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Objective: To characterize surface-bound proteins and to measure the thickness of fibrin fibers bound to extracorporeal membrane oxygenation (ECMO) circuits used in children., Design: Single-center observational prospective study, April to November 2021., Setting: PICU, Royal Children's Hospital, Melbourne, Australia., Patients: Patients aged less than 18 years on venoarterial ECMO and without preexisting disorder., Interventions: None., Measurements and Main Results: ECMO circuits were collected from six patients. Circuit samples were collected from five different sites, and subsequently processed for proteomic and scanning electron microscopy (SEM) studies. The concentration of proteins bound to ECMO circuit samples was measured using a bicinchoninic acid protein assay, whereas characterization of the bound proteome was performed using data-independent acquisition mass spectrometry. The Reactome Over-representation Pathway Analyses tool was used to identify functional pathways related to bound proteins. For the SEM studies, ECMO circuit samples were prepared and imaged, and the thickness of bound fibrin fibers was measured using the Fiji ImageJ software, version 1.53c (https://imagej.net/software/fiji/). Protein binding to ECMO circuit samples and fibrin networks showed significant intra-circuit and interpatient variation. The median (range) total protein concentration was 19.0 (0-76.9) μg/mL, and the median total number of proteins was 2011 (1435-2777). A total of 933 proteins were commonly bound to ECMO circuit samples from all patients and were functionally involved in 212 pathways, with signal transduction, cell cycle, and metabolism of proteins being the top three pathway categories. The median intra-circuit fibrin fiber thickness was 0.20 (0.15-0.24) μm, whereas the median interpatient fibrin fiber thickness was 0.18 (0.15-0.21) μm., Conclusions: In this report, we have characterized proteins and fiber fibrin thickness bound to ECMO circuits in six children. The techniques and approaches may be useful for investigating interactions between blood, coagulation, and the ECMO circuit and have the potential for circuit design., Competing Interests: Drs. McCafferty and Monagle’s institution received funding from the National Health and Medical Research Council (NHMRC) grant APP1129317. Dr. Attard’s institution received funding from the National Blood Authority, Bayer, and Janssen; he received funding from Anthos; he received support for article research from the NHMRC. Dr. MacLaren reported that he serves on the board of directors of the Extracorporeal Life Support Organization (unpaid). The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2024 by the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies.)

Competing Interests: Disclosure: G.M. is the President of the Extracorporeal Life Support Organization (ELSO) (unpaid). The other authors have no conflicts of interest to report. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants, or patents received or pending royalties.

The continuous contact between blood and the foreign surface of the extracorporeal membrane oxygenation (ECMO) circuit contributes to hemostatic, inflammatory, and other physiological disturbances observed during ECMO. Although previous studies have extensively investigated blood samples from patients on ECMO, cell adsorption to the ECMO circuit as an additional factor that could potentially influence clinical outcomes, has largely been overlooked. Here we provide a detailed immunofluorescence (IF) protocol designed to characterize cellular binding on ECMO circuits collected from patients. Extracorporeal membrane oxygenation circuits were collected from three pediatric patients and an albumin primed-only ECMO circuit was used as control. Circuit samples from five different sites within each ECMO circuit were collected and processed for the IF protocol. CD14 and CD42a antibodies were used to identify platelets and leukocytes bound to each ECMO circuit sample and images captured using inverted fluorescence microscopy. The protocol enables the comprehensive characterization of platelet and leukocyte binding to ECMO circuits collected from patients, which could in turn extend our knowledge of the characteristics of circuit binding and may provide guidance for improved ECMO circuit design., Competing Interests: G.M. is the president of the Extracorporeal Life Support Organization (ELSO). The other authors have no conflicts of interest to report., (Copyright © ASAIO 2024.)

Background: The NITric oxide during cardiopulmonary bypass (CPB) to improve Recovery in Infants with Congenital heart defects (NITRIC) trial, a 1320-patient, multicentre, randomised controlled trial, is aiming to improve survival free of ventilation after CPB by using nitric oxide delivered into the oxygenator of the CPB. Objective: To provide a statistical analysis plan before completion of patient recruitment and data monitoring. Final analyses for this study will adhere to this statistical analysis plan, which details all key pre-planned analyses. Stata scripts for analyses have been prepared alongside this statistical analysis plan. Methods: The statistical analysis plan was designed collaboratively by the chief investigators and trial statistician and builds on the previously published study protocol. All authors remain blinded to treatment allocation. Detail is provided on statistical analyses including cohort description, analysis of primary and secondary outcomes and adverse events. Statistical methods to compare outcomes are planned in detail to ensure methods are verifiable and reproducible. Results: The statistical analysis plan developed provides the trial outline, list of mock tables, and analysis scripts. The plan describes statistical analyses on cohort and baseline description, primary and secondary outcome analyses, process of care measures, physiological descriptors, and safety and adverse event reporting. We define the pre-specified subgroup analyses and the respective statistical tests used to compare subgroups. Conclusion: The statistical analysis plan for the NITRIC trial establishes detailed pre-planned analyses alongside Stata scripts to analyse the largest trial in the field of neonatal and paediatric heart surgery. The plan ensures standards for trial analysis validity aiming to minimise bias of analyses. Trial registration: ACTRN12617000821392., Competing Interests: Yves d’Udekem receives consultancy fees from Actelion (Janssen) and travel fees from Berlin Heart., (© 2021 College of Intensive Care Medicine of Australia and New Zealand.)