Systemic Oxygen Utilization in Severe COVID-19 Respiratory Failure: A Case Series.

BACKGROUND: Management of hypoxemia in patients with severe COVID-19 respiratory failure is based on the guideline recommendations for specific SpO2 targets. However, limited data exist on systemic O2 utilization. The objective of this study was to examine systemic O2 utilization in a case series of patients with this disease. PATIENTS AND METHODS: Between March 24, and April 9, 2020, 8 patients intubated for severe COVID-19 respiratory failure had near-simultaneous drawing of arterial blood gas (ABG), central venous blood gas (cVBG), and central venous oxygen saturation (ScvO2) at a mean of 6.1 days into hospitalization. Three patients were managed with indirect cardiac output (CO) monitoring by FloTrac sensor and Vigileo monitor (Edwards Lifesciences, Irvine, CA). The oxygen extraction index (OEI; SaO2-ScvO2/SaO2) and oxygen extraction fraction (OEF; CaO2-CvO2/CaO2 ≥ 100) were calculated. Values for hyperoxia (ScvO2 ≥ 90%), normoxia (ScvO2 71-89%), and hypoxia (ScvO2 ≤ 70%) were based on the literature. Mean values were calculated. RESULTS: The mean partial pressure of oxygen (PaO2) was 102 with a mean fraction of inspired O2 (FiO2) of 44%. One patient was hyperoxic with a reduced OEI (17%). Five patients were normoxic, but 2 had a reduced OEF (mean 15.9%). Two patients were hypoxic but had increased systemic O2 utilization based on OEF or OEI. CONCLUSION: In select patients with severe COVID-19 respiratory failure, O2 delivery (DO2) was found to exceed O2 utilization. SpO2 targets based on systemic O2 utilization may help in reducing oxygen toxicity, especially in the absence of anaerobic metabolism. Further data are needed on the prevalence of systemic O2 utilization in COVID-19. HOW TO CITE THIS ARTICLE: Garg RK, Kimbrough T, Lodhi W, DaSilva I. Systemic Oxygen Utilization in Severe COVID-19 Respiratory Failure: A Case Series. Indian J Crit Care Med 2021;25(2):215-218.

Challenges in Brain Death Determination and Apnea Testing for Patients with COVID-19.

INTRODUCTION: Apnea testing remains essential for the clinical evaluation of brain death determination. In patients who test positive for SARS-CoV-2, disconnecting the patient from the ventilator and introducing high flow oxygen into the endotracheal tube increases the risk for aerosolization of airway secretions and exposure of the examiner. METHODS: Case report of a patient with an intracerebral hemorrhage that evolved to significant cerebral edema and herniation, who underwent apnea test using a method involving a t-piece and an HME filter. RESULTS: Patient successfully pronounced brain dead using a safe method to minimize exposure to SARS-CoV-2. CONCLUSION: At a time where healthcare workers are at high risk of exposure to COVID-19, the above described method is a safe process for apnea testing in declaration of brain death.

Acute Ischemic Stroke and COVID-19: Experience From a Comprehensive Stroke Center in Midwest US.

Background: COVID-19 has been associated with increased risk of venous and arterial thromboembolism including ischemic stroke. We report on patients with acute ischemic stroke and concomitant COVID-19 in a diverse patient population. Methods: This is a retrospective analysis of patients hospitalized with acute ischemic stroke (AIS) and COVID-19 to our comprehensive stroke center in Chicago, IL, between March 1, 2020, and April 30, 2020. We reviewed stroke characteristics, etiologies, and composite outcomes. We then compared our cohort with historic patients with AIS without COVID-19 admitted in the same time frame in 2019 and 2020. Results: Out of 13 patients with AIS and COVID-19, Latinos and African-Americans compromised the majority of our cohort (76.8%), with age ranging from 31-80 years. Most strokes were cortical (84.6%) and more than 50% of patients had no identifiable source, and were categorized as embolic stroke of unknown source (ESUS). A trend toward less alteplase administration was noted in the COVID-19 stroke patients compared to the non-COVID group from 2020 and 2019 (7.1 vs. 20.7% p 0.435 and 7.1 vs. 27.2% p 0.178). Endovascular thrombectomy was performed in 3 (23%) patients. Systemic thrombotic complications occurred in 3 (23%) COVID-19 AIS patients. Median National Institutes of Health Stroke Scale and modified Rankin Scale at discharge were 11 (IQR 4-23) and 4 (IQR 3-4), respectively. In the logistic regression model corrected for age and sex, COVID-19 was associated with discharge to mRS > 2 (p 0.046, OR 3.82, CI 1.02-14.3). Eight patients (63.8%) were discharged home or to acute rehabilitation, and two deceased from COVID-19 complications. Conclusion: AIS in the setting of COVID-19 is associated with worse outcomes, especially among African-American and Latino populations. Large vessel disease with ESUS was common suggesting an increased risk of coagulopathy and endothelial dysfunction as a potential etiology.

Neurological manifestations and COVID-19: Experiences from a tertiary care center at the Frontline.

OBJECTIVE: To report neurological manifestations seen in patients hospitalized with Coronavirus disease 2019 (COVID-19) from a large academic medical center in Chicago, Illinois. METHODS: We retrospectively reviewed data records of 50 patients with COVID-19 who were evaluated by the neurology services from March 1, 2020 - April 30, 2020. Patients were categorized into 2 groups based on timing of developing neurological manifestations: the "Neuro first" group had neurological manifestations upon initial assessment, and the "COVID first" group developed neurological symptoms greater than 24 h after hospitalization. The demographics, comorbidities, disease severity and neurological symptoms and diagnoses of both groups were analyzed. Statistical analysis was performed to compare the two groups. RESULTS: A total of 50 patients (48% African American and 24% Latino) were included in the analysis. Most common neurological manifestations observed were encephalopathy (n = 30), cerebrovascular disease (n = 20), cognitive impairment (n = 13), seizures (n = 13), hypoxic brain injury (n = 7), dysgeusia (n = 5), and extraocular movement abnormalities (n = 5). The "COVID-19 first" group had more evidence of physiologic disturbances on arrival with a more severe/critical disease course (83.3% vs 53.8%, p 0.025). CONCLUSION: Neurologic manifestations of COVID-19 are highly variable and can occur prior to the diagnosis of or as a complication of the viral infection. Despite similar baseline comorbidities and demographics, the COVID-19 patients who developed neurologic symptoms later in hospitalization had more severe disease courses. Differently from previous studies, we noted a high percentage of African American and Latino individuals in both groups.