硬膜外小剂量氯胺酮用于膝关节松解术后镇痛的临床观察

目的观察硬膜外小剂量氯胺酮用于膝关节松解术后早期康复治疗时镇痛的量效关系及副作用的发生率，探讨这种镇痛方法在早期康复治疗中的可行性。方法选择拟在腰-硬联合麻醉下行单侧膝关节松解术的患者80 例，随机分成4 组，即股神经阻滞组(C 组，n=20)、股神经阻滞加硬膜外注射氯胺酮0.15 mg/kg 组(K1 组，n=20)、股神经阻滞加硬膜外注射氯胺酮0.2 mg/kg 组(K2 组，n=20)和股神经阻滞加硬膜外注射氯胺酮0.25 mg/kg 组(K3 组，n=20)。麻醉成功后，K1 组、K2 组和K3 组的患者在硬膜外中注射对应剂量的氯胺酮，C组患者在硬膜外中注入等量生理盐水。所有患者术后在股神经鞘中留置导管并且注入0.2%罗哌卡因30 ml。术后8 h、24 h、32 h、48 h 接受康复训练，每次训练前5 min 经股神经鞘留置导管注射0.2%罗哌卡因30 ml用于镇痛。观察康复训练中的视觉模拟评分(VAS)和患肢主动关节活动度，并记录4 组副作用的发生情况。结果73 例患者参与最后的统计分析。在术后8 h，K1 组、K2 组和K3 组在康复训练中的VAS评分明显低于C组(P<0.01)，而在其他时间点，K2 组和K3 组在康复训练中的VAS评分低于C组和K1 组(P<0.05)；K2 组和K3 组的患肢主动关节活动度明显大于C组和K1 组(P<0.05)，K3 组中5 例患者出现精神症状(P<0.05)。结论硬膜外超前应用小剂量氯胺酮用于早期康复治疗的镇痛具有可行性，0.2 mg/kg 是相对有效和安全的剂量。

Effects of Small Dose of Epidural Ketamine on Analgesia for Patients after Surgical Intervention for Knee Stiffness

Objective To observe the dose-effect relationship and side effects caused by epidural ketamine for patients after surgical intervention for knee stiffness (SIKS). Methods 80 patients undergoing SIKS at one knee joint under combined spinal and epidural anesthesia were randomly divided into 4 groups. Patients in these groups would receive analgesia respectively provided by femoral nerve block (FNB)(group C, n=20), FNB combined with 0.15 mg/kg epidural ketamine (group K1, n=20), FNB combined with 0.2 mg/kg epidural ketamine(group K2, n=20), and FNB combined with 0.25 mg/kg epidural ketamine (group K3, n=20). When spinal anesthesia was finished, the corresponding dose of ketamine was injected in patients in groups K1, K2, and K3 and 0.9% sodium chloride was injected in group C via an epidural catheter. After the operation, a catheter was left in the femoral nerve sheath and the solution of 60 mg ropivacaine in 30 ml (0.2%) was injected. All patients were performed rehabilitation therapy at postoperative 8, 24, 32, and 48 h and the same ropivacaine solution was injected in the femoral nerve sheath before each rehabilitation therapy started. Visual analogue score (VAS), active range of motion (AROM) of the suffered knee joint, and side effects were observed. Results There were 73 patients enrolled in the final statistic analysis. At postoperative 8 h, the VAS scores were lower in groups K1, K2 and K3 than in group C (P<0.05). At postoperative 24 h, 32 h, and 48 h, the VAS scores were lower in groups K2 and K3 than in groups C and K1 (P<0.05). AROM was larger in groups K2 and K3 than in groups C and K1. patients appeared psychiatric symptoms in group K3. Conclusion Small dose of epidural ketamine is a feasible method for analgesia in early rehabilitation therapy and the dose of 0.2 mg/kg is effective and safe.