Colon-Semidey A J, Marshik P, Crowley M, Katz R, Kelly H W
Division of Pulmonary and Critical Care, Department of Pediatrics, University of New Mexico-Health Sciences Center, Albuquerque, New Mexico, USA.
Pediatr Pulmonol. 2000 Nov;30(5):385-92. doi: 10.1002/1099-0496(200011)30:5<385::aid-ppul4>3.0.co;2-#.
Recent trials measuring exhaled nitric oxide (eNO) concentrations have suggested that it may be a useful measure of ongoing airway inflammation in patients with asthma. The purpose of this study was to examine the relationship between eNO levels and baseline as well as postbronchodilator spirometry, a measurement commonly used in the clinical setting to determine the severity of asthma and as a guide to therapeutic decisions. Forty-nine patients between the ages of 5-16 years with physician-diagnosed asthma who attended the pediatric pulmonary clinic for a routine asthma visit with spirometric evaluation were recruited for the study. eNO levels prior to spirometry were obtained before and after receiving inhaled beta(2) agonist. eNO samples were collected in impermeable bags (Tedlar) and assayed within 24 hr by chemiluminescence. Regression analysis was used to assess the relationships between pre- and postbronchodilator eNO and spirometric variables. eNO was also compared in patients receiving and not receiving inhaled corticosteroids (ICS), as well as those whose therapy had been increased after evaluation by a pediatric pulmonologist or allergist. We found no significant difference between the levels of eNO before and after inhalation of beta(2) agonist (P = 0.60 paired t-test). Positive correlation was found between eNO vs. percentage change in FEV(1) (r = 0.35, P = 0.01) and percentage change in FEF(25-75% )(r = 0.29, P = 0.04). A negative correlation was found between prebronchodilator FEV(1) and eNO (r = -0.29, P = 0.03). Patients on ICS had lower mean eNO levels (29.9 vs. 47.6 parts per billion (ppb), P = 0.053) than those not receiving ICS. Patients whose ICS therapy was increased had higher mean eNO levels (47.2 vs. 26.9 ppb, P = 0.018) than those not having ICS therapy increased. We suggest that eNO levels could be a clinically useful measurement of asthma severity and could be used as an adjunct to spirometry to determine appropriate treatment plans. Longitudinal clinical trials are needed to determine if eNO can enhance therapeutic decisions for asthmatic children.
近期测量呼出一氧化氮（eNO）浓度的试验表明，它可能是衡量哮喘患者气道炎症持续情况的一项有用指标。本研究的目的是探讨eNO水平与基线以及支气管扩张剂后肺量计测量结果之间的关系，肺量计测量是临床常用的一种用于确定哮喘严重程度并指导治疗决策的方法。招募了49名年龄在5至16岁之间、经医生诊断为哮喘且到儿科肺病门诊进行常规哮喘就诊并接受肺量计评估的患者参与本研究。在接受吸入β₂激动剂之前和之后获取肺量计测量前的eNO水平。eNO样本收集于不渗透袋（Tedlar）中，并在24小时内通过化学发光法进行检测。采用回归分析来评估支气管扩张剂前后eNO与肺量计变量之间的关系。还对接受和未接受吸入性皮质类固醇（ICS）治疗的患者，以及那些经儿科肺病专家或过敏症专科医生评估后治疗方案有所增加的患者的eNO水平进行了比较。我们发现吸入β₂激动剂前后的eNO水平无显著差异（配对t检验，P = 0.60）。eNO与第一秒用力呼气容积（FEV₁）的百分比变化（r = 0.35，P = 0.01）以及用力呼气中期流速（FEF₂₅₋₇₅%）的百分比变化（r = 0.29，P = 0.04）之间呈正相关。支气管扩张剂前的FEV₁与eNO之间呈负相关（r = -0.29，P = 0.03）。接受ICS治疗的患者平均eNO水平（29.9 vs. 47.6十亿分比（ppb），P = 0.053）低于未接受ICS治疗的患者。ICS治疗方案增加的患者平均eNO水平（47.2 vs. 26.9 ppb，P = 0.018）高于ICS治疗方案未增加的患者。我们认为eNO水平可能是哮喘严重程度的一项临床有用指标，可作为肺量计的辅助手段来确定合适的治疗方案。需要进行纵向临床试验来确定eNO是否能改善对哮喘儿童的治疗决策。
