Severe alkalemia in the emergency department : Acid-base patterns, clinical presentation and short-term outcomes in hospitalized patients.

introductionAlkalemia is the most common acid-base disorder in hospitalized patients; however, data on patients with severe alkalemia admitted to the emergency department are limited. This study aimed to characterize the acid-base patterns of patients with severe alkalemia presenting to the emergency department and to describe the clinical presentation and short-term clinical outcomes of those requiring hospitalization. PATIENTS, MATERIAL AND

methodsWe conducted a retrospective analysis of arterial and venous blood gas measurements and medical records of all adult nontrauma patients admitted to the emergency department of a tertiary university hospital in Austria with a pH> 7.55, between 1 June 2022, and 31 December 2023.

resultsAmong 215 patients with severe alkalemia, 84 (39%) required hospitalization. Acute respiratory alkalosis was the predominant acid-base disorder (57%), followed by mixed respiratory and metabolic alkalosis (35%), whereas isolated metabolic alkalosis was not observed. Detailed clinical data were available for 80 hospitalized patients. Pain (67%) and emesis (49%) were the most common presenting symptoms, while psychiatric disease was the most prevalent comorbidity (38%). Despite severe alkalemia, the disorder was documented as a diagnosis in only 4% of hospitalized patients. No in-hospital deaths occurred. Application of a published venous-to-arterial correction algorithm resulted in only minor changes in the classification of acid-base disorders.

conclusionIn contrast to previous reports from intensive care populations, patients with severe alkalemia requiring hospitalization had a clinically distinct phenotype and favorable short-term outcomes. Despite marked alkalemia, the condition was very rarely documented as a diagnosis, suggesting that severe alkalemia might be underrecognized in the emergency department.