Acute exacerbation of chronic obstructive pulmonary disease
||It has been suggested that Acute exacerbations of chronic bronchitis be merged into this article. (Discuss) Proposed since November 2010.|
An acute exacerbation of COPD is a sudden worsening of COPD symptoms (shortness of breath, quantity and color of phlegm) that typically lasts for several days. It may be triggered by an infection with bacteria or viruses or by environmental pollutants. Typically, infections cause 75% or more of the exacerbations; bacteria can roughly be found in 25% of cases, viruses in another 25%, and both viruses and bacteria in another 25%. Airway inflammation is increased during the exacerbation resulting in increased hyperinflation, reduced expiratory air flow and worsening of gas transfer.
In absence of concomitant presence of emphysema, the underlying condition may be classified as chronic bronchitis alone, and the exacerbations are then termed "acute exacerbations of chronic bronchitis" (AECB), and shares many characteristics with that of acute exacerbation of COPD. As COPD progresses, exacerbations tend to become more frequent, the average being about three episodes per year.
As the lungs tend to be vulnerable organs due to their exposure to harmful particles in the air, several things can cause an acute exacerbation of COPD:
- Respiratory infection, being responsible for approximately half of COPD exacerbations. Approximately half of these are due to viral infections and another half appears to be caused by bacterial infections.
- Air pollution
- Pulmonary embolism
- Failing to follow a Drug therapy program, e.g. improper use of an Inhaler
In one-third of all COPD exacerbation cases, the cause cannot be identified.
Although the condition of a patient with COPD can become exacerbated by many other factors as well, the scope is generally restricted to the ones that cause the symptoms below.
Signs and symptoms 
For the most part, symptoms of a COPD exacerbation will remain of the same variations experienced in COPD patients, but will be worsened due to environmental and other factors. These may include, but are not limited to: an increased amount of cough and sputum productions from usual day-to-day variations. This may be accompanied by a change in the usual appearance of the sputum produced. Other symptoms include increased wheezing, fever and a sensation of tightness in the chest.
Acute exacerbations can be partially prevented. Some infections can be prevented by vaccination against pathogens such as influenza and Streptococcus pneumoniae. Regular medication use can prevent some COPD exacerbations; long acting beta-adrenoceptor agonists (LABAs), long-acting anticholinergics, inhaled corticosteroids and low-dose theophylline have all been shown to reduce the frequency of COPD exacerbations.
High flow oxygen may be harmful in those with an acute exacerbation of COPD. In the prehospital environment those given high flow O2 rather that titrating their O2 sats to 88% to 92% had worse outcomes.
The symptoms of acute exacerbations are treated using short-acting bronchodilators. A course of corticosteroids, usually in tablet or intravenous rather than inhaled form, can speed up recovery. The IV and oral forms of steroids have been found to be equivalent. Antibiotics are often used but will only help if the exacerbation is due to an infection. Antibiotics are indicated when a patient notes increased sputum production, purulent sputum, increased dyspnea, has an elevated white count, or is febrile. Examples of first-line antibiotics are amoxicillin, doxycycline and co-trimoxazole.
Mechanical ventilation 
Severe exacerbations can require hospital care where treatments such as oxygen and mechanical ventilation may be required. Mechanical ventilation can be invasive (endotracheal intubation) or non-invasive forms of ventilation such as continuous positive airway pressure.
Ambiguous definitions 
The definition of a COPD exacerbation is commonly described as "lost in translation," meaning that there is no universally accepted standard with regard to defining an acute exacerbation of COPD. Many organizations consider it a priority to create such a standard, as it would be a major step forward in the diagnosis and quality of treatment of COPD.
See also 
- Rabe KF, Hurd S, Anzueto A, et al. (2007). "Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease: GOLD Executive Summary". Am. J. Respir. Crit. Care Med. 176 (6): 532–55. doi:10.1164/rccm.200703-456SO. PMID 17507545.
- Uppsala Academic Hospital > Guidelines for treatment of acute lung diseases. August 2004. Authors: Christer Hanson, Carl-Axel Karlsson, Mary Kämpe, Kristina Lamberg, Eva Lindberg, Lavinia Machado Boman, Gunnemar Stålenheim
- Calverley PM, Anderson JA, Celli B, et al. (2007). "Salmeterol and fluticasone propionate and survival in chronic obstructive pulmonary disease". N. Engl. J. Med. 356 (8): 775–89. doi:10.1056/NEJMoa063070. PMID 17314337.
- Tashkin DP, Celli B, Senn S, et al. (October 2008). "A 4-year trial of tiotropium in chronic obstructive pulmonary disease". The New England Journal of Medicine 359 (15): 1543–54. doi:10.1056/NEJMoa0805800. PMID 18836213.
- Zhou Y, Wang X, Zeng X, et al. (2006). "Positive benefits of theophylline in a randomized, double-blind, parallel-group, placebo-controlled study of low-dose, slow-release theophylline in the treatment of COPD for 1 year". Respirology 11 (5): 603–10. doi:10.1111/j.1440-1843.2006.00897.x. PMID 16916334.
- Burge PS, Calverley PM, Jones PW, Spencer S, Anderson JA, Maslen TK (2000). "Randomised, double blind, placebo controlled study of fluticasone propionate in patients with moderate to severe chronic obstructive pulmonary disease: the ISOLDE trial". BMJ 320 (7245): 1297–303. doi:10.1136/bmj.320.7245.1297. PMC 27372. PMID 10807619.
- Austin MA, Wills KE, Blizzard L, Walters EH, Wood-Baker R (2010). "Effect of high flow oxygen on mortality in chronic obstructive pulmonary disease patients in prehospital setting: randomised controlled trial". BMJ 341: c5462. doi:10.1136/bmj.c5462. PMC 2957540. PMID 20959284.
- Lindenauer PK, Pekow PS, Lahti MC, Lee Y, Benjamin EM, Rothberg MB (June 2010). "Association of corticosteroid dose and route of administration with risk of treatment failure in acute exacerbation of chronic obstructive pulmonary disease". JAMA 303 (23): 2359–67. doi:10.1001/jama.2010.796. PMID 20551406.
- Gibson, et al. Evidence-based Respiratory Medicine. Blackwell Publishing, 2005. ISBN 0-7279-1605-X. pp. 390-392.
- Quon BS, Gan WQ, Sin DD (March 2008). "Contemporary management of acute exacerbations of COPD: a systematic review and metaanalysis". Chest 133 (3): 756–66. doi:10.1378/chest.07-1207. PMID 18321904.
- Makris D, Bouros D (January 2009). "COPD Exacerbtion: Lost in Translation". BMC Pulm Med 9 (6): 6. doi:10.1186/1471-2466-9-6. PMC 2640343. PMID 19178701.