Peak In- and Expiratory Flow Revisited: Reliability and Reference Values in Adults.

Area of Science:

• Pulmonary Function Testing
• Respiratory Physiology

Background:

• Peak inspiratory and expiratory flow rates are valuable for respiratory disease management.
• High variability has limited their routine clinical use.

Purpose of the Study:

• To achieve reproducible measurements of maximal inspiratory flow rates (PIF).
• To establish reference equations for peak inspiratory flow (PIF) and peak expiratory flow (PEF).

Main Methods:

• 187 healthy adults underwent coached maximal inspiratory and expiratory maneuvers.
• PIF repeatability and effect of preceding expiration type were assessed.
• Reference values derived using the Lambda-Mu-Sigma method.

Main Results:

• Valid PIF obtained within 3.3 attempts with 4.6% within-test variability.
• Between-day PIF repeatability showed a high intraclass correlation coefficient (0.981).
• PIF variability was lower than previously reported and predictable by gender, age, and height.

Conclusions:

• Reproducible PIF and PEF measurements are feasible with standardized effort criteria.
• Current ATS/ERS standards facilitate routine clinical application of these flow rates.