The Influence of the Extracorporeal Membrane Oxygenation Circuit and Components on Anticoagulation Management: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference.

OBJECTIVES: To derive systematic-review informed, modified Delphi consensus regarding the influence of extracorporeal membrane oxygenation (ECMO) circuit components on anticoagulation practices for pediatric ECMO for 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 2021. STUDY SELECTION: Management of ECMO anticoagulation in the setting of different ECMO circuit components. DATA EXTRACTION: Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Twenty-nine references were used for data extraction and informed recommendations, evidence-based consensus statements, and good practice statements. 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 or good practice statements for the influence of ECMO circuit and components on anticoagulation management. 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. One good practice statement, 2 weak recommendations, and 2 consensus statements are presented. CONCLUSIONS: The incorporation of new component technologies into clinical practice has outpaced clinical investigations of anticoagulation strategies for pediatric ECMO. Future investigations should leverage academic and industrial collaborations, translational platforms, and modern biostatistical methods to improve patient outcomes.

Executive Summary: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE (PEACE) Consensus Conference.

OBJECTIVES: To present recommendations and consensus statements with supporting literature for the clinical management of neonates and children supported with extracorporeal membrane oxygenation (ECMO) from the Pediatric ECMO Anticoagulation CollaborativE (PEACE) consensus conference. DATA SOURCES: Systematic review was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021, followed by serial meetings of international, interprofessional experts in the management ECMO for critically ill children. STUDY SELECTION: The management of ECMO anticoagulation for critically ill children. DATA EXTRACTION: Within each of eight subgroup, two authors reviewed all citations independently, with a third independent reviewer resolving any conflicts. DATA SYNTHESIS: A systematic review was conducted using MEDLINE, Embase, and Cochrane Library databases, from January 1988 to May 2021. Each panel developed evidence-based and, when evidence was insufficient, expert-based statements for the clinical management of anticoagulation for children supported with ECMO. These statements were reviewed and ratified by 48 PEACE experts. Consensus was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed 23 recommendations, 52 expert consensus statements, and 16 good practice statements covering the management of ECMO anticoagulation in three broad categories: general care and monitoring; perioperative care; and nonprocedural bleeding or thrombosis. Gaps in knowledge and research priorities were identified, along with three research focused good practice statements. CONCLUSIONS: The 91 statements focused on clinical care will form the basis for standardization and future clinical trials.

Anticoagulation-Free Pediatric Extracorporeal Membrane Oxygenation: Single-Center Retrospective Study.

OBJECTIVES: To analyze hemorrhage and thrombosis data related to anticoagulation-free pediatric extracorporeal membrane oxygenation (ECMO). DESIGN: Retrospective cohort study. SETTINGS: High-volume ECMO single institution data. PATIENTS: Children (0-18 yr) supported with ECMO (>24 hr) with initial anticoagulation-free period of greater than or equal to 6 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Utilizing consensus American Thoracic Society definitions for hemorrhage and thrombosis on ECMO, we evaluated thrombosis and associated patient and ECMO characteristics during anticoagulation-free period. Thirty-five patients met inclusion criteria from 2018 to 2021 having a median age (interquartile range [IQR]) of 13.5 months (IQR, 3-91 mo), median ECMO duration of 135 hours (IQR, 64-217 hr), and 964 anticoagulation-free hours. Increased RBC transfusion needs were associated with longer anticoagulation-free periods ( p = 0.03). We identified 20 thrombotic events: only four during the anticoagulation-free period and occurring in three of 35 (8%) patients. Compared with those without thrombotic events, anticoagulation-free clotting events were associated with younger age (i.e., 0.3 mo [IQR, 0.2-0.3 mo] vs 22.9 mo [IQR, 3.6-112.9 mo]; p = 0.02), lower weight (2.7 kg [IQR, 2.7-3.25 kg] vs 13.2 kg [5.9-36.4 kg]; p = 0.006), support with lower median ECMO flow rate (0.5 kg [IQR, 0.45-0.55 kg] vs 1.25 kg [IQR, 0.65-2.5 kg]; p = 0.04), and longer anticoagulation-free ECMO duration (44.5 hr [IQR, 40-85 hr] vs 17.6 hr [IQR, 13-24.1]; p = 0.008). CONCLUSIONS: In selected high-risk-for-bleeding patients, our experience is that we can use ECMO in our center for limited periods without systemic anticoagulation, with lower frequency of patient or circuit thrombosis. Larger multicentered studies are required to assess weight, age, ECMO flow, and anticoagulation-free time limitations that are likely to pose risk for thrombotic events.

Validation of extracorporeal membrane oxygenation mortality prediction and severity of illness scores in an international COVID-19 cohort.

BACKGROUND: Veno-venous extracorporeal membrane oxygenation (V-V ECMO) is a lifesaving support modality for severe respiratory failure, but its resource-intensive nature led to significant controversy surrounding its use during the COVID-19 pandemic. We report the performance of several ECMO mortality prediction and severity of illness scores at discriminating survival in a large COVID-19 V-V ECMO cohort. METHODS: We validated ECMOnet, PRESET (PREdiction of Survival on ECMO Therapy-Score), Roch, SOFA (Sequential Organ Failure Assessment), APACHE II (acute physiology and chronic health evaluation), 4C (Coronavirus Clinical Characterisation Consortium), and CURB-65 (Confusion, Urea nitrogen, Respiratory Rate, Blood Pressure, age >65 years) scores on the ISARIC (International Severe Acute Respiratory and emerging Infection Consortium) database. We report discrimination via Area Under the Receiver Operative Curve (AUROC) and Area under the Precision Recall Curve (AURPC) and calibration via Brier score. RESULTS: We included 1147 patients and scores were calculated on patients with sufficient variables. ECMO mortality scores had AUROC (0.58-0.62), AUPRC (0.62-0.74), and Brier score (0.286-0.303). Roch score had the highest accuracy (AUROC 0.62), precision (AUPRC 0.74) yet worst calibration (Brier score of 0.3) despite being calculated on the fewest patients (144). Severity of illness scores had AUROC (0.52-0.57), AURPC (0.59-0.64), and Brier Score (0.265-0.471). APACHE II had the highest accuracy (AUROC 0.58), precision (AUPRC 0.64), and best calibration (Brier score 0.26). CONCLUSION: Within a large international multicenter COVID-19 cohort, the evaluated ECMO mortality prediction and severity of illness scores demonstrated inconsistent discrimination and calibration highlighting the need for better clinically applicable decision support tools.

Neuromonitoring During ECMO Support in Children.

Extracorporeal membrane oxygenation is a potentially lifesaving intervention for children with severe cardiac or respiratory failure. It is used with increasing frequency and in increasingly more complex and severe diseases. Neurological injuries are important causes of morbidity and mortality in children treated with extracorporeal membrane oxygenation and include ischemic stroke, intracranial hemorrhage, hypoxic-ischemic injury, and seizures. In this review, we discuss the epidemiology and pathophysiology of neurological injury in patients supported with extracorporeal membrane oxygenation, and we review the current state of knowledge for available modalities of monitoring neurological function in these children. These include structural imaging with computed tomography and ultrasound, cerebral blood flow monitoring with near-infrared spectroscopy and transcranial Doppler ultrasound, and physiological monitoring with electroencephalography and plasma biomarkers. We highlight areas of need and emerging advances that will improve our understanding of neurological injury related to extracorporeal membrane oxygenation and help to reduce the burden of neurological sequelae in these children.

Is anticoagulation with bivalirudin comparable to heparin for pediatric extracorporeal life support? Results from a high-volume center.

There is a paucity of data regarding the use of direct thrombin inhibitors such as bivalirudin for children on extracorporeal life support (ECLS). We sought to compare the outcomes of children on ECLS anticoagulated with bivalirudin versus heparin. Patients transitioned from heparin to bivalirudin were treated as a separate group. A single-institution, retrospective review of all consecutive children (neonate to 18 years) placed on ECLS in the cardiac or pediatric intensive care units was performed (June 2018-December 2019). Data collected included demographics, anticoagulation strategy, number of circuit interventions, blood product use on ECLS, survival to decannulation, and survival to discharge. Fifty-four children were placed on ECLS for a total of 56 runs. Demographics and venovenous versus venoarterial ECLS were similar. The bivalirudin group had longer median duration of support compared to the heparin group--11.0 days [IQR 6.2, 23.1] versus 3.3 days [2.1, 6.2], P < .001. Patients switched from heparin to bivalirudin had a similar duration of support (10.3 days [8.3, 18.3]) as those on bilvalirudin alone. However, there was no difference in red blood cell, fresh frozen plasma, or platelet transfusions. There was no difference in the number of circuit interventions, survival to decannulation or discharge. The freedom to first circuit intervention was longer with bivalirudin compared to heparin. Our data suggest that even with longer pediatric ECLS runs on bivalirudin, there were no differences in the outcomes between the heparin and bivalirudin groups, with longer freedom from first circuit intervention with bivalirudin. While this is the largest reported series comparing children on ECLS anticoagulated with heparin versus bivalirudin, larger studies are needed to determine the optimal anticoagulation strategy for this diverse and complicated group of children.

Changes in Sedation Practices in Association with Delirium Screening in Infants After Cardiopulmonary Bypass.

Sedation in the cardiac intensive care unit (CICU) is necessary to keep critically ill infants safe and comfortable. However, long-term use of sedatives may be associated with adverse neurodevelopmental outcomes. We aimed to examine sedation practices in the CICU after the implementation of the Cornell Assessment of Pediatric Delirium (CAPD). We hypothesize the use of the CAPD would be associated with a decrease in sedative weans at CICU discharge. This is a single institution, retrospective cohort study. The study inclusion criteria were term infants, birthweight > 2.5 kg, cardiopulmonary bypass (CPB), and mechanical ventilation (MV) on postoperative day zero. During the study period, 50 and 35 patients respectively, met criteria pre- and post-implementation of CAPD screening. Our results showed a statistically significant increase in the incidence of sedative habituation wean at CICU discharge after CAPD implementation (24% vs. 45.7%, p = 0.036). There was a statistically significant increase in exposure to opiate (56% vs. 88.6%, p = 0.001) and dexmedetomidine infusions (52% vs 80%, p = 0.008), increased likelihood of clonidine use at CICU discharge (OR 9.25, CI 2.39-35.84), and increase in the duration of intravenous sedative infusions (8.1 days vs. 5.1 days, p = 0.04) No statistical difference was found in exposure to fentanyl (42% vs. 58.8%, p = 0.13) or midazolam infusions (22% vs. 25.7%, p = 0.691); and there was no change in benzodiazepine or opiate use at CICU discharge or dosage. The prevalence of delirium in the CAPD cohort was 92%. CAPD implementation in the CICU was associated with changes in sedation practices, specifically an increase in the use of dexmedetomidine, which possibly explains the increased clonidine weans at CICU discharge. This is the first report of the association between CAPD monitoring and changes in sedative practices. Multi-center prospective studies are recommended to evaluate sedative practices, delirium, and its effects on neurodevelopment.

Extracorporeal Membrane Oxygenation for Pediatric Patients With Coronavirus Disease 2019-Related Illness.

OBJECTIVE: To describe current hospital guidelines and the opinions of extracorporeal membrane oxygenation leaders at U.S. children's hospitals concerning the use of extracorporeal membrane oxygenation for coronavirus disease 2019-positive pediatric patients. DESIGN: Confidential, self-administered questionnaire. SETTING: One hundred twenty-seven U.S. pediatric extracorporeal membrane oxygenation centers. SUBJECTS: Extracorporeal membrane oxygenation center program directors and coordinators. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In March 2020, a survey was sent to 127 pediatric extracorporeal membrane oxygenation centers asking them to report their current hospital extracorporeal membrane oxygenation guidelines for coronavirus disease 2019-positive patients. Respondents were also asked their opinion on three ethical dilemmas including: prioritization of children over adults for extracorporeal membrane oxygenation use, institution of do-not-resuscitate orders, and the use of extracorporeal cardiopulmonary resuscitation for coronavirus disease 2019-positive patients. Forty-seven extracorporeal membrane oxygenation centers had enacted guidelines including 46 (100%) that offer venovenous-extracorporeal membrane oxygenation and 42 (89%) that offer venoarterial-extracorporeal membrane oxygenation for coronavirus disease 2019-positive pediatric patients. Forty-four centers (94%) stated that the indications for extracorporeal membrane oxygenation candidacy in coronavirus disease 2019 disease were similar to those used in other viral illnesses, such as respiratory syncytial virus or influenza. Most program directors (98%) did not endorse that children hospitalized with coronavirus disease 2019 should be made do-not-resuscitate and had variable opinions on whether children should be given higher priority over adults when rationing extracorporeal membrane oxygenation. Over half of program directors (60%) did not support the use of extracorporeal cardiopulmonary resuscitation for coronavirus disease 2019. CONCLUSIONS: The majority of pediatric extracorporeal membrane oxygenation centers have proactively established guidelines for the use of extracorporeal membrane oxygenation for coronavirus disease 2019-related illnesses. Further work is needed to help guide the fair allocation of extracorporeal membrane oxygenation resources and to determine the appropriateness of extracorporeal cardiopulmonary resuscitation.

Successful preoperative bridge with extracorporeal membrane oxygenation in three neonates with D-transposition of the great vessels and pulmonary hypertension.

Pulmonary hypertension with transposition of the great arteries is associated with significant morbidity and mortality. At the worst end of the spectrum are patients who undergo extracorporeal support perioperatively. We describe our experience with three patients who received preoperative extracorporeal support and separated from cardiopulmonary bypass successfully on conventional postoperative care, with no significant deficits on follow-up.

RBC Distribution Width: Biomarker for Red Cell Dysfunction and Critical Illness Outcome?

OBJECTIVES: RBC distribution width is reported to be an independent predictor of outcome in adults with a variety of conditions. We sought to determine if RBC distribution width is associated with morbidity or mortality in critically ill children. DESIGN: Retrospective observational study. SETTING: Tertiary PICU. PATIENTS: All admissions to St. Louis Children's Hospital PICU between January 1, 2005, and December 31, 2012. INTERVENTIONS: We collected demographics, laboratory values, hospitalization characteristics, and outcomes. We calculated the relative change in RBC distribution width from admission RBC distribution width to the highest RBC distribution width during the first 7 days of hospitalization. Our primary outcome was ICU mortality or use of extracorporeal membrane oxygenation as a composite. Secondary outcomes were ICU- and ventilator-free days. MEASUREMENTS AND MAIN RESULTS: We identified 3,913 eligible subjects with an estimated mortality (by Pediatric Index of Mortality 2) of 2.94% ± 9.25% and an actual ICU mortality of 2.91%. For the study cohort, admission RBC distribution width was 14.12% ± 1.89% and relative change in RBC distribution width was 2.63% ± 6.23%. On univariate analysis, both admission RBC distribution width and relative change in RBC distribution width correlated with mortality or the use of extracorporeal membrane oxygenation (odds ratio, 1.19 [95% CI, 1.12-1.27] and odds ratio, 1.06 [95% CI, 1.04-1.08], respectively; p < 0.001). After adjusting for confounding variables, including severity of illness, both admission RBC distribution width (odds ratio, 1.13; 95% CI, 1.03-1.24) and relative change in RBC distribution width (odds ratio, 1.04; 95% CI, 1.01-1.07) remained independently associated with ICU mortality or the use of extracorporeal membrane oxygenation. Admission RBC distribution width and relative change in RBC distribution width both weakly correlated with fewer ICU- (r = 0.038) and ventilator-free days (r = 0.05) (p < 0.001). CONCLUSIONS: Independent of illness severity in critically ill children, admission RBC distribution width is associated with ICU mortality and morbidity. These data suggest that RBC distribution width may be a biomarker for RBC injury that is of sufficient magnitude to influence critical illness outcome, possibly via oxygen delivery impairment.