The role of peak inspiratory flow in the selection of inhalation therapy in patients with chronic obstructive pulmonary disease

Abstract

Pharmacotherapy for chronic obstructive pulmonary disease (COPD) primarily relies on inhalation therapy. The choice of an appropriate inhalation device is of particular importance as it impacts the frequency of device use errors, patient adherence to treatment, and overall treatment effectiveness. Peak inspiratory flow (PIF) represents the maximum air flow rate generated by a patient during inhalation and is measured in liters per minute. Dry powder inhalers (DPIs) possess internal device resistance that patients must overcome to activate the device. Measuring PIF is an integral component of optimizing COPD therapy when utilizing dry powder inhalers (DPIs). For most DPIs, an optimal PIF value is considered to be no less than 60 L/min, while with a PIF of less than 30 L/min, the medication can’t reach the lower airways. At the same time, the clinical effectiveness of the use of DPI at values of PIF from 30 L/min to 60 L/min may be insufficient, therefore, it is necessary to take into account the value of PIF for the selection of basic COPD therapy. Given the lack of portable fluometers among doctors in real clinical practice, it is important to identify risk factors for suboptimal PIF in patients with COPD. Patients with emphysema, pulmonary hyperinflation, elderly, female, short height, obesity and comorbidity are at risk for insufficient PIF value for further effective use of DPI.This review provides essential information about the role of inspiratory flow for the effective use of DPIs, presents methods for its measurement, discusses predictors of suboptimal PIF, and offers recommendations for selecting inhalation devices for COPD patients based on PIF values.