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Coagulopathic bleeding is common during adult extracorporeal membrane oxygenation (ECMO), and acquired von Willebrand syndrome is a contributing factor. We compared ECMO patient blood samples that were treated in vitro with recombinant von Willebrand Factor concentrate and plasma-derived von Willebrand Factor concentrate. Our hypothesis was that recombinant von Willebrand Factor (vWF) would have greater efficacy in increasing vWF function. Secondarily, we hypothesized that recombinant vWF would have less impact on thrombin generation.Thirty ECMO patients and 10 cardiac surgical controls were enrolled in the study. ECMO patient blood samples were treated in vitro with low- and high-dose recombinant vWFs and low- and high-dose plasma-derived vWFs. Whole blood ristocetin-induced platelet aggregation (RIPA), plasma ristocetin cofactor activity (RCo), and thrombin generation were compared between ECMO patient blood samples and control blood samples and between vWF-treated ECMO patient blood samples and nontreated samples.ECMO patient blood samples had severely reduced median RIPA compared to control samples 2 ohms (1-12 [25th-75th percentile]) vs 20 ohms (11-42) (P.001). Treatment of ECMO patient blood samples with high-dose recombinant vWF significantly increased median RIPA to 10 ohms (2-15) (P.001), while low-dose recombinant vWF and low- and high-dose plasma-derived vWFs did not significantly increase RIPA; 6 ohms (3-14), 4 ohms (1-13), and 6 ohms (2-10), respectively (P = .25,.99, and.99). Treatment with high-dose recombinant vWF and low- and high-dose plasma-derived vWFs significantly increased median plasma RCo to 4.7 international units (IU)/mL (3.7-5.9), 3.3 IU/mL (2.7-4.8), and 3.9 IU/mL (3.4-5.3), respectively, compared to controls 1.8 IU/mL (1.5-2.3) (all P.001). Treatment with low- and high-dose plasma-derived vWFs significantly increased mean endogenous thrombin potential (6270.2 ± 2038.7 and 6313.1 ± 1913.3) compared to nontreated samples (5856.7 ± 1924.6) (P = .04 and .006), whereas treatment with low- and high-dose recombinant vWFs had no significant effect on mean endogenous thrombin potential (5776.1 ± 2087.3 and 5856.2 ± 1946.4) (P.99 for both comparisons).In vitro treatment of ECMO patient blood samples with high-dose recombinant vWF was superior to low-dose recombinant vWF and plasma-derived vWF in terms of improving RIPA. In addition, recombinant vWF treatment did not increase endogenous thrombin potential, which may reduce overall thrombotic risk if it used to treat acquired von Willebrand syndrome in ECMO patients.

A 57-year-old man with nonischemic cardiomyopathy who was dependent on venoarterial extracorporeal membrane oxygenation (ECMO) and was not a candidate for standard therapeutics, including a traditional allograft, received a heart from a genetically modified pig source animal that had 10 individual gene edits. Immunosuppression was based on CD40 blockade. The patient was weaned from ECMO, and the xenograft functioned normally without apparent rejection. Sudden diastolic thickening and failure of the xenograft occurred on day 49 after transplantation, and life support was withdrawn on day 60. On autopsy, the xenograft was found to be edematous, having nearly doubled in weight. Histologic examination revealed scattered myocyte necrosis, interstitial edema, and red-cell extravasation, without evidence of microvascular thrombosis - findings that were not consistent with typical rejection. Studies are under way to identify the mechanisms responsible for these changes. (Funded by the University of Maryland Medical Center and School of Medicine.).

Thrombocytopenia is common during extracorporeal membrane oxygenation (ECMO), and platelets are sometimes transfused to meet arbitrary goals. We performed a retrospective cohort study of veno-arterial (VA) ECMO patients from a single academic medical center and explored the relationship between platelet transfusion and in-hospital mortality using multivariable logistic regression. One hundred eighty-eight VA ECMO patients were included in the study. Ninety-one patients (48.4%) were transfused platelets during ECMO. Patients who received platelet transfusion had more coronary artery disease, lower platelet counts at cannulation, higher predicted mortality, lower nadir platelet counts, more ECMO days, and more red blood cell (RBC) and plasma transfusion. Mortality was 19.6% for patients who received no platelets, 40.8% for patients who received 1-3 platelets, and 78.6% for patients who received 4 or more platelets ( Plt; 0.001). After controlling for confounding variables including baseline severity of illness, central cannulation, postcardiotomy status, RBC and plasma transfusion, major bleeding, and total ECMO days, transfusion of 4 or more platelets remained associated with in-hospital mortality; OR = 4.68 (95% CI = 1.18-27.28), P = 0.03. Our findings highlight the need for randomized controlled trials that compare different platelet transfusion triggers, so that providers can better understand when platelet transfusion is indicated in VA ECMO patients.

To explore if atrial arrhythmias are associated with in-hospital mortality in veno-venous extracorporeal membrane oxygenation (VV-ECMO) patients.Retrospective observational cohort study.Quaternary care academic medical center.Patients with respiratory failure requiring VV-ECMO for24 hours between January 1, 2016, and January 1, 2019.None, observational study.Two hundred nineteen VV-ECMO patients were included. Patients were stratified by absence or presence of clinically significant atrial arrhythmias during the VV-ECMO run. Atrial arrhythmias were defined as either atrial fibrillation or atrial flutter that occurred during VV-ECMO and required pharmacologic or electrical intervention. The primary outcome was in-hospital mortality. Secondary outcomes included a composite of thrombotic events, which included ischemic stroke and on-pump arterial thrombosis. Other objectives of this analysis included characterization of atrial arrhythmia incidence, risk factors, and management. A total of 67 patients (30.5%) experienced new-onset atrial arrhythmias post-ECMO cannulation. Age, male sex, and norepinephrine use were independently associated with atrial arrhythmia development. In-hospital mortality was significantly higher in the atrial arrhythmia group (38.8% v 19.1%; p = 0.003). In the multivariate logistic regression analysis, atrial arrhythmias during VV-ECMO were independently associated with increased odds of in-hospital mortality (odds ratio, 2.21; 95% confidence interval, 1.08-4.55; p = 0.03), after controlling for Respiratory Extracorporeal Membrane Oxygenation Survival Prediction score, acute renal failure, total norepinephrine dose, and total cannulation time.New-onset atrial arrhythmias are a frequent complication during VV-ECMO and are independently associated with excessive in-hospital mortality. Thus, their presence may serve as an important prognostic tool in this patient population.

After orthotopic lung transplantation, hyperammonemia can be a rare complication secondary to infection by organisms that produce urease or inhibit the urea cycle. This can cause neurotoxicity, cerebral edema, and seizures. Ammonia is unique in that it has a large volume of distribution. However, it is also readily dialyzable given its small molecular weight. As such, removal of ammonia requires renal replacement modalities that can both rapidly remove ammonia from the plasma space and allow for continuous removal to prevent rebound accumulation from intracellular stores. Prevention of iatrogenic osmotic lowering in this setting is required to prevent worsening of cerebral edema. Herein, we describe use of sequential in-line renal replacement therapy using both intermittent hemodialysis and continuous venovenous hemofiltration within an extracorporeal membrane oxygenation circuit in conjunction with higher sodium dialysate and 7.5% hypertonic saline to achieve these treatment goals.

The ability of current renal replacement therapy modalities to achieve rapid solute removal is limited by membrane surface area and blood flow rate. Extracorporeal membrane oxygenation offers high blood flow and hemodynamic support that may be harnessed to overcome limitations in traditional renal replacement therapy. Using an extracorporeal membrane oxygenation circuit, we describe a high blood flow, high-efficiency hemofiltration technique using in-line hemofilters (hemoconcentrators) and standard replacement fluid to enhance solute clearance. Using this approach and a total of 5 L of replacement volume per treatment, creatinine (Cr) clearances of 8.3 L/hour and 11.2 L/hour using one and two hemoconcentrators, respectively, were achieved. With use of a high blood flow rate of up to 5 L/min, this hemofiltration technique can potentially offer clearance of 30 times that of continuous renal replacement therapy and of 6 times that of hemodialysis which may expand the ability to remove substances traditionally not considered removable via existing extracorporeal therapies.

Objectives To explore whether precannulation international normalized ratio (INR) is associated with in-hospital mortality in venoarterial extracorporeal membrane oxygenation (VA-ECMO) patients. Design A retrospective, observational cohort study. Setting A quaternary care academic medical center. Participants Patients with cardiogenic shock on VA-ECMO for >24 hours. Interventions None, observational study. Measurements and Main Results A total of 188 patients who were on VA-ECMO were included over three years. Patients were stratified into three groups based on their pre-ECMO INR: INR 1.8. For all patients, demographics, comorbidities, and ECMO details were recorded. The study's primary outcome was in-hospital mortality and secondary outcomes included major bleeding, minor bleeding, allogeneic transfusion, ischemic stroke, intracranial hemorrhage, acute renal failure, acute liver failure, gastrointestinal bleeding, intensive care unit and hospital lengths of stay. A multivariate logistic regression was used to determine whether precannulation INR was associated independently with in-hospital mortality. In-hospital mortality differed significantly by INR group (51.6% INR >1.8 v 42.3% INR 1.5-1.8 v 24.3% INR 1.8 was associated independently with an increased odds of mortality (odds ratio, 2.48; 95% confidence interval, 1.05-6.04) after controlling for sex, Survival after VA- ECMO score, and ECMO indication. An INR within 1.5 to 1.8 did not confer an increased mortality risk. Conclusions An INR >1.8 before VA-ECMO cannulation is associated independently with in-hospital mortality. Precannulation INR should be considered by clinicians so that ECMO resources can be better allocated and risks of organ failure and intracranial hemorrhage can be better understood.

Background: Heparin induced thrombocytopenia (HIT) is reported at a variable rate in extracorporeal membrane oxygenation (ECMO) patients. A critical factor impacting platelet factor-4 (PF4)-heparin antibody formation is plasma PF4 concentration. We hypothesized that PF4 concentration would be increased during veno-arterial (VA) ECMO. Methods: Plasma PF4 concentration was measured during the first 5 ECMO days in 20 VA ECMO patients and 10 control plasma samples. PF4-heparin ratios were estimated using an assumed heparin concentration of 0.4 IU/mL. This correlates with an activated partial thromboplastin time of 60 to 80 seconds, which is the anticoagulation target in our center. Results: Twenty VA ECMO patients were enrolled, 10 of which had pulmonary embolism. Median PF4 concentration was 0.03 µg/mL [0.01, 0.13] in control plasma. Median PF4 concentration was 0.21 µg/mL [0.12, 0.34] on ECMO day 1 or 2, 0.16 µg/mL [0.09, 0.25] on ECMO day 3, and 0.12 µg/mL [0.09, 0.22] on ECMO day 5. Estimated median PF4-heparin ratios were 0.04, 0.03, and 0.02 respectively. Two patients (10%) developed HIT that was confirmed by serotonin release assay. PF4 concentration did not differ significantly in these patients compared to non-HIT patients (p = 0.37). No patient had an estimated PF4-heparin ratio between 0.7 and 1.4, which is the reported optimal range for PF4-heparin antibody formation. Conclusion: Our data suggest that PF4 concentration is mildly elevated during VA ECMO compared to control plasma. Estimated PF4-heparin ratios were not optimal for HIT antibody formation. These data support epidemiologic studies where HIT incidence is low during VA ECMO.

Critically ill patients with coronavirus disease 2019 (COVID-19) have been observed to be hypercoagulable, but the mechanisms for this remain poorly described. Factor VIII is a procoagulant factor that increases during inflammation and is cleaved by activated protein C. To our knowledge, there is only 1 prior study of factor VIII and functional protein C activity in critically ill patients with COVID-19. Here, we present a case series of 10 critically ill patients with COVID-19 who had severe elevations in factor VIII activity and low normal functional protein C activity, which may have contributed to hypercoagulability.