Bivalirudin for Maintenance Anticoagulation During Venovenous Extracorporeal Membrane Oxygenation for COVID-19

Association of Argatroban Dose With Coagulation Laboratory Test in Patients on Extracorporeal Membrane Oxygenation: Activated Clotting Time vs Activated Partial Thromboplastin Time

BACKGROUND

Only some studies have directly compared and analyzed the roles of activated partial thromboplastin time (aPTT) and activated clotting time (ACT) in coagulation monitoring during argatroban administration.

OBJECTIVES

This study aims to assess the correlation of argatroban dose with ACT and aPTT values and to identify the optimal coagulation test for argatroban dose adjustment.

METHODS

We evaluated 55 patients on extracorporeal membrane oxygenation (ECMO) who received argatroban for more than 72 hours. The correlation between argatroban dose and aPTT and ACT values was evaluated. To compare argatroban dose and bleeding events according to liver dysfunction, the patients were divided into 2 groups based on alanine aminotransferase and total bilirubin.

RESULTS

Among the 55 patients, a total of 459 doses and coagulation tests were evaluated. The aPTT and ACT values showed a weak correlation with argatroban dose, with the Pearson correlation coefficients of 0.261 (P < 0.001) and 0.194 (P = 0.001), respectively. The agreement between the target 150 to 180 seconds for ACT and 55 to 75 seconds for aPTT was observed in 140 patients (46.1%). Twenty-four patients (43.6%) had liver dysfunction when they started argatroban. The median argatroban dose was lower in the liver dysfunction group than in the control group (0.094 mcg/kg/min vs 0.169 mcg/kg/min, P = 0.020). Difference was not observed between the 2 groups in the amount of red blood cell (0.47 vs 0.43 pack, P = 0.909) and platelet (0.60 vs 0.08 pack, P = 0.079) transfusion per day.

CONCLUSION AND RELEVANCE

A weak correlation was observed between argatroban dose and the aPTT and ACT values. However, the agreement between aPTT and ACT was only 46.1% regarding the scope of target range. Further research is necessary to determine how to assess the optimal argatroban dose for patients administered argatroban while undergoing ECMO at the intensive care unit.

Endothelium dysfunction and thrombosis in COVID-19 with type 2 diabetes

SARS-CoV-2 can directly or indirectly damage endothelial cells. Endothelial injury, especially phosphatidylserine (PS) exposure on the outer membrane of cells, can more easily promote thrombosis. Type 2 diabetes(T2D) patients were more susceptible to COVID-19, they had more severe symptoms, higher risk of thrombotic complications, and longer duration of post-COVID-19 sequelae. This review provided a detailed overview of the mechanisms underlying endothelial dysfunction in T2D patients with COVID-19 (including long COVID), which may be influenced by hyperglycemia, hypoxia, and pro-inflammatory environments. The mechanisms of thrombosis in T2D patients with COVID-19 are also explored, particularly the effects of increased numbers of PS-exposing particles, blood cells, and endothelial cells on hypercoagulability. Given the high risk of thrombosis in T2D patients with COVID-19, early antithrombotic therapy can both minimize the impact of the disease on patients and maximize the chances of improvement, thereby alleviating patient suffering. We provided detailed guidance on antithrombotic drugs and dosages for mild, moderate, and severe patients, emphasizing that the optimal timing of thromboprophylaxis is a critical factor in influencing prognosis. Considering the potential interactions between antidiabetic, anticoagulant, and antiviral drugs, we proposed practical and comprehensive management recommendations to supplement the incomplete efficacy of vaccines in the diabetic population, reduce the incidence of post-COVID-19 sequelae, and improve patient quality of life.

Anticoagulation strategies in COVID-19 infected patients receiving ECMO support

BACKGROUND

Hospitalized COVID-19 patients with hypoxemic respiratory failure may deteriorate despite invasive mechanical ventilation and thus require extracorporeal membrane oxygenation (ECMO) support. Unfractionated heparin (UFH) is the antithrombotic of choice, however, bivalirudin may offer more predictable pharmacokinetics resulting in consistent anticoagulant effects with lower bleeding and thrombotic occurrences. The aim of this study was to evaluate efficacy and safety outcomes in patients undergoing venovenous (VV) ECMO receiving bivalirudin or UFH-based anticoagulation.

METHODS

This retrospective, single-center, observational cohort study included patients with confirmed COVID-19 infection requiring VV ECMO support receiving anticoagulation with UFH or bivalirudin. Primary endpoints were time to reach therapeutic aPTT, percent time spent in aPTT range, and the occurrence of thrombotic events over the entire course of ECMO support. Secondary endpoints included the incidence of major/minor bleeding, the ability to wean off ECMO support, in-hospital mortality, and length of stay.

RESULTS

Twenty-two patients were included in the study (n = 10 UFH, n = 12 bivalirudin). Time to therapeutic aPTT was achieved faster with UFH (10 h vs. 20 h). The percentage time spent within the goal aPTT range was similar between UFH and bivalirudin (50% vs. 52%). Thrombotic events were significantly higher in the UFH group (40% DVT, 40% PE, 80% oxygenator thrombus in ECMO machine, 10% ischemic stroke) versus bivalirudin (8% DVT, 17% PE, 33% oxygenator thrombus, no ischemic strokes) (CI 95%, p = 0.04). The overall bleeding incidence was higher in the UFH arm (90% vs. 75%). The mortality rate was 90% in the UFH group and 58% in the bivalirudin group. The length of stay was similar between the two study arms.

CONCLUSION

In hospitalized patients with COVID-19-associated acute respiratory distress syndrome (ARDS) on VV ECMO support, the use of bivalirudin showed to be a viable anticoagulation alternative in terms of efficacy compared to UFH and resulted in a favorable safety profile with lower rates of bleeding and thrombotic events.

Early Tracheostomy May Be Performed Safely in Obese COVID-19 Patients Supported on VV-ECMO

OBJECTIVE

Obese patients with coronavirus disease 2019 (COVID-19)-associated acute respiratory failure (ARDS) often require prolonged intubation. However, data are sparse regarding optimal tracheostomy timing in obese adults with COVID-19 requiring venovenous extracorporeal membrane oxygenation (VV-ECMO). This study retrospectively describes the course of obese patients with COVID-19 who underwent tracheostomy on VV-ECMO between March 2020 and December 2022.

METHODS

There were 62 participants with a median age of 43 (interquartile range [IQR] 33 to 53) years and a median body mass index of 42 (IQR 34 to 50) kg/m2 who received VV-ECMO for COVID-19-associated ARDS. Of those, 42 underwent tracheostomy on VV-ECMO, and 50% (n = 21) of the 42 patients underwent early (within 14 days of initiated ventilatory support) tracheostomy.

RESULTS

Among patients who received tracheostomies, the combined respiratory tract and lung parenchymal bleeding rate was 29% (n = 12), but only 7% required surgical intervention for bleeding from the tracheostomy site (n = 3). The hospital length of stay (LOS) was 42 (IQR 36 to 57) days, and mortality rate was 38% (n = 16). Tracheostomy timing was not associated with differences in respiratory tract bleeding, mechanical ventilatory support duration, VV-ECMO support duration, intensive care unit LOS, hospital LOS, mortality, or survival probability.

CONCLUSIONS

Although an individualized and holistic approach to clinical decision making continues to be necessary, the findings of this study suggest that early tracheostomy may be performed safely in obese patients with COVID-19 on VV-ECMO.

ECMO During COVID-19: A Society of Thoracic Surgeons/Extracorporeal Life Support Organization Survey

BACKGROUND

The Society of Thoracic Surgeons Workforce on Critical Care and the Extracorporeal Life Support Organization sought to identify how the coronavirus disease 2019 (COVID-19) pandemic has changed the practice of venoarterial (VA) and venovenous (VV) extracorporeal membrane oxygenation (ECMO) programs across North America.

METHODS

A 26-question survey covering 6 categories (ECMO initiation, cannulation, management, anticoagulation, triage/protocols, and credentialing) was emailed to 276 North American Extracorporeal Life Support Organization centers. ECMO practices before and during the COVID-19 pandemic were compared.

RESULTS

Responses were received from 93 (34%) programs. The percentage of high-volume (>20 cases per year) VV ECMO programs increased during the pandemic from 29% to 41% (P < .001), as did institutions requiring multiple clinicians for determining initiation of ECMO (VV ECMO, 25% to 43% [P = .001]; VA ECMO, 20% to 32% [P = .012]). During the pandemic, more institutions developed their own protocols for resource allocation (23% before to 51%; P < .001), and more programs created sharing arrangements to triage patients and equipment with other centers (31% to 57%; P < .001). Direct thrombin inhibitor use increased for both VA ECMO (13% to 18%; P = .025) and VV ECMO (12% to 24%; P = .005). Although cardiothoracic surgeons remained the primary cannulating proceduralists, VV ECMO cannulations performed by pulmonary and critical care physicians increased (13% to 17%; P = .046).

CONCLUSIONS

The Society of Thoracic Surgeons/Extracorporeal Life Support Organization collaborative survey indicated that the pandemic has affected ECMO practice. Further research on these ECMO strategies and lessons learned during the COVID-19 pandemic may be useful in future global situations.

Extracorporeal membrane oxygenation for COVID-19-related acute respiratory distress syndrome: a narrative review

A growing body of evidence supports the use of extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS) refractory to maximal medical therapy. ARDS may develop in a proportion of patients hospitalized for coronavirus disease 2019 (COVID-19) and ECMO may be used to manage patients refractory to maximal medical therapy to mitigate the risk of ventilator-induced lung injury and provide lung rest while awaiting recovery. The mortality of COVID-19-related ARDS was variously reassessed during the pandemic. Veno-venous (VV) ECMO was the default choice to manage refractory respiratory failure; however, with concomitant severe right ventricular dysfunction, venoarterial (VA) ECMO or mechanical right ventricular assist devices with extracorporeal gas exchange (Oxy-RVAD) were also considered. ECMO has also been used to manage special populations such as pregnant women, pediatric patients affected by severe forms of COVID-19, and, in cases with persistent and seemingly irreversible respiratory failure, as a bridge to successful lung transplantation. In this narrative review, we outline and summarize the most recent evidence that has emerged on ECMO use in different patient populations with COVID-19-related ARDS.

Outcomes of Extracorporeal Membrane Oxygenation (ECMO) for COVID-19 Patients: A Multi-Institutional Analysis

BACKGROUND

In March 2020, COVID-19 was announced as a global pandemic. The first COVID-19 patient was connected to an ECMO device in Israel during that time. Since then, over 200 patients have required ECMO support due to COVID-19 infection. The present study is a multi-institutional analysis of all COVID-19 patients requiring veno-venous (VV) ECMO in Israel. The aim was to characterize and compare the survivors and deceased patients as well as establish risk factors for mortality.

METHODS

This retrospective multi-institutional study was conducted from March 2020 to March 2021 in eleven of twelve ECMO centers operating in Israel. All COVID-19 patients on VV ECMO support were included in the cohort. The patients were analyzed based on their comorbidities, procedural data, adverse event on ECMO, and outcomes. Univariate and multivariate analyses were used to compare the deceased and the surviving patients.

RESULTS

The study included 197 patients, of which 150 (76%) were males, and the mean age was 50.7 ± 12 years. Overall mortality was 106 (54%). Compared with the deceased subjects, survivors were significantly younger (48 ± 11 vs. 53 ± 12 years), suffered less from ischemic heart disease (IHD) (3% vs. 12%), and were ventilated for a significantly shorter period (≤4 days) prior to cannulation (77% vs. 63%). Patients in the deceased group experienced more kidney failure and sepsis. Rates of other complications were comparable between groups.

CONCLUSIONS

Based on this study, we conclude that early cannulation (≤4 days) of younger patients (≤55 years) may improve overall survival and that a history of IHD might indicate a reduced prognosis.

Bivalirudin vs. Enoxaparin in Intubated COVID-19 Patients: A Pilot Multicenter Randomized Controlled Trial

(1) Background: In COVID-19 patients, the occurrence of thromboembolic complications contributes to disease progression and mortality. In patients at increased risk for thrombotic complications, therapeutic enoxaparin should be considered. However, critically ill COVID-19 patients could develop resistance to enoxaparin. Bivalirudin, a thrombin inhibitor, may be an alternative. This pilot multicenter randomized controlled trial aims to ascertain if bivalirudin may reduce the time spent under invasive mechanical ventilation, as compared to enoxaparin. (2) Methods: Intubated COVID-19 patients at risk for thrombo-embolic complications were randomized to receive therapeutic doses of enoxaparin or bivalirudin. We ascertained the time spent under invasive mechanical ventilation during the first 28 days from Intensive Care Unit (ICU) admission. A standardized weaning protocol was implemented in all centers. In addition, we assessed the occurrence of thromboembolic complications, the number of patients requiring percutaneous tracheostomy, the gas exchange, the reintubation rate, the ICU length of stay, the ICU and 28-days mortalities. (3) Results: We enrolled 58 consecutive patients. Bivalirudin did not reduce the time spent under invasive mechanical ventilation as compared to enoxaparin (12 [8; 13] vs. 13 [10; 15] days, respectively; p = 0.078). Thrombotic (p = 0.056) and embolic (p = 0.423) complications, need for tracheostomy (p = 0.423) or reintubation (p = 0.999), the ICU length of stay (p = 0.076) and mortality (p = 0.777) were also similar between treatments. Patients randomized to bivalirudin showed a higher oxygenation at day 7 and 15 after randomization, when compared to enoxaparin group. (4) Conclusions: In intubated COVID-19 patients at increased risk for thromboembolic complications, bivalirudin did not reduce the time spent under invasive mechanical ventilation, nor improved any other clinical outcomes.

Transfusion Strategies for Hemostatic Blood Products in Critically Ill Children: A Narrative Review and Update on Expert Consensus Guidelines

Critically ill children commonly receive coagulant products (plasma and/or platelet transfusions) to prevent or treat hemorrhage or correct coagulopathy. Unique aspects of pediatric developmental physiology, and the complex pathophysiology of critical illness must be considered and balanced against known transfusion risks. Transfusion practices vary greatly within and across institutions, and high-quality evidence is needed to support transfusion decision-making. We present recent recommendations and expert consensus statements to direct clinicians in the decision to transfuse or not to transfuse hemostatic blood products, including plasma, platelets, cryoprecipitate, and recombinant products to critically ill children.

Anticoagulant Use During Extracorporeal Membrane Oxygenation Using Heparin and Direct Thrombin Inhibitors in COVID-19 and ARDS Patients

Coagulopathies develop in patients supported with the use of extracorporeal membrane oxygenation (ECMO) and can be hemorrhagic and/or thrombophilic in spite of the use of systemic anticoagulation. The purpose this study was to examine the use of heparin and direct thrombin inhibitors (DTI) in COVID-19 patients with acute respiratory distress syndrome (ARDS) on ECMO, with a subset analysis by disease state. Following IRB approval, 570 consecutive records were reviewed of adult patients on venovenous ECMO between May 2020 and December 2021. Patients were grouped by anticoagulant use: Heparin Only (n = 373), DTI Only (bivalirudin or argatroban, n = 90), or DTI after Heparin (n = 107). The effect of anticoagulant grouping was assessed using Bayesian mixed-effects logistic regression adjusting for age, body mass index (BMI), gender, days of mechanical ventilation prior to ECMO, indication for ECMO support, hepatic and renal failure, hours on ECMO, hours off anticoagulation, coagulation monitoring target, and hospital. The primary endpoint was circuit failure requiring change-out with secondary endpoints of organ failure and mortality. Regression-adjusted probability of circuit change-outs were as follows: DTI after Heparin patients-32.7%, 95% Credible Interval [16.1-51.9%]; DTI Only patients-23.3% [7.5-40.8%]; and Heparin Only patients-19.8% [8.1-31.3%]. The posterior probability of difference between groups was strongest for DTI after Heparin vs. Heparin Only (97.0%), moderate for DTI after Heparin vs. DTI Only (88.2%), and weak for DTI Only vs. Heparin only (66.6%). The occurrence of both hepatic and renal failure for DTI Only and DTI after Heparin patients was higher than that of Heparin Only patients. Unadjusted mortality was highest for DTI after Heparin (64.5%) followed by DTI Only (56.7%), and Heparin Only (50.1%, p = 0.027). DTI after Heparin was associated with an increased likelihood of circuit change-out. Unadjusted hepatic failure, renal failure, and mortality were more frequent among DTI patients than Heparin Only patients.

Fibrin clot characteristics and anticoagulant response in a SARS‐CoV‐2‐infected endothelial model

Coronavirus disease 2019 (COVID‐19) patients have increased thrombosis risk. With increasing age, there is an increase in COVID‐19 severity. Additionally, adults with a history of vasculopathy have the highest thrombotic risk in COVID‐19. The mechanisms of these clinical differences in risk remain unclear. Human umbilical vein endothelial cells (HUVECs) were infected with SARS‐CoV‐2, influenza A/Singapore/6/86 (H1N1) or mock‐infected prior to incubation with plasma from healthy children, healthy adults or vasculopathic adults. Fibrin on surface of cells was observed using scanning electron microscopy, and fibrin characteristics were quantified. This experiment was repeated in the presence of bivalirudin, defibrotide, low‐molecular‐weight‐heparin (LMWH) and unfractionated heparin (UFH). Fibrin formed on SARS‐CoV‐2 infected HUVECs was densely packed and contained more fibrin compared to mock‐infected cells. Fibrin generated from child plasma was the thicker than fibrin generated in vasculopathic adult plasma (p = 0.0165). Clot formation was inhibited by LMWH (0.5 U/ml) and UFH (0.1–0.7 U/ml). We show that in the context of the SARS‐CoV‐2 infection on an endothelial culture, plasma from vasculopathic adults produces fibrin clots with thinner fibrin, indicating that the plasma coagulation system may play a role in determining the thrombotic outcome of SARS‐CoV‐2 infection. Heparinoid anticoagulants were most effective at preventing clot formation.

The Year in Extracorporeal Membrane Oxygenation: Selected Highlights From 2021

This review summarizes the extracorporeal membrane oxygenation (ECMO) or extracorporeal life support literature published in 2021. This Selected Highlights article is not intended to be an exhaustive review of the literature, but rather a summarizing of key themes that developed in the ECMO literature during 2021. The primary topics presented include the following: ECMO for coronavirus disease 2019, extracorporeal cardiopulmonary resuscitation, periprocedural cardiopulmonary support with ECMO, and anticoagulation for ECMO.

Anticoagulation strategies in critically-ill SARS-CoV-2 patients: the role of direct thrombin inhibitors

Objectives

To compare heparin-based anticoagulation and bivalirudin-based anticoagulation within the context of critically ill patients with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Design

An observational study.

Setting

At the intensive care unit of a university hospital.

Participants and Interventions

Critically ill patients with a SARS-CoV-2 infection receiving full anticoagulation with heparin or bivalirudin.

Measurements and Main Results

Twenty-three patients received full anticoagulation with bivalirudin and 60 with heparin. Despite patients in the bivalirudin group having higher mortality risk scores (SAPS II 60 ± 16 v 39 ±7, p < 0.001) and a higher need for extracorporeal support compared to the heparin group, hospital mortality was comparable (57% v 45, p = 0.3). No difference in thromboembolic complications was observed, and bleeding events were more frequent in patients treated with bivalirudin (65% v 40%, p = 0.01). Similar results were confirmed in the subgroup analysis of patients undergoing intravenous anticoagulation; in addition to comparable thrombotic complications occurrence and thrombocytopenia rate, however, no difference in the bleeding rate was observed (65% v 35%, p = 0.08).

Conclusions

Although heparin is the most used anticoagulant in the intensive care setting, bivalirudin-based anticoagulation was safe and effective in a cohort of critically ill patients with SARS-CoV-2. Bivalirudin may be given full consideration as an anticoagulation strategy for critically ill patients with SARS-CoV-2, especially in those with thrombocytopenia and on extracorporeal support.

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.

Evaluation of Bivalirudin as the Primary Anticoagulant in Patients Receiving Extracorporeal Membrane Oxygenation for SARS-CoV-2-Associated Acute Respiratory Failure

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a potential option for the management of severe acute respiratory failure secondary to COVID-19. Conflicting the use of this therapy is the known coagulopathy within COVID-19, leading to an incidence of venous thrombotic events of 25% to 49%. To date, limited guidance is available on optimal anticoagulation strategies in this population.

OBJECTIVE

The purpose of this study was to evaluate the utilization of a pharmacist-driven bivalirudin dosing protocol for anticoagulation in the setting of ECMO for COVID-19-associated respiratory failure.

METHODS

This was a single-center retrospective chart review over a 9-month period of patients receiving bivalirudin while on ECMO. All patients with acute respiratory failure requiring ECMO with a positive SARS-CoV-2 polymerase chain reaction were included. Bivalirudin was dosed via aPTT monitoring after a starting dose of 0.2 or 0.3 mg/kg/h.

RESULTS

There were 33 patients included in this study, all receiving mechanical ventilation. The most common starting dose of bivalirudin was 0.2 mg/kg/h, with an average time to therapeutic range of 20 hours. Compared to previous reports, rates of bleeding were low at 15.1%, and 6.1% of patients developed a new venous thromboembolic event while on ECMO. ECMO survival was 51.5%, with an ICU mortality rate of 48.5%.

CONCLUSION AND RELEVANCE

In the first published report of its use within this population, bivalirudin was found to be a viable choice for anticoagulation in those patients on ECMO for severe respiratory failure secondary to COVID-19.

Comparison of Bivalirudin Versus Heparin for Maintenance Systemic Anticoagulation During Adult and Pediatric Extracorporeal Membrane Oxygenation

OBJECTIVES

To provide a comparative analysis of conventional heparin-versus bivalirudin-based systemic anticoagulation in adult and pediatric patients supported on extracorporeal membrane oxygenation.

DESIGN

Retrospective chart review study of adult and pediatric patients receiving extracorporeal membrane oxygenation from January 1, 2014, to October 1, 2019.

SETTING

A large, high-volume tertiary referral adult and pediatric extracorporeal membrane oxygenation center.

PATIENTS

Four hundred twenty-four individuals requiring extracorporeal membrane oxygenation support and systemically anticoagulated with either unfractionated heparin (223 adult and 65 pediatric patients) or bivalirudin (110 adult and 24 pediatric patients) were included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Digital data abstraction was used to retrospectively collect patient details. The majority of both groups were cannulated centrally (67%), and the extracorporeal membrane oxygenation type was predominantly venoarterial (84%). The adult bivalirudin group had a greater occurrence of heparin-induced thrombocytopenia (12% vs 1%; p < 0.01) and was more likely to require postcardiotomy extracorporeal membrane oxygenation (36% vs 55%; p < 0.01). There were no statistical differences between the groups in regards to age, sex, and extracorporeal membrane oxygenation initiation location. The main finding was a reduced mortality in the adult bivalirudin group (odds ratio, 0.39; p < 0.01), whereas no difference was noted in the pediatric group. A significant reduction in the composite transfusion requirement in the first 24 hours was noted in the pediatric bivaluridin group with an odds ratio of 0.28 (p = 0.02). Groups did not differ in regard to laboratories per day, anticoagulant dose adjustments, or ischemic complications.

CONCLUSIONS

When compared with heparin-based systemic anticoagulation, bivalirudin demonstrated feasibility and safety as established by the absence of increases in identifiable adverse outcomes while manifesting substantial improvements in hospital mortality in adult patients. Further studies are necessary to corroborate these findings and further elucidate the role of bivalirudin during extracorporeal membrane oxygenation support.

Continuous renal replacement therapy in patients treated with extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a life‐saving therapy utilized for patients with severe life‐threatening cardiorespiratory failure. Patients treated with ECMO are among the most severely ill encountered in critical care and are at high‐risk of developing multiple organ dysfunction, including acute kidney injury (AKI) and fluid overload. Continuous renal replacement therapy (CRRT) is increasingly utilized inpatients on ECMO to manage AKI and treat fluid overload. The indications for renal replacement therapy for patients on ECMO are similar to those of other critically ill populations; however, there is wide practice variation in how renal supportive therapies are utilized during ECMO. For patients requiring both CRRT and ECMO, CRRT may be connected directly to the ECMO circuit, or CRRT and ECMO may be performed independently. This review will summarize current knowledge of the epidemiology of AKI, indications and timing of CRRT, delivery of CRRT, and the outcomes of patients requiring CRRT with ECMO.

A Comprehensive Summary of the Knowledge on COVID-19 Treatment

Currently, the world is challenged by the coronavirus disease 2019 (COVID-19) pandemic. Epidemiologists and researchers worldwide are invariably trying to understand and combat this precarious new disease. Scrutinizing available drug options and developing potential new drugs are urgent needs to subdue this pandemic. Several intervention strategies are being considered and handled worldwide with limited success, and many drug candidates are yet in the trial phase. Despite these limitations, the development of COVID-19 treatment strategies has been accelerated to improve the clinical outcome of patients with COVID-19, and some countries have efficiently kept it under control. Recently, the use of natural and traditional medicine has also set the trend in coronavirus treatment. This review aimed to discuss the prevailing COVID-19 treatment strategies available globally by examining their efficacy, potential mechanisms, limitations, and challenges in predicting a future potential treatment candidate and bridging them with the effective traditional Chinese medicine (TCM). The findings might enrich the knowledge on traditional alternative medication and its complementary role with Western medicine in managing the COVID-19 epidemic.

Targeting coagulation activation in severe COVID-19 pneumonia: lessons from bacterial pneumonia and sepsis

Novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has rapidly spread throughout the world, resulting in a pandemic with high mortality. There are no effective treatments for the management of severe COVID-19 and current therapeutic trials are focused on antiviral therapy and attenuation of hyper-inflammation with anti-cytokine therapy. Severe COVID-19 pneumonia shares some pathological similarities with severe bacterial pneumonia and sepsis. In particular, it disrupts the haemostatic balance, which results in a procoagulant state locally in the lungs and systemically. This culminates in the formation of microthrombi, disseminated intravascular coagulation and multi-organ failure. The deleterious effects of exaggerated inflammatory responses and activation of coagulation have been investigated in bacterial pneumonia and sepsis and there is recognition that although these pathways are important for the host immune response to pathogens, they can lead to bystander tissue injury and are negatively associated with survival. In the past two decades, evidence from preclinical studies has led to the emergence of potential anticoagulant therapeutic strategies for the treatment of patients with pneumonia, sepsis and acute respiratory distress syndrome, and some of these anticoagulant approaches have been trialled in humans. Here, we review the evidence from preclinical studies and clinical trials of anticoagulant treatment strategies in bacterial pneumonia and sepsis, and discuss the importance of these findings in the context of COVID-19.