Measuring Peak Inspiratory Flow in Patients with Chronic Obstructive Pulmonary Disease

Abstract

Dry powder inhalers (DPIs) are breath actuated, and patients using DPIs need to generate an optimal inspiratory flow during the inhalation maneuver for effective drug delivery to the lungs. However, practical and standardized recommendations for measuring peak inspiratory flow (PIF)-a potential indicator for effective DPI use in chronic obstructive pulmonary disease (COPD)-are lacking. To evaluate recommended PIF assessment approaches, we reviewed the Instructions for Use of the In-Check™ DIAL and the prescribing information for eight DPIs approved for use in the treatment of COPD in the United States. To evaluate applied PIF assessment approaches, we conducted a PubMed search from inception to August 31, 2021, for reports of clinical and real-life studies where PIF was measured using the In-Check™ DIAL or through a DPI in patients with COPD. Evaluation of collective sources, including 47 applicable studies, showed that instructions related to the positioning of the patient with their DPI, instructions for exhalation before the inhalation maneuver, the inhalation maneuver itself, and post-inhalation breath-hold times varied, and in many instances, appeared vague and/or incomplete. We observed considerable variation in how PIF was measured in clinical and real-life studies, underscoring the need for a standardized method of PIF measurement. Standardization of technique will facilitate comparisons among studies. Based on these findings and our clinical and research experience, we propose specific recommendations for PIF measurement to standardize the process and better ensure accurate and reliable PIF values in clinical trials and in daily clinical practice.

Utility of peak inspiratory flow measurement for dry powder inhaler use in chronic obstructive pulmonary disease

“…Standardization of technique will facilitate comparisons among studies. Specific recommendations for PIF measurement have been proposed to standardize the process and better ensure accurate and reliable PIF values in clinical trials and in daily clinical practice [16 ▪▪ ].…”

“…An international panel of experts recommended a standardized approach to measuring PIF in clinical trials and daily clinical practice [16 ▪▪ ].…”

Impact of Sex on Proper Use of Inhaler Devices in Asthma and COPD: A Systematic Review and Meta-Analysis

“…Thus, since inadequate hand-breath coordination may affect the proper use of MDI, along with poor fine motor control and hand or finger muscle weakness [77,78], we expected that females would have had more difficulty in using MDI instead of DPI. Conversely, we can suppose that the greater difficulty for females suffering from asthma and COPD in correctly using DPI may be related to a lower peak inspiratory flow (PIF) than male patients, as suboptimal PIF is a limiting factor for the correct actuation of DPI, a condition leading to inadequate drug-carrier disaggregation and insufficient drug deposition into the airways [79]. As a matter of fact, in both asthma and COPD, the PIF value reported for females is consistently lower than that reported for males, irrespective of the types of DPI used [80,81].…”

“…Indeed, the slow-moving aerosol produced by SMI gives more time for a better inhalation-actuation coordination, which may enhance drug delivery [83]. However, according to the evidence that some patients may find the procedure of loading the cartridge into the inhaler challenging [79], we can speculate that sex difference in the development of three-dimensional spatial abilities [76] may explain the greater error rates reported for females compared to males in using SMI.…”

Relationship between Peak Inspiratory Flow and Patient and Disease Characteristics in Individuals with COPD—A Systematic Scoping Review

“…Adoption of standardized recommendations for PIF measurement can help to ensure accurate and reliable PIF values, both in clinical trials and in daily clinical practice. [ 15 ].…”