Role of Arterial Blood Gas in Risk Stratification of Patients With Acute Exacerbation of Chronic Obstructive Pulmonary Disease in the Emergency Department: A Systematic Review.

Acute exacerbations of chronic obstructive pulmonary disease are a leading cause of emergency department visits and hospital admissions, associated with high morbidity, mortality, and healthcare costs. Accurate risk stratification in the emergency department is vital for identifying patients at risk of deterioration and guiding decisions regarding intensive care unit admission or ventilatory support. Arterial blood gas analysis remains the gold standard for assessing respiratory failure, providing direct measurements of potential of hydrogen (pH), partial pressure of carbon dioxide in arterial blood (PCO₂), and partial pressure of oxygen in arterial blood (PaO₂), as well as the fraction of inspired oxygen (PaO₂/FiO₂). This systematic review, based on five eligible studies with a total sample size of 1,305 patients, found that arterial blood gas derangements such as acidosis, hypercapnia, and impaired oxygenation consistently predicted poor outcomes, including increased mortality and need for invasive ventilation. Compared to clinical scores and venous blood gas analysis, arterial blood gas offered more precise insights into ventilatory compromise and gas exchange abnormalities. These findings support arterial blood gas as an indispensable tool in the early risk stratification of acute exacerbation of chronic obstructive pulmonary disease. patients in the emergency department, complementing existing clinical models and improving prognostic accuracy. Larger multicenter studies are warranted to validate arterial blood gas-integrated prediction frameworks and optimize triage strategies in this high-risk population.