Chronic obstructive pulmonary disease airflow obstruction

Cell BR, Cote CG, Marin JM et al (2004) The body-mass index, airflow obstruction, dyspnea, and exercise capacity index in chronic obstructive pulmonary disease. New Engl J Med 350 1005-1012... 

Other disorders of the lower respiratory tract include emphysema (lung disorder in which the terminal bronchioles or alveoli become enlarged and plugged with mucus) and chronic bronchitis (chronic inflammation and possibly infection of die bronchi). Chronic obstructive pulmonary disease (COPD) is die name given collectively to emphysema and chronic bronchitis because die obstruction to die airflow is present most of the time. Asdima diat is persistent and present for most of die time may also be referred to as COPD. 

Chronic obstructive pulmonary disease (COPD) is a progressive disease characterized by airflow limitation that is not fully... 

Hogg JC. Pathophysiology of airflow limitation in chronic obstructive pulmonary disease. Lancet 2004 364 709-721. 

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. The most common conditions comprising COPD are chronic bronchitis and emphysema. 

The TP receptor requires the G/G protein to activate the Src-Ras-ERKl/2 (extracellular signal-regulated kinase 1 and 2) cascade to induce the proliferative response, which in turn promotes the rapid nuclear translocation of activated ERKl/2 (201). Because TP receptor may be activated by many inflammatory mediators (202-204), these findings suggest new therapeutic strategies that alter the ASM hypertrophy or hyperplasia observed in the chronic airflow obstruction and airway inflammation that characterizes asthma, chronic bronchitis, bronchiolitis obliterans, and chronic obstructive pulmonary disease. 

Chronic obstructive pulmonary disease (COPD) associated with chronic bronchitis For the twice-daily maintenance treatment of airflow obstruction in patients with COPD associated with chronic bronchitis. Fluticasone propionate/salmeterol 250 meg per 50 meg twice daily is the only approved dosage for the treatment of COPD associated with chronic bronchitis. Fligher doses, including fluticasone propionate/salmeterol 500 meg per 50 meg, are not recommended. 

CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) A general term to describe airflow obstruction due to emphysema and chronic bronchitis. 

Stachybotrys chartarum is one of the most commonly noted agents associated with so-called sick building or damp building-related syndrome and damp building-related illnesses (DBRI). While upper and some lower respiratory tract symptoms have been accepted as causally linked to human exposure to moldy damp indoor environments, other reported effects, including airflow obstruction, chronic obstructive pulmonary disease, pulmonary hemorrhage, neurologic effects and cancer, have not (Institute of Medicine, 2004). An excellent recent review of S. chartarum, associated trichothecene mycotoxins, and DBRI is available (Pestka et al, 2008). 

Fabbri LM, Romagnoli M, Corbetta L, Casoni G, Busljetic K, Turato G, Ligabue G, Ciaccia A, Saetta M, Papi A. Differences in airway inflammation in patients with flxed airflow ohstruction due to asthma or chronic obstructive pulmonary disease. Am. J. Respir. Crit. Care Med. 2003 167 418-424. 

A number of patients who have persistent airflow obstruction exhibit considerable variation in airways resistance and hence in their benefit from bronchodilators drugs for asthma. It is important to recognise the coexistence of asthma with chronic obstructive pulmonary disease in some patients, and to assess their responses to bronchodilators or glucocorticoids over a period of time (as formal tests of respiratory function may not reliably predict clinical response in this setting). 

Nebulizers are generally used to treat acute exacerbations of asthma or chronic obstructive pulmonary disease. Other indications include long-term bronchodilator treatment of chronic airflow obstruction prophylactic treatment for asthma antimicrobial drugs for cystic fibrosis, bronchiectasis, and HIV/AIDS and symptomatic relief in palliative care. 

Tiotropium is inhaled from the HandiHaler, a dry-powder, breath-activated inhaler system that delivers particles to the lung over a wide range of airflow limitations in patients with chronic obstructive pulmonary disease (COPD) it can be effectively delivered at inspiratory flow rates as low as 201/minute (2). Pharmacodynamic steady-state studies have shown that most of the bronchodUator activity is achieved with one to two doses within 48 hours, although a carryover effect on forced vital capacity was observed beyond 48 hours (3). 

Engelen MP, et al. Skeletal muscle weakness is associated with wasting of extremity fat-free mass but not with airflow obstruction in patients with chronic obstructive pulmonary disease. Am J Chn Nutr 2000 71 733-738. 

Hasegawa I, Boiselle PM, Raptopoulos V, Hatabu H (2003) Tracheomalacia incidentally detected on CT pulmonary angiography of patients with suspected pulmonary embolism. AJR Am J Roentgenol 181 1505-1509 Hasegawa M, Nasuhara Y, Onodera Y etal. (2006) Airflow limitation and airway dimensions in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 173 1309-1315... 

Pulmonary function testing usually discloses a mild-to-moderate restrictive ventilatory defect, moderately reduced carbon monoxide difiusion capacity, and mild-to-moderate hypoxemia (2-6,9,16). Severe hypoxemia may occasionally occur due to a right-to-left blood shunt through densely consolidated lung parenchyma (72). Airflow obstruction is found in a minority of cases, usually smokers (2), and probably reflects preexisting chronic obstructive pulmonary disease. 

Figure 8 Continuous recordings of airflow (Flow) and esophageal pressure (Pes) in a long-term ventilator-dependent patient with COPD during a brief period of unassisted breathing. Arrows indicate ineffective inspiratory efforts—inspiratory efforts not associated with inspiratory flow. In one study (41), ineffective inspiratory efforts were recorded in 40% of long-term ventilator-dependent patients with COPD but not in patients with COPD who were successfully weaned after a period of prolonged ventilatory support. Abbreviations Pes, esophageal pressure COPD, chronic obstructive pulmonary disease. Source From Ref. 41.

Careful patient selection prevents unsafe levels of alveolar hypoventilation with subsequent hypoxemia and hypercapnea, especially if the tidal volume leakage is >20%. Any compensatory increase in respiratory rate and shortened expiratory time, attributable to the air leakage, may aggravate dynamic hyperinflation, especially among patients with airflow obstruction (15). Ventilator-supported speech has been reported in patients with neuromuscular diseases (NMD) and intact bulbar function (16-19). The physiologic characteristics that enable this population to tolerate ventilator-supported speech include little or no decrease in chest wall or lung compliance and the absence of airflow obstmction. Therefore, patients with NMD may be ventilated with a deflated or cuffless tracheostomy tube accepting the modest compromise in alveolar ventilation (16,20-22). Patient populations, such as those with chronic obstructive pulmonary disease may be able to tolerate cuff deflation for short periods provided there is adequate supervision. 

Attaran, D., Lari, S.M., Towhidi, M., et ah, 2010. Interleukin-6 and airflow limitation in chemical warfare patients with chronic obstructive pulmonary disease. Int. J. Chron. Obstruct. Pulmon. Dis. 5, 335-340. 

Becklake MR (1985) Chronic airflow limitation its relationship to work in dusty occupations. Chest 88 608-617 Becklake MR (1989a) Occupational exposures evidence for a causal association with chronic obstructive pulmonary disease. Am Rev Respir Dis 140 S85-S91 Becklake MR (1989b) Occupational pollution. Chest 96 372S-378S... 

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