Delirium and Associated Factors in a Cohort of Hospitalized Patients With Coronavirus Disease 2019.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic dramatically increased the number of patients requiring treatment in an intensive care unit or invasive mechanical ventilation worldwide. Delirium is a well-known neuropsychiatric complication of patients with acute respiratory diseases, representing the most frequent clinical expression of acute brain dysfunction in critically ill patients, especially in those undergoing invasive mechanical ventilation. Among hospitalized patients with COVID-19, delirium incidence ranges from 11% to 80%, depending on the studied population and hospital setting. OBJECTIVE: To determine risk factors for the development of delirium in hospitalized patients with COVID-19 pneumonia. METHODS: We retrospectively studied consecutive hospitalized adult (≥18 y) patients with confirmed COVID-19 pneumonia from March 15 to July 15, 2020, in a tertiary-care hospital in Mexico City. Delirium was assessed by the attending physician or trained nurse, with either the Confusion Assessment Method for the Intensive Care Unit or the Confusion Assessment Method brief version, according to the appropriate diagnostic tool for each hospital setting. Consultation-liaison psychiatrists and neurologists confirmed all diagnoses. We calculated adjusted hazard ratios (aHR) with 95% confidence interval (CI) using a Cox proportional-hazards regression model. RESULTS: We studied 1017 (64.2% men; median age, 54 y; interquartile range 44-64), of whom 166 (16.3%) developed delirium (hyperactive in 75.3%); 78.9% of our delirium cases were detected in patients under invasive mechanical ventilation. The median of days from admission to diagnosis was 14 (interquartile range 8-21) days. Unadjusted mortality rates between delirium and no delirium groups were similar (23.3% vs. 24.1; risk ratio 0.962, 95% CI 0.70-1.33). Age (aHR 1.02, 95% CI 1.01-1.04; P = 0.006), an initial neutrophil-to-lymphocyte ratio ≥9 (aHR 1.81, 95% CI 1.23-2.65; P = 0.003), and requirement of invasive mechanical ventilation (aHR 3.39, 95% CI 1.47-7.84; P = 0.004) were independent risk factors for in-hospital delirium development. CONCLUSIONS: Delirium is a common in-hospital complication of patients with COVID-19 pneumonia, associated with disease severity; given the extensive number of active COVID-19 cases worldwide, it is essential to detect patients who are most likely to develop delirium during hospitalization. Improving its preventive measures may reduce the risk of the long-term cognitive and functional sequelae associated with this neuropsychiatric complication.

Critical role of acute hypoxemia on the cognitive impairment after severe COVID-19 pneumonia: a multivariate causality model analysis.

BACKGROUND: A high proportion of coronavirus disease 2019 (COVID-19) survivors may develop long-term cognitive impairment. We aimed to develop a multivariate causal model exposing the links between COVID-19-associated biomarkers, illness-related variables, and their effects on cognitive performance. METHODS: In this prospective study, we assess the potential drivers for the development of cognitive impairment in patients with severe COVID-19 pneumonia aged ≥ 18 years at 6-month follow-up after hospital discharge, using the Montreal Cognitive Assessment (MoCA). Patients with pre-existing cognitive impairment were excluded. Laboratory results at hospital admission were clustered by principal component analysis (PCA) and included in a path analysis model evaluating the causal relationship between age, comorbidities, hypoxemia, invasive mechanical ventilation (IMV) requirement, in-hospital delirium, and cognitive performance. RESULTS: We studied 92 patients: 54 (58.7%) men and 38 (41.3%) women, with median age of 50 years (interquartile range 42-55), among whom 50 (54.4%) tested positive for cognitive impairment at 6-month follow-up. Path analysis revealed a direct link between the thrombo-inflammatory component of PCA (C-reactive protein, fibrinogen, and neutrophils) and hypoxemia severity at hospital admission. Our model showed that low PaO2/FiO2 ratio values, unlike the thrombo-inflammatory component, had a direct effect on cognitive performance, independent from age, in-hospital delirium, and invasive mechanical ventilation. CONCLUSION: In this study, biomarkers of thrombo-inflammation in COVID-19 and low PaO2/FiO2 had a negative effect on cognitive performance 6 months after hospital discharge. These results highlight the critical role of hypoxemia as a driver for impaired cognition in the mid-term.

Characteristics and predictors for silent hypoxemia in a cohort of hospitalized COVID-19 patients.

BACKGROUND: An intriguing feature recently unveiled in some COVID-19 patients is the "silent hypoxemia" phenomenon, which refers to the discrepancy of subjective well-being sensation while suffering hypoxia, manifested as the absence of dyspnea. OBJECTIVE: To describe the clinical characteristics and predictors of silent hypoxemia in hospitalized COVID-19 patients. METHODS: We conducted a prospective cohort study including consecutive hospitalized adult (≥ 18 years) patients with confirmed COVID-19 presenting to the emergency department with oxygen saturation (SpO2) ≤ 80% on room air from March 15 to June 30, 2020. We analyzed the characteristics, disease severity, and in-hospital outcomes of patients presenting with dyspnea and those without dyspnea (silent hypoxemia). RESULTS: We studied 470 cases (64.4% men; median age 55 years, interquartile range 46-64). There were 447 (95.1%) patients with dyspnea and 23 (4.9%) with silent hypoxemia. The demographic and clinical characteristics, comorbidities, laboratory and imaging findings, disease severity, and outcomes were similar between groups. Higher breathing and heart rates correlated significantly with lower SpO2 in patients with dyspnea but not in those with silent hypoxemia. Independent predictors of silent hypoxemia were the presence of new-onset headache (OR 2.919, 95% CI 1.101-7.742; P = 0.031) and presenting to the emergency department within the first eight days after symptoms onset (OR 3.183, 95% CI 1.024-9.89; P = 0.045). CONCLUSIONS: Patients with silent hypoxemia sought medical attention earlier and had new-onset headache more often. They were also likely to display lower hemodynamic compensatory responses to hypoxemia, which may underestimate the disease severity.

Neurologic manifestations in hospitalized patients with COVID-19 in Mexico City.

BACKGROUND: The coronavirus disease 2019 (COVID-19) is a systemic entity that frequently implies neurologic features at presentation and complications during the disease course. We aimed to describe the characteristics and predictors for developing in-hospital neurologic manifestations in a large cohort of hospitalized patients with COVID-19 in Mexico City. METHODS: We analyzed records from consecutive adult patients hospitalized from March 15 to June 30, 2020, with moderate to severe COVID-19 confirmed by reverse transcription real-time polymerase chain reaction (rtRT-PCR) for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Neurologic syndromes were actively searched by a standardized structured questionnaire and physical examination, confirmed by neuroimaging, neurophysiology of laboratory analyses, as applicable. RESULTS: We studied 1,072 cases (65% men, mean age 53.2±13 years), 71 patients had pre-existing neurologic diseases (diabetic neuropathy: 17, epilepsy: 15, history of ischemic stroke: eight, migraine: six, multiple sclerosis: one, Parkinson disease: one), and 163 (15.2%) developed a new neurologic complication. Headache (41.7%), myalgia (38.5%), dysgeusia (8%), and anosmia (7%) were the most common neurologic symptoms at hospital presentation. Delirium (13.1%), objective limb weakness (5.1%), and delayed recovery of mental status after sedation withdrawal (2.5%), were the most common new neurologic syndromes. Age, headache at presentation, preexisting neurologic disease, invasive mechanical ventilation, and neutrophil/lymphocyte ratio ≥9 were independent predictors of new in-hospital neurologic complications. CONCLUSIONS: Even after excluding initial clinical features and pre-existing comorbidities, new neurologic complications in hospitalized patients with COVID-19 are frequent and can be predicted from clinical information at hospital admission.