Seminars in respiratory and critical care medicine
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Semin Respir Crit Care Med · Apr 2005
Review Comparative StudyRole of bronchodilators in chronic obstructive pulmonary disease.
The prevalence of chronic obstructive pulmonary disease (COPD) continues to be on the rise. Bronchodilators are first line agents for the symptomatic management of this disease and have proven to be effective in both stable disease status and exacerbations. The stepwise escalation of therapy for COPD according to severity has been outlined in international guidelines. ⋯ In contrast, the usage of theophylline, which used to be part of the mainstay of treatment for COPD, has declined, mainly secondary to a narrow therapeutic margin and side effects, but it is inexpensive and still has its role. New agents like phosphodiesterase-4-inhibitors are interesting substances that may become important adjuncts in COPD management, but there is limited experience so far. None of the bronchodilators have been shown to change outcome in COPD, but this issue is under active investigation.
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Semin Respir Crit Care Med · Apr 2005
Review Comparative StudySurgical therapy for chronic obstructive pulmonary disease.
Many patients with severe chronic obstructive pulmonary disease (COPD) experience incapacitating breathlessness and exercise limitation. Multiple surgical techniques have been utilized to achieve resection of giant, localized bullae with documented short-term benefit in pulmonary function and dyspnea in highly selected patients. The poorest long-term outcome has been noted in those with greater degrees of emphysema in the remaining lung, greater underlying chronic bronchitis, and a bulla occupying less than one third of the hemithorax, particularly if compressed normal lung is not evident. ⋯ Long-term results of lung transplantation are limited by significant complications that impair survival; an approximately 80% 1-year, 50% 5-year, and 35% 10-year survival has been reported. Bronchiolitis obliterans is the most important long-term complication of lung transplantation resulting in decreased pulmonary function. In general, a COPD patient can be considered an appropriate candidate for transplantation when the FEV (1) is below 25% predicted and/or the paCO (2) is > or = 55 mm Hg.
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Semin Respir Crit Care Med · Apr 2005
Review Comparative StudyNew concepts in the radiological assessment of COPD.
Chronic obstructive pulmonary disease (COPD) is a complex genetic disorder in which environmental factors, such as tobacco smoke, interact with genetic susceptibility to cause disease. Airway obstruction in COPD is due to an exaggerated inflammatory response that ultimately destroys the lung parenchyma (emphysema) and increases airway resistance by remodeling the airway wall. ⋯ This review describes some of the new CT techniques for quantitative assessment of lung structure. These techniques are extremely important to study the pathogenesis of COPD as well as differentiate patients with predominantly emphysema disease from those with airway wall remodeling, and to assess the effects of therapeutic interventions.
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Semin Respir Crit Care Med · Apr 2005
Review Comparative StudyAssessment of pulmonary function in COPD.
Pulmonary function testing is used in the diagnosis of chronic obstructive pulmonary disease (COPD) and the staging of COPD severity. The current diagnostic criterion for airflow obstruction is a ratio of forced expiratory volume in 1 second (FEV (1)) to forced vital capacity (FVC) < 70%. However this absolute definition can lead to false-negative determinations in younger patients and false-positive determinations in the elderly. ⋯ Small airways disease can be detected by various techniques that measure airway and total respiratory system resistance. There is renewed interest in the forced oscillation technique and impulse oscillometry because of their noninvasiveness and potential ability to distinguish small from larger airway disease. Finally, pulmonary function testing has an important role in preoperative risk assessment; for example, in patients being considered for lung volume reduction surgery or resection of a lung nodule.
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Semin Respir Crit Care Med · Apr 2005
Review Comparative StudyA review of alpha-1 antitrypsin deficiency.
Alpha-1 antitrypsin (AAT) is a protein that prevents enzymes such as elastin from degrading normal host tissue. Individuals who are deficient in AAT (those with levels < 11 micromol/L) are at risk for developing such clinical manifestations as emphysema, cirrhosis, panniculitis, and anticytoplasmic neutrophilic antibody (C-ANCA)-positive vasculitis (Wegener's granulomatosis). Estimates suggest that 75 to 85% of those with severe deficiency of AAT will develop emphysema. ⋯ Diagnosis of AAT deficiency is made by measuring serum levels of AAT and, if reduced, an effort should then be made to identify the genetic abnormality responsible for the reduction. A recent evidence-based review has offered testing recommendations for AAT deficiency and includes the recommendation that all patients with COPD be tested for AAT deficiency. Augmentation with an intravenous form of purified pooled human plasma has been shown to increase the serum levels of AAT among deficient patients and its use appears to impact the rate of forced expiratory volume in 1 second (FEV (1)) decline and overall survival; to date, no confirmatory, large, prospective, randomized trials are available.