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BACKGROUND: There are several tests recommended by the American Thoracic Society (ATS) to evaluate for airway hyper-responsiveness (AHR), one of which is methacholine challenge testing (MCT). Few studies have examined the correlation of baseline spirometry to predict AHR in MCT, especially in the younger, relatively healthy military population under clinical evaluation for symptoms of exertional dyspnea. The study aim was to retrospectively correlate baseline spirometry values with MCT responsiveness. METHODS: This study is a retrospective review of all MCT performed at Brooke Army Medical Center/Wilford Hall Medical Center over a 12-y period; all completed studies were obtained from electronic databases. The following parameters were analyzed from the studies: baseline FEV1, FVC, FEV1/FVC, mid-expiratory flow (FEV25-75%), FEV25-75%/FVC. Studies were categorized based on baseline obstruction, restriction, FEF25-75% lower limit of normal, and response to bronchodilator testing (if completed); these values were compared based on methacholine reactivity and severity. RESULTS: Methacholine challenge studies (n = 1,933) were reviewed and categorized into reactive (n = 577) and nonreactive (n = 1,356) as determined by ATS guidelines. The mean baseline FEV1 (% predicted) with MCT reactivity was 88.0 6 13.0% versus no MCT reactivity was 92.7 6 13.0% (P < .001). The mean baseline FVC (% predicted) was 93.1 ± 13.7% versus 95.3 ± 13.5% (P < .001). The mean baseline FEV25-75% (% predicted) was 80.0 ± 22.1% versus 89.0 ± 23.4% (P < .001). Based on partition analysis, methacholine reactivity was most prevalent with baseline obstruction, n = 115 (43%), and in the absence of obstruction, when the FEF25-75% (% predicted) was below 0.70, n = 111 (40%). The negative predictive value with normal spirometry was 73%. CONCLUSIONS: The analysis of baseline spirometry prior to MCT proved useful in the evaluation of exertional dyspnea in a military population. The presence of airways obstruction (FEV1/FVC < lower limit of the normal range) followed by a reduction in FEV25-75% < 70% predicted showed a positive correlation with underlying AHR. In patients with exertional dyspnea and normal baseline spirometry, the use of the FEF25-75% may be a useful surrogate measurement to predict reactivity during MCT and consideration for additional testing or treatment [ABSTRACT FROM AUTHOR]

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 deploymentrelated respiratory complaints. [ABSTRACT FROM AUTHOR]

A patient with long-standing cirrhosis due to hepatitis C and hepatic hydrothorax was evaluated for increasing symptoms and presence of a large right pleural effusion. Thoracentesis revealed evidence of a chylothorax with rapid reaccumulation of pleural fluid. Repeat thoracentesis with manometry identified presence of entrapped lung which complicated treatment options. This is the first case report of a hepatic chylothorax with features of entrapped lung. [ABSTRACT FROM AUTHOR]