Prevalence of Low Peak Inspiratory Flow Rate at Discharge in Patients Hospitalized for COPD Exacerbation

Abstract

Background: Low peak inspiratory flow rate (PIFR) (<60 L/min) among patients with chronic obstructive pulmonary disease (COPD) may result in ineffective medication inhalation, leading to poor bronchodilation. Objective: The objectives of this analysis were to evaluate the prevalence of low PIFR at the time of discharge from a COPD-related hospitalization and to examine the real-world treatment patterns and rehospitalizations by PIFR. Methods: Patients at 7 sites in the United States were screened for enrollment at hospital discharge. PIFR was measured using the InCheck TM DIAL to simulate resistance of the DISKUS® dry powder inhaler (DPI). An equal number of patients were enrolled into low PIFR (<60 L/min) or normal PIFR (≥60 L/min) cohorts. Demographics, COPD-related clinical characteristics, health status, treatment and rehospitalization data were collected. Results: Mean PIFR was 71±22.12 L/min among 268 screened patients; 31.7% (n=85) of patients had low PIFR. Among all enrolled patients (n=170), the low PIFR cohort was older (66.2±10.04 years versus 62.1±9.41 years, p=0.006) and more likely to be female (61.2% versus 42.4%, p=0.014). There was an increase in DPI use at discharge, compared with admission, in the low PIFR cohort (62.4% versus 70.6%, p=0.020). The incidences of allcause rehospitalization up to 180 days were similar between the low and normal PIFR cohorts. Conclusions: At discharge following hospitalization for an exacerbation of COPD, approximately one-third of patients had a PIFR <60 L/min. More patients with a low PIFR were discharged with a DPI medication compared with use at admission. There was no difference in the rehospitalization rates by PIFR. AbstractAbbreviations: peak inspiratory flow rate, PIFR; chronic obstructive pulmonary disease, COPD; dry powder inhaler, DPI; metered dose inhalers, MDI; soft mist inhalers, SMI; modified Medical Research Council, mMRC; COPD Assessment Test, CAT; Morisky Medication Adherence Scale, MMAS; forced expiratory volume in 1 second, FEV 1 ; forced vital capacity, FVC; body mass index, BMI; length of stay, LOS; short-acting beta-agonist, SABA; short-acting muscarinic antagonist, SAMA; long-acting muscarinic antagonist, LAMA; long-acting beta2-agonist, LABA; inhaled corticosteroids, ICS

The Confusing World of Dry Powder Inhalers: It Is All About Inspiratory Pressures, Not Inspiratory Flow Rates

“…However, this is an uncommon observation in clinical practice. For example, <5% of stable COPD patients in the study by Mahler et al (50) (n = 213) had flow rates below 30 L/min using the In-Check DIAL against the simulated resistance of a Diskus device (DP < 0.6 kPa), and the study by Sharma et al (69) (n = 268) observed similar results in patients admitted to the hospital for acute exacerbations of COPD on the day before discharge. The vast majority of patients hospitalized for acute exacerbations of COPD achieved peak inspiratory flows of >30 L/min using an In-Check DIAL against the simulated resistance of four commonly used DPIs.…”

“…The vast majority of patients hospitalized for acute exacerbations of COPD achieved peak inspiratory flows of >30 L/min using an In-Check DIAL against the simulated resistance of four commonly used DPIs. (69) Azouz et al (18) found large variability in inhalation patterns among patients who used lowresistance devices. In contrast, they noted that Turbuhaler and Easyhaler (medium to high resistance) provided a more favorable set of inhalation characteristics in terms of formulation deaggregation and delivery of the emitted dose compared with low-resistance devices.…”

Personalizing medicine - could the smart inhaler revolutionize treatment for COPD and asthma patients?

“…However, the high inspiratory flow rates required to correctly use certain DPIs are difficult to achieve for patients with compromised lung function, leading to reduced lung deposition and increased systemic absorption. This is particularly problematic in COPD, where disease progression is associated with reduced inspiratory flow [1]. Numerous studies have identified frequent technique errors associated with commonly used DPI designs, while studies using an acoustic device to estimate inspiratory flow rates during inhaler use found that insufficient inspiratory flow is a problem affecting approximately 25% of inhaler uses in moderate to severe COPD [2,3].…”

Dry Powder Inhalers—Between the Doctor and the Patient

“…In these groups of patients, there is a high risk of not generating the optimal inspiratory flow. And only the optimal inspiratory flow guarantees the appropriate process of disaggregation and aerosolisation of the powder, an optimal penetration and deposition of such an aerosol in the respiratory tract and, as a result, a clinically effective inhalation [7][8][9][10][11][12][13].…”