COPD is characterized by incomplete spirometric reversibility to pharmacologic intervention. Patients are often characterized as reversible (R) or irreversible (IR) on the basis of a single test day. We hypothesized that such characterization does not adequately profile a patientÕs ability to respond on subsequent test days. We therefore sought to determine the reproducibility of reversibility to ipratropium (as defined by a ³15% increase in FEV1 within 3 hours) and whether an ÒirreversibleÓ patient could show reversibility on another test day. A retrospective analysis was conducted of patients who completed all test days in a one-year COPD clinical trial where serial spirometry was performed before and after ipratropium 40 mcg (0.5, 1, 2, 3 hours) on 7 occasions. Mean (SE) FEV1 =1.22 (0.03)L, mean (SE) age = 64 (0.8) years. Proportion (%) of patients showing reversibility on a given test day is noted in the table according to whether reversibility was achieved on day 1 (R day 1 vs. IR day 1).
| Study Day | 1 | 8 | 50 | 92 | 182 | 273 | 364 |
| All (n=114) | 80 | 77 | 83 | 77 | 70 | 68 | 65 |
| R day 1 (n=91) | 100 | 81 | 87 | 84 | 75 | 73 | 67 |
| IR day 1 (n=23) | 0 | 61 | 70 | 52 | 52 | 52 | 57 |
Of 7 test days, only 0.9% were always IR and 33% were always R. Approximately 83% of patients demonstrated R on at least 4/7 test days. In conclusion, reversibility to ipratropium 40 mcg is frequent and a response of less than 15% on a given test day does not preclude a response on a subsequent test day.
This work is supported by Boehringer Ingelheim
OF-02-151