Koniuch Katherine L, Buys Michael Jay, Campbell Blake, Gililland Jeremy M, Pelt Christopher E, Pace Nathan L, Johnson Ken B
Department of Anesthesiology, University of Utah Hospital, Salt Lake City, Utah, USA
Department of Anesthesiology, University of Utah Hospital, Salt Lake City, Utah, USA.
Reg Anesth Pain Med. 2019 Jan 11. doi: 10.1136/rapm-2018-100043.
A common analgesic technique for total knee arthroplasty (TKA) is to inject local anesthetic into the periarticular tissue during surgery, known as local infiltration analgesia (LIA). Since the solution used typically contains a large amount of local anesthetic, concerns arise about exceeding the maximum dosage when adding a peripheral nerve block. Little research exists that addresses serum ropivacaine concentrations following LIA combined with peripheral nerve block. We hypothesized that after combining LIA and adductor canal blockade (ACB), serum ropivacaine concentrations would remain below levels associated with local anesthetic toxicity.
This was a prospective observational study that included 14 subjects undergoing TKA with intraoperative LIA containing 270 mg ropivacaine with epinephrine. Patients weighing less than 80 kg were excluded due to standardized dosing by our pharmacy. Seven patients were assigned consecutively to receive LIA alone (Group LIA) and seven were assigned to receive LIA plus ACB with 100 mg ropivacaine with epinephrine (Group LIA+ACB). Venous serum ropivacaine concentrations were measured over 24 hours.
Peak serum concentrations (Cmax) in Group LIA ranged from 0.23 to 0.75 µg/mL and occurred at times from 4 to 24 hours. Cmax in Group LIA+ACB ranged from 0.46 to 1.00 µg/mL and occurred at times from 4 to 8 hours. No participants demonstrated signs or symptoms of local anesthetic toxicity.
Total serum concentration of ropivacaine after LIA using 270 mg ropivacaine with and without an additional 100 mg perineural ropivacaine remained well below the toxicity threshold of 3.0 µg/mL at all time points. Additional studies are needed to ascertain the safety of combining LIA with peripheral nerve blockade.
全膝关节置换术（TKA）常用的镇痛技术是在手术期间将局部麻醉剂注射到关节周围组织，即局部浸润镇痛（LIA）。由于通常使用的溶液含有大量局部麻醉剂，因此在添加外周神经阻滞时，人们担心会超过最大剂量。关于LIA联合外周神经阻滞后罗哌卡因血清浓度的研究很少。我们假设，在联合LIA和内收肌管阻滞（ACB）后，罗哌卡因血清浓度将保持在低于局部麻醉剂毒性相关水平。
这是一项前瞻性观察研究，纳入了14例接受TKA手术的患者，术中使用含270 mg罗哌卡因和肾上腺素的LIA。由于我们药房采用标准化给药，体重不足80 kg的患者被排除。7例患者连续分配接受单纯LIA（LIA组），7例患者接受含100 mg罗哌卡因和肾上腺素的LIA加ACB（LIA+ACB组）。在24小时内测量静脉血清罗哌卡因浓度。
LIA组血清峰值浓度（Cmax）范围为0.23至0.75μg/mL，出现时间为4至24小时。LIA+ACB组Cmax范围为0.46至1.00μg/mL，出现时间为4至8小时。没有参与者表现出局部麻醉剂毒性的体征或症状。
使用270 mg罗哌卡因进行LIA，无论是否额外添加100 mg神经周围罗哌卡因，罗哌卡因的总血清浓度在所有时间点均远低于3.0μg/mL的毒性阈值。需要进一步研究以确定LIA与外周神经阻滞联合使用的安全性。
