机械通气慢性阻塞性肺疾病患者皮质-膈肌通路的电生理评价

目的:探讨机械通气慢性阻塞性肺疾病(COPD)患者膈神经运动传导(PNC)及磁刺激膈肌运动诱发电位(dMEP)的特点.方法:选取10例常规机械通气COPD患者(上机时间≤7 d)和10例长期机械通气COPD患者(上机时间＞7 d),健康体检者10例为对照组,分别行PNC和dMEP检测.结果:3组间脱机前后PNC、经C7棘突dMEP、经皮质dMEP潜伏期及波幅对数值差异均有统计学意义(P＜0.01或P＜0.05);3组间脱机前后中枢运动传导时间(CMCT)差异有统计学意义(P＜0.01),其中脱机前2组COPD患者与对照组相比CMCT延长(P＜0.01),2组COPD患者间CMCT差异无统计学意义(P＞0.05);脱机后长期机械通气组与常规机械通气组相比CMCT延长(P＜0.01),而脱机后常规机械通气组与对照组相比CMCT差异无统计学意义(P＞0.05).结论:机械通气COPD患者存在不同程度的皮质-膈肌通路功能障碍,长期机械通气可加重其功能障碍,PNC和dMEP检测有助于明确机械通气COPD患者呼吸功能障碍的原因.

Electrophysiological Evaluation of the Cortico-Diaphragmatic Pathway in Mechanical Ventilation of Patients with Chronic Obstructive Pulmonary Disease

Objective:To investigate the characteristics of phrenic nerve motor conduction (PNC)and motor evoked potentials of diaphragm elicited through magnetic stimulation (dMEP)in mechanical ventilation of patients with chronic obstructive pulmonary disease(COPD).Methods:PNC and dMEP were performed in 10 COPD patients with regular mechanical ventilation(the duration of mechanical ventilation≤7 d),10 COPD patients with prolonged mechanical ventilation(the duration of mechanical ventilation＞7 d),and 10 healthy subjects(control group).Results:There were significant differences in the latency and the common logarithm of the amplitude of PNC,cervical dMEP and cortical dMEP between three groups before and after weaning(P＜0.01 or P＜0.05).There were significant differences in central motor conduction time(CMCT)in three groups before and after weaning(P＜0.01).There was longer CMCT before weaning in two COPD groups than that of control group(P＜0.01).It showed no statistical difference in CMCT before weaning between two COPD groups(P＞0.05).There was a longer CMCT after weaning in prolonged mechanical ventilation than that of regular mechanical ventilation(P＜0.01).However,there was no statistical difference in CMCT after weaning between the regular mechanical ventilation group and the control group(P＞0.05).Conclusion:There were dysfunctions in the cortico-diaphragmatic pathway in COPD patients with mechanical ventilation,which may be aggravated by the prolonged mechanical ventilation.PNC and dMEP may help to define the cause of respiratory dysfunction in COPD patients with mechanical ventilation.