Platelet Transfusion Practice and Related Outcomes in Pediatric Extracorporeal Membrane Oxygenation

[Explanation and interpretation of blood transfusion provisions for critically ill and severely bleeding pediatric patients in the national health standard "Guideline for pediatric transfusion"]

To guide clinical blood transfusion practices for pediatric patients, the National Health Commission has issued the health standard "Guideline for pediatric transfusion" (WS/T 795-2022). Critically ill children often present with anemia and have a higher demand for transfusions compared to other pediatric patients. This guideline provides guidance and recommendations for blood transfusions in cases of general critical illness, septic shock, acute brain injury, extracorporeal membrane oxygenation, non-life-threatening bleeding, and hemorrhagic shock. This article interprets the background and evidence of the blood transfusion provisions for critically ill and severely bleeding children in the "Guideline for pediatric transfusion", aiming to enhance understanding and implementation of this aspect of the guidelines. Citation:Chinese Journal of Contemporary Pediatrics, 2025, 27(4): 395-403.

Comparison of red blood cell transfusions and hemostatic transfusions and their relation to thromboses in pediatric patients receiving extracorporeal membrane oxygenation therapy

ObjectiveTo evaluate the association of RBC transfusions with thrombosis in pediatric patients on extracorporeal membrane oxygenation (ECMO) and compare this with the transfusion of other blood products and their association with thrombosis.MethodsThis was a secondary analysis of the Bleeding and Thrombosis during ECMO (BATE) study, which was a multicenter prospective observational study involving patients less than 19 years of age treated with ECMO.Results514 patients were analyzed, of which 282 (55%) were neonates (≤31 days) and 302 (58.7%) were male. When analyzing the entire cohort independently of other blood products, each 10 mL/kg of packed red blood cells (PRBCs) was associated with a 1.0% increase in the average number of thromboses (1.010; 1.008,1.013; p < .001). In neonates, each 10 mL/kg of PRBC was associated with a 0.9% increase in the average number of thromboses (1.009; 1.003,1.013; p < .001). In pediatric patients, each 10 mL/kg of PRBC was associated with a 1.2% increase in the average number of thromboses (1.012; 1.008,1.012; p < .001). The percent increase in the average number of thromboses was similar between PRBCs, platelets, and FFP, but increased significantly with cryoprecipitate.ConclusionsRBC transfusions and hemostatic transfusions are likely associated with thromboses in pediatric patients on ECMO.

Platelet transfusion stated practices among neonatal and paediatric veno-arterial extracorporeal membrane oxygenation providers: A survey

BACKGROUND AND OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) provides cardiopulmonary support to over 4000 neonates and children annually worldwide. Although potentially lifesaving, ECMO carries bleeding and thromboembolic risks, often managed with platelet transfusions to maintain specific thresholds. Platelet transfusions themselves carry many risks. This survey aimed to describe stated prophylactic platelet transfusion practices among paediatric veno-arterial (VA)-ECMO providers and identify factors influencing transfusion decisions.

MATERIALS AND METHODS

This is a cross-sectional electronic survey of paediatric ECMO providers from 10 centres evaluating platelet transfusion thresholds based on six patient scenarios (non-bleeding, minimally bleeding and resolved bleeding in neonates and children). Descriptive statistics were used for analysis.

RESULTS

The survey response rate was 56% (114 of 204). Paediatric intensivists comprised 66% of respondents. The median pre-transfusion platelet count varied across VA-ECMO scenarios, with a threshold of 50 × 109/L (interquartile range [IQR] 45-75) for non-bleeding children and 70 × 109/L (IQR 50-85) for non-bleeding neonates. The threshold for minimally bleeding children, minimally bleeding neonates and resolved bleeding in children was 75 × 109/L (IQR 50-100). The threshold for resolved bleeding in neonates was 80 × 109/L (IQR 50-100). There was significant heterogeneity between and within sites (p < 0.001). Uncertainty about the level of evidence was high (59%), with clinical judgement being the most influential factor in transfusion decisions (85%).

CONCLUSION

Prophylactic platelet transfusion practices in paediatric ECMO vary widely, highlighting uncertainty and the need for clinical trials to improve patient outcomes.

Optimizing Congenital Diaphragmatic Hernia Repair on ECMO: Evaluating the Risk of Bleeding

BACKGROUND

Institutions lack consensus on the management of patients with congenital diaphragmatic hernia (CDH) who are repaired on extracorporeal membrane oxygenation (ECMO). Our study aimed to evaluate risk factors associated with bleeding complications in patients with CDH repaired on ECMO.

METHODS

A single-institution retrospective review evaluated all patients with CDH who underwent on-ECMO repair between January 2005 and December 2023. A significant bleeding complication post-repair was defined as bleeding necessitating re-operation. The association between preoperative factors and bleeding complications was evaluated.

RESULTS

Forty-six patients were included. Bleeding complications developed in 11/46 (24%) patients. Birthweight (2.5 vs. 3.2 kg, p = 0.02), platelet count <100/mm3 (64% vs. 29%, p = 0.04), elevated blood urea nitrogen (BUN; 24.5 vs. 17.5 mg/dL, p = 0.05), and older age at repair (8 vs. 5 days, p = 0.04) were associated with bleeding. In univariate analysis, patients with platelets under 100/mm3 were more likely to develop a bleeding complication (OR = 4.4, p = 0.04). Patients who experienced a significant bleeding event experienced increased ECMO days (12 vs. 7 days, p < 0.01), ventilator days (31 vs. 18 days, p < 0.05), and lower survival to discharge (36% vs. 74%, p = 0.03).

CONCLUSION

Among CDH patients undergoing repair on ECMO, those with lower birth weight, platelet counts under 100/mm3, elevated BUN, and older age at repair had an increased risk of a significant bleeding complication, resulting in more ECMO and ventilator days and higher mortality. Patients undergoing on-ECMO repair should have platelet count transfused to greater than 100/mm3. Patients at high risk for bleeding may benefit from early repair on ECMO.

LEVEL OF EVIDENCE

Level III.

Bleeding Complications between Bivalirudin and Heparin for Extracorporeal Membrane Oxygenation in Neonates with Congenital Diaphragmatic Hernia

INTRODUCTION

Neonates with congenital diaphragmatic hernia (CDH) who undergo repair while on extracorporeal membrane oxygenation (ECMO) are at risk of developing post-operative bleeding complications. Balanced anticoagulation is critical to maintain ECMO flow and avoid bleeding. Heparin has historically been our first-line anticoagulant; however, recently, we transitioned to bivalirudin, a direct thrombin inhibitor. The objective of this pilot study was to compare post-operative surgical bleeding complications between the two groups.

METHODS

We performed a single center retrospective cohort study of patients who underwent CDH repair while on ECMO between 2008 and 2023. Neonates were stratified based on the type of anticoagulant initiated after CDH repair. Outcomes included bleeding requiring surgical re-operation, intracranial hemorrhage, volume of blood products transfused, number of circuit changes, days on ECMO, and overall survival.

RESULTS

Among 62 neonates with CDH who underwent repair on ECMO, 44 (71%) were managed post-CDH repair with heparin and 18 (29%) with bivalirudin. One (5.6%) neonate managed with bivalirudin underwent re-operation following CDH repair for a bleeding complication compared to 17 (38.6%) managed with heparin (p = 0.022). In addition, the bivalirudin cohort utilized half of the total blood product volume compared to the heparin cohort (p = 0.020). Despite these benefits, there were no significant differences between groups for incidence of intracranial hemorrhage, number of circuit changes, days on ECMO, and overall survival.

CONCLUSION

Anticoagulation with bivalirudin in neonates who underwent CDH repair while on ECMO was associated with decreased surgical bleeding complications and less total blood product transfused. This pilot analysis is the first to compare heparin to bivalirudin and stresses the importance of a multicenter study.

Analysis of platelet transfusion efficacy during extracorporeal membrane oxygenation (ECMO) treatment in pediatric patients post-cardiac surgery-a retrospective cohort study

BACKGROUND

Postoperative extracorporeal membrane oxygenation (ECMO) may be necessary for pediatric patients following cardiac surgery, with associated risks of thrombocytopenia and bleeding. Prophylactic platelet transfusions are utilized to mitigate these risks, but the effectiveness of platelet transfusion cannot be reliably predicted. The aim of this study was to investigate the effect of platelet transfusion during postoperative treatment with ECMO in children undergoing cardiac surgery and to explore the optimal transfusion thresholds to reduce the number of platelet transfusions in patients and reduce the risk of death.

METHODS

We included in our study patients from the Pediatric Cardiac Surgery Department at the First Affiliated Hospital of Tsinghua University who underwent cardiac surgery and received ECMO treatment from January 1, 2019, to December 31, 2023, and received platelets transfusion at least once during the ECMO therapy. The platelet counts were determined both before and 24 hours posttransfusion of the platelet product. The corrected count increment (CCI) was calculated for the effectiveness estimation of platelet transfusion. The research subjects were divided into 3 groups based on the platelet count before transfusion (pretransfusion platelet count ≤30×109/L was the low-threshold group, pretransfusion count 31-50×109/L was the medium-threshold group, and ≥51×109/L was the high-threshold group) and the effective rates of each group were calculated.

RESULTS

A total of 11 patients received 47 platelet transfusions, an average of 4.27 ± 1.67 per patient. According to the 24-hour postinfusion platelet (Plt) corrected critical control increase index (24-hour CCI) ≥4500, the infusion was considered to be effective, and ineffective when the CCI was <4500. Out of these, 22 transfusions (46.8%) proved effective, whereas 25 (53.2%) were deemed ineffective. The effective transfusion rates across the 3 groups were 69.2%, 50%, and 27.7%, respectively.

CONCLUSION

The efficacy of platelet transfusion may be higher if a low threshold of platelet transfusion is chosen during ECMO treatment, on the premise of ensuring life safety.

Management of Bleeding and Thrombotic Complications During Pediatric Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding the management of bleeding and thrombotic complications during pediatric extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE Consensus Conference.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021.

STUDY SELECTION

The management of bleeding and thrombotic complications of ECMO.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Twelve references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

DATA SYNTHESIS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. Two good practice statements, 5 weak recommendations, and 18 consensus statements are presented.

CONCLUSIONS

Although bleeding and thrombotic complications during pediatric ECMO remain common, limited definitive data exist to support an evidence-based approach to treating these complications. Research is needed to improve hemostatic management of children supported with ECMO.

Prophylactic Transfusion Strategies in Children Supported by Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding prophylactic transfusions in neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021.

STUDY SELECTION

Included studies assessed use of prophylactic blood product transfusion in pediatric ECMO.

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Thirty-three references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

MEASUREMENTS AND MAIN RESULTS

The evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation system. Forty-eight experts met over 2 years to develop evidence-informed recommendations and, when evidence was lacking, expert-based consensus statements or good practice statements for prophylactic transfusion strategies for children supported with ECMO. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was based on a modified Delphi process with agreement defined as greater than 80%. We developed two good practice statements, 4 weak recommendations, and three expert consensus statements.

CONCLUSIONS

Despite the frequency with which pediatric ECMO patients are transfused, there is insufficient evidence to formulate evidence-based prophylactic transfusion strategies.

Patient-tailored platelet transfusion practices for children supported by extracorporeal membrane oxygenation

BACKGROUND AND OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) serves as cardiopulmonary therapy in critically ill patients with respiratory/heart failure and often necessitates multiple blood product transfusions. The administration of platelet transfusions during ECMO is triggered by the presence or risk of significant bleeding. Most paediatric ECMO programmes follow guidelines that recommend a platelet transfusion threshold of 80-100 × 109/L. To reduce exposure to platelets, we developed a practice to dynamically lower the threshold to ~20 × 109/L. We describe our experience with patient-tailored platelet thresholds and related bleeding outcomes.

MATERIALS AND METHODS

We retrospectively evaluated our platelet transfusion policy, bleeding complications and patient outcome in 229 ECMO-supported paediatric patients in our unit.

RESULTS

We found that more than 97.4% of patients had a platelet count <100 × 109/L at some point during their ECMO course. Platelets were transfused only on 28.5% of ECMO days; and 19.2% of patients never required a platelet transfusion. The median lowest platelet count in children who had bleeding events was 25 × 109/L as compared to 33 × 109/L in children who did not bleed (p < 0.001). Our patients received fewer platelet transfusions and did not require more red blood cell transfusions, nor did they experience more haemorrhagic complications.

CONCLUSION

We have shown that a restrictive, 'patient-tailored' rather than 'goal-directed' platelet transfusion policy is feasible and safe, which can greatly reduce the use of platelet products. Although there was a difference in the lowest platelet counts in children who bled versus those who did not, the median counts were much lower than current recommendations.

Transfusion policy in pediatric extracorporeal membrane oxygenation patients: Less could be more

OBJECTIVE

To evaluate a restrictive transfusion policy of red blood cells (RBC) and platelets in pediatric patients submitted to extracorporeal membrane oxygenation (ECMO).

METHODS

Retrospective descriptive study of pediatric patients supported with ECMO, from January 2010 to December 2019. Hemoglobin, platelet, lactate and mixed venous oxygen saturation (SvO2) values of each patient while on ECMO, were collected. Transfusion efficiency and tissue oxygenation were statistically evaluated comparing pre-transfusion hemoglobin, lactate and SvO2 with post-transfusion values. Ranges of hemoglobin and platelets were established, and the number of transfusions registered. The bleeding complications and outcome were documented.

RESULTS

Of a total of 1016 hemoglobin values, the mean value before transfusion was 8.6 g/dl. Hemoglobin and SvO2 increased significantly post-transfusion. Red blood cell transfusion varied with hemoglobin values: when hemoglobin value was less than 7 g/dl, 89% (41/46) were transfused but just 23% (181/794) when greater or equal to 7 g/dl. In the presence of active bleeding, the frequency of RBC transfusion increased from 32% to 62%, with hemoglobin between 7 g/dl and 8 g/dl.The mean value for platelet transfusion was 32 x 109/L. Thirty-eight (43%) platelet values between 20 x 109/L and 30x109/L, and 31 (40%) between 30 x 109/L and 40 x 109/L led to platelet transfusion; between 40 x 109/L and 50 x 109/L, only 7 (9%) prompted platelet transfusion.Comparing the 2010-2015 to 2016-2019 periods there was a decrease in RBC and platelet transfusion threshold with similar survival (p = .528). Survival to discharge was 68%.

CONCLUSIONS

Using a restrictive RBC and platelet transfusion policy was safe and allowed a good outcome in this case series. The presence of active bleeding was an important decision factor when hemoglobin was above 7 g/dl and platelets were above 30 x 109/L.

Transfusion in Neonatal Extracorporeal Membrane Oxygenation: A Best Practice Review

Extracorporeal Membrane Oxygenation (ECMO) is an important tool for managing critically ill neonates. Bleeding and thrombotic complications are common and significant. An understanding of ECMO physiology, its interactions with the unique neonatal hemostatic pathways, and appreciation for the distinctive risks and benefits of neonatal transfusion as it applies to ECMO are required. Currently, there is variability regarding transfusion practices, related to changing norms and a lack of high-quality literature and trials. This review provides an analysis of the neonatal ECMO transfusion literature and summarizes available best practice guidelines.

Transfusion Strategies in the 21st Century: A Case-Based Narrative Report

The transfusion of all blood components (red blood cells, plasma, and platelets) has been associated with increased morbidity and mortality in children. It is essential that pediatric providers weigh the risks and benefits before transfusing a critically ill child. A growing body of evidence has demonstrated the safety of restrictive transfusion practices in critically ill children.

Causes of platelet loss during extracorporeal life support

BACKGROUND

Most pediatric patients show a decline in platelet counts while on extracorporeal life support (ECLS) and require multiple platelet transfusions. To better understand platelet loss during ECLS, this study estimated platelet loss rates due to diagnostic phlebotomy, platelet activation, bleeding and other causes.

METHODS

We collected data on 91 patients (1d-20y, 50 M, 41F). Platelet losses were estimated based on changes in platelet count, patient+circuit blood volume, and transfused platelet volumes. Platelet extracellular vesicles were measured by flow cytometry.

RESULTS

Median platelet loss was 2.8 × 10⁹ /L/hr, more than twice the normal rate of platelet removal and equivalent to a 67 000/μl decrease in platelet count per day. While platelet loss was correlated with platelet transfusion (r²  = 0.51), transfusion underestimated platelet loss in patients with large decreases in platelet count and over-estimated platelet loss in neonates where the circuit volume > patient blood volume. Patients with disseminated intravascular coagulation before or significant bleeding during ECLS have double the rate of platelet loss. Platelet activation accounted for ~32% of total platelet loss, bleeding ~36% and phlebotomy 4%, with the remaining one-third due to other causes. Annexin-negative platelet extracellular vesicle release, a measure of platelet damage, was increased 9-fold during ECLS.

CONCLUSION

Our study is the first to quantitate total, phlebotomy and activation related platelet loss during ECLS. Platelet activation accounts for ~32% of total platelet loss, while bleeding doubles the platelet loss rate. The etiology of the remaining platelet loss is unknown.

Blood transfusion is associated with increased mortality for neonates with congenital diaphragmatic hernia on extracorporeal membrane oxygenation support

BACKGROUND AND OBJECTIVES

Blood transfusion is frequently needed to maintain adequate haemostasis and improve oxygenation for patients treated with extracorporeal membrane oxygenation (ECMO). It is more so for neonates with immature coagulation systems who require surgical intervention such as congenital diaphragmatic hernia (CDH) repair. There is growing evidence suggesting an association between blood transfusions and increased mortality. The aim of this study is to evaluate the association of blood transfusions during the peri-operative period of CDH repair, among other clinical parameters, with mortality in neonates undergoing on-ECMO CDH repair.

MATERIALS AND METHODS

We performed a single centre retrospective chart review of all neonates with CDH undergoing on-ECMO surgical repair from January 2010 to December 2020. Logistic regression was used to investigate associations with survival status.

RESULTS

Sixty-two patients met the inclusion criteria. Platelet transfusions (odds ratio [OR] 1.42, 95% confidence interval [CI]: 1.06-1.90) in the post-operative period and ECMO duration (OR 1.17, 95% CI: 1.05-1.30) were associated with increased mortality. Major bleeding complications had the strongest association with mortality (OR 10.98, 95% CI: 3.27-36.91). Gestational age, birth weight, Apgar scores, sex, blood type, right versus left CDH, venovenous versus venoarterial ECMO and duration of ECMO before CDH repair and circuit change after adjusting for ECMO duration were not significantly associated with survival.

CONCLUSION

Platelet transfusion in the post-operative period and major bleeding are associated with increased mortality in CDH neonates with surgical repair. The data suggest a need to develop robust plans for monitoring and preventing coagulation aberrancies during neonatal ECMO support.

Seven-day in vivo testing of a novel, low-resistance, pumpless pediatric artificial lung for long-term support

INTRODUCTION

For children with end-stage lung disease that cannot wean from extracorporeal life support (ECLS), a wearable artificial lung would permit extubation and provide a bridge to recovery or transplantation. We evaluate the function of the novel Pediatric MLung-a low-resistance, pumpless artificial lung developed specifically for children-in healthy animal subjects.

METHODS

Adolescent "mini sheep" weighing 12-20 kg underwent left thoracotomy, cannulation of the main pulmonary artery (PA; inflow) and left atrium (outflow), and connection to the MLung.

RESULTS

Thirteen sheep were studied; 6 were supported for 7 days. Mean PA pressure was 23.9 ± 6.9 mmHg. MLung blood flow was 633±258 mL/min or 30.0 ± 16.0% of CO. MLung pressure drop was 4.4 ± 3.4 mmHg. Resistance was 7.2 ± 5.2 mmHg/L/min. Device outlet oxygen saturation was 99.0 ± 3.3% with inlet saturation 53.8 ± 7.3%. Oxygen delivery was 41.1 ± 18.4 mL O₂/min (maximum 84.9 mL/min) or 2.8 ± 1.5 mL O₂/min/kg. Platelet count significantly decreased; no platelet transfusions were required. Plasma free hemoglobin significantly increased only on day 7, at which point 2 of the animals had plasma free hemoglobin levels above 50 mg/dL.

CONCLUSION

The MLung provides adequate gas exchange at appropriate blood flows for the pediatric population in a PA-to-LA configuration. Further work remains to improve the biocompatibility of the device.

LEVEL OF EVIDENCE

N/A.

Platelet Transfusion and In-Hospital Mortality in Veno-Arterial Extracorporeal Membrane Oxygenation Patients

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 ( P &lt; 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.

Red blood cell volume, but not platelet or plasma volume is associated with mortality in neonatal ECMO

BACKGROUND

Blood product transfusions are necessary for critically ill neonates on extracorporeal membrane oxygenation (ECMO). Transfusions are administered in response to unstudied arbitrary thresholds and may be associated with adverse outcomes. The objective of this study was to identify relationships between blood product components and mortality in neonates receiving ECMO support for respiratory indications.

STUDY DESIGN AND METHODS

A retrospective review of neonates receiving ECMO for respiratory indications from 2002 to 2019 from a single quaternary-referral neonatal intensive care unit (NICU). Demographic and outcome data and transfusion volume (ml/kg/day) were harvested from the medical record, and baseline mortality risk was assessed using NEO-RESCUERS scores. The association between volume of red blood cells (RBC), platelet, plasma transfusion rates (ml/kg/day), and mortality on ECMO were assessed after adjustment for NEO-RESCUERS score. Cox proportional hazards (CPH) competing risk model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for each variable and mortality outcome.

MEASUREMENTS AND MAIN RESULTS

Among 248 neonates undergoing ECMO for respiratory failure, overall survival was 93%. RBC, platelet, and plasma volume were highly associated with mortality during ECMO in an unadjusted model. After adjusting for NEO-RESCUERS score, RBC volume was associated with increased mortality risk (HR 1.013, 95% CI 1.004-1.022, p = .0043), but platelet and plasma volume were not associated with mortality.

CONCLUSIONS

RBC, but not platelet or plasma volume, is associated with mortality in neonates on ECMO. Our findings refute previous studies demonstrating an association between platelet volume and mortality for neonates on ECMO.

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.

Hemostatic complications and systemic heparinization in pediatric post-cardiotomy veno-arterial extracorporeal membrane oxygenation failed to wean from cardiopulmonary bypass

BACKGROUND

Hemostatic complications and the need for large amounts of blood products are major obstacles during veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Additionally, the occurrence of coagulopathy after cardiopulmonary bypass (CPB) affects systemic heparinization in pediatric post-cardiotomy patients. This study compares hemostatic complications in pediatric post-cardiotomy VA-ECMO patients for failure to wean from CPB with those who received post-cardiotomy VA-ECMO for other indications, while also exploring the relationship between different stages-hemostatic complications and the timing of systemic heparinization.

METHODS

We retrospectively analyzed 146 pediatric patients who received post-cardiotomy VA-ECMO support (CPB-ECMO, n=96 vs. non-CPB-ECMO, n=50) from January 2005 to June 2020. Patients were divided into survivors (n=46) and non-survivors (n=50) according to in-hospital mortality in the CPB-ECMO group. We compared clinical outcomes between the groups, then examined the associations between the timing of systemic heparinization after ECMO implantation and different stages-hemostatic complications, in the CPB-ECMO group.

RESULTS

We found that the risk of early bleeding was significantly increased in patients who failed to wean from CPB. The presence of early bleeding was accompanied by the higher demand for blood products transfusion in the CPB-ECMO group, and for treatment the patients received a longer delayed continuous heparin infusion. As a result of using delayed systemic heparinization to avoid early bleeding, early hemolysis increased in the CPB-ECMO group. A delayed systemic heparinization of 9.5 hours showed the best Youden index results and the overall greatest accuracy in predicting early hemolysis.

CONCLUSIONS

A direct transition from CPB to ECMO in pediatric post-cardiotomy patients significantly increases early bleeding. Delayed systemic heparinization to reduce early bleeding has good discrimination for predicting early hemolysis in the CPB-ECMO group. Coagulopathy is complex in pediatric post-cardiotomy VA-ECMO patients who failed to wean from CPB, and, as such, it is extremely important to monitor coagulation-related indicators in multiple dimensions to determine the timing of systemic heparinization.

Pediatric platelet transfusions in critical illness: a narrative review of recent studies

PURPOSE OF REVIEW

We sought to describe the current use of platelet transfusions, harms associated with platelet transfusion, new methods of platelet processing that attempt to address these harms, and recent platelet transfusion guidance specific to critically ill children.

RECENT FINDINGS

Platelet transfusions have been associated with significant morbidity and mortality. New processing techniques, such as pathogen reduction, have been developed to combat infectious risks but in a recent trial of platelet transfusion thresholds in neonates, transfusing platelets more liberally was associated with increased bleeding and mortality.

SUMMARY

Recent efforts to develop evidence-based guidelines for platelet transfusion in critically ill children were limited by the lack of evidence. However, given the significant risks, restrictive transfusion thresholds should be considered.

Hemostasis in Pediatric Extracorporeal Life Support: Overview and Challenges

Extracorporeal membrane oxygenation (ECMO) and ventricular assist devices (VADs) are increasingly used in critically ill children. Despite improvements in mechanical design and clinical management, thromboembolic and hemorrhagic events remain significant causes of morbidity and mortality related to the use of both devices. Choice of anticoagulant agents and assays for monitoring continue to present challenges in management. In this review, we describe the incidence and risk factors for thrombosis and hemorrhage, the different types of anticoagulants currently in use, the assays available for monitoring anticoagulation, and management of thromboembolic and bleeding complications in children on mechanical circulatory support (MCS). We conclude by emphasizing the areas that need further study to minimize the risk for thrombosis and hemorrhage in the use of ECMO and VAD in children.

Severe thrombocytopenia in adults undergoing extracorporeal membrane oxygenation is predictive of thrombosis

Extracorporeal membrane oxygenation (ECMO) provides lifesaving circulatory support and gas exchange, although hematologic complications are frequent. The relationship between ECMO and severe thrombocytopenia (platelet count <50 × 109/L) remains ill-defined. We performed a cohort study of 67 patients who received ECMO between 2016 and 2019, of which 65.7% received veno-arterial (VA) ECMO and 34.3% received veno-venous (VV) ECMO. All patients received heparin and 25.4% received antiplatelet therapy. In total, 23.9% of patients had a thrombotic event and 67.2% had a hemorrhagic event. 38.8% of patients developed severe thrombocytopenia. Severe thrombocytopenia was more common in patients with lower baseline platelet counts and increased the likelihood of thrombosis by 365% (OR 3.65, 95% CI 1.13-11.8, P = .031), while the type of ECMO (VA or VV) was not predictive of severe thrombocytopenia (P = .764). Multivariate logistic regression controlling for additional clinical variables found that severe thrombocytopenia predicted thrombosis (OR 3.65, CI 1.13-11.78, P = .031). Over a quarter of patients requiring ECMO developed severe thrombocytopenia in our cohort, which was associated with an increased risk of thrombosis and in-hospital mortality. Additional prospective observation is required to clarify the clinical implications of severe thrombocytopenia in the ECMO patient population.

Viscoelastic Testing in Pediatric Mechanical Circulatory Support

Pediatric mechanical circulatory support can be lifesaving. However, managing anticoagulation is one of the most challenging aspects of care in patients requiring mechanical circulatory support. Effective anticoagulation is even more difficult in pediatric patients due to the smaller size of their blood vessels, increased turbulent flow, and developmental hemostasis. Recently, viscoelastic testing (VET) has been used as a qualitative measure of anticoagulation efficacy in patients receiving extracorporeal membrane oxygenation (ECMO) and ventricular assist devices (VAD). Thromboelastography (TEG®) and thromboelastometry (ROTEM®) provide a global qualitative assessment of hemostatic function from initiation of clot formation with the platelet-fibrin interaction, platelet aggregation, clot strength, and clot lysis. This review focuses on the TEG®/ROTEM® and important laboratory and patient considerations for interpretation in the ECMO and VAD population. We summarize the adult and pediatric ECMO/VAD literature regarding VET values, VET-platelet mapping, utility over standard laboratory monitoring, and association with outcome measures such as blood product utilization, bleeding, and thrombosis.

Aptamer-based factor IXa inhibition preserves hemostasis and prevents thrombosis in a piglet model of ECMO

Extracorporeal membrane oxygenation (ECMO) requires anticoagulation to prevent clotting when the patient’s blood contacts the circuit. Unfractionated heparin (UFH) usually prevents clotting but can cause life-threatening bleeding. An anticoagulant that selectively inhibits the contact activation (intrinsic) pathway while sparing the tissue factor (extrinsic) pathway of coagulation might prevent clotting triggered by the circuit while permitting physiologic coagulation at surgical sites. DTRI-178 is an RNA anticoagulant aptamer conjugated to polyethylene glycol that increases its half-life in circulation. This aptamer is based on a previously described molecule (9.3t) that inhibits intrinsic tenase activity by binding to factor IXa on an exosite. Using a piglet model of pediatric venoarterial (VA) ECMO, we compared thromboprevention and blood loss using a single dose of DTRI-178 versus UFH. In each of five experiments, we subjected two litter-matched piglets, one anticoagulated with DTRI-178 and the other with UFH, to simultaneous 12-h periods of VA ECMO. Both anticoagulants achieved satisfactory and comparable thromboprotection. However, UFH piglets had increased surgical site bleeding and required significantly greater blood transfusion volumes than piglets anticoagulated with DTRI-178. Our results indicate that DTRI-178, an aptamer against factor IXa, may be feasible, safer, and result in fewer transfusions and clinical bleeding events in ECMO.

What Laboratory Tests and Physiologic Triggers Should Guide the Decision to Administer a Platelet or Plasma Transfusion in Critically Ill Children and What Product Attributes Are Optimal to Guide Specific Product Selection? From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present consensus statements and supporting literature for plasma and platelet product variables and related laboratory testing for transfusions in general critically ill children from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill pediatric patients at risk of bleeding and receiving plasma and/or platelet transfusions.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of 10 experts developed evidence-based and, when evidence was insufficient, expert-based statements for laboratory testing and blood product attributes for platelet and plasma transfusions. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative - Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed five expert consensus statements and two recommendations in answer to two questions: what laboratory tests and physiologic triggers should guide the decision to administer a platelet or plasma transfusion in critically ill children; and what product attributes are optimal to guide specific product selection?

CONCLUSIONS

The Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding program provides some guidance and expert consensus for the laboratory and blood product attributes used for decision-making for plasma and platelet transfusions in critically ill pediatric patients.

Effect of Platelet Transfusions on Extracorporeal Life Support Oxygenator's Function

OBJECTIVE

Bleeding is a common complication of extracorporeal membrane oxygenation (ECMO), leading to increased mortality. Since one of its main complications is bleeding, platelet transfusions are frequently prescribed for children on ECMO. However, there is currently very little information on the effect of platelet transfusions on the function of the ECMO oxygenator. Our objective was to describe the effect of platelet transfusions on oxygenator function.

METHODS

In this retrospective study, we included all children (<18 years) who received ECMO support in our pediatric intensive care unit (PICU) between January 2017 and December 2019. Oxygenator function, measured before and after platelet transfusion, was assessed by post-oxygenator P _ECMO O₂ and the gradient in pre- post-oxygenator pressures (Delta Pressure).

RESULTS

Over 3 years, we analyzed 235 platelet transfusions from 55 children who received ECMO support. Thirty-two (80%) of children were on veno-arterial ECMO and majority of them were peripherally cannulated. When looking at all transfusions, the post-transfusion change in delta-pressure was 0.1 mmHg (p = 0.69) and post-membrane P _ECMO O₂ was 6 mmHg (p = 0.49). However, in the subgroup with the lowest quartile of pre-transfusion oxygenator function, the post-transfusion change in delta-pressure was -5.2 ± 2.7 mmHg (p < 0.001) and the post-transfusion change in P _ECMO O₂ was -118 ± 49 (p < 0.001). The area under the ROC curve for the pre-transfusion delta-pressure and P _ECMO O₂ to predict a worsening of the oxygenator function were 0.72 (95%CI 0.63-0.81) and 0.71 (95%CI 0.64-0.78), respectively. Using regression models, pre-transfusion delta-pressure and P _ECMO O₂ were the only independent factors associated with oxygenator function worsening (p < 0.001).

CONCLUSION

Our study suggests that overall, platelet transfusions do not seem to impact the ECMO oxygenator's function. However, in the subgroup of patients with the lowest pre-transfusion oxygenator function, platelet transfusions were independently associated with a worsening function. Future studies should investigate if this warrants adjustments of the anticoagulation strategy around the platelet transfusion, especially among patients with lower oxygenator function.

Hemostasis in neonatal ECMO

Extracorporeal membrane oxygenation (ECMO) is a life-saving support for cardio-respiratory function. Over the last 50 years, the extracorporeal field has faced huge technological progress. However, despite the improvements in technique and materials, coagulation problems are still the main contributor to morbidity and mortality of ECMO patients. Indeed, the incidence and survival rates of the main hemorrhagic and thrombotic complications in neonatal respiratory ECMO are relevant. The main culprit is related to the intrinsic nature of ECMO: the contact phase activation. The exposure of the human blood to the non-endothelial surface triggers a systemic inflammatory response syndrome, which chronically activates the thrombin generation and ultimately leads to coagulative derangements. Pre-existing illness-related hemostatic dysfunction and the peculiarity of the neonatal clotting balance further complicate the picture. Systemic anticoagulation is the management's mainstay, aiming to prevent thrombosis within the circuit and bleeding complications in the patient. Although other agents (i.e., direct thrombin inhibitors) have been recently introduced, unfractionated heparin (UFH) is the standard of care worldwide. Currently, there are multiple tests exploring ECMO-induced coagulopathy. A combination of the parameters mentioned above and the evaluation of the patient's underlying clinical context should be used to provide a goal-directed antithrombotic strategy. However, the ideal algorithm for monitoring anticoagulation is currently unknown, resulting in a large inter-institutional diagnostic variability. In this review, we face the features of the available monitoring tests and approaches, mainly focusing on the role of point-of-care (POC) viscoelastic assays in neonatal ECMO. Current gaps in knowledge and areas that warrant further study will also be addressed.

Plasma and Platelet Transfusions Strategies in Neonates and Children Undergoing Cardiac Surgery With Cardiopulmonary Bypass or Neonates and Children Supported by Extracorporeal Membrane Oxygenation: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present the recommendations and consensus statements with supporting literature for plasma and platelet transfusions in critically ill neonates and children undergoing cardiac surgery with cardiopulmonary bypass or supported by extracorporeal membrane oxygenation from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of nine experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed one good practice statement, two recommendations, and three expert consensus statements.

CONCLUSIONS

Whereas viscoelastic testing and transfusion algorithms may be considered, in general, evidence informing indications for plasma and platelet transfusions in neonatal and pediatric patients undergoing cardiac surgery with cardiopulmonary bypass or those requiring extracorporeal membrane oxygenation support is lacking.

Variation in Neonatal Transfusion Practice

OBJECTIVE

To estimate the incidence of blood product transfusion, including red blood cells, platelets, and plasma, and characterize pretransfusion hematologic values for infants during their initial hospitalization after birth.

STUDY DESIGN

Retrospective cohort study using data from 7 geographically diverse US academic and community hospitals that participated in the National Heart Lung and Blood Institute Recipient Epidemiology and Donor Evaluation Study-III (REDS-III) from 2013 to 2016. Pretransfusion hematologic values were evaluated closest to each transfusion and no more than 24 hours beforehand.

RESULTS

Data from 60 243 infants were evaluated. The incidence of any transfusion differed by gestational age (P < .0001), with 80% (95% CI 76%-84%) transfused at <27 weeks of gestation (n = 329) and 0.5% (95% CI 0.5%-0.6%) transfused at ≥37 weeks of gestation (n = 53 919). The median pretransfusion hemoglobin was 11.2 g/dL (10th-90th percentile 8.8-14.1) for the entire cohort, ranging from 10.5 g/dL (8.8-12.3) for infants born extremely preterm at <27 weeks of gestation to 13.0 g/dL (10.5-15.5) for infants born at term. The median pretransfusion platelet count (×10⁹/L) was 71 (10th-90th percentile 26-135) for the entire cohort, and was >45 for all gestational age groups examined. The median pretransfusion international normalized ratio for the entire cohort was 1.7 (10th-90th percentile 1.2-2.8).

CONCLUSIONS

There is wide variability in pretransfusion hemoglobin, platelet count, and international normalized ratio values for neonatal transfusions. Our findings suggest that a large proportion of neonatal transfusions in the US are administered at thresholds greater than supported by the best-available evidence and highlight an opportunity for improved patient blood management.

Platelet, Red Cell, and Endothelial Activation and Injury During Extracorporeal Membrane Oxygenation

Extracorporeal membrane oxygenation (ECMO) can be lifesaving but suffers from high rates of bleeding and repeated transfusions. Current monitoring of blood cell damage during ECMO is limited to platelet counts, hematocrit, and plasma hemoglobin levels. Extracelluar vesicles (EV) are small cell fragments released when cells are activated/injured. The objective was to evaluate flow cytometric measurements of EV during ECMO as an indication of platelet, red cell, and endothelial activation/injury. Samples were collected from 55 patients (1 day to 19 years) during 58 ECMO runs. ECMO activated or injured blood cells, but the extent was highly variable and patient dependent. On average platelet activation was increased sevenfold during ECMO with up to 60-fold increased activation during the first 24 hours in some patients. EV associated with platelet and red-cell injury were increased eightfold on average but up to 200-fold in patients with disseminated intravascular coagulation, severe hemolysis, or massive transfusion. Approximately 9% of ECMO patients showed a red-cell and endothelial activation pattern that was associated with poor prognosis. Extracellular vesicles with autofluorescence similar to bilirubin appeared to come from monocytes processing hemoglobin. ECMO is associated with a highly variable, sustained increase in platelet, red-cell, and endothelial activation and injury that is a combination of circuit and transfusion related events, the patients underlying condition and possibly genetic influences on blood cell activation and injury. Extracellular vesicle measurements may improve our understanding of cellular activation and injury during ECMO as we work to improve the biocompatibility of these systems.

Neonatal respiratory and cardiac ECMO in Europe

Neonatal extracorporeal membrane oxygenation (ECMO) is a life-saving procedure for critically ill neonates suffering from a potentially reversible disease, causing severe cardiac and/or respiratory failure and refractory to maximal conventional management. Since the 1970s, technology, management, and clinical applications of neonatal ECMO have changed. Pulmonary diseases still represent the principal neonatal diagnosis, with an overall 74% survival rate, and up to one-third of cases are due to congenital diaphragmatic hernia. The overall survival rate in cardiac ECMO is lower, with congenital heart defect representing the main indication. This review provides an overview of the available evidence in the field of neonatal ECMO. We will address the changing epidemiology, basic principles, technologic advances in circuitry, and monitoring, and deliver a current multidisciplinary management framework, focusing on ECMO applications, complications, and long-term morbidities. Lastly, areas for further research will be highlighted.Conclusions: ECMO is a life support with a potential impact on long-term patients' outcomes. In the next years, advances in knowledge, technology, and expertise may push neonatal ECMO boundaries towards more premature and increasingly complex infants, with the final aim to reduce the burden of ECMO-related complications and improve overall patients' outcomes. What is Known: • ECMO is a life-saving option in newborns with refractory respiratory and/or cardiac failure. • The multidisciplinary ECMO management is challenging and may expose neonates to complications with an impact on long-term outcomes. What is New: • Advances in technology and biomaterials will improve neonatal ECMO management and, eventually, the long-term outcome of these complex patients. • Experimental models of artificial placenta and womb technology are under investigation and may provide clinical translation and future research opportunities.

Bridging the Gap Between Intensivists and Primary Care Clinicians in Extracorporeal Membrane Oxygenation for Respiratory Failure in Children: A Review

IMPORTANCE

Extracorporeal membrane oxygenation (ECMO) is a form of advanced life support that may be used in children with refractory respiratory or cardiac failure. While it is required infrequently, in the US, ECMO is used to support childhood respiratory failure as often as children receive kidney or heart transplants. ECMO is complex, resource intensive, and potentially lifesaving, but it is also associated with risks of short-term complications and long-term adverse effects, most importantly with neurodevelopmental outcomes that are relevant to all pediatric clinicians, even those remote from the child's critical illness.

OBSERVATIONS

The 2009 influenza A(H1N1) pandemic, along with randomized clinical trials of adult respiratory ECMO support and conventional management, have catalyzed sustained growth in the use of ECMO. The adult trials built on earlier neonatal ECMO randomized clinical trials that demonstrated improved survival in severe perinatal lung disease. For children outside of the neonatal period, there appear to have been no respiratory ECMO clinical trials. Applying evidence from adult respiratory failure or perinatal lung disease to children outside the neonatal period has important potential pitfalls. For these children, the underlying diseases and risks of ECMO are different. Despite these differences, both neonates and older children are at risk of neurologic complications, such as intracranial hemorrhage, ischemic stroke, and seizures, and those complications may contribute to adverse neurodevelopmental outcomes. Without specific screening, subtle neurodevelopmental impairments may be missed, but when they are identified, children have the opportunity to receive therapy to optimize long-term development.

CONCLUSIONS AND RELEVANCE

All pediatric clinicians should be aware not only of the potential benefits and complications of ECMO but also that survivors need effective screening, support, and follow-up.

Transfusion management for children supported by extracorporeal membrane oxygenation

Due to the patients' underlying illness, in combination with circuit-induced coagulopathy, as well as PLT dysfunction, children supported by ECMO are a risk of receiving large volumes of blood components. Given the increasing use of modified blood products and newer biologics, it is unknown whether these products have equal efficacy and safety, in ECMO. The majority of guidance for transfusion therapy is based on expert opinion alone, and research on indications for RBC, plasma, and PLT transfusions for children on ECMO should be a priority.

Epidemiology of the Use of Hemostatic Agents in Children Supported by Extracorporeal Membrane Oxygenation: A Pediatric Health Information System Database Study

Objectives: Children supported by extracorporeal membrane oxygenation (ECMO) are at high risk of bleeding. Though practitioners often prescribe blood components and/or medications to prevent or treat bleeding, the utilization of these hemostatic measures in children is not well-understood. We sought to evaluate the use of hemostatic blood products (platelet, plasma and cryoprecipitate transfusions) and medications [aminocaproic acid, tranexamic acid (TXA) and Factor VIIa] in children supported by ECMO. Design: Retrospective observational study using the Pediatric Health Information System (PHIS) database from 2011-2017. Setting: Fifty-one U.S. children's hospitals. Patients: Children (aged 0-18 years) supported by ECMO. Interventions: None. Measurements and Main Results: ECMO was employed in the care of 7,910 children for a total of 56,079 ECMO days. Fifty-five percent of the patients were male with a median (IQR) age of 0 (0-2) years. The median (IQR) length of ECMO was 5 (2-9) days with a hospital mortality rate of 34%. Platelets were transfused on 49% of ECMO days, plasma on 33% of ECMO days and cryoprecipitate on 17% of ECMO days. Twenty-two percent of children received TXA with the majority receiving it on the first day of ECMO and the use of TXA increased during the 6-year period studied (p < 0.001). Seven percent of children received aminocaproic acid and 3% received Factor VIIa. Conclusions: Children supported by ECMO are exposed to a significant number of hemostatic blood products. Antifibrinolytics, in particular TXA, are being used more frequently. Given the known morbidity and mortality associated with hemostatic blood products, studies are warranted to evaluate the effectiveness of hemostatic strategies.

Development and Internal Validation of Model Predicting Postoperative Blood Loss Risk Among Children with Pulmonary Atresia Undergoing Cardiopulmonary Bypass

To develop and internally validate nomogram predicting postoperative blood loss risk among pediatric patients with pulmonary atresia (PA) undergoing cardiopulmonary bypass (CPB). All patients aged from 6 months to 6 years with PA who underwent surgery at Fuwai Hospital from June 2015 to December 2019 were selected. And the prediction nomogram model was developed in the training set based on the selected patients. The demographic characteristics and laboratory data from each enrolled patient were gathered. Postoperative blood loss was defined as a blood loss exceeding 20.0 ml/kg within the first 24 postoperative hours. The least absolute shrinkage and selection operator (LASSO) method was used to optimize feature selection for multivariate logistic regression analysis that was applied to build a nomogram composed of all the features selected in the LASSO algorithm. The concordance index (C-index), calibration plot, and decision curve analysis (DCA) were used to evaluate the discrimination, calibration, and clinical net benefit of the nomogarm, respectively. Finally, internal validation was performed using the bootstrap technique. Of the 66 pediatric patients in the training set, 21 (31.82%) and 45 (68.18%) patients were assigned into bleeding group and non-bleeding group, respectively. The first postoperative 24-h blood loss in the bleeding group was significantly higher than that in the non-bleeding group during ICU stay (P = 0.000). Multivariate logistic regression analysis showed that, the immediate postoperative prothrombin time (odds ratio = 1.419, 95% confidence interval: 1.094-1.841, P = 0.008), the immediate postoperative platelet count (odds ratio = 0.985, 95% confidence interval: 0.973-0.997, P = 0.015) and the immediate postoperative red blood cell (RBC) count (odds ratio = 0.335, 95% confidence interval: 0.166-0.667, P = 0.002) were independent predictors of postoperative blood loss risk. The model presented favorable calibration and good discrimination with satisfactory calibration curve and a C-index of 0.858 (95% confidence interval: 0.758-0.958). High C-index value of 0.837 was achieved in the internal validation. The DCA revealed that the nomogram was great clinical effect when intervention was decided among nearly the entire range of threshold probabilities. We developed and internally validated an accurate nomogram to assist in the clinical decision-making concerning the presence of postoperative blood loss in pediatric patients with PA undergoing CPB. However, the nomogram should be endorsed by external validation before it can be recommended for routine practice.

Platelet transfusion is associated with 90-day and 1-year mortality for adult patients requiring veno-arterial extracorporeal membrane oxygenation

BACKGROUND

Studies examining one-year mortality respecting component blood transfusion are sparse. We hypothesize that component blood product transfusions are negatively associated with 90-day and 1-year survival for all patients requiring veno-arterial (VA) or veno-venous (VV) ECMO.

STUDY DESIGN AND METHODS

This was an IRB-approved retrospective cohort analysis of 676 consecutive patients requiring ECMO at the University of Pittsburgh between 2005 and 2016. Patients were analysed both as an entire cohort and as two subsets with respect to ECMO modality (VA vs. VV). Additional data collected and analysed included patient characteristics, laboratory values and blood product transfusion.

RESULTS

Multivariable analysis revealed that platelet transfusion was associated with 90-day mortality (OR: 1·05, P = 0·037) and one-year mortality for the entire cohort (OR = 1·05, P = 0·046,). Platelet transfusion volume was also associated with mortality in the VA-ECMO subset of patients at both 90 days (OR = 1·08, P = 0·03) and one year (OR: 1·11, P = 0·014). Age, peak International Normalized Raton ECMO, nadir haemoglobin (on ECMO) and final haemoglobin (after ECMO) were significantly associated with mortality for patients requiring VA-ECMO. For VV-ECMO patients, age, INR and peak creatinine on ECMO were associated with mortality. No individual component blood product was associated with one-year mortality for patients requiring VV-ECMO.

CONCLUSION

Platelet transfusion was associated with increased 90-day and 1-year mortality for patients requiring VA-ECMO.

Epidemiology of Hemostatic Transfusions in Children Supported by Extracorporeal Membrane Oxygenation

OBJECTIVE

To evaluate the epidemiology of hemostatic transfusions (plasma, platelet, and cryoprecipitate) in children supported by extracorporeal membrane oxygenation.

DESIGN

Secondary analysis of a large observational cohort study.

SETTING

Eight pediatric institutions within the Eunice Kennedy Shriver National Institute of Child Health and Human Development's Collaborative Pediatric Critical Care Research Network.

PATIENTS

Critically ill children supported by extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Extracorporeal membrane oxygenation was used in the care of 514 consecutive children. Platelets were transfused on 68% of extracorporeal membrane oxygenation days, plasma on 34% of the days on extracorporeal membrane oxygenation, and cryoprecipitate on 14%. Only 24% of the days on extracorporeal membrane oxygenation were free of any hemostatic transfusions. Daily platelet transfusion dose was independently associated with chest tube output (p < 0.001), other bleeding requiring RBC transfusion (p = 0.03), and daily set platelet goal (p = 0.009), but not with total platelet count (p = 0.75). Daily plasma transfusion dose was independently associated with chest tube output (p < 0.001), other bleeding requiring RBC transfusion (p = 0.01), activated clotting time (p = 0.001), and antithrombin levels (p = 0.02), but not with international normalized ratio (p = 0.99) or activated partial thromboplastin time (p = 0.29). Daily cryoprecipitate transfusion dose was independently associated with younger age (p = 0.009), but not with chest tube bleeding (p = 0.18), other bleeding requiring RBC transfusion (p = 0.75), fibrinogen level (p = 0.67), or daily fibrinogen goal (p = 0.81).

CONCLUSIONS

Platelets were transfused on two third of the days on extracorporeal membrane oxygenation, plasma on one third, and cryoprecipitate on one sixth of the days. Although most hemostatic transfusions were independently associated with bleeding, they were not independently associated with the majority of hemostatic testing. Further studies are warranted to evaluate the appropriateness of these transfusion strategies.

Impact of massive blood transfusion during adult extracorporeal membrane oxygenation support on long-term outcomes: a nationwide cohort study in Taiwan

OBJECTIVES

Bleeding is a common problem during adult extracorporeal membranes oxygenation (ECMO) support, requiring blood transfusion for correction of volume depletion and coagulopathy. The goal of this study is to investigate the long-term outcomes for adults under support of ECMO with massive blood transfusion (MBT).

DESIGN

Retrospective nationwide cohort study.

SETTING

Data were provided from Taiwan National Health Insurance Research Database (NHIRD).

PARTICIPANTS AND INTERVENTIONS

Totally 2757 adult patients were identified to receive MBT (red blood cell ≥10 units) during ECMO support from 2000 to 2013 via Taiwan NHIRD.

MAIN OUTCOME MEASURES

The outcomes included in-hospital major complications/mortality, all-cause mortality, cardiovascular death, newly onset end-stage renal disease and respiratory failure during the follow-up period.

RESULTS

Patients with MBT had higher in-hospital mortality (65.6% vs 52.1%; OR 1.74; 95% CI 1.53 to 1.98) and all-cause mortality during the follow-up (47.0% vs 35.8%; HR 1.46; 95% CI 1.25 to 1.71) than those without MBT. Not only higher incidences of post ECMO sepsis, respiratory failure and acute kidney injury, but also longer duration of ECMO support, ventilator use and intensive care unit stay were demonstrated in the MBT group. Moreover, a subdistribution hazard model presented higher cumulative of respiratory failure (19.8% vs 16.2%; subdistribution HR 1.36; 95% CI 1.07 to 1.73) for the MBT cohort. Positive dose-dependent relationship was found between the amount of transfused red blood cell product and in-hospital mortality. In the MBT subgroup analysis for the impact of transfused ratio (fresh frozen plasma/packed red blood cell) on in-hospital mortality, ratio ≥1.0 had higher mortality.

CONCLUSIONS

Patients with MBT during ECMO support had worse long-term outcomes than non-MBT population. The transfused amount of red blood cell had positive dose-dependent effect on in-hospital mortality.

Hematologic concerns in extracorporeal membrane oxygenation

This ISTH "State of the Art" review aims to critically evaluate the hematologic considerations and complications in extracorporeal membrane oxygenation (ECMO). ECMO is experiencing a rapid increase in clinical use, but many questions remain unanswered. The existing literature does not address or explicitly state many pertinent details that may influence hematologic complications and, ultimately, patient outcomes. This review aims to broadly introduce modern ECMO practices, circuit designs, circuit materials, hematologic complications, transfusion-related considerations, age- and size-related differences, and considerations for choosing outcome measures. Relevant studies from the 2019 ISTH Congress in Melbourne, which further advanced our understanding of these processes, will also be highlighted.

Overview of Plasma and Platelet Transfusions in Critically Ill Children

Critically ill children are a unique population who frequently receive plasma and platelet transfusions for both active bleeding and mitigation of bleeding risk. While these products are frequently administered, transfusion indications in this population remain unclear, and practice varies across institutions and providers. In this manuscript, we will outline the current evidence regarding plasma and platelet transfusions for hemostasis in the pediatric intensive care setting. For both products, we will describe the product composition, epidemiology, and product indications and discuss the potential risks and benefits involved with the transfusion. We will also discuss knowledge gaps and future areas of research.