Can all patients with COPD use the correct inhalation flow with all inhalers and does training help?

The inhalation rate is important when patients use an inhaler. Dry powder inhalers (DPIs) require an inhalation rate >30L min(-1) whereas metered dose inhalers (MDIs) should be used at <90L min(-1). Within the setting of a routine clinic, we have measured peak inhalation flows (PIF) of COPD patients when they used a Diskus (SDSK), Turbuhaler (STBH), Handihaler (SHAND) and MDI. Subjects were then randomised into trained (VT) and nontrained (NT) groups. One hundred and sixty-three patients with a mean (S.D.) age and % predicted FEV1 of 72.5 (9.9) years and 47.8 (22.2)% completed the study. Of the patients, 4.9%, 14.2% and 57.0% inhaled <30L min(-1) through SDSK, STHB and SHAND, respectively and 59.5% inhaled > 90 L min(-1) with the MDI. Generally, the more severe the COPD, the slower was their PIF with aR inhalers. The MDI PIF values in the VT group (n = 84) posttraining were significantly (p<0.001) slower but there was no change for the DPIs. Of the 55 VT patients inhaling >90L min(-1) through the MDl only 7 (p<0.001) inhaled too fast post-training. Pre-training 3, 15 and46 VT subjects inhaled <30 L min(-1) through the SDSK, STBH and SHAND and after training none, 5 and 26 did not inhale faster than this minimum required rate. Some COPD patients have problems achieving required PlFs through DPIs but training is useful to help some exceed the minimum required rate despite only small improvements. The patients found it easier to stow their PIF through the MD1. (C) 2007 Elsevier Ltd. All rights reserved.