Thrombocytopenia-associated Multiple Organ Failure Research Articles

Plasma exchange and COVID 19

Plasma exchange and COVID 19

Therapeutic plasma exchange application in the treatment of sepsis in a pediatric burn center

Objective: In our study, we aimed to analyze the use of Therapeutic plasma exchange (TPE) in the manage-ment of septic and Thrombocytopenia-associated multiple-organ failure (TAMOF) in the burn in-tensive care unit of a children’s hospital retrospectively. Material and Methods: Demographic, clinical, and laboratory data of the pediatric burn patients who were applied TPE between 1 January 2016 and 1 January 2021 were obtained from the hospital information system and medical records and analyzed. The patients were divided into two groups those who died du-ring follow-up and those who recovered. Results: TPE was performed on 14 burned children (Boy: Girl 5:9). The median age of the patients was 6,6 years (range 1-18 years). The mean TBSA of the patients was 47.76% (20-75). The most common cause of burns was flame burn. The mean hospital stay of the patients was 18.4±12.6 (7-94) days. 4 patients in group 1 recovered and 10 patients in group 2 died during follow-up. There was no statistical difference between the groups in terms of age, gender, and TBSA (p=0.590, 0.890, 0.990). We determined that patients in group 2 were statistically higher in terms of MODS (p=0.030), Pelod score (p=0.001), and expected death rate according to Pelod score (p=0.003). It was observed that the application of TPE in the first 24 hours after the occurrence of TAMOF significantly reduced mortality (p=0.010). Conclusion: TPE should be used as an additional treatment method to conventional therapy in critically ill pati-ents in pediatric burn intensive care units. TPE application in the first 24 hours after the occurrence of TAMOF reduces mortality.

Machine learning derivation of four computable 24-h pediatric sepsis phenotypes to facilitate enrollment in early personalized anti-inflammatory clinical trials

BackgroundThrombotic microangiopathy-induced thrombocytopenia-associated multiple organ failure and hyperinflammatory macrophage activation syndrome are important causes of late pediatric sepsis mortality that are often missed or have delayed diagnosis. The National Institutes of General Medical Science sepsis research working group recommendations call for application of new research approaches in extant clinical data sets to improve efficiency of early trials of new sepsis therapies. Our objective is to apply machine learning approaches to derive computable 24-h sepsis phenotypes to facilitate personalized enrollment in early anti-inflammatory trials targeting these conditions.MethodsWe applied consensus, k-means clustering analysis to our extant PHENOtyping sepsis-induced Multiple organ failure Study (PHENOMS) dataset of 404 children. 24-hour computable phenotypes are derived using 25 available bedside variables including C-reactive protein and ferritin.ResultsFour computable phenotypes (PedSep-A, B, C, and D) are derived. Compared to all other phenotypes, PedSep-A patients (n = 135; 2% mortality) were younger and previously healthy, with the lowest C-reactive protein and ferritin levels, the highest lymphocyte and platelet counts, highest heart rate, and lowest creatinine (p < 0.05); PedSep-B patients (n = 102; 12% mortality) were most likely to be intubated and had the lowest Glasgow Coma Scale Score (p < 0.05); PedSep-C patients (n = 110; mortality 10%) had the highest temperature and Glasgow Coma Scale Score, least pulmonary failure, and lowest lymphocyte counts (p < 0.05); and PedSep-D patients (n = 56, 34% mortality) had the highest creatinine and number of organ failures, including renal, hepatic, and hematologic organ failure, with the lowest platelet counts (p < 0.05). PedSep-D had the highest likelihood of developing thrombocytopenia-associated multiple organ failure (Adj OR 47.51 95% CI [18.83–136.83], p < 0.0001) and macrophage activation syndrome (Adj OR 38.63 95% CI [13.26–137.75], p < 0.0001).ConclusionsFour computable phenotypes are derived, with PedSep-D being optimal for enrollment in early personalized anti-inflammatory trials targeting thrombocytopenia-associated multiple organ failure and macrophage activation syndrome in pediatric sepsis. A computer tool for identification of individual patient membership (www.pedsepsis.pitt.edu) is provided. Reproducibility will be assessed at completion of two ongoing pediatric sepsis studies.

Management of thrombocytopenia-associated multiple organ failure: plasma infusion vs plasma exchange

Thrombocytopenia-associated multiple organ failure (TAMOF) causes a high ratio of mortality in pediatric patients. Only anticoagulants and profibrinolytic molecules can be replaced with plasma infusion (PI), while therapeutic plasma exchange (TPE) eliminates antifibrinolytic and thrombogenic molecules and charges inadequate anticoagulants and profibrinolytic molecules. This study aims to compare the efficacy of plasma exchange to plasma infusion in pediatric TAMOF patients. Twenty-seven patients with TAMOF were included and the efficacy of PI and TPE was compared. The demographic data, admission laboratory values, Pediatric Logistic Organ Dysfunction (PELOD) scores before the beginning of treatment and PELOD at the end of treatment, and outcomes of groups were compared. Sixteen children were in the plasma infusion group, eleven children were in the plasma exchange group. The total mortality rate of all patients was 37%. The PELOD scores were significantly reduced on the 5th day of treatment in both groups and also PELOD scores were significantly higher on the 5th day of study in the non-survivor group (p: < 0.001). The fifth day of PELOD scores and ferritin had a significant effect on mortality (OR: 1.85, 95% CI: 1.02-2.69; p: 0.04, OR: 1.43, 95% CI: 0.97-2.03; p: 0.05). The overall mortality ratio was not different between TPE and PI groups (p: 0.12). Although there was no difference in mortality rates in children who received plasma exchange compared to children who received plasma infusion, mechanical ventilation and length of pediatric intensive care unit (PICU) day were shorter in the TPE group. The small patient population may be the major cause for the lack of significant statistical difference.

The role of the microcirculation in the pathogenesis of organ dysfunction

The microcirculation includes all blood and lymph vessels with a diameter < 100 µm. Microcirculatory dysfunction is common in critically ill patients and is closely associated with both the severity of (multi-)organ dysfunction and mortality. The nature and extent of microcirculatory dysfunction differ depending on the underlying disease and are most pronounced in patients with systemic inflammation (e. g. sepsis), specific infections (e. g. malaria, dengue) or thrombocytopenia-associated multiple organ failure. This manuscript provides an overview of the pathophysiology, monitoring and therapy of microcirculatory dysfunction in the critically ill patient.

Simultaneous Extracorporeal Membrane Oxygenation, Renal Replacement Therapy, and Plasma Exchange for Thrombocytopenia-Associated Multiple Organ Failure

Simultaneous Extracorporeal Membrane Oxygenation, Renal Replacement Therapy, and Plasma Exchange for Thrombocytopenia-Associated Multiple Organ Failure

Therapeutic Plasma Exchange in Children With Thrombocytopenia-Associated Multiple Organ Failure: The Thrombocytopenia-Associated Multiple Organ Failure Network Prospective Experience.

The objective was to compare the resolution of organ dysfunction, 28-day mortality, and biochemical markers in children with thrombocytopenia-associated multiple organ failure who received therapeutic plasma exchange versus no therapeutic plasma exchange. Observational longitudinal cohort study. Nine U.S. PICUs. Eighty-one children with sepsis-induced thrombocytopenia-associated multiple organ failure. Therapeutic plasma exchange. Adjusted relative risk for 28-day mortality was modeled using standard multivariate regression with propensity score weighting to reduce covariate confounding. Change from baseline Pediatric Logistic Organ Dysfunction scores between therapeutic plasma exchange and no therapeutic plasma exchange differed in temporal pattern during the first week (p = 0.009). By day 4, mean Pediatric Logistic Organ Dysfunction score declined by 7.9 points (95% CI, -10.8 to -5.1) in the therapeutic plasma exchange-treated group compared with no change with no therapeutic plasma exchange. Use of therapeutic plasma exchange was associated with reduced 28-day mortality by multivariate analysis (adjusted relative risk, 0.45; 95% CI, 0.23-0.90; p = 0.02) and by propensity score weighting (adjusted relative risk, 0.46; 95% CI, 0.22-0.97; p = 0.04). Therapeutic plasma exchange use in thrombocytopenia-associated multiple organ failure was associated with a decrease in organ dysfunction. After accounting for several risk factors, 28-day all-cause mortality was lower in children treated with therapeutic plasma exchange compared with those receiving no therapeutic plasma exchange. A multicenter randomized clinical trial is necessary to determine a causal relationship.

Role of Damage-Associated Molecular Patterns and Uncontrolled Inflammation in Pediatric Sepsis-Induced Multiple Organ Dysfunction Syndrome.

The incidence of multiple organ dysfunction syndrome (MODS) in sepsis varies from 17 to 73% and furthermore, increases the risk of death by 60% when controlled for the number of dysfunctional organs. Several MODS phenotypes exist, each unique in presentation and pathophysiology. Common to the phenotypes is the stimulation of the immune response by pathogen-associated molecular patterns (PAMPs), or danger-associated molecular patterns (DAMPs) causing an unremitting inflammation. Two of the MODS phenotypes are discussed in detail, thrombocytopenia-associated multiple organ failure (TAMOF) and the hyperinflammatory phenotype-macrophage activating syndrome (MAS) and hemophagocytic lymphohistiocytosis (HLH). In the end, we will briefly review the role of mitochondrial dysfunction as a significant contributor to the pathogenesis of MODS.

Pediatric Tandem Therapeutic Apheresis: A Multidisciplinary Approach.

The epidemiology, safety, and efficacy of pediatric multiple tandem extracorporeal therapies are not well understood. We conducted a retrospective chart review of therapeutic apheresis (TA) from January 1, 2012 to October 31, 2015. We collected procedural/clinical demographics, American Society for Apheresis (ASFA) indication, complications, and mortality. One hundred eighty tandem TA procedures were performed in 53 patients. Median age was 9 years (range: 2 months to 21 years) with a median weight of 28 kg (range: 6-170.3 kg) with nine patients weighing < 10 kg. Forty-five percent of patients were in tandem with continuous veno-venous hemofiltration (CVVH), 21% cardiopulmonary bypass (CPB), 4% extracorporeal membrane oxygenation (ECMO), and 11% had multiple extracorporeal therapies (CVVH and ECMO). Common indications were solid organ transplant (50% cardiac, 13% renal) and sepsis-induced thrombocytopenia-associated multiple organ failure (26%). Equipment (4%) and patient (4%) complications occurred, with rare failure (1%) and no procedure-related mortality. Tandem procedures are used in critically ill pediatric patients with higher morbidity and mortality (21%) than typical TA patients. The high percentage of patients outside of category I or II (83%) underscores the emerging nature of tandem extracorporeal therapies and need for further investigation.

Three Hypothetical Inflammation Pathobiology Phenotypes and Pediatric Sepsis-Induced Multiple Organ Failure Outcome.

We hypothesize that three inflammation pathobiology phenotypes are associated with increased inflammation, proclivity to develop features of macrophage activation syndrome, and multiple organ failure-related death in pediatric severe sepsis. Prospective cohort study comparing children with severe sepsis and any of three phenotypes: 1) immunoparalysis-associated multiple organ failure (whole blood ex vivo tumor necrosis factor response to endotoxin < 200 pg/mL), 2) thrombocytopenia-associated multiple organ failure (new onset thrombocytopenia with acute kidney injury and a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 activity < 57%), and/or 3) sequential multiple organ failure with hepatobiliary dysfunction (respiratory distress followed by liver dysfunction with soluble Fas ligand > 200 pg/mL), to those without any of these phenotypes. Tertiary children's hospital PICU. One hundred consecutive severe sepsis admissions. Clinical data were recorded daily, and blood was collected twice weekly. Multiple organ failure developed in 75 cases and eight died. Multiple organ failure cases with any of the three inflammation phenotypes (n = 37) had higher inflammation (C-reactive protein, p = 0.009 and ferritin, p < 0.001) than multiple organ failure cases without any of these phenotypes (n = 38) or cases with only single organ failure (n = 25). Development of features of macrophage activation syndrome and death were more common among multiple organ failure cases with any of the phenotypes (macrophage activation syndrome: 10/37, 27%; death: 8/37, 22%) compared to multiple organ failure cases without any phenotype (macrophage activation syndrome: 1/38, 3%; p = 0.003 and death: 0/38, 0%; p = 0.002). Our approach to phenotype categorization remains hypothetical, and the phenotypes identified need to be confirmed in multicenter studies of pediatric multiple organ dysfunction syndrome.

Leptospirosis in a child with acute respiratory distress syndrome

Yeşilbaş O, Şevketoğlu E, Kıhtır HS, Hatipoğlu N, Yıldırım HM, Akyol MB, Aktay-Ayaz N, Gökçe İ. Leptospirosis in a child with acute respiratory distress syndrome. Turk J Pediatr 2017; 59: 688-692. Leptospirosis is an infectious vasculitis, which can occur with different clinical features. While it is generally a subclinical and self-limited infection; kidney and liver dysfunction, pulmonary hemorrhage, thrombocytopenia, and cardiovascular collapse may occurr. A six-year-old boy presented with acute respiratory distress syndrome, shock, thrombocytopenia-associated multiple organ failure, and persistent high fever secondary to leptospirosis. Persistent high fever was resistant to intravenous immunoglobulin and pulse steroid therapy. He was successfully treated with plasmapheresis and hemofiltration with endotoxin-cytokine cleaning filter. In conclusion; leptospirosis may cause thrombocytopenia-associated multiple organ failure, persistent high fever, and acute respiratory distress syndrome. Plasmapheresis and hemofiltration should be considered in cases of severe leptospirosis with multiorgan failure.

Pediatric Sepsis Biomarker Risk Model-II: Redefining the Pediatric Sepsis Biomarker Risk Model With Septic Shock Phenotype

The Pediatric Sepsis Biomarker Risk Model (PERSEVERE), a pediatric sepsis risk model, uses biomarkers to estimate baseline mortality risk for pediatric septic shock. It is unknown how PERSEVERE performs within distinct septic shock phenotypes. We tested PERSEVERE in children with septic shock and thrombocytopenia-associated multiple organ failure (TAMOF), and in those without new onset thrombocytopenia but with multiple organ failure (MOF). PERSEVERE-based mortality risk was generated for each study subject (n = 660). A priori, we determined that if PERSEVERE did not perform well in both the TAMOF and the MOF cohorts, we would revise PERSEVERE to incorporate admission platelet counts. Multiple PICUs in the United States. Standard care. PERSEVERE performed well in the TAMOF cohort (areas under the receiver operating characteristic curves [AUC], 0.84 [95% CI, 0.77-0.90]), but less well in the MOF cohort (AUC, 0.71 [0.61-0.80]). PERSEVERE was revised using 424 subjects previously reported in the derivation phase. PERSEVERE-II had an AUC of 0.89 (0.85-0.93) and performed equally well across TAMOF and MOF cohorts. PERSEVERE-II performed well when tested in 236 newly enrolled subjects. Sample size calculations for a clinical trial testing the efficacy of plasma exchange for children with septic shock and TAMOF indicated PERSEVERE-II-based stratification could substantially reduce the number of patients necessary, when compared with no stratification. Testing PERSEVERE in the context of septic shock phenotypes prompted a revision incorporating platelet count. PERSEVERE-II performs well upon testing, independent of TAMOF or MOF status. PERSEVERE-II could potentially serve as a prognostic enrichment tool.

Plasma exchange therapy in sepsis

Sepsis is a systemic inflammatory syndrome in response to an infection. With the current resuscitation practice, up to 16% of children with severe sepsis and septic shock still progress to develop multiple organ failure (MOF), a condition that is associated with poor outcome. In this review, we focus on the thrombotic microangiopathic paradigm for the development of sepsis-induced MOF. We describe the clinical observations, emerging experimental and laboratory evidence supporting the concept that sepsis-induced MOF may be a secondary thrombotic microangiopathy, manifest as thrombocytopenia-associated MOF. Drawing the pathologic similarities such as a disintegrin and metalloprotease with thrombospondin motifs-13 deficiency, impaired ultra-large von Willebrand factor multimers proteolysis, and von Willebrand factor-rich microthrombi and therapeutic success with plasma exchange in treating thrombotic thrombocytopenic purpura, a primary thrombotic microangiopathy, we propose a rationale for the role of plasma exchange therapy for sepsis and thrombocytopenia-associated multiple organ failure.

Use of therapeutic plasma exchange in children with thrombocytopenia-associated multiple organ failure in the Turkish TAMOF network

Thrombocytopenia-associated multiple organ failure (TAMOF) can lead to high mortality in critically ill children, possibly related to consequences of thrombotic microangiopathy. Plasma exchange therapy may improve thrombotic microangiopathy [1]. The purpose of this observational cohort study is to describe whether there is an association between use of plasma exchange therapy and outcome in the Turkish TAMOF network.

Use of therapeutic plasma exchange in children with thrombocytopenia-associated multiple organ failure in the Turkish thrombocytopenia-associated multiple organ failure network.

Thrombocytopenia-associated multiple organ failure can lead to high mortality in critically ill children, possibly related to consequences of thrombotic microangiopathy. Plasma exchange therapy may improve thrombotic microangiopathy. The purpose of this observational cohort study is to describe whether there is an association between use of plasma exchange therapy and outcome in the Turkish thrombocytopenia-associated multiple organ failure network. We performed a retrospective cohort analysis in patients with thrombocytopenia-associated multiple organ failure at three different PICUs comparing those who received plasma exchange (+) plus standard therapies with those who did not receive plasma exchange (-) and only received standard therapies. Among 42 of the enrolled patients with thrombocytopenia-associated multiple organ failure, all had a primary or secondary sepsis diagnosis. Fifteen received plasma exchange therapy (PE [+] group) and 27 received standard medical treatment without plasma exchange (PE [-] group). The mean age was 17.69 months (8.24-54.22) in the PE (+) group and 13.46 months (6.47-20.55) in the PE (-) group. Age (p = 0.232), gender (p = 0.206), thrombocyte count (p = 0.09), Organ Failure Index score (p = 0.111), and pediatric logistic organ dysfunction score (p = 0.177) at admission were not statistically different between groups. The overall 28-day mortality was higher in the PE (-) group (70.37%) compared with the PE (+) group (26.67%) (univariate p = 0.006; multivariate controlling for pediatric logistic organ dysfunction, Organ Failure Index, Pediatric Risk of Mortality scores, and neurological failure p = 0.048). Length of stay was increased in the PE (+) group (p = 0.004). The positive association found between use of plasma exchange therapy and improved survival supports the potential of this therapy in Turkish children with thrombocytopenia-associated multiple organ failure. The positive, although less so, associated treatment effect observed after controlling for illness severity provides further rationale for performing a randomized controlled trial in the pediatric Turkish thrombocytopenia-associated multiple organ failure network. Sample size calculations call for a 100-patient trial with a pre hoc interim analysis after enrollment of 50 patients with thrombocytopenia-associated multiple organ failure.

Septic shock in ICU: advanced therapeutics, immunoparalysis and genomics. State of the art

New and important concepts have emerged for the advanced management of the child with septic shock in the recent decades. Attending physicians in the Pediatric intensive care unit must be fully aware of them to improve patient care in the critical care unit. It should be considered the use of immune therapy only in selected groups of patients. Continuous renal replacement therapies are well tolerated and their early use prevents deleterious fluid overload. Removal of inflammatory mediators by using high volume hemofiltration may play a role in hyperdynamic septic patients. The use of plasmapheresis is recommended in patients with thrombocytopenia-associated multiple organ failure. Extracorporeal support use should be considered in those with refractory septic shock despite goals directed therapy. The immunoparalysis has been associated with nosocomial infections and late mortality. The information from genetic markers may allow early intervention and preventive genomics-based medicine.

Cyclosporine-associated Thrombotic Microangiopathy and Thrombocytopenia-associated Multiple Organ Failure

Thrombotic microangiopathy (TMA) is characterized by microvascular thrombosis, thrombocytopenia, and microangiopathic hemolytic anemia. Previous studies have shown that cyclosporine (CsA) is associated with TMA but the number of reported cases is very limited. We describe a 13-year-old girl with CsA-associated TMA and thrombocytopenia-associated multiple organ failure (TAMOF). The patient was diagnosed with polyglandular deficiency syndrome and had a history of celiac disease, autoimmune thyroiditis, and diabetes mellitus type I. CsA was started 7 months before her admission to our pediatric intensive care unit for persistent diarrhea associated with celiac disease. At the time of her admission to our pediatric intensive care unit, she was thrombocytopenic and anemic with multiple organ failure. Laboratory and clinical findings were consistent with TMA and TAMOF. CsA was discontinued and therapeutic plasma exchange was performed daily for 5 days. The patient improved clinically, laboratory findings normalized, and TMA and multiple organ failure dissolved. This case report indicates that therapeutic plasma exchange may be effective in the treatment of CsA-associated TMA and TAMOF, especially in the presence of systemic findings.

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Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation. The clinical phenotype of HLH-induced multiple organ failure (MOF) is very similar to other phenotypes of MOF in critically ill children such as thrombocytopenia-associated MOF (TAMOF) syndrome and immune paralysis/lymphoid depletion syndrome. Methods: We reviewed consecutive autopsy reports of children who died with a diagnosis of HLH between 2005-2012 in a tertiary care university-based pediatric hospital. Two autopsies were limited - one with liver/spleen/bone marrow, and the other with chest/abdomen. Results: Twelve autopsy reports were analyzed. All patients had received treatment with dexamethosone and etoposide. 83.3% (10/12) of patients met criteria for TAMOF at death: platelet count < 100K/mm3 and at least 3 failing organs. 60% (6/10) of patients who met criteria for TAMOF had evidence of microvascular thrombosis on autopsy, 50% (3/6) had evidence of microvascular thrombosis in more than one organ: 2/6 brain, 2/6 heart, 1/6 in lungs, 1/6 in liver, 3/6 in kidneys, 1/6 in pancreas and 2/6 in spleen. Two thirds (4/6) patients also had hypocellular bone marrow. Of the 4 patients who met criteria for TAMOF without microvascular thrombosis on autopsy, 3 had hypocellular bone marrow and one had occlusive aggregates of septated hyphae in blood vessels and no bone marrow was obtained at autopsy. 83% (10/12) of patients had evidence of infection at time of autopsy, categorized as: bacterial (58%), viral (50%), fungal (42%), and 42% of patients had infections in more than one category. 50% (6/12) of patients had lymphocyte depletion in spleen, thymus or bone marrow, and 66% (4/6) of whom were chronically lymphopenic (>7 days absolute lymphocyte count <1000/microliter), and 83% (5/6) with infection on autopsy. Conclusions: Many patients who died with HLH have 1) clinical evidence of TAMOF syndrome and autopsy evidence of disseminated microvascular thrombosis and 2) clinical lymphopenia and autopsy evidence of lymphoid depletion and unresolved infection. These autopsy findings suggest that MOF in patients with HLH is complex with overlapping MOF phenotypes. Further studies are warranted.

Thrombocytopenia-associated multiple organ failure or severe haemolysis, elevated liver enzymes, low platelet count in a postpartum case

Thrombocytopenia-associated multiple organ failure (TAMOF) is a thrombotic microangiopathic syndrome that includes thrombotic thrombocytopenic purpura, secondary thrombotic microangiopathy, and disseminated intravascular coagulation. We report a case of postpartum female who presented with TAMOF or severe Haemolysis, elevated liver enzymes, low platelet count (HELLP) which was managed with plasma exchange. This case report is to make clinicians aware that TAMOF, severe HELLP, and other differential diagnosis in a postpartum case have a thin differentiating line and plasma exchange can be considered as one of the management options.

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Introduction: Pediatric Thrombocytopenia-Associated Multiple Organ Failure (TAMOF), defined as greater than 2 organ failures and platelet count < 100,000/uL, is associated with high mortality in sepsis. Plasma exchange (PEx) has been suggested to improve survival (Nguyen et al., CCM, 2008). In preliminary prospective studies of the multicenter Prospective TAMOF Network, PEx was associated with increased likelihood of survival (Fortenberry, CCM, 2011 abstr). A subset of gravely ill patients received PEx while on ECMO. We evaluated this subgroup to better determine response and outcome. Hypothesis: Patients on ECMO receiving PEx have greater severity of illness and greater likelihood of death than non-ECMO patients receiving PEx. Methods: Analysis of data from network prospective observational trial of 81 children 1 mth-21 years diagnosed with TAMOF. Pts.on ECMO receiving PEx were compared to non-ECMO pts. for severity of illness scores, outcome. ADAMTS-13 levels and platelet counts were serially obtained. Results: PEx pts had lower survival (53.8%) than non-ECMO PEx patients (79.4%; p = 0.05), but not lower than ECMO non-PEx patients (50%; p = NS). PELOD scores >21 did not predict outcome difference. PELOD scores remained higher over time in ECMO PEx pts. and in non-survivors (N-S) (p=.009). ECMO PEx pts had greater PELOD score improvement over time than non-ECMO PEx pts (p=.0077). Platelet counts were lower in non-ECMO PEx N-S, but were improved in ECMO pts vs. non-ECMO PEx, likely due to platelet therapy on ECMO. ECMO PEx survivors showed a trend for improvement in ADAMTS-13 vs. N-S (p=0.0615) and with time (p <.001). Conclusions: TAMOF patients on ECMO who received PEx were more critically ill at onset and more likely to die than TAMOF non-ECMO patients, but had significant improvement in PELOD score and reasonable survival for severity of illness. Stratification for ECMO should be considered for future PEx RCTs.