吸气和呼气肌肉活动指标联合评价呼吸中枢驱动变化临床意义研究

The evaluation of the central drive with both inspiratory and expiratory respiratory muscles activities

目的探讨更加准确客观评价呼吸中枢驱动水平变化的方法。方法选择2009年10月至2011年10月10名体检健康志愿者。通过CO2重复呼吸法使呼气末CO2分压(PCO2-ET)增高,动态监测膈肌肌电图(EMGdi)、腹肌肌电图(EMGab)和跨膈肌压(Pdi)的变化,观察上述指标与PCO2-ET的关系。结果重复呼吸后,PCO2-ET从(40.0±1.3)mmHg上升到(81.2±6.6)mmHg。随着PCO2-ET水平的增高,均方根EMGdi(RMSdi)和均方根EM-Gab(RMSab)逐渐增高,而后者增加的比例高于前者。随着PCO2-ET的增高,RMSdi和RMSab与Pdi的相关性均有统计学意义(P=0.000),其中,RMSdi与Pdi的相关性程度变化不明显,而RMSab与Pdi的相关性程度逐渐增高。RMSdi和RMSab共同预测Pdi的相关系数高于单独RMSdi或RMSab预测Pdi的相关系数。结论呼吸中枢的驱动水平不但与吸气肌肉活动有关,而且与呼气肌肉活动也有关,联合使用吸气和呼气肌肉活动的指标,能够更客观地反映呼吸中枢的驱动水平的变化。

Objective To investigate the appropriate method for evaluating the dynamic change of respiratory central drive. Methods 10 normal volunteers were recruited for the study from the colleagues of The State Key Laboratory of Respiratory Disease. Rebreathing method was used to increase partial pressure of CO2 at the end tidal expiration（ PCO2-ET） in order to stimulate the increase of respiratory central drive. The electromyogram of Diaphragmatic muscle （EMGdi）, electromyogram of Abdominal muscle （EMGab）and transdiaphragmatic pressure （Pdi）were dynamically monitored in order to evaluate their relationship with PCO2 -ET. Results After re-breathing, PCO2 -ET raised from （ 40 ± 1.3 ） mmHg to （ 81.2 ± 6.6 ） mmHg. As the PCO2-ET rising, RMSdi and RMSab increased gradually. The increment of RMSab was higher than RMSdi. There is sta- tistically significant relationship between Pdi and RMSdi or RMSab during the process of re-breathing with rising of PCO2- ET（ both P = 0. 000）. The correlation efficiency between RMSab and Pdi increased as the PCO2-ET increased while the correlation efficiency between RMSdi and Pdi remained stable. The correlation efficiency in prediction Pdi with both RMSab and RMSdi as variables was higher than with RMSdi or RMSab alone. Conclusion The activity of respiratory central drive was related to not only the activity of inspiratory muscles, but also activity of expiratory muscles. Appropriate evaluation of respiratory central drive should include both inspiratory and expiratory muscles activities. drive