BRONCHODILATOR RESPONSES TO SALBUTAMOL FOLLOWED BY IPRATROPIUM BROMIDE IN PARTIALLY REVERSIBLE AIR-FLOW OBSTRUCTION

We have performed a retrospective survey on 296 patients, who attended the Respiratory Function Unit at Guy'sHospital to have their bronchodilator responses (BR) tested. The aim of the study was to see the effect of ipratropium bromide (IB) in a group of patients with incomplete reversibility after salbutamol (S). Patients were routinely given salbutamol and ipratropium bromide sequentially by inhalation, and spirometric changes were recorded after each drug. We identified two groups: Group A, 95 patients with FEV1 response ≥0·21 after either drug and FEV1<80% predicted after salbutamol; and, Group B, 49 with change in FEV1<0·021, FVC less than 80% predicted after salbutamol and an improvement in FVC≥0·331. Seventy-nine of the 95 patients in Group A also had an FVC response. In Group A, age was negatively correlated with response to salbutamol (r=−0·41, P<0·0001), and withinGroup B baseline FVC was negatively correlated with response to ipratropium bromide (r=−0·30, P=0·03). There were no differences in age, sex, or doses given to each group (median dose: salbutamol, 800 μg,ipratropium bromide 120 μg). Baseline FEV1 and FVC (% predicted) were significantly higher in FEV1 responders. Mean (sd) FEV1 were 43% (14) in Group A vs. 29% (14) in Group B, while FVC were 62% (16) vs. 47% (13), P<0·001. Responses to ipratropium bromide were more frequent in Group B; in Group A 87% improved after salbutamol and 26% after ipratropium bromide, while in Group B 68% responded to salbutamol and 47% to ipratropium bromide (P=0·03). Most patients responded to salbutamol, but in 33% ipratropium bromide had an additional effect. The FEV1 response to salbutamol declined with age. Isolated volume responders had more severe airflow obstruction, had less responses to salbutamol and were more likely to show a response to ipratropium bromide. These results support a trial of ipratropium bromide in patients with inadequate β responsiveness, especially in those with severe airflow obstruction. © 1990, Baillière Tindall. All rights reserved.