Nitrogen washout slope in poorly controlled asthma.

摘要: 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 persistent inflammation and structural modification. Noninvasive assessment small 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) various severity FEV1 were compared 24 healthy volunteers studied at steady-state after bronchodilatation (400 μg salbutamol). Spirometric values, plethysmographic data, phase III (slope SBNT, dN2) IV [closing (CV), closing capacity (CC) = CV + residual (RV)] SBNT checked. Asthma severity, recent control, exacerbation rate, therapy requirements assessed on basis validated questionnaires (ACQ) international guidelines. Patients prospectively pooled into two equal groups according their rate. The reproducibility measurements obtained 2 following days assessed. All except total lung (TLC), differentiated asthmatic patients from controls. CC/TLC [124 (117–148) vs 117 (112–123), P = 0.04] dN2 [110 (99–190) 94 (75–111), P = 0.02] increased asthma. significantly frequent exacerbations [100 (83–105) 195 (141–212), P = 0.0005]. A correlation between (ρ: 0.62; P = 0.003), number 0.71, P = 0.0008), RV/TLC 0.49, P = 0.026). This study demonstrated that ventilation inequalities by represent an important indicator poor high rate symptom perceivers. New therapies focused should now developed.