Wheatley Courtney M, Cassuto Nicholas A, Foxx-Lupo William T, Snyder Eric M
Department of Pharmacy Practice and Science, University of Arizona, Tucson, AZ 85721, USA.
Clin Med Insights Circ Respir Pulm Med. 2010 Aug 27;4:25-34. doi: 10.4137/ccrpm.s4718.
The assessment of inflammatory markers and ions in exhaled breath condensate (EBC) is being utilized more frequently in diseases such as asthma and cystic fibrosis with marked variability in EBC measures, including those of exhaled Na(+). We sought to determine if variability in exhaled Na(+) was due to differences in pulmonary blood flow (PBF) or Na(+) in the mouth (salivary Na(+)). We measured exhaled Na(+) three times with coinciding sampling of salivary Na(+) and assessment of PBF (using acetylene rebreathing) in 13 healthy subjects (54% female, age = 27 ± 7 yrs., ht. = 172 ± 10 cm, wt. = 70 ± 21 kg, BMI = 22 ± 7 kg/m(2) mean ± SD). Exhaled Na(+) averaged 2.7 ± 1.2 mmol/l, and salivary Na(+) averaged 5.51 ± 4.58 mmol/l. The coefficients of variation across all three measures in all 13 subjects averaged 30% for exhaled Na(+) and 83% for salivary Na(+), within subjects the variability across the three measures averaged 30% for exhaled Na(+) and 38% for salivary Na(+). Across all three measures in all 13 subjects the relationship between PBF and exhaled Na(+) averaged 0.027 (P = 0.87), and the relationship between salivary Na(+) and exhaled Na(+) concentrations averaged 0.59 (P = 0.001). Also, we sought to determine the relationship between exhaled Na(+) and serum Na(+) in an addition 20 subjects. There was a moderate and significant relationship between serum Na(+) and exhaled Na(+) (r = 0.37, P = 0.04). These findings suggest there that the variability in exhaled Na(+) is caused, at least in part, by droplet formation from within the mouth as turbulent air passes through and that there is a flux of ions from the pulmonary blood into the airways.
呼出气体冷凝物（EBC）中炎症标志物和离子的评估在哮喘和囊性纤维化等疾病中使用得越来越频繁，EBC测量值存在显著差异，包括呼出钠（Na(+)）的测量值。我们试图确定呼出Na(+)的变异性是否是由于肺血流量（PBF）的差异或口腔中Na(+)（唾液Na(+)）的差异所致。我们对13名健康受试者（54%为女性，年龄=27±7岁，身高=172±10厘米，体重=70±21千克，体重指数=22±7千克/平方米，平均值±标准差）进行了三次呼出Na(+)测量，同时采集唾液Na(+)并评估PBF（使用乙炔再呼吸法）。呼出Na(+)平均为2.7±1.2毫摩尔/升，唾液Na(+)平均为5.51±4.58毫摩尔/升。所有13名受试者的三次测量中，呼出Na(+)的变异系数平均为30%，唾液Na(+)的变异系数平均为83%；在受试者内部，三次测量中呼出Na(+)的变异性平均为30%，唾液Na(+)的变异性平均为38%。在所有13名受试者的三次测量中，PBF与呼出Na(+)之间的关系平均为0.027（P=0.87），唾液Na(+)与呼出Na(+)浓度之间的关系平均为0.59（P=0.001）。此外，我们试图确定另外20名受试者呼出Na(+)与血清Na(+)之间的关系。血清Na(+)与呼出Na(+)之间存在中度且显著的关系（r=0.37，P=0.04）。这些发现表明，呼出Na(+)的变异性至少部分是由湍流空气通过口腔时口腔内形成液滴所致，并且存在离子从肺血流入气道的通量。
