AN AUDIT OF ANTIASTHMATIC DRUG INHALATION TECHNIQUE AND UNDERSTANDING

Inhaled rather than oral antiasthmatic therapy is accepted as more adv antageous but depends on patient technique and understanding. In 74 as thmatic outpatients, technique using metered-dose inhaler (MDI) was po or; in 56 patients inhaling beta-agonist, the mean peak expiratory flo w rate (PEFR) increase was only 15 L/min (6%) greater than in 18 contr ols, p < 0.05, 95% confidence intervals 2-27 L/min or 2-11%. Tilting t he head back and actuation ''stopping'' inspiration produced the least favorable PEFR responses; taken together, regression analysis yielded a statistically significant negative correlation with absolute or per centage PEFR change (R2 = 0.15; p < 0.02). Patients were unclear about which drugs to inhale as required or regularly. Among 19 patients rea ssessed inhaling beta-agonist, only 8 had baseline PEFR values within 10% of each other during both assessments. In the latter, the mean pos tinhalation PEFR increase was 36 L/min (or 13%) greater than the corre sponding increase (or % change) at first assessment, p = 0.05 (0.08), 95% confidence intervals 0-73 L/min (-2 to 29%). Thus, MDI users shoul d avoid tilting the head back, actuation stopping inhalation, and be m ore aware of prophylactic (steroid) versus symptomatic (beta-agonist) treatment.