Effects of breathing pattern and inspired air conditions on breath condensate volume, pH, nitrite, and protein concentrations
Effects of breathing pattern and inspired air conditions on breath condensate volume, pH, nitrite, and protein concentrations
复制标题
呼吸模式和吸入空气条件对呼吸冷凝液量、pH、亚硝酸盐和蛋白质浓度的影响
作者：
J. McCafferty;T. Bradshaw;S. Tate;A. Greening;J. Innes
背景：研究了呼吸方式和吸入空气条件对呼出冷凝水（EBC）体积和含量的影响。方法：测定3组10名健康受试者在不同目标分通气量（Vm）、潮气量（Vt）和吸入空气条件下进入冷凝器的总呼出水量（TEW）、EBC体积、pH、亚硝酸盐和蛋白质浓度。结果：随着Vm的增加，TEW和EBC的体积均显著增加。Vm为7.5、15和22.5 l/min时，平均（SD） EBC分别为627 (258)μl、1019 (313)μl和1358 (364)μl (p<0.001)， TEW分别为1879 (378)μl、2986 (496)μl和4679 (700)μl （p<0.001）。TEW明显高于EBC，反映出在目标Vm为7.5 l/min时冷凝器效率为40%，而在Vm为22.5 l/min时冷凝器效率降至29%。低Vt组TEW小于高Vt组（26.6 v 30.7 μl/l，平均差4.1 (95% CI 2.6 ~ 5.6), p<0.001）， EBC体积较小（4.3 v 7.6 μl/l，平均差3.4 (95% CI 2.3 ~ 4.5), p<0.001）。与标准条件相比，较冷和较干燥的空气产生的水蒸气和呼吸冷凝水较少（p<0.05）。呼吸方式的改变对EBC蛋白、亚硝酸盐浓度和ph值没有影响。结论：高Vt和高Vm可以在不影响样品稀释度的情况下增加凝结液体积。
Background: The effects of breathing pattern and inspired air conditions on the volume and content of exhaled breath condensate (EBC) were investigated. Methods: Total exhaled water (TEW), EBC volume, pH, nitrite and protein concentrations were measured in three groups of 10 healthy subjects breathing into a condenser at different target minute ventilations (Vm), tidal volumes (Vt), and inspired air conditions. Results: The volumes of both TEW and EBC increased significantly with Vm. For Vm 7.5, 15 and 22.5 l/min, mean (SD) EBC was 627 (258) μl, 1019 (313) μl, and 1358 (364) μl, respectively (p<0.001) and TEW was 1879 (378) μl, 2986 (496) μl, and 4679 (700) μl, respectively (p<0.001). TEW was significantly higher than EBC, reflecting a condenser efficiency of 40% at a target Vm of 7.5 l/min which reduced to 29% at Vm 22.5 l/min. Lower Vt gave less TEW than higher Vt (26.6 v 30.7 μl/l, mean difference 4.1 (95% CI 2.6 to 5.6), p<0.001) and a smaller EBC volume (4.3 v 7.6 μl/l, mean difference 3.4 (95% CI 2.3 to 4.5), p<0.001). Cooler and drier inspired air yielded less water vapour and less breath condensate than standard conditions (p<0.05). Changes in the breathing pattern had no effect on EBC protein and nitrite concentrations and pH. Conclusion: These results show that condensate volume can be increased by using high Vt and increased Vm without compromising the dilution of the sample.
影响因子：
2.9
作者：
GREEN, LC;WAGNER, DA;TANNENBAUM, SR
通讯作者：
TANNENBAUM, SR
DOI：
10.1164/ajrccm.165.5.2101018
发表时间：
2002-03-01
影响因子：
24.7
作者：
Effros, RM;Hoagland, KW;Sun, F
通讯作者：
Sun, F