Seminars in respiratory and critical care medicine
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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.
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Semin Respir Crit Care Med · Apr 2005
Review Comparative StudyEpidemiology and global impact of chronic obstructive pulmonary disease.
Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease that causes a heavy health and increasing economic burden both in the United States and around the world. Most of the risk factors for COPD are well known and include smoking, occupational exposures, air pollution, airway hyperresponsiveness, asthma, and certain genetic variations, although many questions, such as why a minority of smokers develop significant airway obstruction, remain. ⋯ In most of the world, COPD prevalence and mortality are still increasing and will likely continue to rise in response to increases in smoking, particularly by women and adolescents. Resources aimed at smoking cessation and prevention, COPD education and early detection, and better treatment will be of the most benefit in our continuing efforts against this important cause of morbidity and mortality.