Measuring Peak Inspiratory Flow in Patients with Chronic Obstructive Pulmonary Disease

Abstract

Jill A Ohar,1 Gary T Ferguson,2 Donald A Mahler,3 M Bradley Drummond,4 Rajiv Dhand,5 Roy A Pleasants,4,6 Antonio Anzueto,7 David MG Halpin,8 David B Price,9,10 Gail S Drescher,11 Haley M Hoy,12 John Haughney,9 Michael W Hess,13 Omar S Usmani14 1Section of Pulmonary, Critical Care, Allergy, and Immunology, School of Medicine, Wake Forest University, Winston-Salem, NC, USA; 2Pulmonary Research Institute of Southeast Michigan, Farmington Hills, MI, USA; 3Geisel School of Medicine at Dartmouth, Hanover, NH, USA; 4Division of Pulmonary Diseases and Critical Care Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; 5Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Tennessee Graduate School of Medicine, Knoxville, TN, USA; 6Department of Quality, University of Michigan, Ann Arbor, MI, USA; 7Pulmonology Section, University of Texas Health, and South Texas Veterans Health Care System, San Antonio, TX, USA; 8University of Exeter Medical School, College of Medicine and Health, University of Exeter, Exeter, UK; 9Academic Primary Care, Division of Applied Health Sciences, University of Aberdeen, Aberdeen, UK; 10Observational and Pragmatic Research Institute, Singapore; 11Pulmonary Services Department, MedStar Washington Hospital Center, Washington, DC, USA; 12Transplant Center, Vanderbilt University Medical Center, Nashville, TN, USA; 13COPD Foundation, Kalamazoo, MI, USA; 14National Heart and Lung Institute, Imperial College London and Royal Brompton Hospital, London, UKCorrespondence: Jill A OharSection of Pulmonary, Critical Care, Allergy, and Immunology, School of Medicine, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, NC 27109, USATel [phone]Fax [phone]Email [email protected]: 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.Keywords: chronic obstructive pulmonary disease, dry powder inhalers, peak inspiratory flow

Keywords

• chronic obstructive pulmonary disease
• dry powder inhalers
• peak inspiratory flow