Methacholine inhalation challenge after rapid saline infusion in healthy subjects.

Five healthy subjects were challenged with methacholine on 2 different days, 1 week apart, the second day after acute intravenous 30 ml/kg 0.9% saline infusion. After infusion, we observed a significant reduction in vital capacity (VC), maximal expiratory volume in 1 s (FEV1), provocation dose producing a 35% fall in SGaw (PD35SGaw) and in 25% of maximal expiratory flow (MEF25), and an increase in the slopes of log dose-response curves. Our results suggest an increased bronchial reactivity in acute minimal interstitial lung edema.