同一学术机构进行，在试验开始之前，一项内部预试验研究确定需在154名患者中达到80%的疗效。采用先进的计算机分层方法，根据手术过程、年龄、性别和体重指数，将患者按1:1的比例进行随机化分组。手术结束后，使用Bromage评分于每15分钟评估一次非手术下肢的运动功能，一旦Bromage评分达到0分(髋关节、膝盖和踝关节的自发运动)，停止评分。

结果：接受甲哌卡因脊麻的患者与接受小剂量布比卡因的患者相比，下肢运动功能恢复更具预见性。在接受甲哌卡因麻醉的患者中，1%的患者在5小时后恢复了运动功能，而接受布比卡因麻醉的患者中只有11%的患者恢复了运动功能(p=0.013)。接受甲哌卡因麻醉的患者下肢运动功能恢复的平均时间(185min、95%CI、174~196min)比小剂量布比卡因组(210min、95%CI、193min~228min)快26分钟(p=0.016)。与小剂量布比卡因相比，接受甲哌卡因麻醉的患者在疼痛评分、理疗时间、直立性低血压的发生率、尿潴留或暂时性神经系统症状等安全结果方面没有显著差异。

结论：在初次接受THA和TKA的患者中，与小剂量布比卡因相比，使用甲哌卡因腰麻可使下肢运动功能更平稳恢复，而不会增加脊麻药物相关的并发症。这对短期住院和门诊手术更具有价值。

原始文献来源:Wyles CC,  Pagnano MW,  Trousdale RT, et al.More Predictable Return of Motor Function with Mepivacaine Versus Bupivacaine Spinal Anesthetic in Total Hip and Total Knee Arthroplasty: A Double-Blinded, Randomized Clinical Trial.[J].J Bone Joint Surg Am 2020 Sep 16;10218(18).

More Predictable Return of Motor Function with Mepivacaine Versus Bupivacaine Spinal Anesthetic in Total Hip and Total Knee Arthroplasty: A Double-Blinded, Randomized Clinical Trial

ABSTRACT

Background:Spinal anesthesia provides several benefits for patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA), but historically comes at the cost of slow and unpredictable return of lower-extremity motor function related to the use of long-acting local anesthetics. In this prospective, double-blinded, randomized clinical trial we sought to determine if an alternative local anesthetic, mepivacaine, would allow more consistent return of motor function compared with low-dose bupivacaine spinal anesthesia during primary THA and TKA.

Methods:This trial was conducted at a single academic institution. Prior to trial initiation an internal pilot study determined that 154 patients were required to achieve 80% power. Patients were randomized in a 1:1 fashion with use of advanced computerized stratification based on procedure, age group, sex, and body mass index. Following the surgical procedure, motor function was assessed every 15 minutes in the nonoperative lower extremity according to the Bromage scale and discontinued once Bromage 0 was achieved (spontaneous movement at hip, knee, and ankle).

Results:Return of lower-extremity function was more predictable in patients who received mepivacaine than in those who received low-dose bupivacaine. Among patients who received mepivacaine, 1% achieved motor function return beyond 5 hours compared with 11% of patients who received bupivacaine (p = 0.013). The mean time to return of lower-extremity motor function was 26 minutes quicker in patients who received mepivacaine (185 minutes; 95% confidence interval, 174 to 196 minutes) compared with low-dose bupivacaine (210 minutes; 95% confidence interval, 193 to 228 minutes) (p = 0.016). There were no significant differences in safety outcomes including pain scores, time to participation in physical therapy, incidence of orthostatic hypotension, urinary retention, or transient neurologic symptoms in patients receiving mepivacaine compared with low-dose bupivacaine.

Conclusions:In patients undergoing primary THA and TKA, spinal anesthesia with mepivacaine allowed more consistent return of lower-extremity motor function compared with low-dose bupivacaine, without a concomitant increase in complications potentially associated with spinal anesthetics. This is particularly of value in an era of short-stay and outpatient surgical procedures.