Ryan P Butzko1, Anays M Sotolongo2, Drew A Helmer1, Jacquelyn C Klein-Adams2, Omowunmi Y Osinubi3, Andrew R Berman4, Ronaldo Ortiz-Pacheco4, Michael J Falvo5. 1. Airborne Hazards Center of Excellence, War Related Illness and Injury Study Center, Veterans Affairs New Jersey Health Care System, East Orange, NJ, USA; New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, NJ, USA. 2. Airborne Hazards Center of Excellence, War Related Illness and Injury Study Center, Veterans Affairs New Jersey Health Care System, East Orange, NJ, USA. 3. Airborne Hazards Center of Excellence, War Related Illness and Injury Study Center, Veterans Affairs New Jersey Health Care System, East Orange, NJ, USA; School of Public Health, Rutgers Biomedical and Health Sciences, Piscataway, NJ, USA. 4. New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, NJ, USA. 5. Airborne Hazards Center of Excellence, War Related Illness and Injury Study Center, Veterans Affairs New Jersey Health Care System, East Orange, NJ, USA; New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, NJ, USA. Electronic address: Michael.Falvo@va.gov.
Abstract
PURPOSE: To evaluate the utility of the forced oscillation technique (FOT) among military veterans with preserved spirometry and chronic unexplained respiratory symptoms. METHODS: 178 veterans referred for evaluation of unexplained respiratory symptoms completed pulmonary function testing and FOT. Preserved spirometry was defined as FEV1/FVC, FEV1 and FVC ≥ 5th percentile. Frequency dependence of resistance (R4-R20) and reactance area (AX) were assessed via FOT, and R4-R20 ≥ 20% and AX ≥ 95th percentile were considered abnormal. RESULTS: Spirometry was preserved in 71.3%, of whom 124 had acceptable FOT data. 93 of 124 (75.0%) veterans with preserved spirometry had one or more abnormal findings on FOT. Veterans with abnormal R4-R20 and/or AX had reduced FVC, FEV1, FEF25-75, and diffusing capacity (% predicted) in comparison to those with Normal FOT (p = 0.030 to p < 0.001). CONCLUSIONS: In our referral sample, distal airway dysfunction in the presence of preserved spirometry appears common and may represent an at-risk group requiring closer surveillance.
PURPOSE: To evaluate the utility of the forced oscillation technique (FOT) among military veterans with preserved spirometry and chronic unexplained respiratory symptoms. METHODS: 178 veterans referred for evaluation of unexplained respiratory symptoms completed pulmonary function testing and FOT. Preserved spirometry was defined as FEV1/FVC, FEV1 and FVC ≥ 5th percentile. Frequency dependence of resistance (R4-R20) and reactance area (AX) were assessed via FOT, and R4-R20 ≥ 20% and AX ≥ 95th percentile were considered abnormal. RESULTS: Spirometry was preserved in 71.3%, of whom 124 had acceptable FOT data. 93 of 124 (75.0%) veterans with preserved spirometry had one or more abnormal findings on FOT. Veterans with abnormal R4-R20 and/or AX had reduced FVC, FEV1, FEF25-75, and diffusing capacity (% predicted) in comparison to those with Normal FOT (p = 0.030 to p < 0.001). CONCLUSIONS: In our referral sample, distal airway dysfunction in the presence of preserved spirometry appears common and may represent an at-risk group requiring closer surveillance.
Authors: Drew A Helmer; Michael J Falvo; Jennifer H Therkorn; Sean Hu; Anays M Sotolongo; Israel C Christie; Tianshi David Wu; William W Van Doren; Venkata Siva Sai Sujith Sajja; Nisha Jani; Jacquelyn C Klein-Adams Journal: Respir Res Date: 2022-06-10