Chronic Obstructive Pulmonary Disease (COPD), known in Spanish as Enfermedad Pulmonar Obstructiva Crónica (EPOC), is a progressive respiratory condition characterized by persistent airflow limitation that is not fully reversible, primarily caused by long-term exposure to noxious particles or gases such as tobacco smoke [1]. The disease encompasses chronic bronchitis and emphysema, leading to symptoms such as progressive dyspnea, chronic cough, sputum production, and wheezing [2]. COPD is strongly associated with smoking, but occupational exposures to dust, fumes, and air pollution, as well as genetic factors like alpha-1 antitripsina deficiency, also contribute to its development [3]. Diagnosis is confirmed through espirometría, which measures the forced expiratory volume in one second (FEV1) and forced vital capacity (FVC), with a post-bronchodilator FEV1/FVC ratio < 0.7 indicating obstruction [4]. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines classify severity based on FEV1 and incorporate symptom assessment using tools like the cuestionario CAT and the mMRC. Management includes pharmacological treatments such as broncodilatadores de acción prolongada (LABA and LAMA), inhaled corticosteroids (ICS) for high-risk patients, and non-pharmacological interventions like rehabilitación pulmonar, smoking cessation, and long-term oxygen therapy for those with severe hypoxemia [5]. Comorbidities such as cardiovascular disease, osteoporosis, depression, and lung cancer significantly affect prognosis and require integrated care [6]. Despite being incurable, early diagnosis, risk factor reduction, and comprehensive management can slow progression and improve quality of life.

Definition and Basic Medical Overview

Chronic Obstructive Pulmonary Disease (COPD), known in Spanish as Enfermedad Pulmonar Obstructiva Crónica (EPOC), is a chronic respiratory condition characterized by progressive and generally irreversible airflow obstruction in the lungs [1]. This obstruction results from persistent inflammation and permanent damage to the airways and alveoli, impairing gas exchange and making breathing increasingly difficult [2]. The disease primarily encompasses two pathological conditions: chronic bronchitis, defined by a productive cough lasting at least three months for two consecutive years, and emphysema, characterized by the destruction of alveolar walls and loss of lung elasticity [9].

The primary cause of EPOC is prolonged exposure to noxious particles and gases, with tobacco smoke being the most significant factor, responsible for the majority of cases worldwide [3]. However, other environmental exposures, such as indoor air pollution from biomass fuels used for cooking and heating, and occupational hazards like dust, fumes, and chemical vapors, also contribute substantially to disease development [11]. The disease is progressive and incurable, but its course can be significantly slowed through early diagnosis, the elimination of risk factors (especially smoking cessation), and comprehensive management [1].

The most common symptoms of EPOC include progressive dyspnea (shortness of breath), a chronic cough, sputum production, and wheezing [13]. Dyspnea typically worsens with physical activity and is a key indicator of disease severity. A persistent cough, often with morning sputum, may precede noticeable airflow limitation by years, making early detection challenging [14].

The definitive diagnosis of EPOC is established through spirometry, a non-invasive pulmonary function test [15]. This test measures the forced expiratory volume in one second (FEV1) and the forced vital capacity (FVC). A post-bronchodilator FEV1/FVC ratio of less than 0.7 confirms the presence of persistent airflow limitation, which is the hallmark of the disease [16]. This irreversible obstruction differentiates EPOC from other respiratory conditions like asthma, where airflow limitation is typically more reversible. Genetic factors, such as alpha-1 antitripsina deficiency, also play a role in a small subset of patients, predisposing them to lung damage even in the absence of significant smoking history [17].

Causes and Risk Factors

Chronic Obstructive Pulmonary Disease (COPD), known as Enfermedad Pulmonar Obstructiva Crónica (EPOC) in Spanish, arises from a combination of environmental exposures, genetic predispositions, and demographic factors that contribute to chronic inflammation and irreversible airflow limitation in the lungs. The disease is primarily driven by long-term exposure to noxious particles and gases, but a range of interrelated risk factors influence individual susceptibility and disease progression. Understanding these causes and risk elements is essential for prevention, early detection, and targeted management.

Primary Cause: Tobacco Smoking

Tobacco smoking is the leading cause of EPOC, accounting for over 70% of cases in high-income countries and between 30% and 40% in low- and middle-income nations [18]. The inhalation of cigarette smoke triggers a persistent inflammatory response in the airways and lung parenchyma, leading to structural damage, impaired mucociliary clearance, and progressive airflow obstruction. Smoke disrupts the function of respiratory cilia, reduces pulmonary function, and promotes mucus accumulation, exacerbating symptoms such as chronic cough, sputum production, and dyspnea [17]. Even after cessation, residual inflammation can continue to drive disease progression, underscoring the importance of early intervention. The cumulative dose of tobacco exposure, measured in pack-years, strongly correlates with the risk and severity of EPOC, making smoking cessation the most effective preventive and therapeutic strategy.

Environmental and Occupational Exposures

Beyond tobacco, long-term exposure to environmental and occupational pollutants significantly increases the risk of developing EPOC. These exposures are particularly relevant in low-resource settings and among non-smokers.

Outdoor Air Pollution

Chronic exposure to ambient air pollutants such as particulate matter (PM2.5), ozone, nitrogen dioxide, and sulfur dioxide contributes to airway inflammation and accelerates lung function decline. These contaminants are associated with increased frequency and severity of EPOC exacerbations, which can lead to faster deterioration of respiratory health [20]. Urban populations, especially those living near industrial zones or high-traffic areas, face elevated risks due to prolonged inhalation of polluted air.

Occupational Hazards

Workers in industries such as mining, construction, agriculture, and manufacturing are at heightened risk due to exposure to dust, fumes, vapors, and chemical agents like crystalline silica, pesticides, and metal fumes [21]. This form of EPOC, known as occupational EPOC, results from chronic inhalation of these harmful substances and remains underdiagnosed despite its significant contribution to disease burden [22]. Preventive measures, including improved ventilation, use of respiratory protective equipment, and workplace safety regulations, are critical to reducing this risk.

Indoor Air Pollution from Biomass Fuels

In rural and low-income regions, the use of solid fuels such as wood, coal, or animal dung for cooking and heating generates high levels of indoor air pollution. Chronic inhalation of smoke from these biomass fuels leads to airway irritation, inflammation, and progressive lung damage, increasing the risk of EPOC even in individuals who have never smoked [11]. Women are disproportionately affected due to their traditional roles in household cooking, making this a major public health concern in many developing countries.

Genetic Predisposition and Inherited Conditions

While environmental exposures are predominant, genetic factors also play a crucial role in determining individual susceptibility to EPOC.

Alpha-1 Antitrypsin Deficiency

The most well-established genetic risk factor is alpha-1 antitripsina deficiency, an inherited condition that impairs the body's ability to protect lung tissue from enzymatic destruction. Alpha-1 antitrypsin, a protease inhibitor produced in the liver, normally neutralizes neutrophil elastase, a powerful enzyme released during inflammation. In individuals with deficiency, unopposed elastase activity leads to unchecked degradation of alveolar walls, resulting in early-onset emphysema, even in non-smokers [17]. Although rare, this condition highlights the importance of protease-antiprotease imbalance in EPOC pathogenesis and underscores the need for genetic screening in select patient populations.

Polygenic Risk and Hereditary Susceptibility

Emerging research indicates that EPOC susceptibility may also be influenced by polygenic risk scores, which aggregate the effects of multiple common genetic variants associated with lung function and inflammatory responses [25]. These genetic profiles can affect baseline lung development and resilience to environmental insults, explaining why some individuals develop EPOC despite limited exposure, while others remain relatively unaffected despite significant risk factors.

Other Contributing Factors

Several additional elements influence the onset and progression of EPOC, often interacting with primary causes to amplify disease risk.

Age and Cumulative Lung Damage

EPOC is predominantly diagnosed in individuals over the age of 40, as the cumulative effects of environmental exposures and aging lead to progressive decline in lung function [3]. Aging itself is associated with reduced elastic recoil and increased airway closure, which may exacerbate underlying obstructive changes.

Recurrent Respiratory Infections

Frequent respiratory infections, particularly during childhood, can impair normal lung development and predispose individuals to chronic airway disease later in life [11]. Conditions such as severe bronchitis or pneumonia may leave lasting structural and functional deficits, increasing vulnerability to EPOC in adulthood.

Socioeconomic and Demographic Influences

Lower socioeconomic status, limited education, and residence in areas with high environmental pollution are associated with increased EPOC prevalence and worse outcomes [28]. These social determinants often coexist with higher rates of smoking, poor nutrition, limited access to healthcare, and greater occupational exposure, creating a cycle of risk that disproportionately affects vulnerable populations.

Environmental Episodes and Climate Events

Acute environmental events, such as Saharan dust episodes, can worsen air quality and trigger EPOC exacerbations [29]. These episodic exposures highlight the dynamic interaction between climate, air quality, and respiratory health, particularly in regions prone to such phenomena.

In summary, EPOC results from a complex interplay of modifiable and non-modifiable risk factors. While tobacco smoking remains the dominant cause, environmental exposures, genetic predispositions, and socioeconomic conditions significantly shape individual risk. Effective prevention requires a multifaceted approach that includes tobacco control, reduction of indoor and outdoor air pollution, workplace safety improvements, and targeted screening for genetic conditions like alpha-1 antitripsina deficiency.

Symptoms and Disease Progression

Chronic Obstructive Pulmonary Disease (COPD), known as Enfermedad Pulmonar Obstructiva Crónica (EPOC) in Spanish, is characterized by a progressive and generally irreversible airflow limitation that leads to a range of persistent respiratory symptoms. The disease evolves slowly over time, with symptoms worsening as lung function declines, primarily due to the combined effects of chronic bronchitis and emphysema [30]. Early recognition of symptoms is critical, as they often appear years before significant airflow limitation is detected, contributing to frequent underdiagnosis [3].

Common Symptoms of EPOC

The most frequent symptoms of EPOC include progressive dyspnea (shortness of breath), chronic cough, sputum production, and wheezing [30]. Dyspnea is a hallmark symptom and typically worsens gradually with physical activity, eventually limiting even basic daily tasks in advanced stages [33]. The chronic cough is often persistent and accompanied by expectoration, particularly in the mornings, and may precede noticeable airflow obstruction by several years [14]. Sputum production is a common feature, especially in cases associated with chronic bronchitis, and can be a source of recurrent infections. Wheezing, caused by narrowed airways, may occur intermittently and is often more pronounced during exacerbations.

In the early stages, symptoms may be mild or even overlooked, leading many individuals to attribute their breathlessness to aging or lack of fitness. This delay in seeking medical attention contributes to late diagnosis, when significant lung damage has already occurred [3].

Disease Evolution and Progression

EPOC is a progressive disease marked by a persistent and usually irreversible obstruction of airflow, driven primarily by chronic inflammation and structural damage in the airways and alveoli [36]. The progression is typically slow, with a gradual decline in lung function, particularly in the forced expiratory volume in one second (FEV1), which is a key measure of disease severity [37]. However, the rate of decline can vary significantly between individuals, influenced by factors such as continued exposure to risk factors, frequency of exacerbations, and the presence of comorbidities.

A defining feature of EPOC's progression is the occurrence of acute exacerbations, which are sudden worsening of respiratory symptoms that require medical intervention [38]. These episodes are often triggered by respiratory infections or exposure to environmental pollutants and are associated with accelerated loss of lung function and a poorer prognosis [39]. Frequent exacerbations can lead to a stepwise deterioration in health, increasing the risk of hospitalization and mortality.

As the disease advances, dyspnea becomes more severe and may occur even at rest. In later stages, patients experience significant limitations in their daily activities, reduced exercise tolerance, and a marked decline in quality of life [40]. The disease can also lead to systemic complications, including muscle wasting, weight loss, and cardiovascular problems, further compounding disability [37].

Although EPOC is incurable, its progression can be slowed through early diagnosis and comprehensive management. Key interventions include smoking cessation, which is the most effective measure to reduce the rate of lung function decline, along with vaccination, rehabilitación pulmonar, and appropriate pharmacological treatment [42]. The prognosis depends on multiple factors, including the severity of airflow obstruction, the frequency of exacerbations, the patient's body mass index, and the presence of comorbid conditions such as cardiovascular disease or osteoporosis [37]. With timely and sustained intervention, it is possible to improve symptom control, enhance well-being, and delay the onset of severe disability.

Diagnosis and Diagnostic Criteria

The diagnosis of Chronic Obstructive Pulmonary Disease (COPD), known as Enfermedad Pulmonar Obstructiva Crónica (EPOC) in Spanish, is established through a combination of clinical evaluation, patient history, and objective testing. Accurate diagnosis is critical for initiating appropriate management strategies and slowing disease progression. The cornerstone of diagnosis is the identification of persistent airflow limitation, primarily assessed through pulmonary function testing, particularly espirometría. This process is guided by international standards such as those from the Global Initiative for Chronic Obstructive Lung Disease (GOLD), which provide evidence-based criteria for confirmation and classification [44].

Fundamental Diagnostic Criteria According to GOLD Guidelines

The primary diagnostic criterion for COPD, as defined by the GOLD guidelines, is the presence of a persistent and largely irreversible obstruction of airflow in the lungs. This obstruction is confirmed through spirometry and is defined by a post-bronchodilator ratio of the forced expiratory volume in one second (FEV1) to the forced vital capacity (FVC) of less than 0.7 (FEV1/FVC < 0.7) [45]. This fixed ratio is the standard for diagnosing airflow limitation, independent of age, and is used because it provides a consistent and reliable predictor of adverse health outcomes, including mortality [46].

The diagnosis must be made in the appropriate clinical context. Clinicians should consider COPD in any patient over the age of 40 who presents with risk factors—most commonly a history of tobacco smoking or exposure to environmental and occupational pollutants—and symptoms such as progressive dyspnea, chronic cough, sputum production, or wheezing [45]. Early consideration of COPD is essential, as symptoms may be present for years before significant airflow limitation is detected, leading to a high rate of underdiagnosis [3].

Role and Interpretation of Spirometry

Spirometry is the definitive test for diagnosing COPD and is considered the gold standard in pulmonary function assessment [15]. The procedure must be performed with strict adherence to quality control standards to ensure the acceptability and reproducibility of the results. A critical step in the diagnostic process is the administration of a short-acting bronchodilator prior to the test (post-bronchodilator spirometry) to distinguish between reversible and persistent airflow obstruction [50].

The key measurements obtained are the FEV1 and FVC. The FEV1 represents the volume of air a person can forcibly exhale in the first second, while the FVC is the total volume of air that can be forcibly exhaled after a full inhalation. The ratio of these two values (FEV1/FVC) is the primary indicator of airflow obstruction. A ratio below 0.7 after bronchodilator use confirms the diagnosis of COPD. The pre-bronchodilator test can be used for screening, but the post-bronchodilator result is required for a definitive diagnosis [51].

The shape of the flow-volume loop generated during spirometry can also provide additional information, such as a flattened expiratory curve, which is characteristic of obstructive lung disease, although this is a qualitative assessment and not a substitute for the quantitative FEV1/FVC ratio [52].

Severity Classification Based on Spirometry

Once the diagnosis of COPD is confirmed, the severity of airflow limitation is classified according to the percentage of the predicted FEV1 value, which is derived from population norms based on age, sex, height, and race. The GOLD guidelines define four stages of severity:

  • GOLD 1 (Mild): FEV1 ≥ 80% of predicted.
  • GOLD 2 (Moderate): 50% ≤ FEV1 < 80% of predicted.
  • GOLD 3 (Severe): 30% ≤ FEV1 < 50% of predicted.
  • GOLD 4 (Very Severe): FEV1 < 30% of predicted [40].

Complementary Diagnostic Tests

While spirometry is essential, a comprehensive evaluation of a patient with suspected COPD often requires additional tests to confirm the diagnosis, assess severity, rule out other conditions, and guide treatment.

  • Chest Radiography: Although not specific for diagnosing COPD, a chest X-ray is commonly used to exclude other diseases such as lung cancer, tuberculosis, or heart failure. It may show signs suggestive of COPD, including hyperinflation of the lungs, a flattened diaphragm, or signs of emphysema [54].
  • Chest Computed Tomography (CT): This imaging modality is more sensitive than a standard X-ray and is used in select cases to evaluate the extent and distribution of emphysema, detect complications such as bronchiectasis, or identify pulmonary nodules [55].
  • Arterial Blood Gas Analysis: This test measures the levels of oxygen (PaO₂), carbon dioxide (PaCO₂), and pH in the blood. It is particularly important in patients with severe COPD to detect hypoxemia (low blood oxygen), hypercapnia (high blood carbon dioxide), or respiratory acidosis. The results are crucial for determining the need for long-term oxygen therapy [56].
  • Pulse Oximetry: A non-invasive method to estimate blood oxygen saturation (SpO₂). It is useful for screening and monitoring, especially during acute exacerbations, but is less precise than arterial blood gas analysis [57].
  • Additional Pulmonary Function Tests: In some cases, measurements of total lung capacity or the diffusing capacity of the lungs for carbon monoxide (DLCO) may be performed. These tests are particularly helpful when there is a clinical suspicion of emphysema, as DLCO is often reduced in this condition [58].

Distinguishing COPD from Other Conditions

A key aspect of the diagnostic process is differentiating COPD from other respiratory diseases, particularly asthma. While both conditions can cause airflow obstruction, asthma typically shows significant reversibility of obstruction with bronchodilators (an increase in FEV1 of more than 200 mL and more than 12% from baseline), whereas COPD shows little to no reversibility [59]. However, there can be overlap, and some patients may have features of both conditions, a scenario known as asthma-COPD overlap (ACO). The clinical history, including the age of onset and pattern of symptoms, is vital for making this distinction. The presence of chronic bronchitis and emphysema, which are hallmarks of COPD, also helps to confirm the diagnosis [9].

Severity Classification and Clinical Grouping

The classification of Chronic Obstructive Pulmonary Disease (COPD) severity has evolved from a simplistic reliance on spirometric values to a more comprehensive, multidimensional approach that integrates lung function, symptom burden, and risk of exacerbations. This shift reflects a deeper understanding of the disease's heterogeneity and aims to guide personalized treatment strategies. The current framework, primarily defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines, combines an assessment of airflow limitation severity with a clinical grouping based on symptoms and exacerbation history to determine optimal therapeutic pathways [61].

Severity of Airflow Limitation (GOLD Stages 1–4)

The initial component of COPD classification is the severity of airflow limitation, determined solely by spirometry. This is measured by the post-bronchodilator forced expiratory volume in one second (FEV1) as a percentage of the predicted value for an individual of the same age, sex, height, and ethnicity. The GOLD guidelines define four stages of severity based on FEV1:

  • GOLD 1 (Mild): FEV1 ≥ 80% of predicted. At this stage, patients may have minimal symptoms and the disease is often undiagnosed.
  • GOLD 2 (Moderate): 50% ≤ FEV1 < 80% of predicted. This is the most common stage at the time of diagnosis, with symptoms like progressive dyspnea becoming more apparent.
  • GOLD 3 (Severe): 30% ≤ FEV1 < 50% of predicted. Patients experience significant airflow limitation, leading to marked dyspnea and reduced exercise tolerance.
  • GOLD 4 (Very Severe): FEV1 < 30% of predicted. This stage is associated with severe functional impairment, a high risk of respiratory failure, and a significant impact on quality of life [46].

While this staging is essential for diagnosis and provides prognostic information, particularly regarding mortality, it correlates only moderately with a patient's actual symptoms, functional status, and quality of life. A patient with a GOLD 2 FEV1 may be severely disabled by dyspnea, while another with a GOLD 3 FEV1 might be relatively asymptomatic. This limitation necessitated a more holistic classification system [63].

Clinical Grouping (GOLD Groups A, B, E)

To address the shortcomings of spirometry alone, the GOLD guidelines introduced a clinical grouping system that categorizes patients into groups based on two key clinical dimensions: symptom burden and the risk of future exacerbations. This grouping is the primary driver for treatment decisions. The 2024 update consolidated the previous Groups C and D into a single high-risk group, now designated as Group E.

The assessment begins with evaluating symptoms using standardized tools such as the COPD Assessment Test (CAT) or the mMRC. A CAT score of ≥10 or an mMRC score of ≥2 indicates high symptom burden. The risk of exacerbations is determined by the patient's history in the past 12 months: a high risk is defined as two or more moderate exacerbations (requiring treatment with antibiotics and/or oral corticosteroids) or one or more severe exacerbations requiring hospitalization.

Based on these assessments, patients are classified into one of three groups:

  • Group A: Low symptom burden and low risk of exacerbations. These patients typically have mild disease and stable symptoms.
  • Group B: High symptom burden and low risk of exacerbations. The primary clinical challenge for these patients is managing persistent dyspnea and activity limitation.
  • Group E: Any level of symptoms and high risk of exacerbations. This group includes all patients with a history of frequent or severe exacerbations and represents the highest risk for disease progression, hospitalization, and mortality [64][65].

Rationale for the Multidimensional Approach

The shift from a purely spirometric classification to the current ABCD/E grouping system was driven by several key clinical insights. First, the poor correlation between FEV1 and patient-reported outcomes like dyspnea and quality of life meant that treatment based solely on lung function often failed to address the patient's most pressing concerns [63]. Second, the risk of exacerbations emerged as a critical determinant of prognosis, independent of FEV1. Patients with frequent exacerbations experience a faster decline in lung function and have a higher mortality rate, making this a primary target for intervention [67]. This approach allows for a more personalized treatment plan: a Group B patient with severe dyspnea but low exacerbation risk is managed differently from a Group E patient with similar FEV1 but a history of hospitalizations. The multidimensional model acknowledges the diverse phenotypes of COPD, such as the eosinophilic phenotype associated with exacerbations, and facilitates the use of targeted therapies like corticosteroides inhalados [45].

Treatment Approaches and Therapeutic Strategies

The management of Chronic Obstructive Pulmonary Disease (COPD) is multifaceted, aiming to alleviate symptoms, reduce the frequency and severity of exacerbations, improve health status, and enhance exercise tolerance and quality of life. Although the disease is progressive and irreversible, comprehensive treatment strategies can significantly slow its progression and improve patient outcomes. The cornerstone of COPD management involves a combination of pharmacological interventions, non-pharmacological approaches, and a multidisciplinary care model tailored to the individual patient’s clinical profile, symptom burden, and risk of future events.

Pharmacological Treatment Based on Symptom Burden and Exacerbation Risk

Pharmacological therapy for stable COPD is primarily guided by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification, which integrates symptom assessment and exacerbation history into four clinical groups (A, B, C, D) to inform treatment decisions. The primary goal is to match the intensity of therapy to the patient’s clinical needs, balancing symptom control with the prevention of future complications.

For patients in Group A (low symptoms, low exacerbation risk), initial treatment typically involves a single long-acting bronchodilator, either a long-acting muscarinic antagonist (LAMA) or a long-acting beta-2 agonist (LABA). In patients with occasional symptoms, short-acting bronchodilators (SABAs or SAMAs) may be used on an as-needed basis. Inhaled corticosteroids (ICS) are not recommended in this group due to the lack of benefit and increased risk of side effects such as pneumonia [69].

Patients in Group B (high symptoms, low exacerbation risk) are initially treated with a LAMA or LABA monotherapy. If symptoms persist, escalation to dual bronchodilation with a LABA/LAMA combination is recommended. Non-pharmacological interventions such as rehabilitación pulmonar, smoking cessation, and vaccination are essential components of care. ICS are not indicated unless there is evidence of asthma-COPD overlap (ACO) or persistent symptoms despite dual therapy.

For Group C (low symptoms, high exacerbation risk), the preferred initial therapy is a LAMA, which has been shown to be more effective than LABA in reducing exacerbations. If exacerbations continue, dual therapy with LABA/LAMA is recommended. The addition of ICS is not routinely advised unless there is evidence of elevated blood eosinophil counts (≥300 cells/µL), a history of asthma, or frequent exacerbations despite dual bronchodilation.

Patients in Group D (high symptoms, high exacerbation risk) require more intensive therapy. Dual bronchodilation with LABA/LAMA is the recommended first-line treatment due to its superior efficacy in reducing exacerbations and improving symptoms compared to monotherapy. In patients with elevated eosinophil levels (≥300 cells/µL) or a history of severe exacerbations, triple therapy (LABA/LAMA/ICS) may be initiated from the outset. Examples of approved triple therapy medications include Elebrato Ellipta (fluticasone/umeclidinium/vilanterol) and STIOLTO RESPIMAT (tiotropio/olodaterol) [70][71].

Role of Inhaled Corticosteroids and Biomarker-Guided Therapy

Inhaled corticosteroids (ICS) play a selective role in COPD management and should never be used as monotherapy in stable disease. Their use is associated with an increased risk of pneumonia, particularly in patients with low eosinophil counts (<100 cells/µL), older age, or low body mass index [72]. However, ICS are beneficial when added to bronchodilators in patients with a high risk of exacerbations.

The presence of blood eosinophilia is a key biomarker that guides the use of ICS. Patients with eosinophil counts ≥300 cells/µL are more likely to benefit from ICS in terms of reduced exacerbation rates. Similarly, patients with a clinical phenotype suggestive of asthma-COPD overlap (ACO) or a history of atopy and asthma are strong candidates for ICS-containing regimens. In cases where exacerbations persist despite dual bronchodilation, the addition of ICS should be considered, with close monitoring for adverse effects such as oral candidiasis, osteoporosis, and cataracts.

Non-Pharmacological Interventions and Comprehensive Care

Non-pharmacological strategies are fundamental to the holistic management of COPD and are recommended across all stages of the disease. Smoking cessation remains the single most effective intervention to slow disease progression and improve survival. Programs that combine behavioral counseling with pharmacological support, such as nicotine replacement therapy or varenicline, significantly increase quit rates.

Pulmonary rehabilitation is a structured, multidisciplinary program that includes supervised exercise training, education, nutritional counseling, and psychological support. It is strongly recommended for patients with moderate to very severe disease and those who remain symptomatic despite optimal pharmacological treatment. Programs typically last 8 to 12 weeks and have been shown to improve exercise capacity, reduce dyspnea, and enhance quality of life. The benefits are sustained when patients participate in supervised maintenance programs after the initial intervention [73].

Long-term oxygen therapy (LTOT) is indicated in patients with severe resting hypoxemia (PaO₂ ≤ 55 mmHg or 56–59 mmHg with evidence of pulmonary hypertension or polycythemia). Continuous oxygen use for at least 15 hours per day has been shown to improve survival in this subgroup. Nocturnal oxygen therapy alone is not recommended for survival benefit but may be used to relieve symptoms. The prescription of LTOT requires careful patient selection, education on safety (e.g., fire hazards), and regular follow-up to ensure adherence and efficacy [74].

Vaccination and Prevention of Exacerbations

Preventing respiratory infections is a critical component of COPD management. Annual influenza vaccination is strongly recommended for all patients, as it reduces the risk of exacerbations, hospitalizations, and mortality. Pneumococcal vaccination, including both the 13-valent conjugate (PCV13) and 23-valent polysaccharide (PPSV23) vaccines, is also advised to protect against invasive pneumococcal disease. These preventive measures are especially important in patients with advanced disease or comorbid conditions.

Exacerbations are acute worsening of respiratory symptoms that often require systemic corticosteroids and antibiotics. Strategies to reduce exacerbation risk include optimal use of bronchodilators, adherence to pulmonary rehabilitation, smoking cessation, and vaccination. In selected patients, prophylactic antibiotics or macrolides (e.g., azithromycin) may be considered, although their use must be balanced against the risk of antimicrobial resistance and side effects.

Multidisciplinary Management and Patient-Centered Care

Effective COPD management requires a coordinated, multidisciplinary approach involving pulmonologists, primary care physicians, nurses, respiratory therapists, physical therapists, dietitians, and psychologists. This team-based model ensures comprehensive care that addresses not only respiratory symptoms but also comorbidities such as enfermedades cardiovasculares, depresión, osteoporosis, and diabetes mellitus. Nutritional support is essential, as both undernutrition and obesity can negatively impact outcomes. Psychological interventions, including cognitive-behavioral therapy, are effective in managing anxiety and depression, which are prevalent in COPD and associated with poorer adherence and increased mortality.

Patient education is a cornerstone of self-management. Teaching patients about their disease, proper inhaler technique, recognition of exacerbation signs, and action plans empowers them to take an active role in their care. Tools such as the cuestionario CAT and the SGRQ are valuable for assessing health-related quality of life and monitoring response to therapy. A change of ≥2 points in the CAT score or ≥4 points in the SGRQ score is considered clinically significant and should prompt reevaluation of the treatment plan.

In conclusion, the treatment of COPD is a dynamic process that requires individualized, evidence-based strategies integrating pharmacological and non-pharmacological interventions. The use of clinical guidelines such as GOLD and GesEPOC, combined with biomarker-guided therapy and a multidisciplinary care model, enables clinicians to optimize outcomes and improve the daily lives of patients living with this chronic condition.

Role of Pulmonary Rehabilitation and Non-Pharmacological Interventions

Pulmonary rehabilitation and non-pharmacological interventions play a central role in the comprehensive management of chronic obstructive pulmonary disease (COPD), significantly improving patient outcomes beyond what pharmacological treatments alone can achieve. These strategies are designed to reduce symptoms, enhance physical and emotional well-being, and increase independence in daily activities. According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines, pulmonary rehabilitation is strongly recommended for individuals with persistent symptoms despite optimal medical therapy, regardless of the severity of airflow limitation measured by espirometría [75].

Pulmonary Rehabilitation: Core Components and Clinical Impact

Pulmonary rehabilitation is a multidisciplinary, evidence-based program tailored to the individual needs of patients with COPD. It integrates supervised physical exercise, patient education, nutritional counseling, and psychological support to address the systemic effects of the disease. The primary goal is to improve functional capacity, reduce dyspnea, and enhance health-related quality of life (HRQoL) [76].

Key components of an effective pulmonary rehabilitation program include:

  • Supervised exercise training: This includes aerobic conditioning (e.g., walking, cycling), resistance training for upper and lower limbs, and functional exercises that simulate daily activities. High-intensity interval training (HIIT) has shown particular benefits in improving endurance and muscle strength [77].
  • Respiratory muscle training: Techniques such as inspiratory muscle training using threshold devices help strengthen the diaphragm and reduce breathlessness during exertion [78].
  • Patient education: Structured education covers disease management, proper use of dispositivos inhaladores, recognition of exacerbation signs, and strategies for managing dyspnea, including pursed-lip breathing and pacing techniques [79].
  • Psychological and social support: Given the high prevalence of ansiedad and depresión in COPD patients, integrating mental health support is essential. Cognitive-behavioral therapy and group sessions help reduce kinesiophobia (fear of movement) and improve treatment adherence [80].

Clinical evidence from Cochrane reviews confirms that pulmonary rehabilitation leads to significant improvements in exercise tolerance, as measured by the six-minute walk test, and reduces symptom burden, particularly dyspnea [81]. These benefits are sustained when patients participate in supervised maintenance programs after completing the initial phase [73].

Timing and Implementation Across Disease Stages

Pulmonary rehabilitation is recommended across all stages of COPD, not just in advanced disease. Early implementation in patients with mild to moderate COPD who experience functional limitations can prevent deconditioning and slow the decline in physical activity [83]. For patients with severe or very severe COPD, rehabilitation is a cornerstone of care, significantly improving quality of life and reducing hospitalization rates [75].

A critical window for intervention is the post-exacerbation period. Initiating pulmonary rehabilitation within four weeks of hospital discharge after an acute exacerbation improves recovery of functional capacity and reduces the risk of rehospitalization [85]. Programs typically last 8 to 12 weeks, with a minimum of 20 supervised sessions, and should be followed by structured maintenance plans to preserve long-term benefits [86].

Non-Pharmacological Strategies to Improve Adherence and Autonomy

Beyond formal rehabilitation programs, several non-pharmacological strategies enhance treatment adherence and patient autonomy. These include:

  • Structured patient education: Programs that teach self-management skills, such as recognizing early signs of exacerbations and adjusting medications accordingly, empower patients to take control of their condition [87].
  • Use of validated assessment tools: Instruments like the cuestionario CAT and the SGRQ allow clinicians to quantify symptom burden and track changes over time. A CAT score above 20 indicates high symptom impact and guides therapeutic decisions [88].
  • Nursing and pharmaceutical interventions: Regular follow-up by nurses or pharmacists improves inhaler technique, medication adherence, and overall disease management [89].
  • Community and peer support: Patient associations such as EPOC España and the Asociación Latinoamericana de Tórax provide platforms for shared experiences, education, and emotional support, reducing social isolation [90][91].

Integrated Multidisciplinary Management in Resource-Limited Settings

In low- and middle-income countries, where access to specialized care may be limited, adapting multidisciplinary models to local contexts is crucial. Strategies include group-based rehabilitation in primary care, telehealth follow-ups, and task-shifting to trained community health workers. Nutritional support is particularly important, as both undernutrition and obesity negatively affect outcomes [92].

Coordination between primary and specialized care ensures continuity, while tools like the CAT enable efficient monitoring even in resource-constrained environments. Ultimately, a patient-centered, multidisciplinary approach that includes pulmonary rehabilitation and non-pharmacological interventions is essential for optimizing long-term outcomes in COPD, improving not only physical function but also emotional well-being and quality of life [93].

Comorbidities and Systemic Impact

Chronic Obstructive Pulmonary Disease (COPD) is a systemic condition whose impact extends far beyond the lungs, with a high prevalence of comorbidities that significantly influence prognosis, quality of life, and therapeutic management. The chronic inflammation characteristic of COPD contributes to the development of multiple extrapulmonary conditions, necessitating an integrated, multidisciplinary approach to patient care. The presence of comorbidities is associated with increased morbidity, mortality, and healthcare utilization, underscoring the need for comprehensive screening and coordinated treatment strategies GOLD.

Major Comorbidities in COPD

Cardiovascular Diseases

Cardiovascular diseases (CVD) are the most significant comorbidity in terms of mortality and are present in 20% to 50% of COPD patients [6]. These include ischemic heart disease, heart failure, hypertension, and arrhythmias. The risk of myocardial infarction is up to 4.5 times higher in COPD patients, with shared risk factors such as smoking and systemic inflammation contributing to this association [95]. Notably, 20% to 32% of patients with heart failure also have COPD, complicating diagnosis and treatment due to overlapping symptoms like dyspnea [96]. The underlying mechanisms include oxidative stress, endothelial dysfunction, and autonomic imbalance, all exacerbated by chronic hypoxemia and systemic inflammation inflammation.

Osteoporosis

Osteoporosis affects 24% to 44% of COPD patients, particularly those with severe disease [97]. Contributing factors include smoking, low body weight, physical inactivity, chronic hypoxemia, and the use of oral corticosteroids, which accelerate bone loss. This comorbidity increases the risk of vertebral and hip fractures, leading to reduced mobility, worsened respiratory function, and higher mortality rates. Screening with densitometry is recommended in high-risk individuals, and preventive measures such as calcium and vitamin D supplementation, weight-bearing exercise, and pharmacological therapy should be considered corticosteroid therapy.

Mental Health Disorders

Depression and anxiety are highly prevalent in COPD, with reported rates reaching up to 74.6% in some studies [98]. Depression is associated with increased hospitalization rates, more frequent exacerbations, suicidal ideation, and a significant decline in quality of life [99]. Anxiety, often underdiagnosed due to symptom overlap with dyspnea and tachycardia, further limits physical activity and adherence to treatment [100]. Screening tools such as the Hospital Anxiety and Depression Scale (HADS) or the Patient Health Questionnaire (PHQ-9) are recommended for early detection and intervention, which may include psychological therapies and pharmacological treatment [80].

Lung Cancer

Patients with COPD have a three to four times higher risk of developing lung cancer, even among non-smokers [102]. Shared mechanisms include chronic inflammation, epithelial damage, and emphysema, which act as biomarkers of lung cancer risk. The presence of emphysema on CT scan is particularly predictive, and active surveillance with low-dose CT screening is recommended in high-risk patients, especially those with a significant smoking history and advanced COPD tomography.

Diabetes Mellitus

Diabetes affects a substantial proportion of COPD patients and is bidirectionally linked to the disease. The use of inhaled or systemic corticosteroids can worsen glycemic control, necessitating close monitoring of blood glucose levels and adjustment of antidiabetic therapy. Conversely, hyperglycemia may exacerbate inflammation and impair immune function, potentially increasing susceptibility to respiratory infections and exacerbations [103]. Integrated management involving endocrinology and pulmonology is essential to balance respiratory and metabolic control.

Pulmonary Hypertension

Pulmonary hypertension is a complication of advanced COPD, primarily driven by chronic hypoxemia and pulmonary vasoconstriction. It can lead to cor pulmonale, or right-sided heart failure, which worsens dyspnea and functional capacity [104]. Diagnosis may require echocardiography or right heart catheterization, and management focuses on optimizing oxygenation, treating underlying hypoxemia with long-term oxygen therapy, and avoiding therapies that may worsen ventilation-perfusion mismatch.

Impact on Prognosis and Healthcare Utilization

The presence of comorbidities profoundly affects the prognosis of COPD. Cardiovascular diseases alone account for more than 50% of deaths in COPD patients [105]. Comorbidities increase the frequency and severity of exacerbations, prolong hospital stays, and reduce the effectiveness of pulmonary rehabilitation. Patients with multiple comorbidities experience a greater decline in quality of life and functional status, leading to higher healthcare costs and resource utilization [106]. The systemic nature of COPD-related inflammation suggests that managing comorbidities is not merely adjunctive but central to improving survival and reducing the overall disease burden.

Therapeutic Implications and Multidisciplinary Management

An effective approach to COPD must include systematic evaluation and management of comorbidities. Guidelines recommend routine screening for cardiovascular risk, osteoporosis, depression, and lung cancer at diagnosis and during follow-up. Pharmacological treatment must be carefully balanced; for example, bronchodilators such as beta-2 agonists and anticholinergics are generally safe in cardiovascular disease, but caution is needed with anticholinergics in patients with glaucoma or urinary retention [107]. The use of inhaled corticosteroids should be minimized in patients with diabetes or osteoporosis due to the risk of worsening metabolic control and bone loss.

Rehabilitation plays a crucial role in managing comorbidities by improving functional capacity, reducing dyspnea, and enhancing psychological well-being, even in patients with osteoporosis or depression [108]. However, programs must be individualized to accommodate physical limitations and mental health needs. Coordination among specialists—such as pulmonologists, cardiologists, rheumatologists, and psychiatrists—is essential to avoid treatment conflicts and ensure holistic care [6]. The integration of comorbidity assessment into clinical algorithms, as emphasized by GesEPOC and GOLD, ensures that treatment decisions are based on a comprehensive understanding of the patient's overall health status [61].

Epidemiology and Global Health Trends

Chronic Obstructive Pulmonary Disease (COPD), known as EPOC in Spanish, is a major global health burden with significant and evolving epidemiological patterns. In 2019, COPD was responsible for 3.23 million deaths worldwide, making it the third leading cause of death globally [111]. Despite a decline in age-standardized mortality rates since 1990, the absolute number of deaths has increased due to population growth and aging. The global prevalence of COPD is rising, with over 400 million people affected in 2024, and projections suggest this number could reach 600 million by 2050, representing a 23% increase from 2020 [112].

A significant shift in the disease's profile is its increasing prevalence among women and in low- and middle-income countries (LMICs). In LMICs, the burden of COPD is particularly high, with approximately 90% of all COPD-related deaths occurring in these regions [113]. This disparity reflects profound inequities in access to healthcare, preventive measures, and timely diagnosis. In high-income countries, tobacco smoking is the primary risk factor, accounting for about 70% of cases. In contrast, in LMICs, smoking is responsible for only 30-40% of cases, with environmental and domestic exposures playing a more dominant role [114].

Global Variation by Income Level

The epidemiology of COPD varies dramatically based on a country's income level. In high-income nations, the disease is predominantly linked to a history of tobacco use. However, in LMICs, a complex interplay of risk factors drives the epidemic. Socioeconomic factors such as low educational attainment and low income increase the risk of developing COPD by 44.9% and 22.9%, respectively [28]. Poverty, unemployment, and rural residence in areas with high atmospheric pollution are also associated with higher prevalence, hospitalization rates, and mortality from COPD [116]. This highlights how COPD is not just a respiratory disease but a condition deeply rooted in social determinants of health.

The Burden in Latin America

Latin America faces a growing and substantial burden of COPD. More than 13% of the adult population, approximately 65 million people, were affected by moderate to severe disease in 2019 [117]. In Argentina, it is estimated that over 2 million people have COPD, with many cases undiagnosed, leading to the disease being described as a "silent crisis" in public health [118]. Underdiagnosis is a critical issue across the region, with rates as high as 70% in countries with limited resources, which exacerbates the impact on quality of life and increases mortality [119].

The economic cost is also considerable. In Mexico, COPD incurs annual costs exceeding 347 billion pesos, with an average cost per patient of about 89,479 pesos, primarily driven by medication expenses [120]. In 2024, more than 19,000 deaths in Mexico were attributed to COPD, underscoring the urgent need for improved early detection and access to treatment [120]. In Colombia, factors such as comorbidities, low education levels, and lack of access to oxygen therapy have been linked to a higher risk of mortality in COPD patients [122].

Key Risk Factors in the Region

While tobacco smoking remains the leading risk factor in Latin America, its impact varies by country [123]. Occupational exposure to noxious agents such as silica dust, pesticides, gases, and metal fumes is a significant contributor, with estimates suggesting that 15-20% of cases in some countries may be attributable to workplace exposures [124]. Occupational COPD is often underreported and under-recognized in the region [22].

Prevention Strategies and Public Health Policies

In response to this challenge, several Spanish-speaking countries have implemented effective tobacco control policies. In Spain, tobacco control laws in place for over fourteen years have contributed to a reduction in secondhand smoke exposure and associated mortality [126]. In Cuba, cessation strategies, tobacco taxes, and educational campaigns have reduced smoking prevalence to 21.6% in the adult population [127].

At the regional level, the Pan American Health Organization (PAHO) has launched the Strategy and Plan of Action to Strengthen Tobacco Control in the Americas Region 2025-2030, which promotes measures like tobacco taxes, 100% smoke-free environments, graphic warnings, and advertising bans [128]. These policies have shown a positive impact, particularly in reducing tobacco use among adolescents [129]. The Latin American Thoracic Association (ALAT) has also developed evidence-based clinical guidelines to improve COPD diagnosis and management in the region [91]. Tools like the electronic PUMA scale have proven useful for early detection in primary care, representing a key advancement in reducing underdiagnosis [131].

Molecular and Cellular Pathophysiology

Chronic Obstructive Pulmonary Disease (COPD) is characterized by persistent respiratory symptoms and airflow limitation due to airway and/or alveolar abnormalities, primarily caused by significant exposure to noxious particles or gases. The molecular and cellular pathophysiology of EPOC involves a complex interplay of chronic inflammation, oxidative stress, protease-antiprotease imbalance, and structural remodeling of the lungs. These processes lead to the hallmark features of the disease: emphysema, chronic bronchitis, and small airway fibrosis.

Chronic Inflammation and Immune Cell Activation

The central mechanism in the pathogenesis of EPOC is a persistent and exaggerated inflammatory response in the airways and lung parenchyma, triggered by inhaled irritants, most notably tobacco smoke [132]. This inflammation involves the activation of both innate and adaptive immune cells. macrófagos alveolares are among the first responders, releasing pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6, and IL-8 [133]. These cytokines recruit and activate other inflammatory cells, including neutrófilos and linfocitos T, which infiltrate the bronchial walls and pulmonary parenchyma [134].

Neutrófilos play a critical role by releasing proteolytic enzymes such as neutrophil elastase and matrix metalloproteinases (MMPs), particularly MMP-9 and MMP-12, which degrade elastin and collagen in the alveolar walls, contributing to emphysema [135]. They also generate reactive oxygen species (ROS), exacerbating oxidative stress. In certain phenotypes of EPOC, especially those with frequent exacerbations, a type 2 inflammatory response is observed, characterized by the presence of eosinófilos in blood and airways. This phenotype is mediated by cytokines such as IL-4, IL-5, and IL-13 and is associated with a better response to inhaled corticosteroids [136]. Eosinophils serve as key biomarkers in eosinophilic EPOC, enabling a more personalized therapeutic approach [137].

Signaling Pathways and Cytokine Production

The activation of intracellular signaling pathways is fundamental to sustaining chronic inflammation in EPOC. The nuclear factor kappa B (NF-κB) pathway is a central regulator activated by tobacco smoke and inflammatory mediators. NF-κB controls the transcription of multiple pro-inflammatory genes, including TNF-α, IL-8, IL-1β, and MMPs, thereby perpetuating the inflammatory response [133]. This persistent activation, even after smoking cessation, explains the continued progression of the disease. Additionally, dysfunction in regulatory T cells (Treg), which normally suppress inflammation, contributes to an uncontrolled immune response, as their number and function are reduced in EPOC [139].

Oxidative Stress and Cellular Damage

Oxidative stress is another key mechanism in the pathophysiology of EPOC. Chronic inflammation and exposure to pollutants increase the production of reactive oxygen species (ROS), overwhelming the lung's antioxidant defenses [140]. This imbalance leads to oxidative damage to DNA, lipids, and proteins, disrupting cellular function and promoting apoptosis [141]. Oxidative stress also activates NF-κB, creating a vicious cycle that amplifies inflammation [142]. The depletion of antioxidant enzymes such as superoxide dismutase and glutathione further exacerbates this damage.

Protease-Antiprotease Imbalance and Apoptosis

The protease-antiprotease imbalance is a cornerstone in the destruction of the pulmonary parenchyma. Proteases released by neutrophils and macrophages, such as neutrophil elastase and MMPs, overwhelm the action of antiproteases, particularly alfa-1 antitripsina [143]. This deficiency, whether genetic or functional, leads to unchecked degradation of alveolar elastic fibers, resulting in emphysema. The deficiency of alfa-1 antitripsina is a well-known genetic cause of early-onset emphysema, particularly in non-smokers or those with minimal smoke exposure [144].

Apoptosis of structural lung cells, including alveolar type I and II pneumocytes and fibroblasts, also contributes to alveolar loss. This process is mediated by oxidative stress, chronic inflammation, and mitochondrial dysfunction and is closely linked to the progression of emphysema [145]. Recent evidence suggests that necroptosis, a regulated form of cell death, may also be involved in lung injury in EPOC [146].

Airway Remodeling and Systemic Inflammation

Chronic inflammation leads to structural remodeling of the small airways, characterized by subepithelial fibrosis, goblet cell hyperplasia, increased mucus production, and luminal obliteration. These changes significantly contribute to airflow obstruction [147]. Vascular remodeling and pulmonary hypertension are also part of the pathological process, further impairing gas exchange and increasing right heart strain.

Furthermore, a low-grade systemic inflammation is observed in patients with EPOC, which may contribute to comorbidities such as cardiovascular disease, osteoporosis, and muscle wasting [148]. This systemic component underscores the multisystem nature of the disease and the importance of a comprehensive management approach.

In summary, the molecular and cellular pathophysiology of EPOC is driven by a self-perpetuating network of chronic inflammation, oxidative stress, protease-antiprotease imbalance, and structural remodeling. These interconnected mechanisms lead to progressive lung damage and functional decline, highlighting the need for targeted therapies that address specific molecular pathways in different disease phenotypes.

References