Massaro A F, Gaston B, Kita D, Fanta C, Stamler J S, Drazen J M
Respiratory Division, Brigham and Women's Hospital, Boston, MA 02115, USA.
Am J Respir Crit Care Med. 1995 Aug;152(2):800-3. doi: 10.1164/ajrccm.152.2.7633745.
Nitric oxide (NO) is known to be present in measurable quantities in the exhaled air of normal subjects and at higher concentrations in asthmatic subjects not treated with glucocorticoids. We confirmed these findings by analyzing the mean mixed expired NO concentrations of 43 stable asthmatics and 90 normal subjects; NO levels were higher in the asthmatic population (13.9 parts per billion [ppb] versus 6.2 ppb, p < 0.001). Although the effects of glucocorticoids on the NO content of mixed expired air are known, it is not known if beginning systemic glucocorticoid therapy reduces exhaled NO levels in a given individual. To examine this question, seven patients needing emergency therapy for asthma underwent repeated measurements of mixed expired NO levels during their course of treatment with glucocorticoids. All patients had a reduction in mixed expired NO concentration (p = 0.002) and an accompanying improvement in airway obstruction. The decrease in exhaled NO was evident as early as 48 h after the initiation of therapy (p = 0.05). These data suggest mixed expired NO concentrations may prove useful as an index of asthma severity and treatment efficacy for an individual patient.
已知正常受试者呼出的空气中存在可测量量的一氧化氮（NO），在未接受糖皮质激素治疗的哮喘患者中，其浓度更高。我们通过分析43名稳定期哮喘患者和90名正常受试者的平均呼出混合气体NO浓度证实了这些发现；哮喘患者群体中的NO水平更高（13.9十亿分之一[ppb]对6.2 ppb，p<0.001）。虽然糖皮质激素对呼出混合气体中NO含量的影响是已知的，但尚不清楚开始全身糖皮质激素治疗是否会降低特定个体的呼出NO水平。为了研究这个问题，7名需要哮喘紧急治疗的患者在接受糖皮质激素治疗期间，对呼出混合气体NO水平进行了重复测量。所有患者呼出混合气体NO浓度均降低（p = 0.002），同时气道阻塞情况有所改善。呼出NO的降低在治疗开始后48小时就很明显（p = 0.05）。这些数据表明，呼出混合气体NO浓度可能被证明是个体患者哮喘严重程度和治疗效果的有用指标。
