Measurement of peak inhalation rates with an In-Check Meter® to identify an elderly patient's ability to use a Turbuhaler®

Abstract

Dry powder inhalers are designed with resistance to airflow so that a respirable cloud of particles is generated during inhalation. Some of these devices require a certain inhalation rate to produce a consistent dose of respirable particles. The aim of the study was to determine the inhalation rate of elderly patients with chronic obstructive pulmonary disease (COPD) when they inhale through a Turbuhaler® and assess the potential of the In-Check Meter® to identify inhalation rates. Their peak inhalation rate using a normal inhalation, pre- and post-counselling, was measured using a Turbuhaler Trainer® and an In-Check Meter®. Spirometry was also measured. Seventy-four COPD patients with a mean (SD) age of 79.7 (8.4) years and forced expiratory volume in 1 sec (FEV1) 41.9 (12.8)% predicted. Pre-counselling 14 obtained a rate of < 30 1 min-1 with the Turbuhaler Trainer, 31 from 30 to 40 min-1, 23 between 40-60 1 min-1 and 6 > 60 1 min-1. The median (range) peak inhalation rates with the In-Check Meter® were 50 (50-70), 70 (50-130), 100 (60-200) and 225 (200-250) 1 min-1. Post-counselling 7,16,41 and 10 achieved the respective peak inhalation rates using the Turbuhaler Trainer® Similarly, the In-Check inhalation rates were 50 (50-60), 70 (50-130), 90 (60-200) and 250 (200-270) l min-1. The results highlight the potential of the In-Check Meter® to identify patients' inhalation rates through dry powder inhalers. © 2001 Harcourt Publishers Ltd.