A study of bronchial reactivity in relation to baseline pulmonary functions in patients with chronic obstructive lung disease.

ABSTRACT

Baseline bronchial reactivity was studied in 36 patients with chronic obstructive lung disease (COLD) and 20 normal healthy controls using the inhalational histamine challenge test. Using a cut off PD20 dose of 0.195 mg of histamine, 83.3% patients of COLD demonstrated bronchial hyper-reactivity. Presence of bronchial reactivity correlated significantly with the baseline FEV1, FEF25-75 and the ratio FEV1/FVC (p = 0.0019, 0.00001 and 0.008) respectively. Thus, bronchial reactivity in subjects with COLD correlates most significantly with the maximum mid-expiratory flow rate (FEF25-75).