Altered level of consciousness in the emergency department before and after coronavirus disease-19: A four-year multicenter study

Abstract

Background: New-onset altered level of consciousness (ALC) is a frequent and critical presentation in emergency departments (EDs), requiring prompt recognition and management. The coronavirus disease-19 pandemic has significantly affected emergency care systems, yet its impact on ALC remains poorly understood. This study aimed to compare the etiology, patient flow, and outcomes of ALC before (BC) and after (AC) the COVID-19 pandemic.

Methods: In this retrospective multicenter study, board-certified faculty from emergency medicine, internal medicine, and neurology reviewed 17,913 patients with ALC from four university-affiliated EDs serving a population of approximately five million individuals in South Korea. Patients were classified into BC (February 2018 – January 2020) and AC (March 2021 – February 2023). ALCs in the ED were categorized into 10 etiologies by multidisciplinary consensus review.

Results: The incidence of ALC in the ED was 3.1%. The incidence of ALC increased significantly from 2.5% in BC to 3.7% in AC (P<0.001). Metabolic cause was the most common etiology (24.8%), followed by systemic infection (18.0%). Intracranial etiologies accounted for 29.7% of the total. Admission rate increased from 54.5% to 59.3% (P<0.001), while ICU admissions declined and ED deaths rose. Overall mortality increased from 13.5% to 18.4% (P < 0.001), and post-admission mortality from 16.3% to 21.3% (P<0.001). The highest mortality was associated with ALCs due to cardiogenic and vascular etiologies (26.8%).

Conclusion: The observed shifts in etiologies, patient flow, and mortality between BC and AC reflect pandemic-driven changes in emergency care, underscoring the need for multidisciplinary strategies and scalable emergency care systems.