You are leaving Medscape Education
Cancel Continue
Log in to save activities Your saved activities will show here so that you can easily access them whenever you're ready. Log in here CME & Education Log in to keep track of your credits.
 

 

A Review of the GOLD Guidelines for the Diagnosis and Treatment of Patients With COPD: Diagnosing COPD

processing....

Diagnosing COPD

To accurately diagnosis COPD, alternative diagnoses, such as asthma, congestive heart failure, cystic fibrosis and tuberculosis, need to be ruled out. Patient histories, physical examinations and lung function testing are important in diagnosing COPD[26] because patients tend to underreport their symptoms because they may be minimal or perceived to be a normal part of ageing or clinically insignificant.[11,29] Healthcare providers should consider a diagnosis of COPD for any patient, especially those over 40years of age, who present with one or more of the following symptoms: persistent, progressive, exertional dyspnoea; chronic cough, which may be unproductive and intermittent; chronic sputum production; variable wheezing and chest tightness; recurring acute bronchitis; and acute exacerbations of chronic bronchitis.[1] Identifying chronic exposure to environmental risk factors such as tobacco smoke, occupational or outdoor pollutants, or smoke from home cooking and heating fuels is also important. A diagnosis of COPD needs to be confirmed through assessment of lung function with spirometry, as outlined in Table 1.[1,26] AAT deficiency testing should also be considered if symptoms of COPD occur in patients younger than 45years of age where a link with obvious risk factors cannot be made, in patients with lower-lobe predominant emphysema, or in patients within a family cluster of COPD cases where there has been no remarkable exposure to primary or secondary tobacco smoke.[26]

Differentiating COPD from asthma is also important so that correct identification and treatment of patients with COPD can be achieved. Diagnostic confusion between asthma and COPD is common in clinical practice. In a prospective study of patients with obstructive lung disease, Tinkelman et al.[30] compared prior clinical diagnoses with diagnoses based on spirometry results obtained during the study and found that more than half (51%) of the patients with spirometry-confirmed COPD were initially misdiagnosed as having asthma. Although asthma and COPD may coexist, the underlying pathologic characteristics of the two diseases and their treatment options and desired outcomes differ. Therefore, the management strategies of these two conditions should be developed independently as appropriate for individual patients.[30] Asthma symptoms are generally more variable, whereas COPD symptoms are generally more progressive in nature (Table 2).[10] The airflow limitation is usually reversible in asthma and is only partially reversible and progressive in COPD (Table 2).[1,10]

Spirometry

Spirometry is currently the standard assessment tool for diagnosing, staging and monitoring disease progression. It is considered the most objective and reproducible measurement of airflow limitation.[1] COPD guidelines recommend that spirometry be performed in any patient who has a history of exposure to risk factors for COPD (e.g. tobacco smoke, occupational dust/chemicals), a history of chronic respiratory illness, or chronic symptoms of cough, sputum production or dyspnoea.[1,6–8] Spirometry is used to measure a patient's FEV1, which is the volume of air forcibly exhaled during the first second of expiration following maximal inspiration, and forced vital capacity (FVC), which is the maximum volume of air exhaled until the lungs are emptied, which usually takes 3–15s depending on disease severity. Spirometry should be performed both before and after patients are given adequate doses of short-acting inhaled bronchodilators to assess the degree of reversibility, and to exclude the possibility of asthma. The ratio of the two measurements (FEV1/FVC) is calculated to assess a patient's lung function. In patients with COPD, FEV1 and FVC readings, as well as FEV1/FVC ratios, will be lower than predicted (reference) values based on age, sex, height and race. Airflow limitation is clinically confirmed when the FEV1/FVC postbronchodilator value is <0.70. More advanced COPD is associated with an FEV1 <80% of predicted normal.[1] FVC is not always reduced during the early stages of COPD.

Various types of spirometers may be used in assessing and monitoring COPD. Many are portable, readily available, and easy to use in primary-care settings. With a moderate level of instruction and training in spirometry techniques, healthcare providers can easily incorporate spirometry into their practices and increase the likelihood of earlier detection of COPD among their patients.[11]

Stages of COPD

The severity of COPD is classified according to the degree of abnormality in spirometric readings, the level of symptoms and the presence of comorbid conditions that can lead to complications (Table 1).[1] The 2006 GOLD guidelines identify four stages of COPD based on severity, namely, stage I (mild COPD) to IV (very severe COPD). In previous versions of the guidelines, stage 0 (at risk) was used to categorise patients who had chronic cough and sputum production but normal spirometric values. Because there is incomplete evidence that patients with stage 0 COPD necessarily progress to stage I COPD, stage 0 has been removed from the classification of COPD. However, chronic cough and sputum production in any patient should not be considered normal, and healthcare professionals are encouraged to determine the underlying causes. As in past versions of the GOLD guidelines, the degree of spirometric decline continues to be indicative of disease severity.[1] This classification provides the criteria for the pharmacologic and non-pharmacologic treatment options discussed below.

  • Print