Exhaled breath condensate pH stanclardised for CO2 partial pressure
Exhaled breath condensate pH stanclardised for CO2 partial pressure
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DOI：
10.1183/09031936.00084006
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发表时间：
2007-03-01
影响因子：
24.3
通讯作者：
Horvath, I.
中科院分区：
文献类型：
--
作者：
Kullmann, T.;Barta, I.;Horvath, I.
呼气冷凝水（EBC） pH值被认为反映了气道的酸碱平衡。目前的pH值测量没有考虑到二氧化碳的影响。本研究的目的是确定冷凝CO2分压对pH的影响，并提供一个更精确的EBC pH测定模式。12名健康志愿者和12名哮喘患者的凝结水pH值和二氧化碳分压分别使用血气分析仪测量，样品为干净的、氩气的、含二氧化碳的样品。采用回归分析检验pH与CO2的关系，并计算CO2水平为5.33 kPa（肺泡生理CO2分压）时的pH值。使用Bland-Altman试验比较不同pH读数的重复性。在纯氩气和脱气样品中，冷凝CO2浓度都是不同的。CO2和pH值之间存在密切的负对数关系。在CO2水平为5.33 kPa时计算pH值的可重复性大约是目前使用的测量值的六倍。冷凝CO2分压影响pH值测量。在标准CO2水平下的pH值测定提供了迄今为止最可重现的冷凝液pH值。
Exhaled breath condensate (EBC) pH is considered to reflect the acid-base balance of the airways. Current pH measurements do not take into account the effect Of CO2. The aim of the present study was to determine the effect of condensate CO2 partial pressure on pH and to provide a more precise mode of EBC pH determination.Condensate pH and CO2 partial pressure were measured in parallel from 12 healthy volunteers and 12 asthmatics using a blood gas analyser in neat, argon de-aerated and CO2-loaded samples. The regression analysis was used to test the relationship between pH and CO2, and to calculate the pH at a CO2 level of 5.33 kPa (physiological alveolar CO2 partial pressure). Reproducibility of different pH readings was compared using the Bland-Altman test.Condensate CO2 concentration was variable both in neat and argon de-aerated samples. There was a close negative logarithmic relationship between CO2 and pH. Calculation of pH at a CO2 level of 5.33 kPa provided reproducibility approximately six times as good as that of the currently used measurements.Condensate CO2 partial pressure influences pH measurements. Determination of pH at a standard CO2 level provides the most reproducible condensate pH values to date.