Background: 

Periarticular local infiltration analgesia (LIA) is largely utilized for controlling pain after total knee arthroplasty (TKA). The present work aimed to assess the efficacy of a modified LIA cocktail for patients undergoing TKA.

Methods: 

Magnesium sulfate (MgSO₄) and sodium bicarbonate (NaHCO₃) were added to a conventional LIA cocktail comprising ropivacaine, epinephrine, and dexamethasone. After the safety of this modified cocktail was tested in rats, its efficacy and safety were evaluated in a prospective, double-blinded study including 100 individuals randomized to receive periarticular infiltration of the modified cocktail or a conventional cocktail. The primary outcome was postsurgical use of morphine hydrochloride for rescue analgesia. Secondary outcomes were the time until the first rescue analgesia, postsurgical pain (on a visual analog scale [VAS]), functional recovery (assessed by range of knee motion and ambulation distance), time to discharge, and complication rates.

Results: 

Adding NaHCO₃ to the local anesthetics caused some instantaneous precipitation in all cases. Administering the modified cocktail to rats did not obviously damage the injected area of the nerve or surrounding tissues. Administration of the modified cocktail to patients was associated with markedly reduced postsurgical morphine use in the initial 24 hours (4.2 ± 5.0 versus 14.6 ± 8.9 mg, p < 0.001), reduced total morphine use (9.8 ± 8.4 versus 19.6 ± 11.4 mg, p < 0.001), prolonged time to the first rescue analgesia, lower VAS pain scores at rest and during motion at 12 and 24 hours following the operation, better functional recovery on postoperative days 1 and 2, and a shorter hospital stay. The modified and conventional cocktail groups had similar rates of complications.

Conclusions: 

The present modification of a conventional cocktail significantly prolonged analgesia and reduced opioid consumption, which may substantially improve pain control in arthroplasty.

Level of Evidence: 

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

中文翻译：

---

改良鸡尾酒疗法在全膝关节置换术中用于关节周围局部浸润镇痛的疗效：一项前瞻性、双盲、随机对照试验

背景： 

关节周围局部浸润镇痛 (LIA) 主要用于控制全膝关节置换术 (TKA) 后的疼痛。目前的工作旨在评估改良 LIA 鸡尾酒对接受 TKA 患者的疗效。

方法： 

将硫酸镁 (MgSO ₄ ) 和碳酸氢钠 (NaHCO ₃ ) 添加到包含罗哌卡因、肾上腺素和地塞米松的常规 LIA 混合物中。在老鼠身上测试了这种改良鸡尾酒的安全性后，在一项前瞻性双盲研究中评估了其有效性和安全性，该研究包括 100 名随机接受改良鸡尾酒或传统鸡尾酒的关节周围浸润的个体。主要结果是术后使用盐酸吗啡进行抢救镇痛。次要结果是到第一次救援镇痛的时间、术后疼痛（在视觉模拟量表 [VAS] 上）、功能恢复（通过膝关节运动范围和步行距离评估）、出院时间和并发症发生率。

结果： 

在所有情况下，将 NaHCO ₃添加到局部麻醉剂中都会引起一些瞬时沉淀。将改良后的鸡尾酒给药于大鼠并没有明显损伤神经或周围组织的注射区域。给患者服用改良鸡尾酒与术后最初 24 小时内吗啡用量显着减少（4.2 ± 5.0 对 14.6 ± 8.9 mg，p < 0.001）、吗啡总用量减少（9.8 ± 8.4 对 19.6 ± 11.4 mg，p < 0.001)，延长了首次镇痛镇痛时间，术后 12 小时和 24 小时静息和运动时的 VAS 疼痛评分较低，术后第 1 天和第 2 天的功能恢复更好，住院时间更短。改良鸡尾酒组和传统鸡尾酒组的并发症发生率相似。

结论： 

目前对传统鸡尾酒的改进显着延长了镇痛时间并减少了阿片类药物的消耗，这可能会大大改善关节置换术中的疼痛控制。

证据等级： 

治疗一级。有关证据等级的完整描述，请参阅作者须知。