双水平正压通气对稳定期慢阻肺患者呼吸生理学的影响

Effect of BiPAP ventilation on respiratory physiology in patients with stable COPD

目的观察双水平正压通气(BiPAP)对稳定期慢性阻塞性肺疾病(简称慢阻肺)患者呼吸生理学的影响。方法本研究为一项小样本、探索性、干预性研究,选取2018年1—12月在南方医科大学珠江医院呼吸与危重症医学科门诊就诊的稳定期慢阻肺患者10例。呼吸机采用BiPAP模式,调整吸气相正压从10 cmH_(2)O(1 cmH_(2)O=0.098 kPa)开始逐渐递增至24 cmH_(2)O,每次增加2 cmH_(2)O,呼气相正压保持4 cmH_(2)O不变。正式试验和调节压力水平前记录各项指标并进行比较,包括呼吸方式:总呼吸周期(Ttot)、吸气时间(Ti)、呼气时间(Te)、吸气潮气量(VTi)等;呼吸压力:口腔压(Pmo)、食道压(Peso)、跨膈压(Pdi);呼吸做功:食道压力-时间乘积(PTPes)、跨膈压力-时间乘积(PTPdi);中枢驱动及中枢驱动效率:膈肌肌电的均方根(RMS)、通气-中枢偶联(Ve/RMS)以及深吸气量(IC)、呼气末肺容量差值(ΔEELV)、动态内源性呼气末正压(PEEPidyn)等。结果10例稳定期慢阻肺患者全部完成试验。与平静呼吸相比,V_(Ti)、V_(e)、P_(mo)、IC、ΔEELV、V_(e)/RMS随着压力水平升高均显著上升(均P<0.05),Te只在20~22 cmH_(2)O压力水平显著上升(P<0.05)。Pdi、PTP_(es)、PTP_(di)、RMS、RMS/RMS_(max)随着压力水平升高均显著下降(均P<0.05),PTPes、PTPdi在18 cmH_(2)O压力水平后均趋近于稳定并未出现明显变化,RMS、RMS/RMS_(max)在压力水平大于16 cmH_(2)O后趋于平稳。Ti/Ttot只在20 cmH_(2)O压力水平时显著降低。PEEPidyn随着压力水平的升高出现先下降后上升的趋势。结论BiPAP在合适的压力水平上能明显改善稳定期慢阻肺患者的肺通气障碍,减轻呼吸肌肉负荷。

Objective To observe the physiological effect of bi-level positive airway pressure(BiPAP)ventilation among stable chronic obstructive pulmonary disease(COPD)patients.Methods This was a small sample size,exploratory,interventional study.A total of 10 outpatients with stable COPD were included from Department of Pulmonary and Critical Care Medicine of Zhujiang Hospital,Southern Medical University between January 2018 and December 2018.The BiPAP mode of noninvasive mechanical ventilation was adopted.The inspiratory positive airway pressure was gradually increased from 10 cmH_(2)O(1 cmH_(2)O=0.098 kPa)to 24 cmH_(2)O,and each time by 2 cmH_(2)O.The expiratory positive airway pressure remained unchanged at 4 cmH_(2)O.Baseline and test data were collected before and during the ventilation for comparison,including total respiratory cycle time(Ttot),inspiratory time(Ti),inspiratory time(Te),inspiratory tidal volume(VTi);mouth pressure(Pmo),esophageal pressure(Peso),transdiaphragmatic pressure(Pdi),esophageal pressure time product(PTPes),diaphragm pressure time product(PTPdi),root mean square of electromyography of diaphragm(RMS),Ve/RMS,inspiratory capacity(IC),the change in end-expiratory lung volume(ΔEELV)and dynamic PEEPi(PEEPidyn).Results All the 10 patients completed the trial.Compared to calm breathing,V_(Ti),V_(e),P_(mo),IC,ΔEELV score and Ve/RMS increased significantly with increasing pressure levels(all P<0.05);Te only increased significantly at 20-22 cmH_(2)O pressure levels compared to calm breathing(P<0.05).Pdi,PTPes,PTPdi,RMS and RMS/RMS_(max)decreased significantly with increasing levels(all P<0.05).PTPes and PTPdi converged to 0 and no longer showed significant changes after the 18 cmH_(2)O pressure level.RMS and RMS/RMS_(max)flattened out at pressure level greater than 16 cmH_(2)O.Ti/Ttot only significantly decreased at the 20 cmH_(2)O pressure level compared to calm breathing.PEEPidyn showed a tendency to decrease and then increase with increasing pressure levels.Conclusion BiPAP ventilation,at appropriate pressure levels,significantly relieves pulmonary ventilation disorders and reduces the load of respiratory muscle in patients with stable COPD.