New Page 1
 

COPD-X Menu
COPD-X Menu COPD-X Home Page COPD-X Guidelines Management Tools Case Statements News & Resources COPD Institute Contact Us
COPD-X Menu

 

Diagnosis

C2. Diagnosis

C2.1 History
 
Consider COPD in all smokers and ex-smokers over the age of 35 years8  [evidence level B]
 

The main symptoms of COPD are breathlessness, cough and sputum production.22 Patients often attribute breathlessness to ageing or lack of fitness. A persistent cough, typically worse in the mornings with mucoid sputum, is common in smokers. Other symptoms such as chest tightness, wheezing and airway irritability are common.23 Acute exacerbations, usually infective, occur from time to time and may lead to a sharp deterioration in coping ability. Fatigue, poor appetite and weight loss are more common in advanced disease.

The functional limitation from breathlessness due to COPD can be quantified easily in clinical practice24 (see Box 4).
 

Box 4: Medical Research Council grading of functional limitation due to dyspnoea24

Grade
Symptom complex
1  "I only get breathless with strenuous exercise".
2 "I get short of breath when hurrying on the level or walking up a slight hill".
3 "I walk slower than most people of the same age on the level because of breathlessness or have to stop for breath when walking at my own pace on the level".
4 "I stop for breath after walking about 100 yards or after a few minutes on the level".
5 "I am too breathless to leave the house" or "I am breathless when dressing".
 

C2.2 Physical examination

The sensitivity of physical examination for detecting mild to moderate COPD is poor.25 Wheezing is not an indicator of severity of disease and is often absent in stable, severe COPD. In more advanced disease, physical features commonly found are hyperinflation of the chest, reduced chest expansion, hyperresonance to percussion, soft breath sounds and a prolonged expiratory phase. Right heart failure may complicate severe disease.

During an acute exacerbation, tachypnoea, tachycardia, use of accessory muscles, tracheal tug and cyanosis are common.

The presence and severity of airflow limitation are impossible to determine by clinical signs.25 Objective measurements such as spirometry are strongly recommended. Peak expiratory flow (PEF) is not a sensitive measure of airway function in COPD patients, as it is effort dependent and has a wide range of normal values.26

C2.3 Spirometry
 
The diagnosis of COPD rests on the demonstration of airflow limitation which is not fully reversible 27 [evidence level B]
 

Spirometry is the gold standard for finding new cases of COPD by targeted screening, diagnosing, assessing and monitoring COPD (see Box 5). Most spirometers provide predicted ("normal") values obtained from healthy population studies, and derived from formulas based on height, age, sex and ethnicity.

Airflow limitation is non-reversible when, after administration of bronchodilator medication, the ratio of FEV1 to forced vital capacity (FVC) is < 70% and the FEV1 is < 80% of the predicted value. The ratio of FEV1 to vital capacity (VC) is a sensitive indicator for mild COPD.
 

Box 5: Maximal expiratory flow-volume curves in severe chronic obstructive pulmonary disease (COPD) and chronic asthma

Maximal expiratory flow-volume curves in severe chronic obstructive pulmonary disease (COPD) and chronic asthma

The patient with COPD has reduced peak expiratory flow, and severely decreased flows at 25%, 50% and 75% of vital capacity compared with the normal range (vertical bars), and shows minimal response to bronchodilator (BD). By comparison, the patient with chronic asthma shows incomplete, but substantial, reversibility of expiratory flow limitation across the range of vital capacity. After BD the forced expiratory volume in one second (FEV1 ) was within the normal range (82% predicted). Absolute and per cent predicted values for FEV1 and forced vital capacity (FVC) before and after BD are shown for each patient.
 

A recent detailed systematic review states that spirometry, in addition to clinical examination, improves the diagnostic accuracy of COPD compared to clinical examination alone28 (evidence level I). More studies are required to define any benefit from the use of spirometry for case finding in COPD, and to evaluate the effects of spirometric results on smoking cessation. The spirometric tests require high levels of patient effort and cooperation, and there are important quality criteria that should be met in conducting spirometry (ATS/ERS Guidelines on lung function testing).

Indications for spirometry include:

  • breathlessness that seems inappropriate;

  • chronic (daily for two months) or intermittent, unusual cough;

  • frequent or unusual sputum production;

  • relapsing acute infective bronchitis; and

  • risk factors such as exposure to tobacco smoke, occupational dusts and chemicals, and a strong family history of COPD.

C2.4 Flow volume tests

Electronic spirometers allow for the simultaneous measurement of flow and volume during maximal expiration. Reduced expiratory flows at mid and low lung volumes are the earliest indicators of airflow limitation in COPD and may be abnormal even when FEV1 is within the normal range (> 80%).

Next Page Previous Page