阻塞型睡眠呼吸暂停低通气综合征患者膈神经传导功能的研究

The study of phrenic nerve conduction in patients with obstructive sleep apneahypopnea syndrome

目的探讨不同严重程度阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者膈神经传导及膈肌联合肌肉动作电位(CMAP)的变化。方法对7例轻度、9例中度和23例重度OSAHS患者,以及23例正常人使用表面电极,通过单侧磁刺激膈神经,测定膈神经传导时间(PNCT)及CMAP的幅值,其中18例受试者使用食道电极记录上述指标。结果①经食道电极测定的PNCT:左侧为(7.79±0.89)ms,右侧为(7.41±0.79)ms;表面电极测定的PNCT:左侧为(7.66±1.20)ms,右侧为(7.19±1.02)ms,两者比较无显著性差异(t=0.378,P=0.708;t=0.735,P=0.467)。②轻度OSAHS患者双侧PNCT及CMAP与正常对照组比较亦无显著性差异(P均>0.05),中度及重度OSAHS患者双侧PNCT较正常对照组及轻度OSAHS组显著延长(P均<0.001);重度OSAHS患者双侧CMAP幅值显著低于正常对照组(P均<0.001),其右侧CMAP明显低于轻度OSAHS组(P<0.01),而中度OSAHS组双侧CMAP无显著变化;重度OSAHS患者双侧PNCT较中度OSAHS患者显著延长(P均<0.05),而双侧CMAP无明显变化(P均>0.05)。③所有受试者双侧PNCT和CMAP与微觉醒指数、呼吸紊乱最长时间、平均SaO2、最低SaO2、低氧指数、SaO2<90%占总睡眠时间的比例及AHI均有显著相关性。结论①经表面电极进行单侧磁刺激膈神经代替食道电极和电刺激具有较高的应用价值;②OSAHS患者膈神经传导的潜伏期延长,和/或膈肌复合肌肉动作电位减弱,且随病情严重程度不同有不同的变化。

Objective To explore the changes of phrenic nerve conduction and diaphrgm compound muscle action potential （CMAP） in patients with obstructive sleep apnea-hypopnea syndrome （OSAHS） of different severity. Methods The phrenic nerve conduction time （PNCT） and diaphragm CMAP elicited by unilateral magnetic stimulation（UMS） of the phrenic nerve were recorded from chest wall surface electrodes in 23 normal subjects and 39 patients with OSAHS （7 mild, 9 mederate and 23 severe）, while oesophageal electrodes were also used to record the PNCT and diaphragm CMAP in 18 subjects （5 normal subjects and 13 OSAHS patients）. Results （ 1 ） PNCTs measured by oesophageal electrodes [ left： （ 7.79 ± 0.89 ） ms; right： （ 7.41 ± 0. 79） ms ] were similar with those measured by surface electrode [left： （7.66 ± 1.20） ms; right： （7.19 ± 1.02） ms] （ t = 0.378, P= 0.708; t = 0.735, P = 0.467）. （2）There were no significant differences of PNCTs and CMAPs of both sides between mild OSAHS patients and normal subjects （ P 〉 0.05 for each）. The PNCTs of moderate and severe OSAHS patients were longer significantly than those of normal subjects and mild OSAHS patients （compared with normal subjects, P 〈 0.001 for each; compared with mild OSAHS patients, mederate patients： P 〈 0.01 for left side, P 〈 0.05 for right side;severe patients： both P 〈 0.001 ）. The CMAPs of severe OSAHS patients on both sides were much lower than those of normal subjects （both P 〈 0.001 ）,and they were similar on the right side in severe patients compared with mild patients（ P 〈 0.01 ）.The PNCTs on both sides of severe pa- tients were longer significantly than those of moderate patients （both P 〈 0.05）,but no significant difference of CMAPs on both sides was revealed（both P 〉 0.05）. （3） PNCTs and CMAPs on both sides had significant correlation with arousal index, maximal length of respiratory events, average SaO2, minimum SaO2, oxygen desaturation index （ODI）, the percentage of total sleep time below 90% SaO2, and apnea-hypopnea index （AHI）. Conclusions UMS with surface electrode is a valuable alternative to esophageal electrode and electrical stimulation. The latency of phrenic nerve conduction is prolonged and amplitude of CMAP of diaphragm is weakened in OSAHS patients.