Nitrogen washout slope in poorly controlled asthma
Nitrogen washout slope in poorly controlled asthma
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DOI：
10.1111/j.1398-9995.2006.00970.x
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发表时间：
2006-01-01
期刊：
影响因子：
12.4
通讯作者：
Chanez, P
中科院分区：
文献类型：
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作者：
Bourdin, A;Paganin, F;Chanez, P
即使1秒用力呼气量（FEV1）仍高于正常值，也常常缺乏哮喘的短期控制。小气道是持续炎症和结构改变的潜在关键部位。小气道的无创评估被认为是困难的，但计算机化单次呼吸氮冲洗试验（SBNT）最近已成功地重新引入这一目的。将24例不同严重程度但FEV1正常的哮喘患者（13名女性）与24名健康志愿者（13名女性）进行比较，并在支气管扩张（400 μ g沙丁胺醇）后进行稳态研究。检查肺活量、容积学数据、第三期（SBNT第三期斜率dN2）和第四期[闭合容积（CV），闭合容量(CC) = CV +剩余容积（RV）]。根据有效问卷（ACQ）和国际指南评估哮喘严重程度、近期控制、加重率和治疗要求。根据患者的加重率，前瞻性地将患者分为两组。评估随后2天测量结果的可重复性。除总肺活量（TLC）外，所有脉搏波描记值均可将哮喘患者与对照组区分开来。哮喘患者CC/TLC[124（117-148）比117 (112-123),P = 0.04]和dN2[110（99-190）比94 (75-111),P = 0.02]升高。频繁加重患者的dN2显著升高[100 (83-105)vs 195 (141-212), P = 0.0005]。dN2与近期哮喘控制（rho: 0.62, P = 0.003）、加重次数（rho: 0.71, P = 0.0008）、RV/TLC （rho: 0.49, P = 0.026）相关。本研究表明，在高症状感知者中，dN2评估的通气不平等是哮喘控制不良和高加重率的重要指标。现在应该开发针对小气道的新疗法。
Short-term control of asthma is often lacking even though forced expiratory volume in 1 s (FEV1) remains above normal value. Small airways are a potential key site of persistent inflammation and structural modification. Noninvasive assessment of small airways was found to be difficult, but the computerized single breath nitrogen washout test (SBNT) has been recently successfully reintroduced with this aim. Twenty-four asthmatics (13 females) of various severity but with normal FEV1 were compared with 24 healthy volunteers (13 females) and studied at steady-state after bronchodilatation (400 mu g salbutamol). Spirometric values, plethysmographic data, phase III (slope of phase III of the SBNT, dN2) and IV [closing volume (CV), with closing capacity (CC) = CV + residual volume (RV)] of the SBNT were checked. Asthma severity, recent control, exacerbation rate, and therapy requirements were assessed on the basis of validated questionnaires (ACQ) and international guidelines. Patients were prospectively pooled into two equal groups according to their exacerbation rate. The reproducibility of the measurements obtained on 2 following days was assessed. All plethysmographic values, except total lung capacity (TLC), differentiated asthmatic patients from controls. The CC/TLC [124 (117-148) vs 117 (112-123), P = 0.04] and dN2 [110 (99-190) vs 94 (75-111), P = 0.02] were increased in asthma. The dN2 was significantly increased in patients with frequent exacerbations [100 (83-105) vs 195 (141-212), P = 0.0005]. A correlation was obtained between dN2 and recent asthma control (rho: 0.62; P = 0.003), number of exacerbations (rho: 0.71, P = 0.0008), and RV/TLC (rho: 0.49, P = 0.026). This study demonstrated that ventilation inequalities assessed by dN2 represent an important indicator of poor asthma control and high exacerbation rate in high symptom perceivers. New therapies focused on small airways should now be developed.