Clayton T. Cowl

Diagnosis and Management of Work-Related Asthma: American College of Chest Physicians Consensus Statement

BACKGROUND A previous American College of Chest Physicians Consensus Statement on asthma in the workplace was published in 1995. The current Consensus Statement updates the previous one based on additional research that has been published since then, including findings relevant to preventive measures and work-exacerbated asthma (WEA). METHODS A panel of experts, including allergists, pulmonologists, and occupational medicine physicians, was convened to develop this Consensus Document on the diagnosis and management of work-related asthma (WRA), based in part on a systematic review, that was performed by the University of Alberta/Capital Health Evidence-Based Practice and was supplemented by additional published studies to 2007. RESULTS The Consensus Document defined WRA to include occupational asthma (ie, asthma induced by sensitizer or irritant work exposures) and WEA (ie, preexisting or concurrent asthma worsened by work factors). The Consensus Document focuses on the diagnosis and management of WRA (including diagnostic tests, and work and compensation issues), as well as preventive measures. WRA should be considered in all individuals with new-onset or worsening asthma, and a careful occupational history should be obtained. Diagnostic tests such as serial peak flow recordings, methacholine challenge tests, immunologic tests, and specific inhalation challenge tests (if available), can increase diagnostic certainty. Since the prognosis is better with early diagnosis and appropriate intervention, effective preventive measures for other workers with exposure should be addressed. CONCLUSIONS The substantial prevalence of WRA supports consideration of the diagnosis in all who present with new-onset or worsening asthma, followed by appropriate investigations and intervention including consideration of other exposed workers.

Conditions Associated With an Abnormal Nonspecific Pattern of Pulmonary Function Tests

BACKGROUND Little is known about a fairly frequent abnormal pattern of pulmonary function test results: reduced FEV(1) and FVC with a normal FEV(1)/FVC and normal total lung capacity. We term this a nonspecific pattern (NSP). We sought to identify medical conditions having this pattern and to explore mechanisms producing it. METHODS From a database of 80,929 test results, the NSP was found in 7,702 subjects from whom was drawn a random sample of 100 subjects. Medical records and all available tests were examined. RESULTS Airway hyperresponsiveness (AHR) and obesity were common. Two groups of subjects were identified. Group A consisted of 68 subjects with evidence of airway disease, including AHR and chronic lung disease. A volume derecruitment model was proposed to explain their NSP. Group B consisted of 32 subjects with no evidence of airway disease. Restricted expansion of the thorax or lung may explain the NSP in most of these subjects. Forty subjects had repeated tests, and in only 17 were the test results consistently nonspecific. CONCLUSIONS In a random sample of 100 subjects with the NSP, the probable underlying cause of the pattern in 68 subjects was airway disease. In most of the remaining 32 subjects, restricted expansion of the thorax or lung may be implicated.

Spirometry in the Occupational Setting

: This position statement reviews several aspects of spirometric testing in the workplace, where spirometry is employed in the primary, secondary, and tertiary prevention of occupational lung disease. Primary prevention includes pre-placement and fitness-for-duty examinations as well as research and monitoring of health status in groups of exposed workers; secondary prevention includes periodic medical screening of individual workers for early effects of exposure to known occupational hazards; and tertiary prevention includes clinical evaluation and impairment/disability assessment. For all of these purposes, valid spirometry measurements are critical, requiring: documented spirometer accuracy and precision, a rigorous and standardized testing technique, standardized measurement of pulmonary function values from the spirogram, adequate initial and refresher training of spirometry technicians, and, ideally, quality assessment of samples of spirograms. Interpretation of spirometric results usually includes comparison with predicted values and should also evaluate changes in lung function over time. Response to inhaled bronchodilators and changes in relation to workplace exposure may also be assessed. Each of these interpretations should begin with an assessment of test quality and, based on the most recent ATS recommendations, should rely on a few reproducible indices of pulmonary function (FEV1, FVC, and FEV1/FVC.) The use of FEF rates (e.g., the FEF25-75%) in interpreting results for individuals is strongly discouraged except when confirming borderline airways obstruction. Finally, the use of serial PEF measurements is emerging as a method for confirming associations between reduced or variable pulmonary function and workplace exposures in the diagnosis of occupational asthma. Throughout this position statement, ACOEM makes detailed recommendations to ensure that each of these areas of test performance and interpretation follow current recommendations/standards in the pulmonary and regulatory fields. Submitted by the Occupational and Environmental Lung Disorder Committee on November 16,1999. Approved by the ACOEM Board of Directors on January 4,2000.

Impact of direct-to-consumer predictive genomic testing on risk perception and worry among patients receiving routine care in a preventive health clinic.

OBJECTIVE To assess the impact of direct-to-consumer (DTC) predictive genomic risk information on perceived risk and worry in the context of routine clinical care. PATIENTS AND METHODS Patients attending a preventive medicine clinic between June 1 and December 18, 2009, were randomly assigned to receive either genomic risk information from a DTC product plus usual care (n=74) or usual care alone (n=76). At intervals of 1 week and 1 year after their clinic visit, participants completed surveys containing validated measures of risk perception and levels of worry associated with the 12 conditions assessed by the DTC product. RESULTS Of 345 patients approached, 150 (43%) agreed to participate, 64 (19%) refused, and 131 (38%) did not respond. Compared with those receiving usual care, participants who received genomic risk information initially rated their risk as higher for 4 conditions (abdominal aneurysm [P=.001], Graves disease [P=.04], obesity [P=.01], and osteoarthritis [P=.04]) and lower for one (prostate cancer [P=.02]). Although differences were not significant, they also reported higher levels of worry for 7 conditions and lower levels for 5 others. At 1 year, there were no significant differences between groups. CONCLUSION Predictive genomic risk information modestly influences risk perception and worry. The extent and direction of this influence may depend on the condition being tested and its baseline prominence in preventive health care and may attenuate with time.

Occupational Asthma: Review of Assessment, Treatment, and Compensation

Occupational asthma refers to asthma induced by exposure in the working environment to airborne dusts, vapors, or fumes, with or without preexisting asthma. Potential triggers of occupational asthma are diverse and involve a variety of postulated mechanisms. After confirming the presence of asthma, diagnosis hinges on obtaining a detailed and accurate occupational and environmental history and documenting a temporal association of symptoms or signs with workplace exposure. Management of occupational asthma centers on prescribing standard asthma therapies in conjunction with instituting preventive strategies, such as appropriate avoidance of environmental triggers, providing work restrictions, and using environmental controls and/or personal respiratory protection. If a worker is determined to be ill or injured, there are a variety of compensation systems that are designed to protect workers financially from disability related to respiratory impairments; however, the administrative process is frequently difficult to navigate for patients and their providers. Focusing on obtaining a detailed occupational and environmental history, establishing clear objective data to substantiate illness, and estimating or apportioning workplace contribution to the condition is important for the diagnosis and treatment of this relatively common form of asthma.

Air travel and pneumothorax

The number of medical emergencies onboard aircraft is increasing as commercial air traffic increases and the general population ages, becomes more mobile, and includes individuals with serious medical conditions. Travelers with respiratory diseases are at particular risk for in-flight events because exposure to lower atmospheric pressure in a pressurized cabin at cruising altitude may result in not only hypoxemia but also pneumothorax due to gas expansion within enclosed pulmonary parenchymal spaces based on Boyles law. Risks of pneumothorax during air travel pertain particularly to those patients with cystic lung diseases, recent pneumothorax or thoracic surgery, and chronic pneumothorax. Currently available guidelines are admittedly based on sparse data and include recommendations to delay air travel for 1 to 3 weeks after thoracic surgery or resolution of the pneumothorax. One of these guidelines declares existing pneumothorax to be an absolute contraindication to air travel although there are reports of uneventful air travel for those with chronic stable pneumothorax. In this article, we review the available data regarding pneumothorax and air travel that consist mostly of case reports and retrospective surveys. There is clearly a need for additional data that will inform decisions regarding air travel for patients at risk for pneumothorax, including those with recent thoracic surgery and transthoracic needle biopsy.

Health assessment of commercial drivers: a meta-narrative systematic review

Background Motor vehicle accidents associated with commercial driving are an important cause of occupational death and impact public safety. Objectives We summarise the evidence regarding the type, prevalence and impact of medical conditions discovered during health assessment of commercial drivers. Evidence review We conducted a systematic review of multiple electronic databases and made a manual search for relevant studies that enrolled commercial drivers in any country and reported the outcomes of health assessment carried out in the context of commercial driving through November 2012. Data were extracted by a pair of independent reviewers and synthesised using a metanarrative approach. Results We identified 32 studies of moderate methodological quality enrolling 151 644 commercial drivers (98% men). The prevalence of multiple health conditions was high (sleep disorders 19%, diabetes 33%, hypertension 23% and obesity 45%). Some conditions, such as sleep disorders and obesity, were linked to increased risk of crashes. Evidence on several other highly relevant medical conditions was lacking. Cost-effectiveness data were sparse. Conclusions Several medical conditions are highly prevalent in commercial drivers and can be associated with increased risk of crashes, thus providing a rationale for health assessment of commercial drivers.

A guide to the diagnosis and treatment of occupational asthma

Occupational asthma is the most prevalent form of occupational lung disease in industrialized nations. As increasing numbers of new chemicals are produced and new manufacturing processes are introduced, the variety of environments in which individuals may become exposed to respiratory sensitizers and irritants makes diagnosing and treating this illness even more challenging. In addition to adverse pulmonary effects, the diagnosis of occupational asthma may bring with it negative social and financial implications that may ultimately affect the patients quality of life. For this reason, it is important for clinicians to recognize work-related respiratory symptoms early on in their course, maintain a high clinical suspicion for an occupational cause in the diagnostic work-up of asthma, and have a high degree of certainty in the diagnosis. While a number of classification schemes have been proposed to simplify the diagnostic approach to occupational asthma, the inciting factors typically involve sensitization (often by an IgE mechanism), direct airway inflammation, various pharmacologic responses, or irritant reflex pathways. Clinicians must first document the presence of asthma, then establish a relationship between asthma and the work-place. The occupational history is the key diagnostic tool, and clinical suspicions may be evaluated further by serial peak expiratory flow measurements, nonspecific hypersensitivity challenges with histamine or methacholine, collaboration with industrial/occupational hygienists to obtain workplace exposure measurements, and specific challenge testing at tertiary referral centers providing specialized laboratories. Removal from the inciting exposure is the mainstay of therapy, and pharmacologic treatment of patients with occupational asthma is similar to the treatment of patients with other forms of asthma.

Use of Antisialogogues in Bronchoscopy

Correspondence Older age was a risk factor for hepatotoxicity in adults, 2 , 4 whereas smaller children were reported to be under risk 5 in childhood. However, our study did not demonstrate any age-specifi c difference for hepatotoxicity. In conclusion, severe hepatotoxicity in children was found to be lower than reported before, and age did not affect the incidence of INH hepatotoxicity, as it did in adults. Nevertheless, the potential of anti-TB drugs for hepatotoxicity and liver failure in children should be kept in mind.

Disability Assessment in Occupational and Environmental Lung Diseases

Assessment and management of administrative issues surrounding occupational and environmental lung disease are often one of the more challenging aspects of caring for individuals encountering illnesses or injuries associated with workplace exposures. Lack of formalized training in providing the forensic aspects of diagnosing and treating these types of conditions is often the reason why many health care providers experience significant frustration in prosecuting this type of work. This includes being able to define and understand the essential concepts of impairment and disability, recognizing the need for work restrictions and how to compose useful recommendations to the employer in order to avoid unnecessary time away from work when the individual patient could be accommodated in alternative work environments, and understanding the variety of programs available to compensate individuals affected by work-related exposures or injuries. The ability to perform these administrative tasks is vital to adequately serve the patient with these conditions.