OBJECTIVES: To document the prevalence of asthma among school-aged children in two Alberta communities, to understand host and indoor environmental factors associated with asthma, and to compare these factors between the two communities.DESIGN: A cross-sectional study with a nested, case-control follow-up.SETTING: Red Deer and Medicine Hat, Alberta.PATIENTS AND METHODS: Questionnaires were sent to families of children aged five to 19 years in Red Deer (n=5292) and Medicine Hat (n=5372) to identify children with current asthma. A random sample of 592 children with current asthma and 443 with no history of asthma constituted a case-control population; they were followed up by telephone to obtain responses to the European Respiratory Health Survey and, in children with current asthma, the Pediatric Quality of Life Questionnaire.RESULTS: Cross-sectional response rates were 84% and 73% for Red Deer and Medicine Hat, respectively. The prevalence of asthma was higher in Medicine Hat (17.0%) than in Red Deer (12.8%). In the follow-up study, factors associated with the presence of asthma were parental asthma or allergies, number of siblings, presence of cats, serious respiratory illnesses before five years of age, sex, age, presence of mould and/or mildew and use of a gas cooking stove. The presence of mould and/or mildew was a significant risk factor in Red Deer but not in Medicine Hat.CONCLUSIONS: Asthma prevalence among school children in Red Deer was consistent with recently published Canadian data; the prevalence in Medicine Hat was higher than expected, especially given the low relative humidity. Risk factor data are consistent with other studies in that parental asthma, especially maternal asthma, was a significant predictor of childhood asthma. Cats in the house (both communities) and environmental tobacco smoke (Medicine Hat only) were significantly less common among children with asthma, suggesting that preventive actions may have been taken in the homes of some children with asthma.

Patrick A Hessel

Justine Klaver

Dennis Michaelchuk

Shawna McGhan

Mary M Carson

Darrel Melvin

The Epidemiology of Childhood Asthma in Red Deer and Medicine Hat, Alberta

Louis-Philippe Boulet

The Changing Medical Research Scene

Norman L Jones

Too Late, Again?

Numerous cases of orthodeoxia and platypnea have been reported. Some have been found to be due to intracardiac shunts despite normal intracardiac pressures. In the case presented, a 79-year-old woman was noted to have orthodeoxia and platypnea secondary to a patent foramen ovale (PFO) despite normal intracardiac pressures. She recovered after closure of the PFO. The authors postulate that recent vertebral fractures and subsequent kyphosis, as well as a dilated thoracic aorta, altered intrathoracic relationships and may have led to a stream of venous return being directed across the PFO in the upright position, despite normal intracardiac pressures.

Mark Varkul

Trevor Robinson

Elane Ng

Robert Hyland

Orthodeoxia and Platypnea Secondary to a Patent Foramen Ovale Despite Normal Right Sided Cardiac Pressures

A case of symptomatic hypersensitivity pneumonitis with normal high resolution computed tomography (CT) scans is presented. The patient, a 32-year-old man with systemic lupus erythematosus, had a chronic, progressive history of respiratory symptoms, abnormal findings on examination and abnormal pulmonary function tests but normal high resolution CT scans of the chest. Diagnosis was made through open lung biopsy. Clinical improvement was seen on removal of the offending antigen. The literature on the utility of high resolution CT scans in hypersensitivity pneumonitis is reviewed.

Farah J Nasser-Sharif

Meyer S Balter

Hypersensitivity Pneumonitis with Normal High Resolution Computed Tomography Scans

OBJECTIVE: To establish the clinical pattern and etiology of exudative pleural effusions in adults in North Lebanon.MATERIALS AND METHODS: All patients aged 21 years and older who were admitted with exudative pleural effusions to the Husseini Hospital, Tripoli, North Lebanon, between 1997 and 1999 were studied prospectively.RESULTS: Of 165 patients with exudative pleural effusions, 114 (69.1%) were men and 51 (30.9%) were women. The most frequent cause of exudative pleural effusions was tuberculosis (43.7%), followed by malignancy (32.1%). The majority (88.7%) of malignant pleural effusions were due to lung cancer. Tuberculous effusions were more frequent in the first five decades of life (66.7%) and were the most common type of pleural effusion, accounting for 68.6% of patients younger than 50 years of age. Malignant effusions were more frequent among the older age groups, with 73.6% of patients with malignant effusions being older than 50 years of age. Most types of exudative pleural effusions showed a preference for the right side of the thorax. Of the diagnostic procedures used in the present study, the most useful were histological examination and culture of pleural biopsies.CONCLUSIONS: In North Lebanon, the clinical pattern and etiology of exudative pleural effusions are similar to those in the developing countries; the most frequent cause of pleural exudates is tuberculosis, followed by malignancy, particularly malignancy due to lung cancer.

Wassim Khalil Kalaajieh

Etiology of Exudative Pleural Effusions in Adults in North Lebanon

Doctors as Patients

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Canadian Respiratory Journal provides a multidisciplinary forum for research in all areas of respiratory medicine. The journal publishes research related to asthma, allergy, COPD, non-invasive ventilation, therapeutic intervention etc.

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Chief Editor, Dr Alice M Turner, is based at the University of Birmingham, UK. Her main research interests are the clinical aspects of alpha 1 antitrypsin deficiency and chronic obstructive pulmonary disease.

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Canadian Respiratory Journal - Table of contents 2001

title

Canadian Respiratory Journal provides a multidisciplinary forum for research in all areas of respiratory medicine. The journal publishes research related to asthma, allergy, COPD, non-invasive ventilation, therapeutic intervention etc.

Canadian Respiratory Journal