Chronic obstructive pulmonary disease other diagnostic studies: Difference between revisions
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==Overview== | ==Overview== | ||
'''Chronic obstructive pulmonary disease''' ('''COPD'''), also known as '''chronic obstructive airway disease''' ('''COAD'''), is a group of [[disease]]s characterized by the pathological limitation of airflow in the [[airway]] that is not fully reversible <ref name="pmid12198919">{{cite journal |author=Mannino DM, Homa DM, Akinbami LJ, Ford ES, Redd SC |title=Chronic obstructive pulmonary disease surveillance--United States, 1971-2000 |journal=[[MMWR. Surveillance Summaries : Morbidity and Mortality Weekly Report. Surveillance Summaries / CDC]] |volume=51 |issue=6 |pages=1–16 |year=2002 |month=August |pmid=12198919 |doi= |url= |accessdate=2012-03-01}}</ref>. COPD is the umbrella term for chronic [[bronchitis]], [[emphysema]] and a range of other lung disorders. It is most often due to [[tobacco smoking]],<ref name="dev">Devereux G. ''ABC of chronic obstructive pulmonary disease. Definition, epidemiology, and risk factors.'' [[British Medical Journal|BMJ]] 2006;332:1142-1144. PMID 16690673</ref> but can be due to other airborne irritants such as coal dust, [[asbestos]] or solvents, [[congenital]] conditions such as [[alpha-1-antitrypsin deficiency]] and as well as preserved meats containing nitrites. | '''Chronic obstructive pulmonary disease''' ('''COPD'''), also known as '''chronic obstructive airway disease''' ('''COAD'''), is a group of [[disease]]s characterized by the pathological limitation of airflow in the [[airway]] that is not fully reversible <ref name="pmid12198919">{{cite journal |author=Mannino DM, Homa DM, Akinbami LJ, Ford ES, Redd SC |title=Chronic obstructive pulmonary disease surveillance--United States, 1971-2000 |journal=[[MMWR. Surveillance Summaries : Morbidity and Mortality Weekly Report. Surveillance Summaries / CDC]] |volume=51 |issue=6 |pages=1–16 |year=2002 |month=August |pmid=12198919 |doi= |url= |accessdate=2012-03-01}}</ref>. COPD is the umbrella term for chronic [[bronchitis]], [[emphysema]] and a range of other lung disorders. It is most often due to [[tobacco smoking]],<ref name="dev">Devereux G. ''ABC of chronic obstructive pulmonary disease. Definition, epidemiology, and risk factors.'' [[British Medical Journal|BMJ]] 2006;332:1142-1144. PMID 16690673</ref> but can be due to other airborne irritants such as coal dust, [[asbestos]] or solvents, [[congenital]] conditions such as [[alpha-1-antitrypsin deficiency]] and as well as preserved meats containing nitrites. | ||
== Diagnosis == | |||
[[File:COPD.JPG|thumb|A chest X-ray demonstrating severe COPD. Note the small size of the heart in comparison to the lungs.]] | |||
The diagnosis of COPD should be considered in anyone who has [[dyspnea]], chronic cough or sputum production, and/or a history of exposure to risk factors for the disease such as regular tobacco smoking.<ref name="pmid17507545"/><ref name="pmid7956395">{{cite journal |author=Badgett RG, Tanaka DJ, Hunt DK, ''et al.'' |title=The clinical evaluation for diagnosing obstructive airways disease in high-risk patients |journal=Chest |volume=106 |issue=5 |pages=1427–31 |year=1994 |pmid=7956395| doi = 10.1378/chest.106.1427 |doi_brokendate=2010-04-06}}</ref> No single symptom or sign can adequately confirm or exclude the diagnosis of COPD,<ref name="pmid7815660">{{cite journal |author=Holleman DR, Simel DL |title=Does the clinical examination predict airflow limitation? |journal=JAMA |volume=273 |issue=4 |pages=313–9 |year=1995 |pmid=7815660| doi = 10.1001/jama.273.4.313}}</ref> although COPD is uncommon under the age of 40 years. | |||
===Spirometry=== | |||
The diagnosis of COPD is confirmed by [[spirometry]],<ref name="pmid17507545"/> a test that measures the forced expiratory volume in one second (FEV<sub>1</sub>), which is the greatest volume of air that can be breathed out in the first second of a large breath. Spirometry also measures the forced vital capacity (FVC), which is the greatest volume of air that can be breathed out in a whole large breath. Normally, at least 70% of the FVC comes out in the first second (i.e. the [[FEV1/FVC|FEV<sub>1</sub>/FVC ratio]] is >70%). A ratio less than normal defines the patient as having COPD. More specifically, the diagnosis of COPD is made when the FEV<sub>1</sub>/FVC ratio is <70%.<ref name=Nathell/> The GOLD criteria also require that values are after [[bronchodilator]] medication has been given to make the diagnosis, and the NICE criteria also require FEV1%.<ref name=Nathell/> According to the ERS criteria, it is [[FEV1% predicted]] that defines when a patient has COPD, that is, when FEV1% predicted is < 88% for men, or < 89% for women.<ref name=Nathell/> | |||
Spirometry can help to determine the severity of COPD.<ref name="pmid17507545"/> The FEV<sub>1</sub> (measured after bronchodilator medication) is expressed as a percentage of a predicted "normal" value based on a person's age, gender, height and weight: | |||
{| class="wikitable" style="text-align:center;width:100%;" | |||
|- | |||
! Severity of COPD (GOLD scale)!! FEV<sub>1</sub> % predicted | |||
|- | |||
| Mild (GOLD 1) || ≥80 | |||
|- | |||
| Moderate (GOLD 2)|| 50–79 | |||
|- | |||
| Severe (GOLD 3) || 30–49 | |||
|- | |||
| Very severe (GOLD 4)|| <30 or chronic respiratory failure symptoms | |||
|} | |||
The severity of COPD also depends on the severity of dyspnea and exercise limitation. These and other factors can be combined with spirometry results to obtain a COPD severity score that takes multiple dimensions of the disease into account.<ref name=Celli04>{{cite journal |author=Celli BR, Cote CG, Marin JM, ''et al.'' |title=The body-mass index, airflow obstruction, dyspnea, and exercise capacity index in chronic obstructive pulmonary disease |journal=N. Engl. J. Med. |volume=350 |issue=10 |pages=1005–12 |year=2004 |month=March |pmid=14999112 |doi=10.1056/NEJMoa021322 }}</ref> | |||
===Other tests=== | |||
On [[chest x-ray]], the classic signs of COPD are overexpanded lung ([[Hyperaeration|hyperinflation]]), a flattened diaphragm, increased retrosternal airspace, and bullae.<ref name=Old2007>{{cite journal |author=Torres M, Moayedi S |title=Evaluation of the acutely dyspneic elderly patient |journal=Clin. Geriatr. Med. |volume=23 |issue=2 |pages=307–25, vi |year=2007 |month=May |pmid=17462519 |doi=10.1016/j.cger.2007.01.007 |url=}}</ref> It can be useful to help exclude other lung diseases, such as [[pneumonia]], [[pulmonary edema]] or a [[pneumothorax]].<ref name=Old2007/> Complete pulmonary function tests with measurements of lung volumes and gas transfer may also show hyperinflation and can discriminate between COPD with emphysema and COPD without emphysema. A high-resolution [[computed tomography]] scan of the chest may show the distribution of emphysema throughout the lungs and can also be useful to exclude other lung diseases. | |||
A blood sample taken from an [[artery]], i.e. [[Arterial Blood Gas]] (ABG), can be tested for blood gas levels which may show low oxygen (hypoxaemia) and/or high carbon dioxide (respiratory acidosis if pH is also decreased). A blood sample taken from a [[vein]] may show a high blood count (reactive polycythemia), a reaction to long-term hypoxemia. | |||
==References== | ==References== | ||
Revision as of 14:50, 2 March 2012
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Philip Marcus, M.D., M.P.H. [2]; Associate Editor(s)-In-Chief: Cafer Zorkun, M.D., Ph.D. [3]
Overview
Chronic obstructive pulmonary disease (COPD), also known as chronic obstructive airway disease (COAD), is a group of diseases characterized by the pathological limitation of airflow in the airway that is not fully reversible [1]. COPD is the umbrella term for chronic bronchitis, emphysema and a range of other lung disorders. It is most often due to tobacco smoking,[2] but can be due to other airborne irritants such as coal dust, asbestos or solvents, congenital conditions such as alpha-1-antitrypsin deficiency and as well as preserved meats containing nitrites.
Diagnosis
The diagnosis of COPD should be considered in anyone who has dyspnea, chronic cough or sputum production, and/or a history of exposure to risk factors for the disease such as regular tobacco smoking.[3][4] No single symptom or sign can adequately confirm or exclude the diagnosis of COPD,[5] although COPD is uncommon under the age of 40 years.
Spirometry
The diagnosis of COPD is confirmed by spirometry,[3] a test that measures the forced expiratory volume in one second (FEV1), which is the greatest volume of air that can be breathed out in the first second of a large breath. Spirometry also measures the forced vital capacity (FVC), which is the greatest volume of air that can be breathed out in a whole large breath. Normally, at least 70% of the FVC comes out in the first second (i.e. the FEV1/FVC ratio is >70%). A ratio less than normal defines the patient as having COPD. More specifically, the diagnosis of COPD is made when the FEV1/FVC ratio is <70%.[6] The GOLD criteria also require that values are after bronchodilator medication has been given to make the diagnosis, and the NICE criteria also require FEV1%.[6] According to the ERS criteria, it is FEV1% predicted that defines when a patient has COPD, that is, when FEV1% predicted is < 88% for men, or < 89% for women.[6]
Spirometry can help to determine the severity of COPD.[3] The FEV1 (measured after bronchodilator medication) is expressed as a percentage of a predicted "normal" value based on a person's age, gender, height and weight:
| Severity of COPD (GOLD scale) | FEV1 % predicted |
|---|---|
| Mild (GOLD 1) | ≥80 |
| Moderate (GOLD 2) | 50–79 |
| Severe (GOLD 3) | 30–49 |
| Very severe (GOLD 4) | <30 or chronic respiratory failure symptoms |
The severity of COPD also depends on the severity of dyspnea and exercise limitation. These and other factors can be combined with spirometry results to obtain a COPD severity score that takes multiple dimensions of the disease into account.[7]
Other tests
On chest x-ray, the classic signs of COPD are overexpanded lung (hyperinflation), a flattened diaphragm, increased retrosternal airspace, and bullae.[8] It can be useful to help exclude other lung diseases, such as pneumonia, pulmonary edema or a pneumothorax.[8] Complete pulmonary function tests with measurements of lung volumes and gas transfer may also show hyperinflation and can discriminate between COPD with emphysema and COPD without emphysema. A high-resolution computed tomography scan of the chest may show the distribution of emphysema throughout the lungs and can also be useful to exclude other lung diseases.
A blood sample taken from an artery, i.e. Arterial Blood Gas (ABG), can be tested for blood gas levels which may show low oxygen (hypoxaemia) and/or high carbon dioxide (respiratory acidosis if pH is also decreased). A blood sample taken from a vein may show a high blood count (reactive polycythemia), a reaction to long-term hypoxemia.
References
- ↑ Mannino DM, Homa DM, Akinbami LJ, Ford ES, Redd SC (2002). "Chronic obstructive pulmonary disease surveillance--United States, 1971-2000". MMWR. Surveillance Summaries : Morbidity and Mortality Weekly Report. Surveillance Summaries / CDC. 51 (6): 1–16. PMID 12198919. Unknown parameter
|month=ignored (help);|access-date=requires|url=(help) - ↑ Devereux G. ABC of chronic obstructive pulmonary disease. Definition, epidemiology, and risk factors. BMJ 2006;332:1142-1144. PMID 16690673
- ↑ 3.0 3.1 3.2 Invalid
<ref>tag; no text was provided for refs namedpmid17507545 - ↑ Badgett RG, Tanaka DJ, Hunt DK; et al. (1994). "The clinical evaluation for diagnosing obstructive airways disease in high-risk patients". Chest. 106 (5): 1427–31. doi:10.1378/chest.106.1427. PMID 7956395. Unknown parameter
|doi_brokendate=ignored (help) - ↑ Holleman DR, Simel DL (1995). "Does the clinical examination predict airflow limitation?". JAMA. 273 (4): 313–9. doi:10.1001/jama.273.4.313. PMID 7815660.
- ↑ 6.0 6.1 6.2 Invalid
<ref>tag; no text was provided for refs namedNathell - ↑ Celli BR, Cote CG, Marin JM; et al. (2004). "The body-mass index, airflow obstruction, dyspnea, and exercise capacity index in chronic obstructive pulmonary disease". N. Engl. J. Med. 350 (10): 1005–12. doi:10.1056/NEJMoa021322. PMID 14999112. Unknown parameter
|month=ignored (help) - ↑ 8.0 8.1 Torres M, Moayedi S (2007). "Evaluation of the acutely dyspneic elderly patient". Clin. Geriatr. Med. 23 (2): 307–25, vi. doi:10.1016/j.cger.2007.01.007. PMID 17462519. Unknown parameter
|month=ignored (help)