Kavitha Venkatnarayan, Mohan Anant, Madan Karan, Hadda Vijay, Khilnani G C, Guleria Randeep
Department of Pulmonary Medicine and Sleep Disorders, All India Institute of Medical Sciences, New Delhi, India.
Lung India. 2017 Mar-Apr;34(2):132-137. doi: 10.4103/0970-2113.201322.
To evaluate the utility of fractional exhaled nitric oxide (FeNO) in monitoring asthma control.
Steroid naïve nonsmoking asthmatics were recruited and followed for 6-8 weeks on standard treatment. Serial measurements of FeNO, peak expiratory flow rate (PEFR) variability, forced expiratory volume in 1 s (FEV1), bronchodilator reversibility (BDR), and asthma control test (ACT) score were measured at baseline and after 6-8 weeks of treatment.
One hundred and fifty-one patients were recruited over an 18-month period. These comprised 79 males (52.3%) with mean (standard deviation) age of 34.2 (11.6). Mean (SD) FeNO levels at baseline and after therapy were 45.4 (35.9) and 38.4 (23.7) ppb, respectively ( = 0.01). Baseline FeNO correlated strongly with FEV1 ( = -0.78, < 0.001), ACT score ( = -0.76, < 0.001), PEFR variability ( = -0.74, < 0.001), and moderately with BDR ( = 0.50, < 0.001). After treatment with inhaled steroids, the correlation remained strong with ACT score ( = -0.68, < 0.001) but weakened with PEFR variability ( = -0.34, = 0.01) and FEV1 ( = -0.36, = 0.01).
FeNO may be useful as an adjunctive noninvasive modality to assess asthma control in both steroid naïve asthmatics and asthmatics on treatment. However, the suboptimal sensitivity and specificity may limit its utility as a point-of-care single monitoring tool.
评估呼出气一氧化氮分数（FeNO）在监测哮喘控制中的作用。
招募未使用过类固醇的非吸烟哮喘患者，采用标准治疗方案随访6 - 8周。在基线期以及治疗6 - 8周后，对FeNO、呼气峰值流速（PEFR）变异性、第1秒用力呼气量（FEV1）、支气管扩张剂可逆性（BDR）和哮喘控制测试（ACT）评分进行系列测量。
在18个月期间招募了151例患者。其中包括79名男性（52.3%），平均（标准差）年龄为34.2（11.6）岁。基线期和治疗后的平均（SD）FeNO水平分别为45.4（35.9）和38.4（23.7）ppb（P = 0.01）。基线FeNO与FEV1（r = -0.78，P < 0.001）、ACT评分（r = -0.76，P < 0.001）、PEFR变异性（r = -0.74，P < 0.001）密切相关，与BDR中度相关（r = 0.50，P < 0.001）。吸入类固醇治疗后，与ACT评分的相关性仍然很强（r = -0.68，P < 0.001），但与PEFR变异性（r = -0.34，P = 0.01）和FEV1（r = -0.36，P = 0.01）的相关性减弱。
FeNO可作为一种辅助性非侵入性方法，用于评估未使用过类固醇的哮喘患者以及正在接受治疗的哮喘患者的哮喘控制情况。然而，其欠佳的敏感性和特异性可能会限制它作为即时护理单一监测工具的效用。
