COPD Guidelines: A Review of the 2018 GOLD Report
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) had first released evidence-based consensus guideline document, the Global Strategy for the Diagnosis, Management, and Prevention of COPD (chronic obstructive lung disease) in the year 2001 and since then has published major revisions of the document in 2006, 2011, and 2017, with minor updates nearly annually.
As with previous editions, the 2018 update seeks to provide comprehensive evidence-based guidance for the diagnosis, management, and prevention of COPD. An accompanying pocket guide was recently published as well, as with previous editions. The present article published in the journal Mayo Clinic Proceedings, reviews the salient features of the GOLD 2018 document
The GOLD 2018 report defines COPD as a “common, preventable and treatable disease that is characterized by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities, usually caused by significant exposure to noxious particles or gases,” with the criteria of “persistent respiratory symptoms” being a new and controversial inclusion since 2017.
What is new?
• With the availability of newer pharmacotherapy options, treatment recommendations are made on the basis of a review of the latest literature and directed by symptom burden and health care utilization.
• Apart from the change in definition, a major shift in the recommendations is the exclusion of severity of airflow limitation as one of the major factors in guiding therapy.
The new guide is organized into 6 chapters as follows:-
(1) Definition and Overview
(2) Diagnosis and Initial Assessment
(3) Evidence Supporting Prevention and Maintenance Therapy
(4) Management of Stable COPD
(5) Management of Exacerbations
(6) COPD and Comorbidities
Chapter 1: Definition And Overview
Chapter 1 addresses the global burden of COPD and cautions the reader about the expected increase in the prevalence and burden of COPD due to continued exposure to risk factors and aging of the world’s population. Also addressed are factors that influence disease development and progression- genetics, environmental and occupational exposures, socioeconomic factors, age, sex, lung growth, and development.
The pathogenesis behind COPD including oxidative stress, protease-antiprotease imbalance, inflammatory mediators and processes, and the ensuing pathophysiologic changes is also highlighted.
Chapter 2: Diagnosis And Initial Assessment
According to GOLD, the diagnosis of COPD requires 3 features:-
(1) a postbronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio of less than 0.70, which “confirms the presence of persistent airflow limitation,”
(2) “appropriate symptoms” including dyspnea, chronic cough, sputum production, or wheezing,
(3) “significant exposures to noxious stimuli” such as a history of smoking cigarettes, or other environmental exposures.
New to the 2018 update is the recommendation for repeat spirometry for patients with an initial FEV1/FVC ratio in the 0.6 to 0.8 range to account for day-to-day biologic variability and to increase the specificity of the diagnosis.
The GOLD update discusses the alternative approach, using the lower limit of normal value for FEV1/FVC ratio, but ultimately reaffirms the use of a fixed FEV1/FVC ratio of less than 0.70, citing its simplicity and historical use as an inclusion criterion for entry into clinical trials. Screening spirometry is, appropriately, not recommended for asymptomatic patients, even those with risk factors.
Chapters 3, 4: Evidence and Recommendations For Mx of Stable COPD
GOLD readdresses the 2-dimensional ABCD schema for classifying patients to guide therapy on the basis of symptom burden and risk of exacerbation. The current document continues pre-2017 GOLD versions’ staging based on severity of airflow limitation (1-4 correlating with FEV1 percent predicted of ≥80, 50-79, 30-49, and <30, respectively). Curiously, the 2017 and 2018 versions do not use the term “stage,” used in previous editions to describe these strata. The biggest change in the 2017 version of GOLD is that staging, or degree of airflow limitation, is no longer used to guide intensity of pharmacologic intervention.
• Patients are placed into groups A to D on the basis of exacerbation frequency along the y-axis and symptom severity along the x-axis.
• Groups A and C have lower symptom burden, as indicated by either a modified Medical Research Council (mMRC) score of less than 2 (dyspnea when walking up a hill)10 or a COPD Assessment Test (CAT) score of less than 10, whereas groups B and D both include a greater symptom burden as defined by mMRC or CAT.
• Groups A and B include patients with 1 or fewer outpatient exacerbation annually, whereas groups C and D represent patients with more frequent (≥2) outpatient exacerbations or 1 or more hospitalizations.
The document addresses smoking cessation in some detail and advises reduction of cumulative individual exposure to other risk factors including indoor and outdoor air pollution as well. Influenza and pneumococcal vaccination are recommended for patients with COPD.
Key recommendations are:-
1. Group A: A trial of short-acting bronchodilator for intermittent symptoms and long-acting bronchodilator for low-grade persistent symptoms is recommended with provision for stopping or switching medications on the basis of response.
2. Group B: Long-acting bronchodilator monotherapy is recommended with escalation to dual bronchodilator therapy for persistent symptoms.
3. Group C: For “frequent exacerbators” with lower symptom burden, recommendations are for use of LAMA as preferred monotherapy. For escalation of treatment, preference is given to a LAMA/LABA combination over a LABA/ICS combination based on results of one study that showed increased efficacy as well as raised concern regarding an increased risk of pneumonia associated with ICS. That may now be challenged by results of a recently published larger study showing a lower rate of moderate or severe exacerbations with LABA/ICS than with LABA/LAMA.
4. Group D: For patients with a high symptom burden and frequent or severe exacerbations, baseline therapy may include a LAMA, LABA/LAMA, or LABA/ICS with escalation to triple therapy with LABA/LAMA/ICS or addition of roflumilast or macrolide based on indications.
Chapter 5: Management of Exacerbations
• The GOLD group defines an acute exacerbation of COPD (AECOPD) as “an acute worsening of respiratory symptoms that results in additional therapy,” and an event that has the largest impact on patients’ quality of life and cost of care. Aside from the obvious burdens of financial impact, health care utilization, and disruptiveness of COPD exacerbations, they carry the risks of death, iatrogenic complications, setbacks to quality of life, and a somewhat faster decline of lung function.
• Given the high prevalence of comorbidity in COPD, GOLD advocates ensuring respiratory symptoms are not attributable to other etiologies such as decompensated heart failure, acute coronary syndrome, pneumonia, or pulmonary embolism.
• Systemic corticosteroids are the backbone of AECOPD therapy in terms of decreasing duration and promoting resolution and are recommended at a modest dose (40 mg) and a short course (5-7 days) without tapering or need for intravenous delivery in moderate and severe exacerbations.
• A 5- to 7-day antibiotic course is recommended for exacerbations with increased sputum purulence or need for mechanical ventilation (invasive or noninvasive).
• Oxygen therapy is indicated to achieve an oxygen saturation of 88% to 92%, with overoxygenation associated with increased hypercapnia and mortality.
• Noninvasive positive pressure ventilation (NIPPV) is recommended as first-line therapy in instances of hypercapnic respiratory failure (PCO2>45 mm Hg and arterial pH≤7.35). Contraindications to NIPPV include emesis, inability to protect airway, and need for urgent intubation.
Chapter 6: COPD and Comorbidities
• The GOLD document highlights 2 principles in approaching patients with COPD and their comorbidities.
• First, the presence of comorbidities does not alter recommended COPD treatment. Second, comorbidities should be treated according to their usual standards of care despite the coexistence of COPD.
• For example, bronchodilators should not be withheld during an acute exacerbation of COPD because of heart failure. Perhaps more importantly, patients with heart failure or ischemic heart disease should not be denied selective beta-blocker therapy because of coexisting COPD.
The new guidelines recognize an important evolution in the primary selection and use of long-acting bronchodilators vs inhaled corticosteroids for the prevention of exacerbations. Although a crucial change is incorporation of symptoms and exacerbation frequency as the main determinants of inhaled medication prescription rather than the severity of airflow obstruction, recently available data show poor utility of this system in predicting outcomes from COPD.
Controversy persists regarding the GOLD Committee’s continued assertion that the presence of airflow obstruction should be defined by a fixed ratio, contrary to the opinion of many other authorities. Furthermore, the new specification that persistent symptoms are required to make the diagnosis leaves out patients whose symptoms vary from day-to-day.
The Global Initiative for Chronic Obstructive Lung Disease (GOLD) was launched in 1997 in collaboration with the National Heart, Lung, and Blood Institute, National Institutes of Health, USA, and the World Health Organization. It works with health care professionals and public health officials around the world to raise awareness of COPD and to improve prevention and treatment of this lung disease.
Note: This list is a brief compilation of some of the key points included in the review of GOLD 2018 report and is not exhaustive and does not constitute medical advice. Kindly refer to the original publications here: https://pxmd.co/e1vss , https://pxmd.co/ZVFes and https://pxmd.co/msV58