异氟醚对上肢运动诱发电位的影响

Influence of isoflurane on motor evoked potentials of forearm muscles

目的 在保持病人肌松程度和镇痛一致的条件下 ,比较丙泊酚和不同呼末浓度的异氟醚对上肢前臂肌群运动诱发电位 (motorevokedpotential,MEP)的影响。 方法 选择 2 0例ASAⅠ～Ⅱ级择期行神经外科手术的病人先后给予三组麻醉状态。A组用丙泊酚 +芬太尼 +维库溴铵全凭静脉麻醉 ;B组用异氟醚 +芬太尼 +维库溴铵静吸复合麻醉 ,调节呼末异氟醚浓度为 0 5MAC ;C组同样静吸复合麻醉 ,调节呼末异氟醚浓度为 1 0MAC。每例病人术中均给予芬太尼以 2 μg·kg 1·h 1持续静脉输注至术毕前 30min。术中以维库溴铵维持T4/T1为 0 2 5。在保持病人血液动力学基本稳定的前提下 ,于A ,B ,C三组状态下监测MEP ,记录并比较潜伏期和波幅的变化。结果 随着异氟醚呼末浓度的升高 ,MEP的潜伏期逐渐延长 (P <0 0 5 ) ,波幅逐渐减小 (P <0 0 5 )。结论 丙泊酚全凭静脉麻醉能得到MEP的高检出率 。

Objective To compare the effects of propofol and inhalational anesthetics on motor evoked potentials(MEP) of forearm muscles under same conditions of neuromuscular blockade. Methods Twenty ASAⅠ-Ⅱ patients aged 20-60 years undergoing neurosurgical operation under general anesthesia were studied in three conditions.Patients with neuromuscular,liver or kidney diseases and those receiving any drug which may affect neuromuscular transmission were excluded.Total intravenous anesthesia with propofol,fentanyl and vecuronium was used in group A,and inhalation-intravenous combined anesthesia with 0.5 MAC of isoflurane in group B,or with 1.0 MAC of isoflurane in group C.The patients were all given a fentanyl infusion at a rate of 2 μg·kg -1·h -1 until 30 min before the end of operation,and continuous injection of vecuronium at TOF(T 4/T 1)=0.25 to achieve same neuromuscular blockade.MEP of forearm muscles were monitored and the latency and amplitude wre recorded and compared under stable hemodynamic status.Results With increasing concentrations of isoflurane,there was a progressive increase in latency(P<0.05) and a decrease in amplitude(P<0.05)of MEP of forearm muscles.Conclusion Isoflurane inhalation can significantly depress the MEP.