COPD (Chronic Obstructive Pulmonary Disease)
Introduction
Chronic obstructive pulmonary disease (COPD) is a common and treatable disease characterized by progressive airflow limitation and tissue destruction. It is associated with structural lung changes due to chronic inflammation from prolonged exposure to noxious particles or gases most commonly cigarette smoke. Chronic inflammation causes airway narrowing and decreased lung recoil. The disease often presents with symptoms of cough, dyspnea, and sputum production. Symptoms can range from being asymptomatic to respiratory failure.[1]
Epidemiology
COPD is primarily present in smokers and those greater than age 40. Prevalence increases with age and it is currently the third most common cause of morbidity and mortality worldwide. In 2015, the prevalence of COPD was 174 million and there were approximately 3.2 million deaths due to COPD worldwide. However, the prevalence is likely to be underestimated due to the underdiagnosis of COPD.[1]
Etiology
COPD is caused by prolonged exposure to harmful particles or gases.
- Cigarette smoking is the most common cause of COPD worldwide.
- Other causes may include second-hand smoke, environmental and occupational exposures, and alpha-1 antitrypsin deficiency (AATD)[1].
Mechani Presentation
COPD will typically present in adulthood and often during the winter months. Patients usually present with complaints of chronic and progressive dyspnea, cough, and sputum production. Patients may also have wheezing and chest tightness. While a smoking history is present in most cases, there are many without such history. They should be questioned on exposure to second-hand smoke, occupational and environmental exposures, and family history.
COPD is a complex interaction between asthma, chronic bronchitis, and emphysema.
Evaluation
COPD is often evaluated in patients with relevant symptoms and risk factors. The diagnosis is confirmed by spirometry. Other tests may include a 6-minute walk test, laboratory testing, and radiographic imaging.
- Assessment – A diagnosis of COPD should be considered in patients over the age of 35 who have a risk factor (generally smoking) and who present with exertional breathlessness, chronic cough, regular sputum production, frequent winter ‘bronchitis’ or wheeze.
- X-Ray – An x-ray of the chest may show an over-expanded lung (hyperinflation) and can be useful to help exclude other lung diseases.
- Pulmonary function tests – Essential in the diagnosis, staging, and monitoring of COPD. Spirometry is performed before and after administering an inhaled bronchodilator. Inhaled bronchodilators may be a short-acting beta2-agonist (SABA), short-acting anticholinergic, or a combination of both. A ratio of the forced expiratory volume in one second to forced vital capacity (FEV1/FVC) less than 0.7 confirms the diagnosis of COPD. Patients with a significantly reduced FEV1 and signs of dyspnea should be evaluated for oxygenation with pulse oximetry or arterial blood gas analysis.
- Blood tests – A blood sample taken from an artery can be tested for blood gas levels which may show low oxygen levels (hypoxemia) and/or high carbon dioxide levels (respiratory acidosis). A blood sample taken from a vein may show a high blood count (reactive polycythemia), a reaction to long-term hypoxemia.
Outcome Measures
There can be a different number of ways of measuring the impact or change of someone’s COPD, examples being from lung function, lung volumes and exercise capacity. A cross-sectional study recommends cardiopulmonary exercise testing (CPET) as an efficient tool in assessing functional capacity and prognosis in Heart Failure and COPD patients[2].
Other outcome measures include:
Bleep Test; Shuttle Walk Test; Ergometry; BORG RPE; 6-minute walk test is commonly performed to assess the submaximal functional capacity of a patient. This test is performed indoors on a flat and straight surface. The length of the hallway is usually 100 feet and the test measures the distance the patient walks over a period of 6 minutes[1]; Grip Strength; 30 second Sit to stand
According to a longitudinal study[3], changes in frailty status of COPD patients were associated with significant clinical outcomes related to: dyspnea; mobility; physical activity; handgrip and quadriceps strength. It was found that five-times sit-to-stand and exacerbations were independent predictors of the improvement in frailty status.
Management / Interventions
The primary goals of treatment are to control symptoms, improve the quality of life, and reduce exacerbations and mortality. The non-pharmacological approach includes smoking cessation and pulmonary rehabilitation.
Annual influenza vaccination is recommended in all patients with COPD.
The classes of commonly used medications in COPD include:
- Bronchodilators (beta2-agonists, antimuscarinics, methylxanthines),
- Inhaled corticosteroids (ICS) and systemic glucocorticoids,
- Phosphodiesterase-4 (PDE4) inhibitors,
- Antibiotics.
Exercise
Exercise prescription is a key component of pulmonary rehabilitation programmes, which are part of the non-pharmacological approach to managing COPD. There is a high level of evidence for the benefits of pulmonary rehabilitation for people with COPD[5] Strength and endurance exercise are endorsed for people with COPD.[6]
Use of protein supplements, in combination with exercise, could also be beneficial, refer to dietician.
Muscles that are required for arm exercise are also involved in movement of the chest wall during respiration and thus the need to breathe often compromises the individual’s ability to undertake daily activities, therefore exercise prescription involving arm exercise needs to be carefully prescribed.[7]
Promote Effective Inhaled Therapy
In people with stable COPD who remain breathless or have exacerbations despite use of short-acting bronchodilators as required, offer the following as maintenance therapy:
- if forced expiratory volume in 1 second (FEV1)≥50% predicted: either long-acting beta2 agonist (LABA) or long-acting muscarinic antagonist (LAMA)
- if FEV1<50% predicted: either LABA with an inhaled corticosteroid (ICS) in a combination inhaler, or LAMA
Offer LAMA in addition to LABA + ICS to people with COPD who remain breathless or have exacerbations despite taking LABA + ICS, irrespective of their FEV1.
Provide Pulmonary Rehabilitation
Pulmonary rehabilitation (PR) should be made available to all appropriate people with COPD including those who have had a recent hospitalisation for an acute exacerbation. A randomised study suggests positive outcomes with functional electrostimulation in patients with severe chronic obstructive pulmonary disease hospitalized for acute exacerbation[8]. A study suggests that patients affected with COPD and pulmonary hypertension experience a lower exercise capacity and quality of life[9]. Another randomized controlled trial examining the effects of virtual training (VR) and exercise training on the rehabilitation of patients with COPD suggests that pulmonary rehabilitation program supplemented with VR training has positive outcomes in improving physical fitness in patients with COPD[10]. Studies suggest PR was useful in patients with moderate to severe COPD[11]. A prospective, multisite, randomised controlled trial will determine whether an 8-week PR programme (exercise training will comprise: overground or treadmill walking, lower limb stationary cycling, lower and upper limb strengthening exercises) is equivalent to a 12-week PR programme in people with COPD[12].
Utilise a Multidisciplinary Team
COPD care should be delivered by a multidisciplinary team.
Palliative Setting
- Opioids should be used when appropriate for the palliation of breathlessness in people with end-stage COPD unresponsive to other medical therapy
- Use benzodiazepines, tricyclic antidepressants, major tranquillisers and oxygen to treat breathlessness
- Provide access to multidisciplinary palliative care teams and hospices
Resources
- KNGF guidelines for physical therapy in patients with chronic obstructive pulmonary disease
- Mesothelioma Resources for Patients
Videos
