复杂全髋关节置换术中应用体感诱发电位监测的初步报告

目的：利用体感诱发电位在复杂全髋关节置换手术中进行监测，以预防坐骨神经损伤。方法：自2002年8月～2003年4月对12例复杂全髓关节置换手术患者术前清醒状态下行体感诱发电位检查．术中麻醉后行体感诱发电位监测。均采用全身麻醉．麻醉药品的使用和单位体重的用药剂量尽量相同。本组复杂全髋关节置换手术患者选择的标准是下肢短缩在4cm以上的初次手术和短缩3cm以上的翻修手术者，术中判断诱发电位异常标准是波幅峰值下降50％并持续10min以上和(或)潜伏期延长10％。重点监测时段为手术中坐骨神经周围暴露和关节复位后。结果：与术前清醒状态下比较，麻醉后患者的体感诱发电位波幅峰值和潜伏期均有不同程度的改变；而与麻醉后体感诱发电位的波幅峰值和潜伏期比较，12例患者术中监测的结果也发生改变、但是两者改变程度均未超过体感诱发电位异常的判断标准。术后下肢延长最短3cm，最长6cm，平均3．9cm，除1例手术前就有腓总神经损伤的患者外，其余患者术后均未出现下肢神经损伤症状.结论:体感诱发电位监测对颈防全髋关节置换术中坐骨抻经损伤有一定帮助．尤其对下肢短缩或翻修病例．术中体感诱发电位监测更有价值。

Monitoring with somatosensory-evoked potential during complicated total hip arthroplasty

Objective To introduce monitoring during complicated total hip arthroplasty with so-matosensory-evoked potentials (SEPs) to avoid the injury of sciatic nerve. Methods From August 2002 to April 2003, SEPs were used to monitor the sciatic nerve condition in 12 patients with complicated hip de-formities. Prior to operation, SEPs was installed in each patient on bilateral lower limbs. During operation, SEPs were elicited after anaesthesia. All patients had a general anaesthesia with the same drugs and dosage according to body weight. There were five males and seven females with an average of 58 years ranging from 23 to 69 years. In the group, the primary arthroplasties were performed for those with over 4cm shortened limb in nigh cases, and revision arthroplasties for those with over 3 cm shortened limb in two cases. The cri-teria for nerve compromise included a 50% reduction in amplitude or a 10% increase in latency. Special at-tentions were paid on during exposure of sciatic nerve and the reduction of joint. Results In the group, the range of limb shortening was from 3 cm to 7 cm with average of 4.6 cm. While postoperatively, the average increase in leg length was average 3.9 cm (range, 3 to 6 cm). Comparing the intraoperative data with that be-fore operation and after anaesthesia, all 12 patients exhibited slight changes in SEPs during the exposure of sciatic nerve or the tentative reduction of joint. The changes did not reach to the criteria for nerve compro-mise. There was no clinical evidence of postoperative nerve injuries except a patient had peroneal nerve palsy before hip arthroplasty. Conclusion Intraoperative monitoring of sciatic nerve using SEPs is effective in assessing the function of the sciatic nerve during hip arthroplasty, especially for revision patients or leg lengthening.