The etiology and mortality of altered level of consciousness in the emergency room: before and after coronavirus disease

Background: Coronavirus disease 2019 (COVID-19) has resulted in social, economic, medical, and psychological changes. New-onset altered level of consciousness (ALC) is a classical presentation in real-world medicine. This study investigated changes in ALC in the emergency room (ER) in the periods before (BC) and after (AC) COVID-19.Methods: This was a retrospective study of patients with ALCs who visited the ER of a tertiary referral center, and their medical records BC and AC were compared. A consortium allocated and analyzed the etiologies of ALC in a case-by-case discussion. The time point for etiological assessment was the time of discharge from the ER.Results: In total, 1,936 patients with ALCs (731 and 1,205 in BC and AC, respectively) were investigated. The most common etiology was systemic infection (25.9%), followed by metabolic causes (20.8%). Systemic infections (22.9% vs. 30.8%, P<0.001) and stroke (14.6% vs. 18.2%, P=0.037) were lower in AC than in BC, respectively, whereas rates of toxicity (15.4% vs. 6.0%, P<0.001) and traumatic brain injury (TBI; 5.9% vs. 0.8%, P<0.001) were higher in AC than in BC. The overall mortality rate of ALC in the ER was 18.5%.Conclusion: This study demonstrated that the major etiologies of ALC in the ER were extra-cranial (58.5%). The mortality of ALC in the ER and the incidence of toxic cause and TBI increased in AC, suggesting a change in medical circumstances after the Pandemic.