Variable extrathoracic airflow obstruction and chronic laryngotracheitis in Gulf War veterans

Presence of variable extrathoracic airflow limitation in patients with a negative methacholine challenge test

PURPOSE

Determine whether variable extrathoracic airflow limitation (VEAL) is observed in patients with negative methacholine challenge tests (MCT).

METHODS

Electronic medical records of patients undergoing MCT at Jesse Brown VA Medical Center between January 2017 and December 2019 were reviewed. Only patients with negative MCT were selected. Pertinent demographic, clinical, and pulmonary function tests (PFT) and MCT data were abstracted from each record. Spirometric flow-volume loops recorded during each test were inspected by one co-author to determine the first inhaled methacholine concentration at which FEF50/FIF50 was either > 1 or further increased if baseline FEF50/FIF50 after nebulized saline (vehicle) already exceeded 1. Student's t-test was used for statistical analysis. P < 0.05 was considered statistically significant.

RESULTS

One hundred and twenty-seven consecutive patients with normal baseline PFT and negative MCT were identified. Thirteen patients (10.2%) had negative MCT and FEF50/FIF50 > 1 after testing. They were predominately obese (BMI, 31.3 ± 6.6), non-smoking (10), White (8) males (9) aged 51.3 ± 14.1 years (mean ± SD) referred for symptoms suggestive of asthma (n = 7) or for chronic cough (n = 6). Five had obstructive sleep apnea, three gastroesophageal reflux disease, and two chronic rhinosinusitis. FEF50/FIF50 increased significantly from 0.72 ± 0.21 after nebulized saline (vehicle) to 1.21 ± 0.13 after inhaled methacholine (p < 0.001). Median inhaled methacholine concentration eliciting these responses was 1.0 mg/mL (range, 0.25-16 mg/mL).

CONCLUSIONS

VEAL is observed in a subset of patients with a negative MCT. This phenomenon should be recognized and reported to the referring healthcare providers and its clinical significance addressed as indicated.

Flow-Volume Curve Analysis for Predicting Recurrence After Endoscopic Dilation of Airway Stenosis

BACKGROUND

The flow-volume curve is a simple test for diagnosing upper airway obstruction. We evaluated its use to predict recurrence in patients undergoing endoscopic dilation for treatment of benign upper airway stenosis.

METHODS

The data of 89 consecutive patients undergoing endoscopic dilation of simple upper airway stenosis were retrospectively reviewed. Morphologic distortion of flow-volume loop (visual analysis) and quantitative criteria, including maximal expiratory flow rate at 50% of the vital capacity (MEF_50%)/maximal inspiratory flow rate at 50% of the vital capacity (MIF_50%) of less than 0.3 or more than 1.0, forced expiratory volume in 1 second/MEF exceeding 10, and forced expiratory volume in 1 second/forced expiratory volume in .05 second exceeding 1.5, were considered predictive of recurrence. In all cases, the recurrence was confirmed by radiologic or bronchoscopic findings, or both. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of visual, quantitative, and aggregate criteria for detecting recurrence were computed and compared.

RESULTS

Of 89 patients treated, 27 (30%) had a recurrence. Visual analysis presented a sensitivity, specificity, PPV, NPV, and accuracy of 63%, 83.9%, 63%, 83.9%, and 77.5%, respectively. Among the quantitative criterion, the MEF_50%/MIF_50% was the most accurate, having a sensitivity, specificity, PPV, NPV, and accuracy of 77.8%, 79%, 61.8%, and 89.1%, and 78.7%, respectively. Aggregate criterion presented the best yield compared with other criteria in sensitivity (81.5%), specificity (91.9%), PPV (81.5%), NPV (91.9%), and accuracy (88.8%).

CONCLUSIONS

The flow-volume curve is a simple and noninvasive method to monitor patients undergoing endoscopic dilation of upper airway stenosis. Morphologic changes in the flow-volume loop and in the MEF_50%/MIF_50% ratio are suggestive of recurrence and guide the physician to implement the follow-up with further diagnostic (non)invasive examinations.

Contribution of flow-volume curves to the detection of central airway obstruction

OBJECTIVE:

To assess the sensitivity and specificity of flow-volume curves in detecting central airway obstruction (CAO), and to determine whether their quantitative and qualitative criteria are associated with the location, type and degree of obstruction.

METHODS:

Over a four-month period, we consecutively evaluated patients with bronchoscopy indicated. Over a one-week period, all patients underwent clinical evaluation, flow-volume curve, bronchoscopy, and completed a dyspnea scale. Four reviewers, blinded to quantitative and clinical data, and bronchoscopy results, classified the morphology of the curves. A fifth reviewer determined the morphological criteria, as well as the quantitative criteria.

RESULTS:

We studied 82 patients, 36 (44%) of whom had CAO. The sensitivity and specificity of the flow-volume curves in detecting CAO were, respectively, 88.9% and 91.3% (quantitative criteria) and 30.6% and 93.5% (qualitative criteria). The most prevalent quantitative criteria in our sample were FEF50%/FIF50% ≥ 1, in 83% of patients, and FEV1/PEF ≥ 8 mL . L^–1 . min^–1, in 36%, both being associated with the type, location, and degree of obstruction (p < 0.05). There was concordance among the reviewers as to the presence of CAO. There is a relationship between the degree of obstruction and dyspnea.

CONCLUSIONS:

The quantitative criteria should always be calculated for flow-volume curves in order to detect CAO, because of the low sensitivity of the qualitative criteria. Both FEF50%/FIF50% ≥ 1 and FEV1/PEF ≥ 8 mL . L^–1 . min^–1 were associated with the location, type and degree of obstruction.

Military service and lung disease

Military personnel can be exposed to toxicants and conditions that can contribute to lung diseases. This article describes what is known about these exposures and diseases, focusing on the Iraq and Afghanistan wars. Adverse lung health outcomes have been reported in US military personnel deployed to Iraq and/or Afghanistan. Most studies to date have been hindered by limited deployment-specific exposure assessment, lack of baseline lung health information, and variable medical evaluations and case definitions. Further research is warranted. Medical surveillance has been recommended for returning troops, but the challenges are substantial.

Tracheal stricture and fistula: management with a barbed silicone-covered retrievable expandable nitinol stent

OBJECTIVE

The purpose of this study was to evaluate the safety and effectiveness of a barbed silicone-covered retrievable expandable nitinol stent in preventing stent migration in patients with tracheal strictures or fistulas.

SUBJECTS AND METHODS

Under fluoroscopic guidance, barbed silicone-covered retrievable expandable nitinol stents were placed in 15 patients with tracheal strictures, two patients with fistulas, two patients with combined strictures and fistulas, and one patient with variable extrathoracic airway obstruction. The three pairs of barbs were attached to the external stent surface at the middle of the stent at equal intervals. Technical success, improvement in respiratory status, complications, and related interventions were evaluated.

RESULTS

The technical success rate was 100%, and respiratory status improved or the fistula closed in all 20 patients. Complications included sputum retention (three patients), tumor overgrowth (three patients), pain (one patient), and granulation tissue formation (one patient). No stent migration occurred, even in the three patients without fixed strictures. Four stents subsequently were removed because of complications, and one stent was removed because the patient's condition improved. Stent removal was not difficult and was uneventful. The silicone membranes and barbs of the removed stents were intact.

CONCLUSION

Use of a barbed silicone-covered retrievable expandable nitinol stent relieves dyspnea and facilitates fistula closure in patients with benign or malignant tracheal strictures or fistulas. The barbed design of the stent is important in preventing migration.

Vocal cord dysfunction in former World Trade Center (WTC) rescue and recovery workers and volunteers

BACKGROUND

Vocal cord dysfunction (VCD) is a condition characterized by paradoxical partial adduction of the vocal cords on inspiration. It has been associated with exposures to irritants, as well as with psychological illnesses and conditions. Workers who participated in the recovery of the WTC disaster site were exposed to a large amount of irritants as well as considerable psychological stressors. We describe the clinical characteristics of 10 symptomatic former WTC workers diagnosed with this condition, as well as the frequency of spirometric findings suggestive of variable extrathoracic obstruction.

METHODS

Workers who became symptomatic after their WTC work experience have been evaluated clinically by a multidisciplinary team at an academic medical center. The evaluation included history, physical examination, chest radiograph, blood tests, and pre- and post-bronchodilator spirometry in all patients. Additional evaluations and diagnostic tests included otolaryngological evaluation with flexible rhinolaryngoscopy and stroboscopy, gastroenterological and psychiatric evaluations. A randomly selected sample of 172 spirometry results were reviewed for evidence of inspiratory flow limitation.

RESULTS

Variable extrathoracic obstruction was found in 18.6% of the spirometries. Ten patients were diagnosed with VCD. In addition to symptoms suggestive of co-morbid conditions (particularly rhinitis and acid reflux disease), most of the 10 patients had (1) hoarseness, (2) dyspnea that was not associated with bronchial hyperreactivity, or (3) dyspnea associated with asthma, with either mild bronchial hyperreactivity and/or poor response to asthma treatment.

CONCLUSIONS

VCD appears to be part of the spectrum of airway disorders caused by occupational exposures at the WTC disaster site. Further study of this association is warranted.

Pulmonary function after exposure to the World Trade Center collapse in the New York City Fire Department

RATIONALE

On September 11, 2001, the World Trade Center collapse created an enormous urban disaster site with high levels of airborne pollutants. First responders, rescue and recovery workers, and residents have since reported respiratory symptoms and developed pulmonary function abnormalities.

OBJECTIVES

To quantify respiratory health effects of World Trade Center exposure in the New York City Fire Department.

MEASUREMENTS

Longitudinal study of pulmonary function in 12,079 New York City Fire Department rescue workers employed on or before 09/11/2001. Between 01/01/1997 and 09/11/2002, 31,994 spirometries were obtained and the FEV(1) and FVC were analyzed for differences according to estimated World Trade Center exposure intensity. Adjusted average FEV(1) during the first year after 09/11/2001 was compared with the 5 yr before 09/11/2001. Median time between 09/11/2001 and a worker's first spirometry afterwards was 3 mo; 90% were assessed within 5 mo.

MAIN RESULTS

World Trade Center-exposed workers experienced a substantial reduction in adjusted average FEV(1) during the year after 09/11/2001 (372 ml; 95% confidence interval, 364-381 ml; p < 0.001) This exposure-related FEV(1) decrement equaled 12 yr of aging-related FEV(1) decline. Moreover, exposure intensity assessed by initial arrival time at the World Trade Center site correlated linearly with FEV(1) reduction in an exposure intensity-response gradient (p = 0.048). Respiratory symptoms also predicted a further FEV(1) decrease (p < 0.001). Similar findings were observed for adjusted average FVC.

CONCLUSIONS

World Trade Center exposure produced a substantial reduction in pulmonary function in New York City Fire Department rescue workers during the first year after 09/11/2001.

After more than 10 years of Gulf War veteran medical evaluations, what have we learned?

Since the 1991 Gulf War, more than 10 years and 1 billion dollars of health evaluations and research have been invested in understanding illnesses among Gulf War veterans. We examined the extensive published healthcare utilization data in an effort to summarize what has been learned. Using multiple search techniques, data as of June 2003 from four different national Gulf War health registries and numerous hospitalization and ambulatory care reports were reviewed. Thus far, published reports have not revealed a unique Gulf War syndrome nor identified specific exposures that might explain postwar morbidity. Instead, they have demonstrated that Gulf War veterans have had an increase in multi-symptom condition, injury, and mental health diagnoses. While these diagnoses are similar to those experienced by other comparable military populations, their explanation is not fully understood. New strategies to identify risk factors for, and to reduce, such postdeployment conditions are summarized.

The problem of Gulf War syndrome

Following a war with widespread attention to and concern over the potential for numerous biological and chemical warfare exposures, some Gulf War veterans returned home and developed various illnesses. Although some of these illnesses are readily diagnosable, the so-called Gulf War syndrome has remained a controversial and nebulous diagnosis. It is characterized by multiple, subjective symptoms, and by a lack of objective pathology. To date, the search for a single disease entity and a biological model to explain this illness has been unsuccessful. Wars have long affected the health of veterans in multiple ways, and a single disease entity is not likely as a viable explanation for these outcomes. Given the nature of the illness, and its overlap with many other controversial chronic illnesses, we suggest that the biopsychosocial model may provide a better solution to this diagnostic conundrum.