Delirium in Covid-19 Patients: Incidence, Risk Factors and Early Outcomes.

Abstract

Background Delirium is a frequent event in severely ill patients; its incidence and prevalence varies depending on several factors; Covid has been associated to high incidence of delirium leading to speculation of specific mechanisms of neurotoxicity by the SARS-CoV-2. We present the analysis of risk factors for delirium incidence and the impact of delirium in the functional outcomes. Methods We included patients admitted to a referral center in Cali, Colombia between April and August 2020. Patients were evaluated for demographics, severity of disease, comorbidities, clinical outcomes, delirium and survival at discharge. We evaluated the association of patient characteristics and disease factors with delirium incidence by multivariate analysis (Hosmer and Lemeshow) and the associations of delirium with functional outcome at discharge Results Among 333 patients, 58 (17.42%. 95% CI: 13.62–21.77%) presented delirium 16 (IQR: 11 − 20) days after symptom onset. Patients with delirium were older, reported muscular weakness more often, had a higher NEWS2 score at admission, and had more comorbidities (mainly Diabetes Mellitus II). Multivariate analysis of hospitalization events and treatments found mechanical ventilation as the only significant covariate. The association between need for mechanical ventilation and delirium development was estimated at OR = 11.72, (95%CI = 4.16–34.23). Patients who developed delirium had a higher frequency of functional impairment: mRs > 2 (70.7% vs 24.7%, p < 0.001) and had a prolonged ICU stay (median 13 days, IQR 8–21 vs median 5, IQR 3–10 days, p < 0.0001) compared to patients without delirium. Conclusion Our data show that premorbid functional status, the severity of respiratory disfunction and the presence of inflammatory markers are determinant in the risk of delirium; we believe that delirium might not be specially related to SARS-CoV-2 infections, its high frequency during this pandemic could be the result of concurring factors shared between critically-ill patients and severe COVID-19 patients. Further research is granted to clarify this aspect