PURPOSE: We study the effect of inhaled ipratropium as a bronchodilation challenge on forced expiratory time (FET) and whether the ipratropium and albuterol have similar effects on delta FEV1/delta FVC ratio identified to differentiate volume versus flow responders.
METHODS: COPD patients were identified based on signs and symptoms, a smoking history of 20 pack-years or more, and previous spirometry showing moderate to severe airflow obstruction. After obtaining informed consent, each COPD patient was studied on 2 separate days. They were asked to omit any inhaled bronchodilator for 12 hours (for short-acting drugs) or 24 hours (for long-acting drugs). On the first study day, baseline spirometry was obtained, Albuterol or Ipratropium (randomly selected) was inhaled, and spirometry was repeated after 30 min. On the second study day, baseline spirometry was obtained, the other drug was inhaled, and spirometry repeated after 30 min.
RESULTS: 25 patients were enrolled with a mean age of 60 ± 10 years with average of 43 pack-year history of smoking. Baseline values were FVC ± 3.13 ± 0.8 L, EFV1 1.56 ± 0.6 L and FEV1/FVC 49 ± 11%. FEV1 improved significantly after ipratropium and albuterol (0.25 ± 0.26 and 0.23 ± 0.21 L respectively) as did FVC (0.44 ± 0.43 and 0.32 ± 0.40 L respectively). Forced expiratory time (FET) before and after inhalation of ipratropium and albuterol was not significantly different (14.33 and 14.44 vs 13.67 and 13.80 seconds respectively (p value of 0.42 and 0.43 respectively). There were 8 volume responders and 17 flow responders in each group. FET response of each COPD patient to ipratropium was well correlated with the response to albuterol.
CONCLUSION: Inhaled ipratropium as a bronchodilator challenge has similar effect on forced expiratory time as well as flow and volume response compared to albuterol.
CLINICAL IMPLICATIONS: The effects of ipratropium inhlation on forced expiratory time and flow and volume response are very similar to albuterol. Further studies are required to confirm this relationship with different stages of COPD.
DISCLOSURE: Majid Mughal, No Financial Disclosure Information; No Product/Research Disclosure Information