Efficacy of Bivalirudin for Therapeutic Anticoagulation in COVID-19 Patients Requiring ECMO Support.

OBJECTIVES: The Coronavirus Disease 2019 (COVID-19) pandemic has been associated with cases of refractory acute respiratory distress syndrome (ARDS) sometimes requiring support with extracorporeal membrane oxygenation (ECMO). Bivalirudin can be used for anticoagulation in patients on ECMO support, but its efficacy and safety in patients with COVID-19 is unknown. The authors set out to compare the pharmacologic characteristics and dosing requirements of bivalirudin in patients requiring ECMO support for ARDS due to COVID-19 versus ARDS from other etiologies. DESIGN AND SETTING: This retrospective case-control study was performed at Indiana University Health Methodist Hospital in Indianapolis, Indiana. PARTICIPANTS: Patients were included if they were on venovenous ECMO support between June 2019 and June 2020, and divided into two groups: ARDS secondary to COVID-19 and those with ARDS from another etiology (Non-COVID). INTERVENTIONS: Patient demographics, such as age, sex, weight, chronic comorbid conditions, baseline antiplatelet and anticoagulant use, antiplatelet use during ECMO, and need for renal replacement therapy were collected, and compared between groups. Time to activated partial thromboplastin time (aPTT) goal, percentage of time at aPTT goal, bivalirudin rates, total bivalirudin requirements, total duration on bivalirudin, total duration on ECMO, mortality, and complications associated with ECMO were collected and compared between groups. MEASUREMENTS AND MAIN RESULTS: A total of 42 patients met inclusion criteria (n = 19 COVID-19, n = 23 non-COVID). However, percentages of aPTTs at goal were maintained more consistently in patients with COVID-19 versus non-COVID (86% v 74%: p < 0.01). Higher median (IQR) daily rates (3.1 µg/kg/min [2.3-5.2] v 2.4 µg/kg/min [1.7-3.3]: p = 0.05) and higher median (IQR) maximum rates of bivalirudin (5 µg/kg/min [3.7-7.5] v 3.8 µg/kg/min [2.5-5]: p = 0.03) were required in the COVID-19 group versus the non-COVID group. Time to goal aPTT was similar between groups. There were no differences in complications associated with anticoagulation, as demonstrated by similar rates of bleeding and thrombosis between both groups. CONCLUSIONS: Patients on ECMO with ARDS from COVID-19 require more bivalirudin overall and higher rates of bivalirudin to maintain goal aPTTs compared with patients without COVID-19. However, COVID-19 patients more consistently maintain goal aPTT. Future randomized trials are needed to support efficacy and safety of bivalirudin for anticoagulation of COVID-19 patients on ECMO.

Supratherapeutic Vancomycin Concentrations Associated With Hypothermia in a Burn Patient.

Hypothermia is a dangerous adverse effect that occurs in burn patients. Hypothermia leads to decreased renal blood flow and may decrease renal clearance of medications. Few human studies examine the effect of hypothermia on drug clearance and no known studies examine its effect on vancomycin clearance in burn patients. This case report describes a 39-year-old female who suffered 60% total body surface area third-degree burns. The patient required vancomycin, empirically, and for definitive treatment of methicillin-resistant Staphylococcus aureus. During three of the vancomycin courses, the patient experienced significant hypothermia. Vancomycin concentrations obtained during normothermia were found to be subtherapeutic or therapeutic. Concentrations obtained during hypothermia were found to be supratherapeutic and rate elimination constants were found to be significantly decreased by 45, 25, and 31%, respectively. These patient data suggest that hypothermia can decrease vancomycin clearance in burn patients as evidenced by supratherapeutic vancomycin concentrations and decreased rate elimination constants. Burn patients should be monitored closely for hypothermia. If hypothermia occurs during treatment, vancomycin concentrations should be obtained frequently, even if renal function appears stable. Dosing based on concentrations may be necessary in order to avoid supratherapeutic vancomycin concentrations and associated adverse drug events.

The effect of cruciferous and leguminous sprouts on genotoxicity, in vitro and in vivo.

Vegetable consumption is associated with a reduced risk of colorectal cancer, which is the second most common cancer after lung/breast cancer within Europe. Some putative protective phytochemicals are found in higher amounts in young sprouts than in mature plants. The effect of an extract of mixed cruciferous and legume sprouts on DNA damage induced by H(2)O(2) was measured in HT29 cells using single cell microgelelectrophoresis (comet). Significant antigenotoxic effect (P < or = 0.05) was observed when HT29 cells were pre-incubated with the extract (100 and 200 microL/mL) for 24 hours and then challenged with H(2)O(2). A parallel design intervention study was carried out on 10 male and 10 female healthy adult volunteers (mean age = 25.5 years) fed 113 g of cruciferous and legume sprouts daily for 14 days. The effect of the supplementation was measured on a range of parameters, including DNA damage in lymphocytes (comet), the activity of various detoxifying enzymes (glutathione S-transferase, glutathione peroxidase, and superoxide dismutase), antioxidant status using the ferric reducing ability of plasma assay, plasma antioxidants (uric acid, ascorbic acid, and alpha-tocopherol), blood lipids, plasma levels of lutein, and lycopene. A significant antigenotoxic effect against H(2)O(2)-induced DNA damage was shown in peripheral blood lymphocytes of volunteers who consumed the supplemented diet when compared with the control diet (P = 0.04). No significant induction of detoxifying enzymes was observed during the study, neither were plasma antioxidant levels or activity altered. The results support the theory that consumption of cruciferous vegetables is linked to a reduced risk of cancer via decreased damage to DNA.