慢性阻塞性肺病呼吸衰竭者潮气末二氧化碳分压的监测

THE CLINICAL VALUE OF MONITORING PARTIAL PRESSURE OF END TIDAL CARBON DIOXIDE IN PATIENTS WITH RESPIRATORY FAILURE RESULTING FROM COPD

对２０例正常人、２０例慢性阻塞性肺病（慢阻肺）及２５例慢性阻塞性肺病呼吸衰竭（慢阻肺呼衰）患者进行潮气末二氧化碳分压（ＰｅｔＣＯ２）和动脉血二氧化碳分压（ＰａＣＯ２）对比研究，并与死腔气量／潮气容积（ＶＤ／ＶＴ）和气道阻力（Ｒａｗ）进行相关分析。结果表明，正常组及慢阻肺组ＰａＣＯ２和ＰｅｔＣＯ２间无明显差异（Ｐ＞０．０５），ＰｅｔＣＯ２可反映ＰａＣＯ２变化。慢阻肺呼衰者ＰａＣＯ２和ＰｅｔＣＯ２间有明显差异，其中ＰｅｔＣＯ２较ＰａＣＯ２低，平均相差达２．１３ｋＰａ±１．２６ｋＰａ（Ｐ＜０．０１）。故在慢阻肺呼衰时ＰｅｔＣＯ２不能反映ＰａＣＯ２变化，此时如以ＰｅｔＣＯ２来估计ＰａＣＯ２是不可靠的。慢阻肺呼衰时ＰａＣＯ２－ＰｅｔＣＯ２之差异与ＶＤ／ＶＴ（ｒ＝０．８１，Ｐ＜０．０１）和Ｒａｗ相关（ｒ＝０．４２，Ｐ＜０．０５）。

The authors compared the difference between PetCO 2 and PaCO 2 and analyzed the correlation of PaCO 2-PetCO 2 with V D/V T and R aw in 20 normal subjects, 20 patients with COPD and 25 patients with respiratory failure resulting from COPD. The results showed that there was no significant difference between PaCO 2 and PetCO 2 ( P >0.05), and that PetCO 2 could represent the levels of PaCO 2 in both the normal group and in the COPD group. However, in patients with respiratory failure resulting from COPD, PetCO 2 was significantly lower than PaCO 2 [(2.13±1.26)kPa, P <0.01]. It is concluded that PetCO 2 does not reflect the changes of PaCO 2, and the prediction of PaCO 2 from PetCO 2 is not reliable in patients with respiratory failure resulting from COPD. In respiratory failure group resulting from COPD, the PaCO 2-PetCO 2 is correlated with the V D/V T and R aw ( r=0.81, P <0.01 and r=0.42, P <0.05, respectively).