Performance of blood bicarbonate in predicting the severity of COPD exacerbations

Abstract

<bold>Introduction:</bold> Blood bicarbonate, measured through blood gas analysis, reflects the acid-base balance and could be a key indicator of the severity of COPD exacerbations. <bold>Aim:</bold> Evaluate the performance of blood bicarbonate in predicting the severity of COPD exacerbations. Méthodes This was a prospective study collecting data from patients with COPD in the pneumology department, Charles Nicolle Hospital, Tunis, from December 2017 to December 2021. These patients were followed for one year. An arterial blood gas analysis was performed on all patients in a stable condition A severe exacerbation was defined as an exacerbation requiring hospitalization. Résultat :A total of 133 patients were included, with a mean age of 65.95±12 years. A male predominance was noted (86.5%). The main noted comorbidities were hypertension (31,6%) and diabetes (20.1%). The majority of patients (85.7%) were classified in Group E. In 91% of patients, at least one exacerbation was recorded, of which 40,5 % were severe. The average blood bicarbonate level was estimated at 28,6 %. The Area Under the Curve for blood bicarbonate to predict a severe exacerbation was 0.72 [0.61-0.81], 95% CI, p=0.05. The optimal cutoff was 27.1mmol/L with a sensitivity of 81.8% and specificity of 55.3%. <bold>Conclusion:</bold> blood bicarbonate levels may be an effective predictor of severe COPD exacerbations, with an optimal cutoff of 27.1 mmol/L demonstrating reasonable diagnostic perfomance. <fig><object-id>erj;66/suppl_69/PA4675/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>