Late Breaking Abstract - Ability of Hong Kong COPD patients to inhale dry powder inhaler

Introduction: Correct inhaler technique is important for effective management of patients with chronic obstructive pulmonary disease (COPD). Aim: To assess the ability of Hong Kong Chinese COPD patients to correctly inhale the dry powder inhaler (DPI) and pressurized metered-dose inhaler (MDI). To identify factors associated with successful (no critical error) in using 2 types of DPI (Genuair® and Ellipta®). Methods: This was a cross-sectional, single-centre, observational study. Peak inspiration flow rate (PIFR) against the simulated resistance of Genuair® and Ellipta® were measured by In-Check DIAL 2016®. Abbreviated mental test (AMT) was preformed to assess cognitive impairment. Standardized training on proper use of DPIs and MDI were given, and their inhaler techniques were tested using corresponding placebo devices. Results: 98 patients (mean age 75±9.6 years) were enrolled, majority being male (79.6%) with GOLD group D (84.7%). Mean PIFR of Genuair® and Ellipta® were 45.8±13.8 and 52.4±14.2 L/min respectively. Fewer patients had inhaler technique errors when using DPI as compared with MDI (Genuair®=39.8%, Ellipta®=22.4%, MDI=65.3%, p<0.001). The commonest critical error of using DPI was failure to breathe in deeply (28.6% for Genuair® and 7.1% for Ellipta®), whilst the commonest critical error of using MDI was poor coordination (28.6%). Successful use of both DPI was significantly associated with higher PIFR (51.4 vs 33.0 L/min, p<0.001 for Genuair®, 53.7 vs 38.1 L/min, p=0.003 for Ellipta®) and higher AMT score (8.99 vs 8.10, p=0.003 for Genuair®, 8.80 vs 7.75, p=0.04 for Ellipta®). Conclusion: COPD patients with higher PIFR and higher AMT score were more likely to successfully inhale DPI Genuair® and Ellipta®.