Dilution of respiratory solutes in exhaled condensates
Dilution of respiratory solutes in exhaled condensates
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DOI：
10.1164/ajrccm.165.5.2101018
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发表时间：
2002-03-01
影响因子：
24.7
通讯作者：
Sun, F
中科院分区：
文献类型：
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作者：
Effros, RM;Hoagland, KW;Sun, F
大多数呼出的水以气态水蒸汽的形式产生，可以在冷却的冷凝器中收集。这些冷凝物中存在非挥发性溶质，表明呼吸道液滴（RF）也被收集。然而，计算冷凝物中的RF溶质浓度需要估计RF液滴被水蒸气稀释的情况。我们用凝析液浓度计算了20名正常受试者凝析液中RF液滴的稀释度。总离子浓度（电导率）为497+/-68（平均+/-SEM） muM。其中，229+/-43的muM为NH4+，但从气管造口的受试者中收集到的NH4+很少，表明口腔形成。凝析液中Na+的浓度（[Na+](cond)）平均为242+/-43 muM。[Na+]（cond）的大变化与冷凝液中K+ ([K+](cond))和冷凝液中Cl- ([Cl-](cond))的变化具有良好的相关性，并归因于呼吸液滴稀释的差异。（[Na+] + [K+]）的凝聚值除以等离子体的凝聚值表明，RF占凝聚体积的0.01% ~ 2.00%。RF中Na+、K+、Cl-、乳酸盐和蛋白质的计算值分别为[Na+](RF) = 91+/-8 mM, [K+](RF) = 60+/-11 mM, [Cl-](RF) = 102+/-17 mM，[乳酸盐](RF) = 44+/-17 mM，[蛋白质](RF) = 7.63+/-1.82 g/dl。
Most exhaled water is produced as gaseous water vapor, which can be collected in cooled condensers. The presence of nonvolatile solutes in these condensates suggests that droplets of respiratory fluid (RF) have also been collected. However, calculation of RF solute concentrations from condensates requires estimation of the dilution of RF droplets by water vapor. We used condensate electrolyte concentrations to calculate the dilution of RF droplets in condensates from 20 normal subjects. The total ionic concentration (conductivity) was 497+/-68 (mean+/-SEM) muM. Of this, 229+/-43 muM was NH4+, but little NH4+ was collected from subjects with tracheostomies, indicating oral formation. The Na+ concentration in condensate ([Na+](cond)) averaged 242+/-43 muM. Large variations in [Na+](cond) correlated well with variations of K+ in condensate ([K+](cond)) and Cl- in condensate ([Cl-](cond)), and were attributed to differences in respiratory droplet dilution. Dividing condensate values of ([Na+] + [K+]) by those of plasma indicated that RF represented between 0.01% and 2.00% of condensate volumes. Calculated values for Na+, K+, Cl-, lactate, and protein in RF were [Na+](RF) = 91+/-8 mM, [K+](RF) = 60+/-11 mM, [Cl-](RF) = 102+/-17 mM, [lactate](RF) = 44+/-17 mM, and [protein](RF) = 7.63+/-1.82 g/dl, respectively.