Clinical significance of acid-base parameters in Emergency Department patient management

Abstract

Background. Acid-base balance (ABB) analysis is a fundamental component in the assessment of critically ill patients in the Emergency Department (ED). It enables rapid identification of metabolic and respiratory disturbances, contributing to the evaluation of case severity and guiding optimal therapeutic management. Objective(s). This study evaluates the role of acid-base parameters as diagnostic and prognostic markers in Emergency Department patients, aiming to improve diagnosis, monitoring, and clinical management. Materials and methods. A retrospective analysis was conducted on ABB parameters from 1930 patients admitted to the ED’s red zone (out of 2146 total). Parameters assessed included pH, base excess (BE), bicarbonate (HCO₃⁻), anion gap (AG), lactate levels, and physicochemical patterns per Stewart’s method. Correlations with clinical status and outcomes were examined. Results. Among the 1930 patients evaluated, 28.4% exhibited severe metabolic acidosis, defined by a base excess (BE) below –6 mEq/L, while 16.2% had elevated lactate levels above 4 mmol/L. Both parameters coexisted in 9.5% of patients and correlated with a mortality rate of 27.1%. An anion gap (AG) exceeding 12 mEq/L was detected in 39.7% of cases, with 61.3% of those also exhibiting hyperlactatemia. In trauma patients, a strong correlation among BE, AG, and lactate (r > 0.7) facilitated early shock detection. Stewart’s method revealed hidden acid-base disturbances in 14.8% of cases undetected by conventional diagnostic methods. Conclusion(s). Integrated analysis of ABB parameters—pH, base excess (BE), bicarbonate (HCO₃⁻), anion gap (AG), and lactate—is vital for accurate and timely diagnosis in the Emergency Department. Utilizing Stewart’s method alongside POCT enhances diagnostic accuracy, guides treatment, and lowers mortality.