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Background: Published guidelines on spirometry interpretation suggest an elevated FVC and FEV1 > 100% of predicted with an obstructive ratio may represent a physiological variant. Further evidence is needed on whether this finding indicates symptomatic airways obstruction and what additional evaluation should be done., Methods: Participants were prospectively enrolled to undergo additional testing for a technically adequate spirometry study with an FEV1 > 90% of predicted, and FEV1/FVC below the lower limit of normal, based on 95th percentile confidence intervals. Further testing consisted of full pulmonary function testing, impulse oscillometry (IOS), post-bronchodilator testing, fractional exhaled nitric oxide (FeNO), and methacholine challenge testing (MCT)., Results: A total of 49 patients meeting entry criteria enrolled and completed testing. Thirty-three were considered symptomatic based on clinical indications for initial testing and 16 were considered asymptomatic. Baseline pulmonary function test values were not different between groups while IOS R5 values (% predicted) were higher in the symptomatic group (126.5 ± 0.37 vs 107.1 ± 0.31). Bronchodilator responsiveness on PFT or IOS was infrequent in both groups. There was a 29% positivity rate for MCT in the symptomatic group compared to one borderline study in asymptomatic participants. FeNO was similar for symptomatic, 26.17 ± 31.3 ppb, compared to asymptomatic, 22.8 ± 13.5 ppb (p = 0.93). The dysanapsis ratio was higher in the symptomatic (0.15 ± 0.03) compared to the asymptomatic (0.13 ± 0.02) (p < 0.05)., Conclusion: Normal FEV1 > 90% of predicted and obstructive indices may not represent a normal physiological variant in all patients. In symptomatic patients, a positive MCT and elevated baseline IOS values were more common than in asymptomatic patients with similar PFT characteristics. These findings suggest that clinicians should still evaluate for airway hyperresponsiveness in patients with exertional dyspnea with airway obstruction and FEV1 > 90% of predicted and consider alternative diagnoses to include a normal physiologic variant if non-reactive., (Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2021. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Background: Significant concern exists regarding the respiratory health of military personnel deployed to Southwest Asia, given their exposures to numerous environmental hazards. Although the deployed military force is generally assumed to be fit, the pre-deployment respiratory health of these individuals is largely unknown., Methods: Soldiers deploying to Southwest Asia were recruited from the pre-deployment processing center at Fort Hood, Texas. Participants completed a general and respiratory health questionnaire and performed baseline spirometry., Results: One thousand six hundred ninety-three pre-deployment evaluations were completed. The average age of the participants was 32.2 y, and 83.1% were male. More than one third of surveyed solders had a smoking history, 73% were overweight or obese, and 6.2% reported a history of asthma. Abnormal spirometry was found in 22.3% of participants. Soldiers with abnormal spirometry reported more asthma (10.1% vs 5.1%, P < .001), failed physical fitness tests (9.0% vs 4.6%, P = .02), and respiratory symptoms (32.8% vs 24.3%, P = .001)., Discussion: This is the first prospective pre-deployment evaluation of military personnel that delineates factors potentially associated with the development of pulmonary symptoms and/or disease. This study suggests that deploying soldiers are older, heavier, frequently smoke, and may have undiagnosed pre-deployment lung disease. Abnormal spirometry is common but may not represent underlying disease. Self-reported asthma, wheezing, and slower 2-mile run times were predictive of abnormal spirometry., Conclusions: Pre-deployment evaluation of military personnel identified numerous soldiers with active pulmonary symptoms and abnormal spirometry. When combined with questions regarding asthma history, wheezing and exercise intolerance, spirometry may identify individuals at risk for deployment-related respiratory complaints., Competing Interests: The authors have disclosed no conflicts of interest. The opinions in this work do not constitute endorsement by San Antonio Military Medical Center, the United States Army Medical Department, the United States Army Office of the Surgeon General, the Department of the Army, the Department of the Air Force, or the United States Government of the information contained therein., (Copyright © 2017 by Daedalus Enterprises.)

Chronic respiratory symptoms are frequently reported after Southwest Asia deployment in support of combat operations. The full spectrum of clinical lung diseases related to these deployments is not well characterized. Military personnel with chronic symptoms, primarily exertional dyspnea, underwent a standardized cardiopulmonary evaluation at two tertiary medical centers. Pulmonary function testing consisted of spirometry, lung volume, diffusing capacity, impulse oscillometry, and bronchodilator testing. Further testing included methacholine challenge, exercise laryngoscopy, high-resolution CT scan, ECG, and transthoracic echocardiography. A total of 380 participants with a mean age of 38.5 ± 8.4 years completed testing. Asthma was the most common diagnosis in 87 patients (22.9%) based on obstructive spirometry/impulse oscillometry and evidence of airway hyperreactivity, whereas another 57 patients (15.0%) had reactivity with normal spirometry. Airway disorders included 25 (6.6%) with laryngeal disorders and 16 (4.2%) with excessive dynamic airway collapse. Interstitial lung disease was identified in six patients (1.6%), whereas 11 patients (2.9%) had fixed obstructive lung disorders. Forty patients (10.5%) had isolated pulmonary function abnormalities and 16 (4.2%) had miscellaneous disorders. The remaining 122 patients (32.1%) with normal studies were classified as undiagnosed exertional dyspnea. Significant comorbidities identified included elevated BMI > 30 kg/m2 (34.2%), smoking (36.4%), positive allergy testing (43.7%), sleep apnea (38.5%), and esophageal reflux (13.6%). Mental health disorders and posttraumatic stress disorder were likewise common. Postdeployment pulmonary evaluation should focus on common diseases, such as asthma and airway hyperreactivity, and include testing for upper airway disorders. Diffuse lung diseases were rarely diagnosed, whereas numerous comorbidities were common. [ABSTRACT FROM AUTHOR]