气管内吹气在CDPD呼衰患者的应用

Clinical study of tracheal gas insufflation in COPD patients with respiratory failure

目的 :探讨气管内吹气 (TGI)对COPD呼衰患者体内CO2 的清除效果。方法 :用自行设计的呼气相TGI装置 ,对 8例CDPD呼衰患者实施TGI ,分别观察在常规机械通气 (CMV)时 ,低潮气量致容许性高碳酸血症(PHC)时以及TGI流速分别为 2L/min、4L/min、6L/min时的体内CO2 及气道压力变化。结果 :①TGI可显著降低COPD呼衰患者PaCO2 及呼气末CO2 分压 (PetCO2 )水平 ,随TGI流量的增大 ,PaCO2 和PetCO2 降低幅度亦增大 ,呈明显的流量依赖性。在VT 降低约 30 % ,实施PHC情况下 ,以 2L/min、4L/min、6L/min的流量行TGI时Pa CO2 分别平均下降 2 7%、48%和 5 2 % ;②PHC时的气道峰压 (Pperk)、平台压 (Ppause)、平均气道压 ( Paw)等指标均较CMV时有显著降低 ,加用TGI后上述压力值均较PHC时显著增高 ,但与CMV时比较无显著差异 ;③TGI可产生一定水平的内源性PEEP(PEEPi)。结论 :TGI可明显促进COPD呼衰患者体内CO2 排除 ,使患者在低潮气量通气状态下 ,保持PaCO2 大致在机体可以耐受的范围内而气道压力无明显增高。

Objective:To evaluate effect of tracheal gas insufflation(TGI) on the elimination of CO 2 in COPD patients with respiratory failure Methods:8 COPD patients with rrespiratory failure were applied to TGI treament Using self designed device,PaCO 2 and end expiratory carbondioxide pressure (P et CO 2) as well as P peak ,P pause , aw were observed at the point while the patients received conventional mechanical ventilation(CMV),permisive hypercapnia(PHC) and PHC with different TGI flows (2 L/min,4 L/min,6 L/min) Results:TGI can significantly decrease the PaCO 2and P et CO 2 levels,the reduction effects of CO 2 are flow dependent The mean reduction rate of PaCO 2 at the different TGI flows(2, 4, 6 L/min)under PHC condition by decreasing tidal volume are 27%,48% and 52% respectively Levels of P peak ,P pause and aw in PHC condition are significantly lower than those of CMV,but all these three pressures are increased significantly after TGI intrducing and in a flow dependent mandent manner There are no difference of the above pressures between the CMVand PHC condition A certain level of intrinsic PEEP can be produced by TGI Conclusion:Our results reveal that TGI can promote the CO 2 elimination profoundly and remain PaCO 2 in the relatively normal range under PHC condition without elevating airway pressure highly in COPD patients with respiratory failure