Inhalation technique and variables associated with misuse of conventional metered-dose inhalers and newer dry powder inhalers in experienced adults.

BACKGROUND

Pressurized metered-dose inhalers (pMDIs) are often poorly used, but little information is available concerning use of the newer dry powder inhalers (DPIs).

OBJECTIVE

To estimate the inhalation technique and variables associated with the misuse of pMDIs and newer DPIs in clinical practice.

METHODS

A multicenter, observational survey was used to evaluate the inhalation technique in 1,404 experienced outpatients aged 15 to 88 years affected mostly by asthma (47%) and chronic obstructive pulmonary disease (39%). A total of 1,056 patients were using pMDIs, 190 in conjunction with a large volume spacer (LVS); regarding DPIs, 230 patients were using the Aerolizer Inhaler, 524 were using the Turbuhaler, and 475 were using the Diskus. In each center, a trained observer recorded patients' inhalation techniques for each inhaler used against a standardized step-by-step checklist.

RESULTS

Twenty-four percent and 3% of patients used pMDIs poorly, alone or with an add-on LVS, respectively. Failure to correctly perform essential steps for reliable lung delivery with the Aerolizer Inhaler, Turbuhaler, and Diskus was found in 17%, 23%, and 24% of patients, respectively. There was no difference in most variables correlated with poor inhalation between patients using pMDIs and those using DPIs.

CONCLUSIONS

The use of DPIs is associated with a similar percentage of inadequate inhalation technique as the use of pMDIs in clinical practice. The addition of an LVS to a pMDI and education from health care personnel, rather than simply changing inhalers, represent the best strategies for minimizing poor inhalation technique.