To determine if peak expiratory flow (PEF) is higher using incorrect technique versus correct technique with five marketed peak flowmeters.Design
Randomized, nonblinded study.Setting
University pulmonary medicine clinic.Patients
Twenty adults with clinically stable asthma.Interventions
After inhaling 2 puffs of albuterol via a valved aerosol holding chamber (Aerochamber), patients were instructed over the next 15 min in correct and incorrect (a "spitting" action) technique when using peak flowmeters. Order of use of five peak flowmeters and correct vs incorrect technique was random.Measurements and results
PEF (percentage of personal best) was recorded for best of three attempts with correct and incorrect technique. Each peak flowmeter had a statistically significant elevation in PEF with incorrect technique. The range for elevation in PEF using incorrect technique was 12.4 to 68.2% above the PEF with the subject using correct technique.Conclusion
Each of the five marketed peak flowmeters had a significant elevation in PEF when a "spitting action" was used. Clinicians need to instruct patients carefully regarding correct technique when using peak flowmeters.