Determinants of Suboptimal Peak Inspiratory Flow Rates among Patients with Chronic Obstructive Pulmonary Disease in Southwest, Nigeria.

BACKGROUND

Inhalational therapy is the cornerstone in the management of chronic obstructive pulmonary disease (COPD) patients. Patients' peak inspiratory flow impacts effective dry powder inhaler (DPI) delivery and management outcome.

OBJECTIVE

This study assessed peak inspiratory flow rates (PIFR) and determined the factors associated with suboptimal inspiratory flow rates among COPD patients.

METHODS

A descriptive cross-sectional study was conducted among 60 participants (30 stable COPD patients and 30 age-and-sex matched controls). Socio-demographic characteristics was obtained and spirometry was done for all participants. PIFR assessment was done using the In-Check Dial Meter and was categorized as suboptimal (< 60L/min) or optimal (≥ 60L/min). P values less than 0.05 were taken as statistically significant.

RESULTS

Mean age of the COPD patients and healthy controls were both 67.8 ± 10.3 years, with 53.3% being females. Post-bronchodilation FEV 1/FVC% for COPD patients was 54.15 ± 11.27%. The mean PIFR among COPD patients was significantly lower than that of healthy controls, in all DPIs simulated, especially for Clickhaler (46.2±13.4 vs 60.5±11.4L/min, p<0.001). A significant proportion of COPD patients had suboptimal PIFR, in the simulated resistances against Clickhaler and Turbuhaler (70% vs 80%; p<0.001). Older age, shorter height and low BMI were associated with suboptimal PIFR among COPD patients. However, independent predictors of suboptimal PIFR were BMI, PEFR, FEV1% and FVC%.

CONCLUSION

Suboptimal PIFR was found in a significant number of COPD patients when compared with healthy respondents. Routine assessment using In-Check Dial meter should be done to determine the suitability of dry powder inhalers for patients with COPD.