Background
The Standards for the Diagnosis and Treatment of Patients with COPD document 2004 updates the position papers on chronic obstructive pulmonary disease (COPD) published by the American Thoracic Society (ATS) and the European Respiratory Society (ERS) in 1995 1, 2. Both societies felt the need to update the previous documents due to the following. 1) The prevalence and overall importance of COPD as a health problem is increasing. 2) There have been enough advances in the field to require an update, especially adapted to the particular needs of the ATS/ERS constituency. 3) It allows for the creation of a “live” modular document based on the web; it should provide healthcare professionals and patients with a user friendly and reliable authoritative source of information. 4) The care of COPD should be comprehensive, is often multidisciplinary and rapidly changing. 5) Both the ATS and the ERS acknowledge the recent dissemination of the Global Initiative of Obstructive Lung Disease (GOLD) 3 as a major worldwide contribution to the battle against COPD. However, some specific requirements of the members of both societies require adaptation of the broad GOLD initiative. Those requirements include specific recommendations on oxygen therapy, pulmonary rehabilitation, noninvasive ventilation, surgery in and for COPD, sleep, air travel, and end-of-life. In addition, special emphasis has been placed on issues related to the habit of smoking and its control.
Goals and objectives
The main goals of the updated document are to improve the quality of care provided to patients with COPD and to develop the project using a disease-oriented approach. To achieve these goals, both organisations have developed a modular electronic web-based document with two components. 1) A component for health professionals that intends to: raise awareness of COPD; inform on the latest advances in the overall pathogenesis, diagnosis, monitoring and management of COPD; and promote the concept that COPD is a treatable disease. 2) A component for the patient that intends to: provide practical information on all aspects of COPD; and promote a healthy lifestyle to all patients afflicted with the disease.
Participants
The committee members who were involved in the production of this document are clinicians, nurses, respiratory therapists and educators interested in the field of COPD. The current Standards for the Diagnosis and Treatment of Patients with COPD document is unique in that it also had input from patients suffering from COPD. The committee members were proposed and approved by the ATS and ERS. The members were selected because of their expertise and willingness to participate in the generation of the document. A unique feature of this project was the development of a patient document that could serve as a formal source of information for the patients, thereby making them partners in the effort to decrease the burden of the disease.
Evidence, methodology and validation
Several well-accepted guidelines served as the blueprint for the document. Namely, the ATS and the ERS standards of 1995 1, 2 and the GOLD initiative published in 2001 3. At the initial meeting, each member of the committee was assigned a specific section of the document and was asked to select a subcommittee to gather literature and review the existing evidence. The document was discussed in four group meetings, and the content and validity of each section was thoroughly reviewed. The final statement is the product of those discussions and has been approved by all the members of the committee. Several of the basic source documents reviewed have used an evidence-based approach, and the committee utilised those references as a source of evidence wherever appropriate.
The draft document was reviewed by a diverse group of experts whose input was also considered. Peer review was identified by the ATS and ERS, and the final document was submitted for review and approval by the Board of Directors of the ATS and the Executive Committee of the ERS.
Concept of a “live”, modular document
Understanding that medicine and, in particular, the area of COPD is constantly undergoing changes, the ATS and the ERS considered that it was time to develop new instruments capable of adjusting to the changes. As such, this is the first statement conceived to be primarily based on the web and capable of being changed as needed. To achieve this goal, the organisations have developed a COPD task force composed of three members from each society whose office will last for 3 yrs. The main task of the members is to constantly review advances in the field of COPD and to propose changes to the modules of the document. As is customary in both organisations, the need to do so may arise from the membership through the current existing mechanisms. One of the members of the task force from each society will represent the society on the executive GOLD committee. The overall goal is to attempt to maintain a synchronous flow with the wider objectives of GOLD.
Organisation of the document
The document has two distinct components. The first, directed at patients and their needs, which can be accessed from the ATS/ERS website (www.copd-ats-ers.org) and from the website of each society (www.ersnet.org and www.thoracic.org), is not the subject of this summary. The second is directed at healthcare practitioners and all those interested in the professional issues related to COPD. This summary highlights the contents of the document for health practitioners, but the readers are encouraged to access the document via the website, where an easy navigational tool will allow you to explore its contents. The reader is also encouraged to access the patient document in order to familiarise themselves with its content. It was designed for and with patients so as to serve as a reliable resource for everyone.
Definition of COPD
Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease state characterised by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and is associated with an abnormal inflammatory response of the lungs to noxious particles or gases, primarily caused by cigarette smoking. Although COPD affects the lungs, it also produces significant systemic consequences.
Diagnosis of COPD
The diagnosis of COPD should be considered in any patient who has the following: symptoms of cough; sputum production; or dyspnoea; or history of exposure to risk factors for the disease.
The diagnosis requires spirometry; a post-bronchodilator forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ≤0.7 confirms the presence of airflow limitation that is not fully reversible (table 1⇓). Spirometry should be obtained in all persons with the following history: exposure to cigarettes; and/or environmental or occupational pollutants; and/or presence of cough, sputum production or dyspnoea. Spirometric classification has proved useful in predicting health status 4, utilisation of healthcare resources 5, development of exacerbations 6, 7 and mortality 8 in COPD. It is intended to be applicable to populations 9 and not to substitute clinical judgment in the evaluation of the severity of disease in individual patients.
Spirometric classification of chronic obstructive pulmonary disease (COPD)
It is accepted that a single measurement of FEV1 incompletely represents the complex clinical consequences of COPD. A staging system that could offer a composite picture of disease severity is highly desirable, although it is currently unavailable. However, spirometric classification is useful in predicting outcomes such as health status and mortality, and should be evaluated. In addition to the FEV1, the body mass index (BMI) 10, 11 and dyspnoea 12 have proved useful in predicting outcomes such as survival, and this document recommends that they be evaluated in all patients.
BMI is easily obtained by dividing weight (in kg) over height (in m2). Values <21 kg·m−2 are associated with increased mortality.
Functional dyspnoea can be assessed by the Medical Research Council dyspnoea scale as follows. 0: not troubled with breathlessness except with strenuous exercise. 1: troubled by shortness of breath when hurrying or walking up a slight hill. 2: walks slower than people of the same age due to breathlessness or has to stop for breath when walking at own pace on the level. 3: stops for breath after walking about 100 m or after a few minutes on the level. 4: too breathless to leave the house or breathless when dressing or undressing.
Poorly reversible airflow limitation associated with bronchiectasis, cystic fibrosis and fibrosis due to tuberculosis are not included in the definition of COPD, and should be considered in its differential diagnosis.
Patients presenting with airflow limitation at a relatively early age (4th or 5th decade) and particularly those with a family history of COPD should be tested for α1‐antitrypsin deficiency.
Epidemiology, risk factors and natural history of COPD
COPD is a leading cause of morbidity and mortality worldwide, and results in an economic and social burden that is both substantial and increasing. The prevalence and morbidity data greatly underestimate the total burden of COPD because the disease is usually not diagnosed until it is clinically apparent and moderately advanced. In people aged 25–75 yrs in the USA, the estimated prevalence of mild COPD (defined as FEV1/FVC <70% and FEV1 ≥80% predicted) was 6.9% and of moderate COPD (defined as FEV1/FVC <70% and FEV1 ≤80% pred) was 6.6%, according to National Health and Nutrition Examination Survey (NHANES). COPD is the fourth-leading cause of death in the USA and Europe, and COPD mortality in females has more than doubled over the last 20 yrs 13. Currently, COPD is a more costly disease than asthma and, depending on country, 50–75% of the costs are for services associated with exacerbations. Tobacco smoke is by far the most important risk factor for COPD worldwide. Other important risk factors are occupational exposures, socio-economic status and genetic predisposition.
COPD has a variable natural history and not all individuals follow the same course 14. The often-quoted statistic that only 15–20% of smokers develop clinically significant COPD may underestimate the toll of COPD.
It is increasingly apparent that COPD often has its roots decades before the onset of symptoms 15. Impaired growth of lung function during childhood and adolescence, caused by recurrent infections or tobacco smoking, may lead to lower maximally attained lung function in early adulthood 16, 17. This abnormal growth will, often combined with a shortened plateau phase in teenage smokers, increase the risk of COPD.
The risk factors for COPD are shown in table 2⇓ and they are separated into host factors and exposures.
Risk factors for chronic obstructive pulmonary disease
Pathology and pathophysiology in COPD
COPD comprises pathological changes in four different compartments of the lungs (central airways, peripheral airways, lung parenchyma and pulmonary vasculature), which are variably present in individuals with the disease 18–22.
Tobacco smoking is the main risk factor for COPD, although other inhaled noxious particles and gases may contribute. This causes an inflammatory response in the lungs, which is exaggerated in some smokers, and leads to the characteristic pathological lesions of COPD. In addition to inflammation, an imbalance of proteinases and antiproteinases in the lungs, and oxidative stress are also important in the pathogenesis of COPD 23. The different pathogenic mechanisms produce the pathological changes which, in turn, give rise to the following physiological abnormalities in COPD: mucous hypersecretion and cilliary dysfunction; airflow limitation and hyperinflation; gas exchange abnormalities; pulmonary hypertension; and systemic effects 24, 25.
Clinical assessment, testing and differential diagnosis of COPD
COPD runs an insidious course, measured over years, with an often undiagnosed initial phase. Its presence can be suspected after a directed clinical evaluation and then confirmed physiologically with simple spirometry. Chest radiography helps in differential diagnosis (table 3⇓), and other tests may be useful to better determine the phenotype and physiological characteristics of individual patients.
Differential diagnosis of chronic obstructive pulmonary disease (COPD)
Some patients with asthma cannot be distinguished from COPD with the current diagnostic tests. The management of these patients should be similar to that of asthma.
Medical history
A directed medical history should assess the following issues: symptoms of cough, sputum production and dyspnoea; past medical history of asthma, allergies and other respiratory diseases; family history of COPD or other respiratory diseases; co-morbidities; any unexplained weight loss; and exposure history, smoking, and occupational and environmental exposures.
Physical signs
A normal physical examination is common in early COPD 13. As the disease progresses, some signs become apparent and in advanced stages many are almost pathognomonic. Examination should aim at eliciting the presence of respiratory and systemic effects of COPD. All patients should have their respiratory rate, weight and height, and BMI measured.
Smoking cessation
Cigarette smoking is an addiction and a chronic relapsing disorder, and is regarded as a primary disorder by the Department of Health and Human Services Guidelines in the USA 26, 27 and by the World Health Organization (WHO). Therefore, treating tobacco use and dependence should be regarded as a primary and specific intervention. Smoking should be routinely evaluated whenever a patient presents to a healthcare facility and all smokers should be offered the best chance to treat this disorder.
The most comprehensive of the guidelines prepared on smoking cessation is “Treating Tobacco Use and Dependence”, an evidence-based guideline sponsored by the US Department of Health and Human Services and released in 2000, which updates the previous evidence-based guideline “Smoking Cessation” released in 1996. The guideline and the meta-analyses on which it is based are available online 28. The key findings of this report are summarised in table 4⇓.
Key points of the Treating Tobacco Use and Dependence guidelines
Brief intervention
The key steps in brief intervention are as follows. Ask: systematically, identify all tobacco users at every visit, implement an office-wide system that ensures that tobacco use is queried and documented for every patient at every clinic visit. Advise: strongly urge all tobacco users to quit, in a clear, strong and personalised manner. Assess: determine willingness to make a quit attempt. Assist: help the patient with a quit plan, provide practical counselling, provide treatment and social support, help the patient obtain extra treatment and social support, recommend the use of approved pharmacotherapy (except in special circumstances), and provide supplementary materials. Arrange: schedule follow-up contact, either in person or via the telephone.
Permanent remissions can be achieved in a substantial percentage of smokers with currently available treatments. Successful treatment of this disorder can have a substantial benefit in reducing many secondary complications of which COPD is one. All patients willing to make a serious attempt to quit should be offered pharmacological support (nicotine replacement therapy and/or bupropion) 26, 27. Smoking cessation activities and support for its implementation should be integrated into the healthcare system.
Management of stable COPD: pharmacological therapy
Effective medications for COPD are available and all patients who are symptomatic merit a trial of drug treatment 1–3. The medications for COPD currently available can reduce or abolish symptoms, increase exercise capacity, reduce the number and severity of exacerbations, and improve health status. At present, no treatment has modified the rate of decline in lung function. The inhaled route is preferred.
The change in lung function after brief treatment with any drug does not help in predicting other clinically related outcomes. Changes in FEV1 following bronchodilator therapy can be small but are often accompanied by larger changes in lung volumes, which contribute to a reduction in perceived breathlessness. Combining different agents produces a greater change in spirometry and symptoms than single agents alone.
Bronchodilators
Three types of bronchodilator are in common clinical use: β‐agonists, anticholinergic drugs and methylxanthines. Despite substantial differences in their site of action within the cell and some evidence for nonbronchodilator activity with some classes of drug, the most important consequence of bronchodilator therapy appears to be airway smooth muscle relaxation and improved lung emptying during tidal breathing. The resultant increase in FEV1 may be relatively small but is often accompanied by larger changes in lung volumes 29, with a reduction in residual volume and/or a delay of the onset of dynamic hyperinflation during exercise. Both of these changes contribute to a reduction in perceived breathlessness 30, 31. In general, the more advanced the COPD, the more important the changes in lung volume become relative to those in FEV1. The clinical use of bronchodilator drugs is illustrated in figure 1⇓.
Algorithm for pharmacological treatment of chronic obstructive pulmonary disease (COPD). SA-BD: short-acting bronchodilator; LA-BD: long-acting bronchodilator; ICS: inhaled corticosteroid. Assess effectiveness by treatment response criteria. If forced expiratory volume <50% predicted and exacerbations of COPD requiring a course of oral corticosteroid or antibiotic occurred at least once within the last year, consider adding regular ICS. Always ensure the patient can use an inhaled device effectively and understands its purpose. If an ICS and a long-acting β‐agonist are used, prescribe a combination inhaler.
Short-acting bronchodilators can increase exercise tolerance acutely 30, 31. Long-acting inhaled β‐agonists improve health status possibly to a greater extent than regular short-acting anticholinergics 32, reduce symptoms, rescue medication use and increase time between exacerbations compared with placebo 33–35. Combining short-acting bronchodilator agents (salbutamol (albuterol)/ipratropium) produces a greater change in spirometry than either agent alone 34. Combining long-acting β‐agonists and ipratropium leads to fewer exacerbations than either drug alone. No good comparative data between different long-acting β‐agonists are presently available, although it is likely that their effects will be similar. Combining long-acting β‐agonists and theophylline appears to produce a greater spirometric change than either drug alone 35. Tiotropium improves health status and reduces exacerbations and hospitalisations compared with both placebo and regular ipratropium 36, 37.
Theophylline is a weak bronchodilator, which may have some anti-inflammatory properties. Its narrow therapeutic index and complex pharmacokinetics make its use difficult, but modern slow-release preparations have improved this problem and lead to more stable plasma levels. Generally, therapeutic levels should be measured and patients should be kept on the lowest effective dose (recommended serum level 8–14 µg·dL−1).
Glucocorticoids
Glucocorticoids act at multiple points within the inflammatory cascade, although their effects in COPD are more modest as compared with bronchial asthma. Data from large patient studies suggest that inhaled corticosteroids can produce a small increase in postbronchodilator FEV1 and a small reduction in bronchial reactivity in stable COPD 38–40. In patients with more advanced disease (usually classified as an FEV1 <50% pred) there is evidence that the number of exacerbations per year and the rate of deterioration in health status can be reduced by inhaled corticosteroids in COPD 38. Evidence from four large prospective 3‐yr studies has shown no effect of inhaled corticosteroids on rate of change of FEV1 in any severity of COPD 38–41.
When therapy is thought to be ineffective, a trial of withdrawing treatment is reasonable. Some patients will exacerbate when this occurs, which is a reason for re-instituting this therapy 42. The results of forthcoming large randomised trials with mortality as an outcome will help clarify the role of inhaled glucocorticoids in COPD.
Outcomes of frequently used drugs
Table 5⇓ summarises the effects of frequently used medications in patients with COPD. The evidence level was obtained from the GOLD document 3 using the same grade of evidence, as follows. Grade A: randomised clinical trial (RCT), rich body of data. Grade B: RCT, limited body of data. Grade C: nonrandomised trials, observational studies. Grade D: panel consensus.
Effect of commonly used medications on important clinical outcomes in chronic obstructive pulmonary disease
Combination therapy
Combining medications of different classes seems a convenient way of delivering treatment and obtaining better results. This includes better lung function and improved symptoms 43–45.
Data from trials combining long-acting inhaled β‐agonists and inhaled corticosteroids show a significant additional effect on pulmonary function and a reduction in symptoms in those receiving combination therapy compared with its components 45. The largest effects in terms of exacerbations and health status are seen in patients with an FEV1 <50% pred, where combining treatment is clearly better than either component drug used alone.
Management of stable COPD: long-term oxygen therapy
Supplemental long-term oxygen therapy (LTOT) improves survival, exercise, sleep and cognitive performance in hypoxaemic patients 1–3, 45–50. Reversal of hypoxaemia supersedes concerns about carbon dioxide (CO2) retention.
Arterial blood gas (ABG) assessment is the preferred method to determine oxygen need because it includes acid-base information. Arterial oxygen saturation as measured by pulse oximetry (Sp,O2) is adequate for trending. Physiological indications for oxygen include a arterial oxygen tension (Pa,O2) <7.3 kPa (55 mmHg). The therapeutic goal is to maintain Sp,O2 >90% during rest, sleep and exertion. If oxygen is prescribed during an exacerbation, ABG should be rechecked in 30–90 days. Withdrawal of oxygen because of improved Pa,O2 in patients whose need for oxygen was determined when in a stable state may be detrimental.
Active patients require portable oxygen. Oxygen sources include gas, liquid and concentrator; while oxygen delivery methods include nasal continuous flow, pulse demand, reservoir cannulae and transtracheal catheters 51. Patient education improves compliance.
Figure 2⇓ shows a flow chart for prescribing home oxygen therapy.
A flow chart for prescribing long-term oxygen therapy (LTOT). Pa,O2: arterial oxygen tension; Sa,O2: arterial oxygen saturation; ABG: arterial blood gases.
Management of stable COPD: pulmonary rehabilitation
Pulmonary rehabilitation is defined as “a multidisciplinary programme of care for patients with chronic respiratory impairment that is individually tailored and designed to optimise physical and social performance and autonomy” 52.
Pulmonary rehabilitation results in improvements in multiple outcome areas of considerable importance to the patient, including dyspnoea, exercise ability, health status and healthcare utilisation 53–57. These positive effects occur despite the fact that it has a minimal effect on pulmonary function measurements. This reflects the fact that much of the morbidity from COPD results from secondary conditions, which are often treatable if recognised. Examples of these treatable conditions are cardiac deconditioning, peripheral muscle dysfunction, and a reduction in total and lean body mass, anxiety and poor coping skills. Elements of comprehensive pulmonary rehabilitation, including promoting a healthy lifestyle, stressing adherence to therapy and encouraging physical activity, should be incorporated into the care of all patients with COPD. Pulmonary rehabilitation is a multidisciplinary programme of care that is individually tailored and designed to optimise physical and social performance, and autonomy.
Pulmonary rehabilitation should be considered for patients with COPD who have dyspnoea or other respiratory symptoms, reduced exercise tolerance, a restriction in activities because of their disease, or impaired health status. There are no specific pulmonary function inclusion criteria that indicate the need for pulmonary rehabilitation, since symptoms and functional limitations direct the need for pulmonary rehabilitation.
The pulmonary rehabilitation programme includes exercise training, education, psychosocial/behavioural intervention, nutritional therapy, outcome assessment and promotion of long-term adherence to the rehabilitation recommendations.
Management of stable COPD: nutrition
Weight loss, as well as a depletion of fat-free mass (FFM), may be observed in stable COPD patients, irrespective of the degree of airflow limitation, and being underweight is associated with an increased mortality risk 58.
Nutritional screening is recommended in the assessment of COPD. Simple screening can be based on measurements of BMI and weight change. Patients are considered underweight (BMI <21 kg·m−2; age >50 yrs), normal weight (BMI 21–25 kg·m−2), overweight (BMI 25–30 kg·m−2) or obese (BMI ≥30 kg·m−2). Criteria to define weight loss are weight loss >10% in the past 6 months or >5% in the past month.
Weight loss and particularly muscle wasting contribute significantly to morbidity, disability and handicap in COPD patients. Weight loss and loss in fat mass is primarily the result of a negative balance between dietary intake and energy expenditure, while muscle wasting is a consequence of an impaired balance between protein synthesis and protein breakdown. In advanced stages of COPD, both energy balance and protein balance are disturbed. Therefore, nutritional therapy may only be effective if combined with exercise or other anabolic stimuli 59, 60.
Management of stable COPD: surgery in and for COPD
Surgery in COPD
Patients with a diagnosis of COPD have a 2.7–4.7‐fold increased risk of postoperative pulmonary complications 61–63. However, COPD is not an absolute contraindication to any surgery. The most important concept determining the risk of surgery is that the further the procedure from the diaphragm, the lower the pulmonary complication rate. Although the value of pre-operative pulmonary function testing in general surgery is debatable, pre-operative pulmonary function studies have a well-documented role in the evaluation of patients undergoing lung surgery 64–67.
Smoking cessation at least 4–8 weeks pre-operatively and optimisation of lung function can decrease post-operative complications. In addition, early mobilisation, deep breathing, intermittent positive-pressure breathing, incentive spirometry and effective analgesia may decrease post-operative complications.
An algorithm for pre-operative evaluation of patients undergoing lung resection is shown in figure 3⇓.
Algorithm for pre-operative testing for lung resection. DL,CO: carbon dioxide diffusing capacity of the lung; FEV1: forced expiratory volume in one second; ppo: predicted postoperative; V′O2,max: maximum oxygen consumption.
Surgery for COPD
Bullectomy, lung volume reduction surgery and lung transplantation may result in improved spirometry, lung volumes, exercise capacity, dyspnoea, health-related quality of life and possibly survival in highly selected patients 68–69. Factors associated with a favourable or unfavourable outcome in bullectomy are shown in table 6⇓.
Factors associated with favourable or unfavourable outcome in classical bullectomy
The recently completed National Emphysema Therapy Trial (NETT) showed benefits for a subset of patients with nonhomogenous emphysema. Figure 4⇓ summarises the stratification of the patients and the results of the trial for each of the groups. Group B is comprised of those patients with nonhomogenous emphysema of upper lobe predominance and limited exercise performance after pre-operative comprehensive rehabilitation. Group C corresponds to patients with predominant upper lobe emphysema and good post-rehabilitation exercise capacity. Group D corresponds to those patients with homogenous emphysema and low post-rehabilitation exercise capacity. Group E was characterised by homogeneous emphysema and good post-rehabilitation exercise capacity. Finally, group A corresponds to those patients with a very high risk for lung reduction surgery 70.
Schematic algorithm from the National Emphysema Therapy Trial for Lung Volume Reduction Surgery (LVRS) (see text). FEV1: forced expiratory volume in one second; DL,CO: carbon dioxide diffusing capacity of the lung. Modified from 69.
The results of this trial showed that patients in group B who underwent surgery had a lower mortality, better exercise capacity and health status than patients randomised to medical therapy. The operated patients in groups C and D did not benefit from improved survival but had significant improvements in exercise capacity and health status compared to patients randomised to medical therapy. The patients in group E had higher mortality and would, therefore, not be candidates for LVRS. The results in this group are similar to those observed in the highest risk group (A) who should not be considered for surgery.
Lung transplantation results in improved pulmonary function, exercise capacity and quality of life, however, its effects on survival remain controversial 71. Specific guidelines for lung transplantation in COPD are shown in table 7⇓.
Disease-specific guidelines for candidate selection for lung transplantation in chronic obstructive pulmonary disease patients
Management of stable COPD: sleep
Sleep in COPD is associated with oxygen desaturation, which is predominantly due to the disease itself rather than to sleep apnoea 72. The desaturation during sleep may be greater than during maximum exercise 73. In COPD, sleep quality is markedly impaired, both subjectively and objectively 74. However, sleep apnoea syndrome is about as prevalent in COPD as in a general population of similar age, but oxygen desaturation during sleep is more pronounced when the two conditions co-exist 75.
The clinical assessment in all patients with COPD should include questions about sleep quality and possible co-existing sleep apnoea syndrome. Sleep studies are not indicated in COPD except in special circumstances. These include: a clinical suspicion of sleep apnoea or complications of hypoxaemia that are not explained by the awake arterial oxygen levels, and pulmonary hypertension out of proportion to the severity of pulmonary function derangement.
Management of sleep problems in COPD should particularly focus on minimising sleep disturbance by measures to limit cough and dyspnoea, and nocturnal oxygen therapy may be indicated for nocturnal hypoxaemia 76. Hypnotics should be avoided, if possible, in patients with severe COPD.
Management of stable COPD: air-travel
Commercial airliners can cruise at >12,192 m (>40,000 feet), as long as the cabin is pressurised from 1,829–2,438 m (6,000–8,000 feet). This is equivalent to an inspired oxygen concentration at sea level of ∼15% 77.
Patients with COPD can exhibit falls in Pa,O2 that average 3.3 kPa (25 mmHg) 78. Pre-flight assessment can help determine oxygen needs and the presence of co-morbidities 79. Oxygen needs can be estimated by using the hypoxia inhalation test or through the use of regression formulae. However, it is currently recommended that the Pa,O2 during air travel should be maintained above 6.7 kPa (50 mmHg) 80. Treatment with 2–3 L·min−1 of oxygen by nasal cannula will replace the inspired oxygen partial pressure lost at 2,438 m (8,000 feet) compared to sea level 81. For high-risk patients, the goal should be to maintain oxygen pressure during flight at the same level at which the patient is clinically stable at sea level. Most airlines will provide supplemental oxygen on request.
Exacerbation of COPD: definition, evaluation and treatment
Definition
An exacerbation of COPD is an event in the natural course of the disease characterised by a change in the patient's baseline dyspnoea, cough and/or sputum beyond day-to-day variability sufficient to warrant a change in management.
There is no agreed classification of exacerbations. The following operational classification of severity can help rank the clinical relevance of the episode and its outcome. Level I: treated at home. Level II: requires hospitalisation. Level III: leads to respiratory failure.
Assessment
Several clinical elements must be considered when evaluating patients with exacerbations. These include the severity of the underlying COPD, the presence of co-morbidity and the history of previous exacerbations. The physical examination should evaluate the effect of the episode on the haemodynamic and respiratory systems. The diagnostic procedures to be performed depend on the setting of the evaluation 82, 83.
The pharmacological treatment of patients with an exacerbation of COPD is based on the same medications utilised in the management of the stable patient 1–3. However, the evidence supports the use of systemic glucocorticosteroids 84–88.
Table 8⇓ shows the elements of the clinical evaluation and diagnostic procedures that are usually informative in patients with exacerbations according to the severity of the episode.
Clinical history, physical findings and diagnostic procedures in patients with exacerbation of chronic obstructive pulmonary disease (COPD)
Indication for hospitalisation
Table 9⇓ provides reasonable guidelines for patient hospitalisation. Based on expert consensus, they consider the severity of the underlying respiratory dysfunction, progression of symptoms, response to outpatient therapy, existence of co-morbid conditions and the availability of adequate home care.
Indications for hospitalisation of patients with a COPD exacerbation
Indications for admission to specialised or intensive care unit
The severity of respiratory dysfunction dictates the need for admission to an intensive care unit (ICU). Depending on the resources available within an institution, admission of patients with severe exacerbations of COPD to intermediate or special respiratory care units may be appropriate if personnel, skills and equipment exist to identify and manage acute respiratory failure successfully.
Indications for ICU or special care unit admission include the following: impending or actual respiratory failure; presence of other end-organ dysfunction, i.e. shock, renal, liver or neurological disturbance; and/or haemodynamic instability.
Treatment of exacerbations
The treatment of exacerbations has to be based on the clinical presentation of the patient, as shown in tables 10, 11 and 12⇓⇓⇓.
Level I: outpatient treatment
Level II: treatment for hospitalised patient
Level III: treatment in patients requiring special or intensive care unit
Exacerbation of COPD: inpatient oxygen therapy
During a severe exacerbation, ABGs should be monitored for Pa,O2, arterial carbon dioxide tension (Pa,CO2) and pH. The Sp,O2 should be monitored for trending and adjusting oxygen settings. The goal of inpatient oxygen therapy is to maintain Pa,O2 >8 kPa (60 mmHg) or Sp,O2 >90% in order to prevent tissue hypoxia and preserve cellular oxygenation. Due to the shape of the oxyhaemoglobin dissociation curve, increasing the Pa,O2 to values much greater than 8 kPa (60 mmHg) confers little added benefit (1–2 vol %) and may increase the risk of CO2 retention, which may lead to respiratory acidosis 89, 90. The main delivery devices include nasal cannula and venturi masks. Alternative delivery devices include nonrebreather masks, reservoir cannulae, nasal cannulae or transtracheal catheters.
As a general principle, prevention of tissue hypoxia supercedes CO2 retention concerns. If CO2 retention occurs, monitor for acidemia. If acidemia occurs, consider noninvasive or invasive mechanical ventilation.
Setting and adjusting oxygen flow
Figure 5⇓ shows an algorithm for correcting hypoxaemia in the COPD patient.
Algorithm to correct hypoxaemia in an acutely ill chronic obstructive pulmonary disease patient. ABG: arterial blood gas; Pa,O2: arterial oxygen tension; O2: oxygen; Sa,O2: arterial oxygen saturation; Pa,CO2: arterial carbon dioxide tension; NPPV: noninvasive positive pressure ventilation.
Monitoring following hospital discharge
Patients may be started on oxygen for the first time during hospitalisation for an acute exacerbation and discharged before recovery is complete. Patients with hypoxaemia at discharge may require short-term oxygen therapy as the effects of the exacerbation are clearing. After 30–90 days, oxygen may no longer be required; thus re-evaluation of the patient's oxygen and medical status should be completed. If the patient no longer meets the prescribing criteria for LTOT, oxygen should be discontinued, as there is no proven survival benefit for patients with mild hypoxaemia 91. Patients recovering from an exacerbation may benefit from pulmonary rehabilitation.
Some patients who needed oxygen prior to hospitalisation may, over time, increase their Pa,O2 to the point that they no longer qualify for oxygen. This phenomenon is thought to be due to a reparative effect of LTOT. Withdrawing oxygen from these patients may negate the reparative effect and cause the patient's status to deteriorate to the point of meeting the physiological requirement for oxygen. Consequently, these patients should continue their oxygen therapy without interruption, as withdrawing their oxygen might be detrimental 92, 93.
Exacerbation of COPD: assisted ventilation
Mechanical ventilation can be administered via noninvasive or invasive ventilation. Noninvasive is preferred whenever possible. Mechanical ventilation, either “invasive” or “noninvasive”, is not a therapy but it is a form of life support until the cause underlying the acute respiratory failure is reversed with medical therapy 94–96. Patients considered for mechanical ventilation should have a measurement of ABGs.
Indications for mechanical ventilation
The institution of mechanical ventilation should be considered when, despite optimal medical therapy and oxygen administration there is acidosis (pH<7.35) and hypercapnia (Pa,CO2 >6–8 kPa (45–60 mmHg)) and respiratory frequency >24 breaths·min−1.
Modes of mechanical ventilation
Mechanical ventilation can be delivered as follows. 1) Through an endotracheal tube, by passing the upper airway, i.e. “conventional” or “invasive” mechanical ventilation. 2) Without the use of an endotracheal tube, i.e. “noninvasive” mechanical ventilation or NIMV, which can be instituted in two modes: noninvasive positive pressure ventilation (NPPV) (nasal or face masks); or negative pressure ventilation (e.g. iron lung, not recommended).
Noninvasive positive pressure ventilation
NPPV is by far the most popular mode of providing noninvasive ventilation. It is typically administered as a combination of continuous positive airway pressure (CPAP) plus pressure support ventilation (PSV) 94–98. ABG improve because of an increase in alveolar ventilation without significant modifications in the alveolar ventilation/perfusion mismatching and gas exchange in the lungs 99.
ABGs are fundamental for the correct assessment and guidance of therapy. Once baseline ABGs are obtained, if the pH is <7.35 in the presence of hypercapnia, NPPV should be delivered in a controlled environment such as intermediate ICUs and/or high-dependency units. If the pH is <7.25, NPPV should be administered in the ICU and intubation should be readily available. The combination of some CPAP (e.g. 4–8 cmH2O) and PSV (e.g. 10–15 cmH2O) provides the most effective mode of NPPV.
Patients meeting exclusion criteria should be considered for immediate intubation and ICU admission. In the first hours, NPPV requires the same level of supervision as conventional mechanical ventilation.
Contraindications for NPPV include the following: respiratory arrest; cardiovascular instability (hypotension, arrhythmias, myocardial infarction); impaired mental status, somnolence, inability to cooperate; copious and/or viscous secretions with high aspiration risk; recent facial or gastro-oesophageal surgery; craniofacial trauma and/or fixed nasopharyngeal abnormality; burns; and extreme obesity.
NPPV can be considered successful when ABGs and pH improve, dyspnoea is relieved, the acute episode resolves without the need of endotracheal intubation, mechanical ventilation can be discontinued and the patient is discharged from the hospital.
One-year mortality was reported to be lower in patients receiving NPPV for exacerbations of COPD, as compared to both conventional mechanical ventilation 100 and optimal medical therapy alone 101.
Figure 6⇓ illustrates a useful flow-chart for the use of NPPV in exacerbation of COPD complicated by acute respiratory failure.
Flow-chart for the use of noninvasive positive pressure ventilation (NPPV) during exacerbation of chronic obstructive pulmonary disease (COPD) complicated by acute respiratory failure. MV: mechanical ventilation; Pa,CO2: arterial carbon dioxide tension.
Invasive ventilation
Intubation should be considered in patients with the following. 1) NPPV failure: worsening of ABGs and or pH in 1–2 h; lack of improvement in ABGs and or pH after 4 h. 2) Severe acidosis (pH <7.25) and hypercapnia (Pa,CO2 >8 kPa (60 mmHg)). 3) Life-threatening hypoxaemia (arterial oxygen tension/inspiratory oxygen fraction <26.6 kPa (200 mmHg)). 4) Tachypnoea >35 breaths·min−1.
Criteria for hospital discharge
As a general rule, patients hospitalised for an acute exacerbation can be considered for discharge once the reasons for admission are controlled and/or reversed. Based on consensus, conditions that need to be met when considering patients for discharge include: symptoms returning to baseline, including eating, sleeping, etc.; haemodynamic stability; oxygenation returning to baseline; inhaled β‐agonist therapy required less frequently; ability to resume ambulation; ability to eat and sleep without frequent awakening by dyspnoea; off-parenteral therapy for 12–24 h; patient (or home caregiver) understands correct use of medications; follow-up and homecare arrangements have been completed (e.g. visiting nurse, oxygen delivery, meal provisions etc.).
Follow-up evaluation
Once discharged, the patient should be followed. There are no studies that have addressed the specific schedules more likely to result in a positive outcome, but patients with frequent exacerbations are more likely to relapse. Likewise, patients who have developed respiratory failure requiring admission to an ICU carry a very high mortality risk. Based on this, the guidelines for the re-evaluation of patients admitted for exacerbation of COPD should include: reassessment within 4 weeks; evaluation of improvement in symptoms and physical exam; assessment of need for supplemental oxygen; repeat examination if previous abnormalities were present; assessment of ability of the patient to cope with the environment; an understanding and re-adjustment of the treatment regimen.
Ethical and palliative care issues in COPD
Patients with COPD experience acute exacerbations of their disease, which may produce respiratory failure and a possible need for either ventilatory support or accepting death. No clinical features can identify patients with respiratory failure who will experience more burden than benefit from life supportive care.
If the patient has, or can have, clear preferences about treatment, respect for the patient requires that care providers give effect to the patient's views. Autonomy of the patient is the predominant ethical principle that drives end-of-life decision-making in many societies.
All healthcare providers should assist patients during stable periods of health to think about their advance care planning by initiating discussions about end-of-life care. These discussions should prepare patients with advanced COPD for a life-threatening exacerbation of their chronic disease, while assisting them to go on living and enjoying life. Pulmonary rehabilitation provides an important opportunity to assist advance care planning for patients with moderate-to-severe COPD. Educational programmes on advance care planning within pulmonary rehabilitation increase the adoption rate for instruments of advance care planning and patient-physician discussion about end-of-life care 102. Patients who choose to refuse life supportive care or have it withdrawn require expert delivery of palliative care.
Patients with COPD sometimes qualify for formal hospice services, especially when they are having repeated exacerbations and very poor measures on tests of pulmonary function. Nevertheless, many patients will have a fatal exacerbation within a short time of having fairly good function, so one cannot wait to consider using hospice until death is nearly certain. Opportunities for hospice care are frequently neglected for patients coming to the end of life with COPD 103, 104. Neglect in offering patients and their families appropriate resources for supportive end-of-life care results in unnecessary admissions to acute care hospitals for worsening respiratory symptoms.
Integrated disease management for primary care in COPD
Disease management can be regarded as an integrated and systematic approach in which healthcare providers work together in a coordinated and cooperative manner to produce an optimal outcome for a particular patient with COPD, throughout the entire continuum of care 105. The concept of the disease as a continuum is depicted in figure 7⇓. This figure also represents the navigation tool for the web-based Standards for the Diagnosis and Treatment of Patients with COPD document 2004.
Continuum of care for chronic obstructive pulmonary disease (COPD). FEV1: forced expiratory volume in one second.
Integrated care for COPD involves the patient and a team of clinical professionals working in primary care, cooperating with secondary care and rehabilitation services. Optimal disease management involves redesigning standard medical care to integrate rehabilitative elements into a system of patient self-management and promotion of a healthy lifestyle.
The following aspects are important: smoking cessation for all patients who smoke; early diagnosis and secondary prevention (healthy lifestyle, vaccinations, exercise); education and self-management; pulmonary rehabilitation; monitoring and early recognition of exacerbation; implementation of rapid action plan; careful attention to end-of-life issues; palliative care.
Referral indications
Referral to specialist care is indicated for COPD patients with the following: disease onset at age <40 yrs; frequent exacerbations (two or more per year) despite adequate treatment; rapidly progressive course of disease (decline in FEV1, progressive dyspnoea, decreased exercise tolerance, unintentional weight loss; severe COPD (FEV1<50% pred) despite optimal treatment; need for LTOT; onset of co-morbid illness (osteoporosis, heart failure, bronchiectasis, lung cancer); evaluation for surgery.
Conclusions
This summary presents an overview of the entire document for the health practitioner, which is readily available online (www.copd-ats-ers, www.ersnet.org and www.thoracic.org). This summary does not include any reference to the patient document, which, due to its inherent characteristics, cannot be presented in a conventional format. The readers are encouraged to visit the website to access both full documents.
The committee that developed this document fully understands that the field is rapidly changing and that individual components of this document need to be updated periodically as the need arises. However, the modular and flexible design allows for this to occur easier than ever before. The challenge for the future is to develop mechanisms to permit the updated flow of valid scientific information to reach all who need it.
- Received February 4, 2004.
- Accepted February 11, 2004.
- © ERS Journals Ltd
References
Jump To
- Article
- Background
- Definition of COPD
- Diagnosis of COPD
- Epidemiology, risk factors and natural history of COPD
- Pathology and pathophysiology in COPD
- Clinical assessment, testing and differential diagnosis of COPD
- Smoking cessation
- Management of stable COPD: pharmacological therapy
- Management of stable COPD: long-term oxygen therapy
- Management of stable COPD: pulmonary rehabilitation
- Management of stable COPD: nutrition
- Management of stable COPD: surgery in and for COPD
- Management of stable COPD: sleep
- Management of stable COPD: air-travel
- Exacerbation of COPD: definition, evaluation and treatment
- Exacerbation of COPD: inpatient oxygen therapy
- Exacerbation of COPD: assisted ventilation
- Ethical and palliative care issues in COPD
- Integrated disease management for primary care in COPD
- Conclusions
- References
- Figures & Data
- Info & Metrics