Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) represent one of the most critical phases in the natural history of COPD and remain a major unmet clinical challenge. They are now widely recognized as key determinants of disease progression and healthcare utilization. AECOPD is not simply a transient worsening of airway function, but rather the result of dynamic interactions between airway inflammation, infection, environmental exposures, and cardiopulmonary mechanisms that may culminate in acute respiratory failure.[1] [2]

Importantly, exacerbations requiring hospitalization are associated with profound and sustained consequences. They accelerate lung function decline, worsen quality of life, increase cardiovascular and thromboembolic risk, and are characterized by high rates of early readmission and mortality.[3] Recovery is often incomplete, with persistent physiological impairment, ongoing systemic inflammation, and reduced functional capacity extending well beyond the acute phase, thereby requiring targeted therapeutic and preventive strategies.[4] These observations challenge the traditional episodic view of exacerbations and instead support a more integrated interpretation of AECOPD as a phase of heightened biological vulnerability, requiring comprehensive, sustained, and patient-centered management strategies.

In this context, there is a compelling need to update current knowledge on hospitalized AECOPD, integrating advances in pathophysiology, clinical phenotyping, biomarker-guided management, and prevention strategies. A shift toward a multidimensional, patient-centered approach is essential, extending beyond acute symptom control to encompass long-term outcomes and the overall disease trajectory.

The present monograph on “New Concepts in Acute Exacerbations of COPD” provides a comprehensive and updated overview of this multifaceted condition.

The contribution by Tonelli et al[5] provides an in-depth analysis of the pathophysiology of AECOPD, presenting a comprehensive and integrated model in which inflammatory, mechanical, and cardiopulmonary factors interact within self-reinforcing loops. Airway inflammation drives mucus hypersecretion, epithelial injury, and airflow obstruction. These processes promote air trapping and dynamic hyperinflation, thereby increasing the work of breathing, impairing diaphragmatic function, and ultimately leading to ventilatory failure. The authors further highlight the central role of ventilation-perfusion mismatch, the development of hypercapnia, and complex cardiopulmonary interactions that contribute to right ventricular strain and systemic consequences, providing a strong pathophysiological rationale for timely and targeted therapeutic interventions.

Lopez-Campos et al[6] explore the epidemiology of COPD exacerbations, highlighting their marked heterogeneity across geographic regions and healthcare systems. Their analysis underscores that exacerbations are the main drivers of healthcare utilization and costs in COPD, particularly when hospitalization is required. The authors describe temporal trends suggesting a decline in exacerbation rates in controlled clinical settings, contrasted with a persistent, and in some contexts increasing burden in real-world populations, largely driven by aging, multimorbidity, and environmental exposures. Seasonal variability, air pollution, and socioeconomic disparities emerge as key determinants of exacerbation risk, reinforcing the need for both individualized and population-level preventive strategies.

The review by Sartori et al[7] on the inflammatory response in AECOPD provides a detailed analysis of the systemic nature of exacerbations. The authors emphasize the role of inflammatory mediators and acute-phase reactants, in particular C-reactive protein (CRP), as accessible and clinically meaningful biomarkers. CRP may enhance diagnostic accuracy, guide antibiotic stewardship, and provide prognostic information on exacerbation severity, risk of relapse, and cardiovascular complications. Importantly, inflammation during AECOPD is not merely an amplification of baseline disease, but rather represents a distinct and dysregulated response with systemic implications.

Fantin et al[8] comprehensively examine the impact of AECOPD on patient outcomes, demonstrating that exacerbations have far-reaching consequences across multiple physiological domains. These include persistent lung hyperinflation, impaired gas exchange, incomplete recovery of lung function, and significant skeletal muscle dysfunction. The resulting decline in exercise capacity and physical activity contributes to a cycle of deconditioning and increased vulnerability. In addition, systemic inflammation and oxidative stress are closely linked to cardiovascular instability, further amplifying the long-term burden of the disease.

Therapeutic management is addressed through complementary perspectives. Carvello et al[9] review the pharmacological treatment of AECOPD, emphasizing the central role of bronchodilators, systemic corticosteroids, and antibiotics, while highlighting the importance of severity-based and guideline-directed approaches. In parallel, Panzuti et al[10] focus on the nonpharmacological management, underscoring the critical role of respiratory support strategies, including oxygen therapy, high-flow nasal cannula, and noninvasive ventilation, in improving gas exchange and reducing complications. The integration of pulmonary rehabilitation, nutritional support, and structured care pathways is also emphasized as a key component of recovery.

Prevention strategies are extensively addressed in this issue. Sartori et al[11] examine the role of vaccination, highlighting its effectiveness in reducing infection-related exacerbations, hospitalizations, and mortality across multiple pathogens, including influenza, pneumococcus, SARS-CoV-2, and RSV. Complementing this perspective, Vitacca et al[12] further explore nonpharmacological strategies to improve disease stability, focusing on smoking cessation, physical activity, environmental control, and long-term supportive therapies aimed at reducing exacerbation recurrence and improving overall outcomes.

Taken together, the contributions in this monograph provide a comprehensive and multidimensional understanding of AECOPD, bridging pathophysiological insights with clinical application. Collectively, they support a paradigm shift toward a more integrated model of care, in which exacerbations are recognized as critical events requiring early identification, targeted treatment, and sustained follow-up.

Beyond the immediate clinical implications, this evolving framework highlights the need to redefine therapeutic priorities in AECOPD. The goal should extend beyond short-term stabilization to encompass restoration of physiological resilience, prevention of recurrent events, and modification of the long-term disease trajectory. This requires closer integration of acute care, rehabilitation, and chronic disease management, along with the adoption of biomarker-driven and phenotype-specific strategies. Healthcare systems must also evolve to ensure continuity of care beyond hospitalization, bridging the gap between acute management and long-term follow-up.

Ultimately, AECOPD should no longer be viewed as an isolated clinical episode, but rather as a defining moment in the patient's disease course, one that demands recognition, rethinking, and decisive action. If outcomes are to improve, this is the point at which clinical practice must change: from reactive management of acute events to proactive, integrated, and individualized care of a vulnerable population.