Acid-Base Disorders in the Emergency Department: Incidence, Etiologies and Outcomes

Objective: Acid-base disorders (ABDs) are usually correlated with high rates of morbidity and mortality. The objective of this study was to analyze the causes, outcomes, types and incidences of ABDs in patients presenting at the emergency department (ED). Material and Methods: We prospectively analyzed data from patients who presented between January 2011 and May 2011. Data on age, gender, chief complaint, and diagnosis in the ED were collected for ABD cases. Results: Of the 736 cases with an ABD, 173 patients (23.5%) had simple ABD and 563 patients (76.5%) had mixed ABD. The most common ABD was a mixed metabolic acidosis and respiratory alkalosis (MACRAL) (n=408, 55.4%). All ABD types were most commonly observed in patients over 65 years of age. Dyspnea was the most common complaint among ABD patients who presented at the ED (44.4%). In cases of ABD, pneumonia was the most common diagnosis (16.3%). Of the ABD cases, 379 patients (51.6%) were discharged, while 318 patients (43.2%) were hospitalized. Death was more commonly observed in cases with mixed metabolic and respiratory acidosis (MRAC) (n=6) and MACRAL (n=11). Conclusion: ABDs are quite common in patients presenting at the ED, especially among patients in a critical condition (71%). Mixed MACRAL was the most commonly noted ABD. Dyspnea and pneumonia were the most common diagnoses in ABD patients. Mortality was more common in cases with a mixed MRAC and MACRAL. This knowledge may provide important information concerning the diagnosis, treatment and early prognosis of patients. (JAEM 2014; 13: 4-9)