Changes in von Willebrand Factor Multimers, Concentration, and Function During Pediatric Extracorporeal Membrane Oxygenation.

OBJECTIVES: To investigate changes in von Willebrand factor (VWF) concentration, function, and multimers during pediatric extracorporeal membrane oxygenation (ECMO) and determine whether routine monitoring of VWF during ECMO would be useful in predicting bleeding. DESIGN: Prospective observational study of pediatric ECMO patients from April 2017 to May 2019. SETTING: The PICU in a large, tertiary referral pediatric ECMO center. PATIENTS: Twenty-five neonates and children (< 18 yr) supported by venoarterial ECMO. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Arterial blood samples were collected within 24 hours pre-ECMO, daily for the first 5 days of ECMO, every second day until decannulation, and 24 hours post-ECMO. The STA R Max analyzer was used to measure VWF antigen (VWF:Ag) and ristocetin cofactor (VWF:RCo) activity. VWF collagen binding (VWF:CB) was measured using an enzyme-linked immunosorbent assay. VWF multimers were measured using the semi-automated Hydragel 11 VWF Multimer assay. Corresponding clinical data for each patient was also recorded. A total of 25 venoarterial ECMO patients were recruited (median age, 73 d; interquartile range [IQR], 3 d to 1 yr). The median ECMO duration was 4 days (IQR, 3-8 d) and 15 patients had at least one major bleed during ECMO. The percentage of high molecular weight multimers (HMWM) decreased and intermediate molecular weight multimers increased while patients were on ECMO, irrespective of a bleeding status. VWF:Ag increased and the VWF:RCo/VWF:Ag and VWF:CB/VWF:Ag ratios decreased while patients were on ECMO compared with the baseline pre-ECMO samples and healthy children. CONCLUSIONS: Neonates and children on ECMO exhibited a loss of HMWM and lower VWF:CB/VWF:Ag and VWF:RCo/VWF:Ag ratios compared with healthy children, irrespective of major bleeding occurring. Therefore, monitoring VWF during ECMO would not be useful in predicting bleeding in these patients and changes to other hemostatic factors should be investigated to further understand bleeding during ECMO.

Platelet Phenotype and Function Changes With Increasing Duration of Extracorporeal Membrane Oxygenation.

OBJECTIVES: To investigate platelet pathophysiology associated with pediatric extracorporeal membrane oxygenation (ECMO). DESIGN: Prospective observational study of neonatal and pediatric ECMO patients from September 1, 2016, to December 31, 2019. SETTING: The PICU in a large tertiary referral pediatric ECMO center. PATIENTS: Eighty-seven neonates and children (< 18 yr) supported by ECMO. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Arterial blood samples were collected on days 1, 2, and 5 of ECMO and were analyzed by whole blood flow cytometry. Corresponding clinical data for each patient was also recorded. A total of 87 patients were recruited (median age, 65 d; interquartile range [IQR], 7 d to 4 yr). The median duration of ECMO was 5 days (IQR, 3-8 d) with a median length of stay in PICU and hospital of 18 days (IQR, 10-29 d) and 35 days (IQR, 19-75 d), respectively. Forty-two patients (48%) had at least one major bleed according to a priori determined definitions, and 12 patients (14%) had at least one thrombotic event during ECMO. Platelet fibrinogen receptor expression decreased (median fluorescence intensity [MFI], 29,256 vs 26,544; p = 0.0005), while von Willebrand Factor expression increased (MFI: 7,620 vs 8,829; p = 0.0459) from day 2 to day 5 of ECMO. Platelet response to agonist, Thrombin Receptor Activator Peptide 6, also decreased from day 2 to day 5 of ECMO, as measured by binding with anti-P-selectin, PAC-1 (binds activated GPIIb/IIIa), and anti-CD63 monoclonal antibodies (P-selectin area under the curve [AUC]: 63.46 vs 42.82, respectively, p = 0.0022; PAC-1 AUC: 93.75 vs 74.46, p = 0.0191; CD63 AUC: 55.69 vs 41.76, p = 0.0020). CONCLUSIONS: The loss of platelet response over time may contribute to bleeding during ECMO. These novel insights may be useful in understanding mechanisms of bleeding in pediatric ECMO and monitoring platelet markers clinically could allow for prediction or early detection of bleeding and thrombosis.

Carboxyhemoglobin levels in children during extracorporeal membrane oxygenation support: a retrospective study.

INTRODUCTION: Hemolysis is a common complication of extracorporeal membrane oxygenation (ECMO). There are few data on whether carboxyhemoglobin (COHb), a potential marker of hemolysis, are elevated during ECMO support. METHODS: We conducted a single-center, retrospective study comparing peak COHb levels of children pre-, during, and post-ECMO from January 2017 to August 2020. RESULTS: There were 154 ECMO runs in 147 children (154 PICU admissions) included in the study. The median age was 3.5 (IQR 0.2, 39.2) months. Veno-arterial ECMO was the predominant mode: 146/154 (94.8%). Eighty-seven children (56.5%) underwent cardiac surgery. Peak COHb levels during ECMO were statistically significantly higher compared to pre ECMO (COHb 1.8% (IQR 1.4, 2.6) vs COHb 1.2% (IQR 0.7, 1.7), p < 0.001) and post ECMO (COHb 1.6% (IQR 1.3, 2.2), p = 0.009). Children with COHb ⩾2% were younger and had longer duration of ECMO support. Plasma hemoglobin weakly correlated with COHb level (r = 0.14; p = 0.04). CONCLUSIONS: Carboxyhemoglobin levels increased during ECMO support compared to the pre and post ECMO period. Younger age and longer ECMO duration were associated with COHb levels ⩾2%. Plasma hemoglobin weakly correlated with COHb level.

The Effect of Patient- and Treatment-Related Factors on Circuit Lifespan During Continuous Renal Replacement Therapy in Critically Ill Children.

OBJECTIVES: To examine the effects of patient and treatment variables on circuit lifespan in critically ill children requiring continuous renal replacement therapy. DESIGN: Retrospective observational study based on a prospective registry. SETTING: Tertiary referral 30-bed PICU. PATIENTS: One hundred sixty-one critically ill children undergoing continuous renal replacement therapy during an 8-year period (2007-2014) were included in the study. INTERVENTIONS: Continuous renal replacement therapy. MEASUREMENTS AND MAIN RESULTS: During the study period, 161 patients received a total of 22,190 hours of continuous renal replacement therapy, with a median duration of 74.75 hours (interquartile range, 32-169.5) per patient. Of the 572 filter circuits used, 276 (48.3%) were changed due to circuit clotting and 262 (45.8%) were electively changed. Median circuit life was 24.62 hours (interquartile range, 10.6-55.3) for all filters and significantly longer for those electively removed as compared to those prematurely removed because of clotting (35.50 hr [interquartile range, 16.9-67.6] vs 22.00 hr [interquartile range, 13.8-42.5]; p < 0.001). Multivariate regression analyses revealed that admission diagnosis (p < 0.001), anticoagulation type (p < 0.001), access type (p = 0.016), and circuit size (p = 0.027) were associated with prolonged circuit life, as well as, in patients on heparin anticoagulation, with higher doses of heparin (p < 0.001) and a prolonged activated partial thromboplastin time (p < 0.001). CONCLUSIONS: In this study, circuit lifespan in pediatric continuous renal replacement therapy was low and appeared to depend upon the patient's diagnosis, the type of access and anticoagulation used as well as the size of the circuit used.

Vancomycin is commonly under-dosed in critically ill children and neonates.

AIMS: Vancomycin is frequently used in critically ill children in whom the drug pharmacokinetics are significantly altered as a result of changes in renal clearance and volume of distribution. Therapeutic drug monitoring (TDM) is recommended to achieve vancomycin trough concentrations between 10 and 20 mg/L. In this study we reviewed vancomycin dosing, TDM and treatment outcomes in paediatric and neonatal intensive care unit patients. METHODS: We reviewed the medical records of all patients receiving intravenous vancomycin in a tertiary paediatric and neonatal intensive care unit over a 10-month period. Demographic, vancomycin dosing, TDM and drug-related adverse effects data were collected. RESULTS: In total, 115 children received 126 courses of vancomycin and had at least 1 TDM blood sample taken at steady state. In only 38/126 (30%) courses was the target concentration (10-20 mg/L) achieved at the initial steady state trough sample. Of the 88 courses that had initial trough concentrations outside the target range, the dose was adjusted in only 49 (56%). Overall, minimum doses of 30 mg/kg/day in neonates with a corrected gestational age of <35 weeks, and 50 mg/kg/day in older children, were required to achieve target vancomycin concentrations. Vancomycin-attributable nephrotoxicity occurred in 10/126 (8%) courses and there were no episodes of red man syndrome. CONCLUSION: In critically ill children, individualised dosing is needed. In the absence of Bayesian model-based dosing, in children with normal renal function, empiric vancomycin doses of at least 30 mg/kg/day in neonates of <35 weeks corrected gestational age, and 50 mg/kg/day in older children, should be considered. Optimisation of TDM practices through the development of protocols, ideally built into electronic medical records, should be considered.

Defining benefit threshold for extracorporeal membrane oxygenation in children with sepsis-a binational multicenter cohort study.

BACKGROUND: The surviving sepsis campaign recommends consideration for extracorporeal membrane oxygenation (ECMO) in refractory septic shock. We aimed to define the benefit threshold of ECMO in pediatric septic shock. METHODS: Retrospective binational multicenter cohort study of all ICUs contributing to the Australian and New Zealand Paediatric Intensive Care Registry. We included patients < 16 years admitted to ICU with sepsis and septic shock between 2002 and 2016. Sepsis-specific risk-adjusted models to establish ECMO benefit thresholds with mortality as the primary outcome were performed. Models were based on clinical variables available early after admission to ICU. Multivariate analyses were performed to identify predictors of survival in children treated with ECMO. RESULTS: Five thousand sixty-two children with sepsis and septic shock met eligibility criteria, of which 80 (1.6%) were treated with veno-arterial ECMO. A model based on 12 clinical variables predicted mortality with an AUROC of 0.879 (95% CI 0.864-0.895). The benefit threshold was calculated as 47.1% predicted risk of mortality. The observed mortality for children treated with ECMO below the threshold was 41.8% (23 deaths), compared to a predicted mortality of 30.0% as per the baseline model (16.5 deaths; standardized mortality rate 1.40, 95% CI 0.89-2.09). Among patients above the benefit threshold, the observed mortality was 52.0% (13 deaths) compared to 68.2% as per the baseline model (16.5 deaths; standardized mortality rate 0.61, 95% CI 0.39-0.92). Multivariable analyses identified lower lactate, the absence of cardiac arrest prior to ECMO, and the central cannulation (OR 0.31, 95% CI 0.10-0.98, p = 0.046) as significant predictors of survival for those treated with VA-ECMO. CONCLUSIONS: This binational study demonstrates that a rapidly available sepsis mortality prediction model can define thresholds for survival benefit in children with septic shock considered for ECMO. Survival on ECMO was associated with central cannulation. Our findings suggest that a fully powered RCT on ECMO in sepsis is unlikely to be feasible.

Mortality of Critically Ill Children Requiring Continuous Renal Replacement Therapy: Effect of Fluid Overload, Underlying Disease, and Timing of Initiation.

OBJECTIVE: To identify risk factors associated with mortality in critically ill children requiring continuous renal replacement therapy. DESIGN: Retrospective observational study based on a prospective registry. SETTING: Tertiary and quaternary referral 30-bed PICU. PATIENTS: Critically ill children undergoing continuous renal replacement therapy were included in the study. INTERVENTIONS: Continuous renal replacement therapy. MEASUREMENTS AND MAIN RESULTS: Overall mortality was 36% (n = 58) among the 161 patients treated with continuous renal replacement therapy during the study period and was significantly higher in patients on extracorporeal membrane oxygenation (47.5%, 28 of 59) than in patients not requiring extracorporeal membrane oxygenation (28.4%, 29 of 102; p = 0.022). According to the admission diagnosis, we found the highest mortality in patients with onco-hematologic disease (77.8%) and the lowest in patients with renal disease (5.6%). Based on multivariate logistic regression analysis, the presence of higher severity of illness score at admission (adjusted odds ratio, 1.49; 95% CI, 1.18-1.89; p < 0.001), onco-hematologic disease (odds ratio, 17.10; 95% CI, 4.10-72.17; p < 0.001), fluid overload 10%-20% (odds ratio, 3.83; 95% CI, 1.33-11.07; p = 0.013), greater than 20% (odds ratio, 15.03; 95% CI, 4.03-56.05; p < 0.001), and timing of initiation of continuous renal replacement therapy (odds ratio, 1.01; 95% CI, 1.00-1.01; p = 0.040) were independently associated with mortality. In our population, the odds of dying increases by 1% for every hour of delay in continuous renal replacement therapy initiation from ICU admission. CONCLUSIONS: Mortality in children requiring continuous renal replacement therapy remains high and seems to be related to the underlying disease, the severity of illness, and the degree of fluid overload. In critically ill children at high risk for developing acute kidney injury and fluid overload, earlier initiation of continuous renal replacement therapy might result in decreased mortality.

Dismal Outcomes of Second-Run Extracorporeal Life Support in the Paediatric Population.

BACKGROUND: In 2011 we reported unfavourable outcomes of second-run extracorporeal life support (ECLS) in children. We wanted to investigate whether this previous report affected our strategy and modified our long-term outcomes. METHODS: Between 1988 and 2015, 31 patients underwent a second-run ECLS. Median age at the time of first support was 9days (0-16 years). Median length of support for the first and second runs were 4.7days (0.1-10) and 3.6days (0.5-8.7) respectively, with an interval of 1.8days (0.1-66) between supports. RESULTS: There was an increasing trend in the number of patients undergoing second-run ECLS after our report: 21 patients between 1988 and mid-2010 (0.9 patients/year) and 10 between mid-2010 and 2015 (two patients/year) (p=0.06). However, among all the patients who underwent ECLS, the proportion of second-run ECLS was not different before and after 2010 (4% vs. 4.2% respectively, p=0.92). While 58% of patients (18/31) survived weaning of support, only 23% (7/31) survived to hospital discharge and 14% (5/31) were still alive after hospital discharge at a median of 6.5 years (1.2-11.6). The three patients who had positive long-term outcomes had the second-run ECLS instituted to allow for major cardiac operations. CONCLUSIONS: Compassionate use of second-run ECLS is difficult to refuse but one should be aware that its outcomes are dismal. In our centre, benefits seem to be limited to cases where the second-run ECLS allows for a major cardiac intervention.

Therapeutic Plasma Exchange in Critically Ill Children Requiring Intensive Care.

OBJECTIVE: To characterize the clinical indications, procedural safety, and outcome of critically ill children requiring therapeutic plasma exchange. DESIGN: Retrospective observational study based on a prospective registry. SETTING: Tertiary and quaternary referral 30-bed PICU. PATIENTS: Forty-eight critically ill children who received therapeutic plasma exchange during an 8-year period (2007-2014) were included in the study. INTERVENTIONS: Therapeutic plasma exchange. MEASUREMENTS AND MAIN RESULTS: A total of 48 patients underwent 244 therapeutic plasma exchange sessions. Of those, therapeutic plasma exchange was performed as sole procedure in 193 (79%), in combination with continuous renal replacement therapy in 40 (16.4%) and additional extracorporeal membrane oxygenation in 11 (4.6%) sessions. The most common admission diagnoses were hematologic disorders (30%), solid organ transplantation (20%), neurologic disorders (20%), and rheumatologic disorders (15%). Complications associated with the procedure occurred in 50 (21.2%) therapeutic plasma exchange sessions. Overall, patient survival from ICU was 82%. Although patients requiring therapeutic plasma exchange alone (n = 31; 64%) had a survival rate of 97%, those with additional continuous renal replacement therapy (n = 13; 27%) and extracorporeal membrane oxygenation (n = 4; 8%) had survival rates of 69% and 50%, respectively. Factors associated with increased mortality were lower Pediatric Index of Mortality 2 score, need for mechanical ventilation, higher number of failed organs, and longer ICU stay. CONCLUSION: Our results indicate that, in specialized centers, therapeutic plasma exchange can be performed relatively safely in critically ill children, alone or in combination with continuous renal replacement therapy and extracorporeal membrane oxygenation. Outcome in children requiring therapeutic plasma exchange alone is excellent. However, survival decreases with the number of failed organs and the need for continuous renal replacement therapy and extracorporeal membrane oxygenation.

Safety of nitric oxide added to the ECMO circuit: a pilot study in children.

We describe our experience of 30 consecutive children supported with ECMO and receiving 20 ppm of nitric oxide in the oxygenator of the ECMO circuit. Administration of nitric oxide into the ECMO circuit is safe and could potentially mitigate ischaemia reperfusion injury and end-organ dysfunction of children requiring mechanical support.

Late-Term Gestation Is Associated With Improved Survival in Neonates With Congenital Heart Disease Following Postoperative Extracorporeal Life Support.

OBJECTIVE: Several population-based studies have shown that gestational age 39-40 weeks at birth is associated with superior outcomes in various pediatric settings. A high proportion of births for neonates with congenital heart disease occur before 39 weeks. We aimed to assess the influence of late-term gestation (39-40 wk) on survival in neonates requiring extracorporeal life support following surgery for congenital heart disease. DESIGN: Retrospective cohort study. SETTING: The Royal Children's Hospital, Melbourne, Australia. PATIENTS: Neonates requiring extracorporeal life support after cardiac surgery for congenital heart disease. MEASUREMENTS AND MAIN RESULTS: From 2005 to 2014, 110 neonates (10.5% of neonates undergoing cardiac surgery) required extracorporeal life support after cardiac surgery. Indications were failure to separate from cardiopulmonary bypass in 40 (36%), extracorporeal cardiopulmonary resuscitation in 48 (44%), progressive low cardiac output in 15 (14%), and other reasons in seven (6%). Extracorporeal life support duration was 94 hours (interquartile range, 53-135), and 54 (49%) underwent single ventricle repair. Gestation at birth (n [%]) was as follows: less than 37 weeks, 19 (17%); 37-38 weeks, 38 (35%); 39-40 weeks, 50 (45%); 41 weeks or more, 3 (3%). By multivariable analysis (controlling for age, era of extracorporeal life support 2005-2009 vs 2010-2014, single ventricle status and acute renal failure), gestational age of 39-40 weeks was associated with the lowest odds for intensive care mortality: using less than 37 weeks as referent, the adjusted odds ratio (95% CI) for 37-38 weeks was 0.41 (0.12-1.33); for 39-40 weeks, 0.27 (0.08-0.84); and for 41 weeks or more, 1.06 (0.07-14.7). Similar association was also seen in a subcohort of study neonates (n = 66) who were commenced on extracorporeal life support after admission to intensive care: using less than 37 weeks as referent, the adjusted odds ratio (95% CI) for 37-38 weeks was 0.52 (0.10-2.80) and for 39-40 weeks, 0.15 (0.03-0.81). CONCLUSIONS: In this cohort of neonates requiring extracorporeal life support following cardiac surgery, 39-40 weeks of gestation at birth is associated with the best survival. The additional maturity gained by reaching a gestation of at least 39 weeks is likely to confer a survival advantage in this high-risk cohort.

Extracorporeal membrane oxygenation for Kawasaki disease: two case reports and the Extracorporeal Life Support Organization experience 1999-2015.

Kawasaki disease is usually a limited illness of early childhood. However, life-threatening cardiac manifestations can occur, either at acute presentation or as a consequence of coronary arterial involvement. We report the successful use of veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) for cardiac support in two children with Kawasaki disease: one with acute Kawasaki disease shock syndrome, the other with complications of coronary arteritis and subsequent surgery. We also reviewed the reported experience in the ELSO database and available literature.

Clinical Effects of Nitric Oxide Added to the Oxygenator of Children on Extracorporeal Membrane Oxygenation: Pre-Post Cohort Study.

Nitric oxide (NO) can be safely delivered through the sweep gas to the oxygenator of an extracorporeal membrane oxygenation (ECMO) circuit. It has theoretical benefits such as preventing platelet adhesion to surfaces, mitigating inflammatory response and protection against ischemia-reperfusion injury. In this uncontrolled before-after study of children on ECMO, the outcomes of those who received NO were compared with those who did not. Among 393 ECMO runs (from 337 patients), 192 of 393 (49%) received NO and 201 of 393 (51%) did not. The use of NO was associated with a 37% reduction in circuit change (adjusted risk ratio [aRR]: 0.63, 95% confidence interval [CI]: 0.42-0.93). The aRR (95% CI) for risk of neurologic injury was 0.72 (0.47-1.11). We observed potential heterogeneity of treatment effect for the risk of neurologic injury in children who had cardiac surgery: the risk with NO was lower in those who had cardiac surgery (aRR: 0.50, 95% CI: 0.26-0.96). There was no difference in survival between the study groups. In children managed with NO delivered through the ECMO circuit, we report a reduction in observed rate of circuit change and lower risk of neurologic injury in children who underwent cardiac surgery. Nitric oxide therapy on ECMO warrants prospective evaluation in children.

Immunofluorescence Protocol for Characterization of Platelet and Leukocyte Binding in Extracorporeal Membrane Oxygenation (ECMO) Circuits.

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.

Top 10 research priorities for congenital diaphragmatic hernia in Australia: James Lind Alliance Priority Setting Partnership.

OBJECTIVES: The Gaps in the Congenital Diaphragmatic Hernia (CDH) Journey Priority Setting Partnership (PSP) was developed in collaboration with CDH Australia, James Lind Alliance (JLA) and the Murdoch Children's Research Institute to identify research priorities for people with CDH, their families and healthcare workers in Australasia. DESIGN: Research PSP in accordance with the JLA standardised methodology. SETTING: Australian community and institutions caring for patients with CDH and their families. PATIENTS: CDH survivors, families of children born with CDH (including bereaved) and healthcare professionals including critical care physicians and nurses (neonatal and paediatric), obstetric, surgical, allied health professionals (physiotherapists, speech pathologists and speech therapists) and general practitioners. MAIN OUTCOME MEASURE: Top 10 research priorities for CDH. RESULTS: 377 questions, from a community-based online survey, were categorised and collated into 50 research questions. Through a further prioritisation process, 21 questions were then discussed at a prioritisation workshop where they were ranked by 21 participants (CDH survivors, parents of children born with CDH (bereaved and not) and 11 multidisciplinary healthcare professionals) into their top 10 research priorities. CONCLUSION: Stakeholders' involvement identified the top 10 CDH-related research questions, spanning from antenatal care to long-term functional outcomes, that should be prioritised for future research to maximise meaningful outcomes for people with CDH and their families.

Individualized vancomycin dosing in infants: prospective evaluation of an online dose calculator.

BACKGROUND: Empiric vancomycin dosing regimens fail to achieve recommended target trough concentrations of 10-20 mg/L in the majority of infants. This study assessed the performance of a model-based dosing calculator (Vanc App) in achieving target vancomycin concentrations at first steady-state level. METHODS: This was a multicenter prospective study in four tertiary pediatric hospitals over an 18-month period. Infants aged 0-90 days with suspected Gram-positive sepsis requiring empiric vancomycin treatment were included if they did not meet any of the exclusion criteria: post-menstrual age (PMA) <25 weeks, weight <500 g, glycopeptide allergy, receiving extracorporeal membrane oxygenation, vancomycin use within the previous 72 h, and renal impairment. The Vanc App used a published population pharmacokinetic model to generate a dose based on the infant's PMA, weight, creatinine, and target vancomycin concentration. RESULTS: A total of 40 infants were included; 40% were female, median (range) weight was 2505 (700-4460) g and median (range) PMA was 37.4 (25.7-49.0) weeks. The median (range) vancomycin dose was 45 (24-79) mg/kg/day. All infants had trough vancomycin concentrations measured at steady-state (24-<48 hours) and 30 (75%) infants achieved target concentrations. Five infants had supratherapeutic (median 25, range 21-38 mg/L) and five had subtherapeutic (median 6, range <5-9 mg/L) concentrations. An area under the concentration-time curve (AUC0-24) of 400-650 mg/L.h was achieved in 33 (83%) infants. There were no infusion-related reactions or nephrotoxicity. CONCLUSION: Individualized intermittent vancomycin dosing using a model-based online calculator resulted in 75% and 83% of infants achieving target trough and AUC0-24, respectively, at first steady-state level. There were no vancomycin-related nephrotoxicity or infusion-related reactions.

Factors XI and XII in extracorporeal membrane oxygenation: longitudinal profile in children.

Background: Extracorporeal membrane oxygenation (ECMO) is used in children with cardiopulmonary failure. While the majority of ECMO centers use unfractionated heparin, other anticoagulants, including factor XI and factor XII inhibitors are emerging, which may prove suitable for ECMO patients. However, before these anticoagulants can be applied in these patients, baseline data of FXI and FXII changes need to be acquired. Objectives: This study aimed to describe the longitudinal profile of FXI and FXII antigenic levels and function before, during, and after ECMO in children. Methods: This is a prospective observational study in neonatal and pediatric patients with ECMO (<18 years). All patients with venoarterial ECMO and with sufficient plasma volume collected before ECMO, on day 1 and day 3, and 24 hours postdecannulation were included. Antigenic levels and functional activity of FXI and FXII were determined in these samples. Longitudinal profiles of these values were created using a linear mixed model. Results: Sixteen patients were included in this study. Mean FXI and FXII antigenic levels (U/mL) changed from 7.9 and 53.2 before ECMO to 6.0 and 34.5 on day 3 and they recovered to 8.8 and 39.4, respectively, after stopping ECMO. Function (%) of FXI and FXII decreased from 59.1 and 59.0 to 49.0 and 50.7 on day 3 and recovered to 66.0 and 54.4, respectively. Conclusion: This study provides the first insights into changes of the contact pathway in children undergoing ECMO. FXI and FXII antigen and function change during ECMO. Results from this study can be used as starting point for future contact pathway anticoagulant studies in pediatric patients with ECMO.

S-Nitrosoglutathione Limits Apoptosis and Reduces Pulmonary Vascular Dysfunction After Bypass.

BACKGROUND: During hypoxia or acidosis, S-nitrosoglutathione (GSNO) has been shown to protect the cardiomyocyte from ischemia-reperfusion injury. In a randomized double-blinded control study of a porcine model of paediatric cardiopulmonary bypass (CPB), we aimed to evaluate the effects of 2 different doses (low and high) of GSNO. METHODS: Pigs weighing 15-20 kg were exposed to CPB with 1 hour of aortic cross-clamp. Prior to and during CPB, animals were randomized to receive low-dose (up to 20 nmol/kg/min) GSNO (n = 8), high-dose (up to 60 nmol/kg/min) GSNO (n = 6), or normal saline (n = 7). Standard cardiac intensive care management was continued for 4 hours post-bypass. RESULTS: There was a reduction in myocyte apoptosis after administration of GSNO (P = .04) with no difference between low- and high-dose GSNO. The low-dose GSNO group had lower pulmonary vascular resistance post-CPB (P = .007). Mitochondrial complex I activity normalized to citrate synthase activity was higher after GSNO compared with control (P = .02), with no difference between low- and high-dose GSNO. CONCLUSIONS: In a porcine model of CPB, intravenous administration of GSNO limits myocardial apoptosis through preservation of mitochondrial complex I activity, and improves pulmonary vascular resistance. There appears to be a dose-dependent effect to this protection.

Outcomes of total anomalous pulmonary venous drainage repair in neonates and the impact of pulmonary hypertension on survival.

Background: Mortality after repair of total anomalous pulmonary venous drainage (TAPVD) in neonates has remained high. Analysis of risk factors may help identify therapeutic targets to improve survival. Methods: Retrospective analysis of all neonates who underwent simple TAPVD repair. Results: Between 1973 and 2021, 175 neonates underwent TAPVD repair, at a median age of 6 days (interquartile range, 2-15 days) and a mean weight of 3.2 ± 0.6 kg. TAPVD was supracardiac in 42.3% of the patients (74 of 175), cardiac in 14.3% (25 of 175), infracardiac in 40% (70 of 175), and mixed type in 3.4% (6 of 175), with obstruction in 65.7% (115 of 175). Pulmonary hypertension (PHT) crisis occurred in 12% (21 of 175). Early mortality was 9.7% (17 of 175) and late mortality was 5.1% (8 of 158), with most deaths occurring within 1 year (75%; 6 of 8). Survival was 86.5% (95% CI, 80.3%-90.8%) at 1 year and 85.8% (95% CI, 79.6%-90.3%) at 5, 10, 15, and 20 years. Survival was lower in patients with obstructed TAPVD, patients with emergent surgery, and those with PHT crisis. PHT crisis (hazard ratio [HR], 4.93; 95% CI, 1.95-12.51; P = .001), urgency of surgery (HR, 2.51; 95% CI, 1.11-5.68; P = .027), and higher pulmonary artery pressure-to-systemic blood pressure percentage ratio (HR, 1.06; 95% CI, 1.01-1.11; P = .026) were identified as risk factors for mortality. Histopathological analysis of 17 patients (9.7%; 17 of 175) showed signs of pulmonary arterial hypertension with media hypertrophy in 58.8% (10 of 17). Conclusions: Mortality after TAPVD repair occurred mainly within the first year of life. Urgency of surgery and persistent PHT appears to be risk factors for mortality. Lung biopsy might be useful for identifying patients at risk and guiding newer treatment modalities.

Role of levosimendan in weaning children requiring veno-arterial extracorporeal membrane oxygenation after cardiac surgery.

OBJECTIVES: Levosimendan use is associated with more successful decannulation from veno-arterial extracorporeal membrane oxygenation (VA ECMO) in adults. We sought to determine the role of levosimendan in children who required VA ECMO after cardiac surgery. METHODS: This observational study compares the outcomes of children who required VA ECMO after cardiac surgery and received levosimendan for weaning with those who did not receive the drug. A doubly robust estimation methodology (inverse probability of treatment weighting with regression adjustment) was used to balance study covariates (age, weight, sex, lactate pre-ECMO, vasoactive-inotropic score pre-ECMO, ECMO indication, ECMO modality, Risk Adjustment for Congenital Heart Surgery-1 category), and the final model was further adjusted for duration of ECMO. RESULTS: Between January 2012 and December 2018, 118 eligible children received 145 ECMO runs [failed weaning from cardiopulmonary bypass, 67/145 (46%); low cardiac output state, 30/145 (21%); extracorporeal cardiopulmonary resuscitation, 47/145 (32%); other reasons in 1]. Levosimendan was administered before decannulation in 54/145 (37%) runs. The median time to start levosimendan after ECMO cannulation was 39 h (interquartile range, 14-83 h). The unadjusted rates of weaning failure in the levosimendan vs control group were 7% (4/54) vs 19% (17/91). In the controlled analysis, levosimendan was associated with decreased risk of weaning failure [adjusted relative risk (95% confidence interval), 0.20 (0.07-0.57)] and decreased risk of in-hospital mortality [adjusted relative risk (95% confidence interval), 0.45 (0.26-0.76)]. CONCLUSIONS: Levosimendan administration in children requiring VA ECMO after cardiac surgery was associated with decreased risk of weaning failure and decreased in-hospital mortality.