Evaluation of an aPTT guided versus a multimodal heparin monitoring approach in patients on extra corporeal membrane oxygenation: A retrospective cohort study.

INTRODUCTION: Bleeding and thrombotic complications are common in extracorporeal membrane oxygenation (ECMO) patients and are associated with increased mortality and morbidity. The optimal anticoagulation monitoring protocol in these patients is unknown. This study aims to compare the incidence of thrombotic and hemorrhagic complications before and after a protocol change. In addition, the association between hemostatic complications, coagulation tests and risk factors is evaluated. METHODS: This is a retrospective single center cohort study of adult ECMO patients. We collected demographics, ECMO parameters and coagulation test results. Outcomes of the aPTT guided and multimodal protocol, including aPTT, anti-Xa assay and rotational thromboelastometry were compared and the association between coagulation tests, risk factors and hemostatic complications was determined using a logistic regression analysis for repeated measurements. RESULTS: In total, 250 patients were included, 138 in the aPTT protocol and 112 in the multimodal protocol. The incidence of thrombosis (aPTT: 14%; multimodal: 12%) and bleeding (aPTT: 36%; multimodal: 40%), did not significantly differ between protocols. In the aPTT guided protocol, the aPTT was associated with thrombosis (Odds Ratio [OR] 1.015; 95% confidence interval [CI] 1.004-1.027). In both protocols, surgical interventions were risk factors for bleeding and thrombotic complications (aPTT: OR 93.2, CI 39.9-217.6; multimodal OR 17.5, CI 6.5-46.9). DISCUSSION: The incidence of hemostatic complications was similar between both protocols and surgical interventions were a risk factor for hemostatic complications. Results from this study help to elucidate the role of coagulation tests and risk factors in predicting hemostatic complications in patients undergoing ECMO support.

Intermittent intravenous paracetamol versus continuous morphine in infants undergoing cardiothoracic surgery: a multi-center randomized controlled trial.

BACKGROUND: To determine whether intermittent intravenous (IV) paracetamol as primary analgesic would significantly reduce morphine consumption in children aged 0-3 years after cardiac surgery with cardiopulmonary bypass. METHODS: Multi-center, randomized, double-blinded, controlled trial in four level-3 Pediatric Intensive Care Units (PICU) in the Netherlands and Belgium. Inclusion period; March 2016-July 2020. Children aged 0-3 years, undergoing cardiac surgery with cardiopulmonary bypass were eligible. Patients were randomized to continuous morphine or intermittent IV paracetamol as primary analgesic after a loading dose of 100 mcg/kg morphine was administered at the end of surgery. Rescue morphine was given if numeric rating scale (NRS) pain scores exceeded predetermined cutoff values. Primary outcome was median weight-adjusted cumulative morphine dose in mcg/kg in the first 48 h postoperative. For the comparison of the primary outcome between groups, the nonparametric Van Elteren test with stratification by center was used. For comparison of the proportion of patients with one or more NRS pain scores of 4 and higher between the two groups, a non-inferiority analysis was performed using a non-inferiority margin of 20%. RESULTS: In total, 828 were screened and finally 208 patients were included; parents of 315 patients did not give consent and 305 were excluded for various reasons. Fourteen of the enrolled 208 children were withdrawn from the study before start of study medication leaving 194 patients for final analysis. One hundred and two patients received intermittent IV paracetamol, 106 received continuous morphine. The median weight-adjusted cumulative morphine consumption in the first 48 h postoperative in the IV paracetamol group was 5 times lower (79%) than that in the morphine group (median, 145.0 (IQR, 115.0-432.5) mcg/kg vs 692.6 (IQR, 532.7-856.1) mcg/kg; P < 0.001). The rescue morphine consumption was similar between the groups (p = 0.38). Non-inferiority of IV paracetamol administration in terms of NRS pain scores was proven; difference in proportion - 3.1% (95% CI - 16.6-10.3%). CONCLUSIONS: In children aged 0-3 years undergoing cardiac surgery, use of intermittent IV paracetamol reduces the median weight-adjusted cumulative morphine consumption in the first 48 h after surgery by 79% with equal pain relief showing equipoise for IV paracetamol as primary analgesic. Trial Registration Clinicaltrials.gov, Identifier: NCT05853263; EudraCT Number: 2015-001835-20.

Pro-opiomelanocortin and ACTH-cortisol dissociation during pediatric cardiac surgery.

In critically ill adults, high plasma cortisol in face of low ACTH coincides with high pro-opiomelanocortin (POMC) levels. Glucocorticoids further lower ACTH without affecting POMC. We hypothesized that in pediatric cardiac surgery-induced critical illness, plasma POMC is elevated, plasma ACTH transiently rises intraoperatively but becomes suppressed post-operatively, and glucocorticoid administration amplifies this phenotype. From 53 patients (0-36 months), plasma was obtained pre-operatively, intraoperatively and on post-operative day 1 and 2. Plasma was also collected from 24 healthy children. In patients, POMC was supra-normal pre-operatively (p<0.0001) but no longer thereafter (p<0.05). ACTH was never high in patients. While in glucocorticoid-naive patients ACTH became suppressed by post-operative day 1 (p<0.0001), glucocorticoid-treated patients had suppressed ACTH already intraoperatively (p≤0.0001). Pre-operatively high POMC, not accompanied by increased plasma ACTH, suggests a centrally-activated HPA-axis with reduced pituitary processing of POMC into ACTH. Increasing systemic glucocorticoid availability with glucocorticoid treatment accelerated the suppression of plasma ACTH.

Acquired von Willebrand disease in children undergoing extracorporeal membrane oxygenation: a prospective observational study.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) provides cardiopulmonary support for children with severe cardiac and/or pulmonary failure. The incidence of bleeding complications during ECMO support is high. Acquired von Willebrand disease (AVWD) might contribute to the development of bleeding complications. OBJECTIVE: To study the incidence and longitudinal profile of AVWD during the first 14 days of ECMO support in children and to investigate the association between AVWD and bleeding complications. METHODS: This prospective observational study included pediatric patients (0-17 years) receiving ECMO. Blood was sampled prior to and after ECMO start, daily and 12 to 24 hours after stopping ECMO. von Willebrand factor (VWF) parameters and multimer patterns were determined. Clinical data were collected for each patient. AVWD was defined as loss of high-molecular weight multimers (ie, decreased compared with baseline) or a VWF:collagen binding/VWF: antigen (Ag) ratio or VWF:activity/VWF:Ag ratio below 0.7. RESULTS: All of 50 (100%) patients developed AVWD during ECMO. The VWF:collagen binding /VWF:Ag ratio, VWF:activity/VWF:Ag ratio, and high-molecular weight multimers decreased during the initial days and recovered to baseline level within 24 hours after stopping ECMO. The incidence and longitudinal profile of AVWD were similar in patients with and without major bleeding complications. CONCLUSION: Children receiving ECMO support commonly develop AVWD. AVWD develops rapidly after ECMO initiation and recovers quickly after ECMO cessation. Importantly, AVWD appears to be independent of major bleeding.

Bacteria in Extracorporeal Membrane Oxygenation Circuit Clots of a Patient With Persistent Bacteremia: A Case Report.

A neonate with pulmonary hypertension was supported with extracorporeal membrane oxygenation (ECMO). During ECMO support, the patient developed Enterococcus faecalis bacteremia, treated with targeted antibiotics. Despite the maximum dose of antibiotics, routine blood cultures remained positive throughout the ECMO treatment. A circuit change was performed due to buildup of thrombotic material and disseminated intravascular coagulation (DIC) inside the circuit. Thrombus formation was more extensive in the first than the second circuit. Gram-positive diplococci were present in all initial circuit clots and gram-positive masses surrounded by fibrin were found inside thrombi of the second circuit. Scanning electron microscopy (SEM) revealed a dense fibrin network with embedded red blood cells and bacteria in the first circuit. In the second circuit, SEM analysis revealed scattered micro thrombi. Polymerase chain reaction for identification of bacteria in the thrombus of the first circuit showed the same bacteria as found in blood cultures and did not achieve a sufficient signal in the second circuit. This case report shows that bacteria can nestle in thrombi of an ECMO circuit and that there is a rationale for a circuit change in a patient with persistent positive blood cultures and DIC.

A Population Pharmacokinetic Model of Pentobarbital for Children with Status Epilepticus and Severe Traumatic Brain Injury.

BACKGROUND: Pentobarbital pharmacokinetics (PK) remain elusive and the therapeutic windows narrow. Administration is frequent in critically ill children with refractory status epilepticus (SE) and severe traumatic brain injury (sTBI). OBJECTIVES: To investigate pentobarbital PK in SE and sTBI patients admitted to the paediatric intensive care unit (PICU) with population-based PK (PopPK) modelling and dosing simulations. METHODS: Develop a PopPK model with non-linear mixed-effects modelling (NONMEM®) with retrospective data (n = 36; median age 1.3 years; median weight 10 kg; 178 blood samples) treated with continuous intravenous pentobarbital. An independent dataset was used for external validation (n = 9). Dosing simulations with the validated model evaluated dosing regimens. RESULTS: A one-compartment PK model with allometrically scaled weight on clearance (CL; 0.75) and volume of distribution (Vd; 1) captured data well. Typical CL and Vd values were 3.59 L/70 kg/h and 142 L/70 kg, respectively. Elevated creatinine and C-reactive protein (CRP) levels significantly correlated to decreased CL, explaining 84% of inter-patient variability, and were incorporated in the final model. External validation using stratified visual predictive checks showed good results. Simulations demonstrated patients with elevated serum creatinine and CRP failed to achieve steady state yet progressed to toxic levels with current dosing regimens. CONCLUSIONS: The one-compartment PK model of intravenous pentobarbital described data well whereby serum creatinine and CRP significantly correlated with pentobarbital CL. Dosing simulations formulated adjusted dosing advice in patients with elevated creatinine and/or CRP. Prospective PK studies with pharmacodynamic endpoints, are imperative to optimise pentobarbital dosing in terms of safety and clinical efficacy in critically ill children.

Withdrawal of Life-Sustaining Therapies in Children With Severe Traumatic Brain Injury.

Neuroprognostication in severe traumatic brain injury (sTBI) is challenging and occurs in critical care settings to determine withdrawal of life-sustaining therapies (WLST). However, formal pediatric sTBI neuroprognostication guidelines are lacking, brain death criteria vary, and dilemmas regarding WLST persist, which lead to institutional differences. We studied WLST practice and outcome in pediatric sTBI to provide insight into WLST-associated factors and survivor recovery trajectory ≥1 year post-sTBI. This retrospective, single center observational study included patients <18 years admitted to the pediatric intensive care unit (PICU) of Erasmus MC-Sophia (a tertiary university hospital) between 2012 and 2020 with sTBI defined as a Glasgow Coma Scale (GCS) ≤8 and requiring intracranial pressure (ICP) monitoring. Clinical, neuroimaging, and electroencephalogram data were reviewed. Multi-disciplinary follow-up included the Pediatric Cerebral Performance Category (PCPC) score, educational level, and commonly cited complaints. Seventy-eight children with sTBI were included (median age 10.5 years; interquartile range [IQR] 5.0-14.1; 56% male; 67% traffic-related accidents). Median ICP monitoring was 5 days (IQR 3-8), 19 (24%) underwent decompressive craniectomy. PICU mortality was 21% (16/78): clinical brain death (5/16), WLST due to poor neurological prognosis (WLST_neuro, 11/16). Significant differences (p < 0.001) between survivors and non-survivors: first GCS score, first pupillary reaction and first lactate, Injury Severity Score, pre-hospital cardiopulmonary resuscitation, and Rotterdam CT (computed tomography) score. WLST_neuro decision timing ranged from 0 to 31 days (median 2 days, IQR 0-5). WLST_neuro decision (n = 11) was based on neurologic examination (100%), brain imaging (100%) and refractory intracranial hypertension (5/11; 45%). WLST discussions were multi-disciplinary with 100% agreement. Immediate agreement between medical team and caregivers was 81%. The majority (42/62, 68%) of survivors were poor outcome (PCPC score 3 to 5) at PICU discharge, of which 12 (19%) in a vegetative state. One year post-injury, no patients were in a vegetative state and the median PCPC score had improved to 2 (IQR 2-3). No patients died after PICU discharge. Twenty percent of survivors could not attend school 2 years post-injury. Survivors requiring an adjusted educational level increased to 45% within this timeframe. Chronic complaints were headache, behavioral problems, and sleeping problems. In conclusion, two-thirds of sTBI PICU mortality was secondary to WLST_neuro and occurred early post-injury. Median survivor PCPC score improved from 4 to 2 with no vegetative patients 1 year post-sTBI. Our findings show the WLST decision process was multi-disciplinary and guided by specific clinical features at presentation, clinical course, and (serial) neurological diagnostic modalities, of which the testing combination was determined by case-to-case variation. This stresses the need for international guidelines to provide accurate neuroprognostication within an appropriate timeframe whereby overall survivor outcome data provides valuable context and guidance in the acute phase decision process.

Review of Scavenged Sampling for Sustainable Therapeutic Drug Monitoring: Do More With Less.

PURPOSE: Innovative and sustainable sampling strategies for bioanalytical quantification of drugs and metabolites have gained considerable interest. Scavenging can be stratified as a sustainable sampling strategy using residual material because it aligns with the green principles of waste reduction and sampling optimization. Scavenged sampling includes all biological fluids' (eg, blood, liquor, and urine) leftover from standard clinical care. This review elaborates on the past and current landscape of sustainable sampling within therapeutic drug monitoring, with a focus on scavenged sampling. METHODS: In February 2021, 4 databases were searched to assess the literature on the clinical use of innovative and sustainable sampling techniques without applying publication date restrictions. Studies reporting the clinical use of scavenged blood sampling and bridging studies of scavenged sampling and normal blood sampling were eligible for inclusion. RESULTS: Overall, 19 eligible studies concerning scavenged sampling were identified from 1441 records. Scavenged sampling is mainly applied in the pediatric population, although other patient groups may benefit from this strategy. The infrastructure required for scavenged sampling encounters several challenges, including logistic hurdles, storage and handling conditions, and documentation errors. A workflow is proposed with identified opportunities that guide the implementation of scavenged sampling. CONCLUSIONS: This review presents current evidence on the clinical use of scavenged sampling strategies. Scavenged sampling can be a suitable approach for drug quantification to improve dosage regimens, perform pharmacokinetic studies, and explore the value of therapeutic drug monitoring without additional sample collection.

The Pharmacokinetics of Beta-Lactam Antibiotics Using Scavenged Samples in Pediatric Intensive Care Patients: The EXPAT Kids Study Protocol.

Background: Emerging evidence supports the importance of optimized antibiotic exposure in pediatric intensive care unit (PICU) patients. Traditional antibiotic dosing is not designed for PICU patients, as the extreme pharmacokinetic (PK) behavior of drugs threatens the achievement of optimal antibiotic treatment outcomes. Scavenged sampling is a sampling strategy which may have positive implications for routine TDM and PK research, as well as monitoring other biomarkers. EXPAT Kids study was designed to analyze whether current empiric dosing regimens of frequently used beta-lactam antibiotics achieve defined therapeutic target concentrations in PICU patients. Methods: A mono-centre, exploratory pharmacokinetic and pharmacodynamic study was designed to assess target attainment of beta-lactam antibiotics. One hundred forty patients will be included within 24 months after start of inclusion. At various time points serum concentration of the study antibiotic (cefotaxime, ceftazidime, ceftriaxone, cefuroxime, flucloxacillin, and meropenem) are determined. In parallel with these sampling moments, residual material is collected to validate the use of blood of scavenged heparinized astrup syringes for the quantification of antibiotic exposure. The primary outcome is the time that the free (unbound) concentration of the study antibiotic remains above one to four the minimal inhibitory concentration during a dosing interval (100%ƒT > MIC and 100%ƒT>4xMIC). Other included outcomes are disease severity, safety, length of stay, and inflammatory biomarkers. Discussion: Potentially, scavenged sampling may enrich the EXPAT Kids dataset, and reduce additional blood sampling and workload for clinical personnel. The findings from the EXPAT Kids study will lead to new insights in the PK parameters of beta-lactams and consecutive effects on target attainment and clinical outcomes. Is there a need for more precision in dosing? Netherlands Trial Register Number: Trial NL9326.

Use of rotational thromboelastometry to predict hemostatic complications in pediatric patients undergoing extracorporeal membrane oxygenation: A retrospective cohort study.

BACKGROUND: The incidence of hemostatic complications in pediatric patients undergoing extracorporeal membrane oxygenation (ECMO) is high. The optimal anticoagulation strategy in children undergoing ECMO is unknown. OBJECTIVES: To study the association between hemostatic complications, coagulation tests, and clinical parameters in pediatric patients undergoing ECMO and their effect on survival. METHODS: We performed a retrospective cohort study of pediatric patients undergoing centrifugal pump ECMO. Collected data included patient characteristics, risk factors, and coagulation test results. Statistical analysis was done using logistic regression analysis for repeated measurements. Dependent variables were thrombosis and bleeding, independent variables were rotational thromboelastometry (ROTEM), activated partial thromboplastin time (aPTT) and antifactor-Xa assay (aXa) results, ECMO duration, age <29 days, sepsis and surgery. RESULTS: Seventy-three patients with 623 ECMO days were included. Cumulative incidences of thrombosis and bleeding were 43.5% (95% confidence interval [CI], 26.0%-59.8%) and 25.4% (95% CI, 13.4%-39.3%), respectively. A lower maximum clot firmness of intrinsic ROTEM (INTEM; odds ratio [OR], 0.946; 95% CI, 0.920-0.969), extrinsic ROTEM (OR, 0.945; 95% CI, 0.912-0.973), and INTEM with heparinase (OR, 0.936; 95% CI, 0.896-0.968); higher activated partial thromboplastin time aPTT; OR, 1.020; 95% CI, 1.006-1.024) and age <29 days (OR, 2.900; 95% CI, 1.282-6.694); surgery (OR, 4.426; 95% CI, 1.543-12.694); and longer ECMO duration (OR, 1.149; 95% CI, 1.022-1.292) significantly increased thrombotic risk. Surgery (OR, 2.698; 95% CI, 1.543-12.694) and age <29 days (OR 2.242, 95% CI 1.282-6.694) were significantly associated with major bleeding. Patients with hemostatic complications had significantly decreased survival to hospital discharge (P = .009). CONCLUSION: The results of this study help elucidate the role of ROTEM, aPTT, anti-factor Xa, and clinical risk factors in predicting hemostatic complications in pediatric patients undergoing ECMO.

Model-Informed Precision Dosing of Antibiotics in Pediatric Patients: A Narrative Review.

Optimal pharmacotherapy in pediatric patients with suspected infections requires understanding and integration of relevant data on the antibiotic, bacterial pathogen, and patient characteristics. Because of age-related physiological maturation and non-maturational covariates (e.g., disease state, inflammation, organ failure, co-morbidity, co-medication and extracorporeal systems), antibiotic pharmacokinetics is highly variable in pediatric patients and difficult to predict without using population pharmacokinetics models. The intra- and inter-individual variability can result in under- or overexposure in a significant proportion of patients. Therapeutic drug monitoring typically covers assessment of pharmacokinetics and pharmacodynamics, and concurrent dose adaptation after initial standard dosing and drug concentration analysis. Model-informed precision dosing (MIPD) captures drug, disease, and patient characteristics in modeling approaches and can be used to perform Bayesian forecasting and dose optimization. Incorporating MIPD in the electronic patient record system brings pharmacometrics to the bedside of the patient, with the aim of a consisted and optimal drug exposure. In this narrative review, we evaluated studies assessing optimization of antibiotic pharmacotherapy using MIPD in pediatric populations. Four eligible studies involving amikacin and vancomycin were identified from 418 records. Key articles, independent of year of publication, were also selected to highlight important attributes of MIPD. Although very little research has been conducted until this moment, the available data on vancomycin indicate that MIPD is superior compared to conventional dosing strategies with respect to target attainment. The utility of MIPD in pediatrics needs to be further confirmed in frequently used antibiotic classes, particularly aminoglycosides and beta-lactams.

Development of entrustable professional activities for paediatric intensive care fellows: A national modified Delphi study.

Entrustable professional activities (EPAs), as a focus of learner assessment, are supported by validity evidence. An EPA is a unit of professional practice requiring proficiency in multiple competencies simultaneously, that can be entrusted to a sufficiently competent learner. Taken collectively, a set of EPAs define and inform the curriculum of a specialty training. The goal of this study was to develop a set of EPAs for Dutch PICU fellows. A multistage methodology was employed incorporating sequential input from task force members, a medical education expert, PICU fellowship program directors, and PICU physicians and fellows via a modified three-round Delphi study. In the first modified Delphi round, experts rated indispensability and clarity of preliminary EPAs. In the subsequent rounds, aggregated scores for each EPA and group comments were provided. In round two, respondents rated indispensability and clarity of revised EPAs. Round three was used to gain explicit confirmation of suitability to implement these EPAs. Based on median ratings and content validity index (CVI) analysis for indispensability in the first two rounds, all nine preliminary EPAs covered activities that were deemed essential to the clinical practice of PICU physicians. Based on median ratings and CVI analysis for clarity however, four EPAs needed revision. With an agreement percentage of 93-100% for all individual EPAs as well as the set as a whole, a high degree of consensus among experts was reached in the third round. The resulting nine PICU EPAs provide a succinct overview of the core tasks of Dutch PICU physicians. These EPAs were created as an essential first step towards developing an assessment system for PICU fellows, grounded in core professional activities. The robust methodology used, may have broad applicability for other (sub)specialty training programs aiming to develop specialty specific EPAs.

Sequestration of Voriconazole and Vancomycin Into Contemporary Extracorporeal Membrane Oxygenation Circuits: An in vitro Study.

Background: Bacterial and fungal infections are common and often contribute to death in patients undergoing extracorporeal membrane oxygenation (ECMO). Drug disposition is altered during ECMO, and adsorption in the circuit is an established causative factor. Vancomycin and voriconazole are widely used, despite the lack of evidence-based prescription guidelines. Objective: The objective of this study was to determine the extraction of voriconazole and vancomycin by the Xenios/Novalung ECMO circuits. Methods: We have set up nine closed-loop ECMO circuits, consisting of four different iLAActivve ® kits for neonatal, pediatric, and adult support: three iLA-ActivveMiniLung ® petite kits, two iLA-ActivveMiniLung ® kits, two iLA-ActivveiLA ® kits, and two iLA-Activve X-lung ® kits. The circuits were primed with whole blood and maintained at physiologic conditions for 24 h. Voriconazole and vancomycin were injected as a single-bolus age-related dose into the circuits. Pre-membrane (P2) blood samples were obtained at baseline and after drug injection at 2, 10, 30, 180, 360 min, and 24 h. A control sample at 2 min was collected for spontaneous drug degradation testing at 24 h. Results: Seventy-two samples were analyzed in triplicate. The mean percentage of drug recovery at 24 h was 20% for voriconazole and 62% for vancomycin. Conclusions: The extraction of voriconazole and vancomycin by contemporary ECMO circuits is clinically relevant across all age-related circuit sizes and may result in reduced drug exposure in vivo.

Hyperoxia in pediatric severe traumatic brain injury (TBI): a comparison of patient classification by cutoff versus cumulative (area-under-the-curve) analysis.

OBJECTIVE: Hyperoxia is associated with adverse outcome in severe traumatic brain injury (TBI). This study explored differences in patient classification of oxygen exposure by PaO2 cutoff and cumulative area-under-the-curve (AUC) analysis. METHODS: Retrospective, explorative study including children (<18 years) with accidental severe TBI (2002-2015). Oxygen exposure analysis used three PaO2 cutoff values and four PaO2 AUC categories during the first 24 hours of Pediatric Intensive Care Unit (PICU) admission. RESULTS: Seventy-one patients were included (median age 8.9 years [IQR 4.6-12.9]), mortality 18.3% (n = 13). Patient hyperoxia classification differed depending on PaO2 cutoff vs AUC analysis: 52% vs. 26%, respectively, were classified in the highest hyperoxia category. Eleven patients (17%) classified as 'intermediate oxygen exposure' based on cumulative PaO2 analysis whereby they did not exceed the 200 mmHg PaO2 cutoff threshold. Patient classification variability was reflected by Pearson correlation coefficient of 0.40 (p-value 0.001). CONCLUSIONS: Hyperoxia classification in pediatric severe TBI during the first 24 hours of PICU admission differed depending on PaO2 cutoff or cumulative AUC analysis. We consider PaO2 cumulative (AUC) better approximates (patho-)physiological circumstances due to its time- and dose-dependent approach. Prospective studies exploring the association between cumulative PaO2, physiological parameters (e.g. ICP, PbtO2) and outcome are warranted as different patient classifications of oxygen exposure influences how its relationship to outcome is interpreted.

Challenges in Maintaining the Hemostatic Balance in Children Undergoing Extracorporeal Membrane Oxygenation: A Systematic Literature Review.

Background: Despite advances in technology and clinical experience, the incidence of hemostatic complications, including bleeding and thrombosis, remains high in children supported with extracorporeal membrane oxygenation (ECMO). These hemostatic complications are important to prevent, since they are associated with increased morbidity and mortality. This systematic literature review aims to outline the most important risk factors for hemostatic complications in children undergoing ECMO treatment, to summarize the reported alternative anticoagulant drugs used in pediatric ECMO and to describe studied associations between coagulation tests and hemostatic complications. Methods: A literature search was performed in Embase, Medline, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and Google Scholar in February 2020. Included studies were studies evaluating children (<18 years old) treated with ECMO, and studies evaluating risk factors for hemostatic complications, alternative anticoagulants, or the association between coagulation tests and hemostatic complications. Results: Out of 1,152 articles, 35 studies were included. Thirteen out of 49 risk factors were investigated in three or more studies. Most consistent results were found regarding ECMO duration and pH. However, evidence for risk factors was equivocal in the majority of studies, which is explained by the variability of populations studied, definitions of hemostatic complications, ECMO circuits, anticoagulation protocols, transfusion triggers and monitoring of anticoagulation. Five studies described alternative anticoagulants, including bivalirudin (n = 3), argatroban (n = 1) and FUT (n = 1). Higher anti-factor Xa levels were associated with less clotting events in one of nine studies, investigating the association between tests and hemostatic complications. Two studies revealed an association between anti-factor Xa assay-based protocols and a decreased number of transfusions, bleedings and need for circuit change. Conclusion: Studies regarding risk factors showed conflicting results and a few retrospective studies reported the use of new anticoagulants and data on coagulation tests in relation to hemostatic complications. To decrease hemostatic complications in ECMO children, prospective multicenter studies are needed with clear bleeding and thrombotic definitions, and the best possible standardization of ECMO circuits used, anticoagulation protocols, and transfusion triggers.

In Vitro Recovery of Sufentanil, Midazolam, Propofol, and Methylprednisolone in Pediatric Cardiopulmonary Bypass Systems.

OBJECTIVES: To evaluate in vitro drug recovery in cardiopulmonary bypass (CPB) systems used for pediatric cardiac surgery. DESIGN: Observational in vitro study. SETTING: Single-center university hospital. PARTICIPANTS: In vitro CPB systems used for pediatric cardiac surgery. INTERVENTIONS: Three full neonatal, infant, and pediatric CPB systems were primed according to hospital protocol and kept running for 6 hours. Midazolam, propofol, sufentanil, and methylprednisolone were added to the venous side of the systems in doses commonly used for induction of general anesthesia. Blood samples were taken from the postoxygenator side of the circuit immediately after injection of the drugs and after 2, 5, 7, 10, 30, 60, 180, and 300 minutes. MEASUREMENTS AND MAIN RESULTS: Linear mixed model analyses were performed to assess the relationship between log-transformed drug concentration (dependent variable) and type of CPB system and sample time point (independent variables). The mean percentage of drug recovery after 60 and 180 minutes compared with T1 was 41.7% (95% confidence interval [CI] 35.9-47.4) and 23.0% (95% CI 9.2-36.8) for sufentanil, 87.3% (95% CI 64.9-109.7) and 82.0% (95% CI 64.6-99.4) for midazolam, 41.3% (95% CI 15.5-67.2) and 25.0% (95% CI 4.7-45.3) for propofol, and 119.3% (95% CI 101.89-136.78) and 162.0% (95% CI 114.09-209.91) for methylprednisolone, respectively. CONCLUSIONS: The present in vitro experiment with neonatal, infant, and pediatric CPB systems shows a variable recovery of routinely used drugs with significant differences between drugs, but not between system categories (with the exception of propofol). The decreased recovery of mainly sufentanil and propofol could lead to suboptimal dosing of patients during cardiac surgery with CPB.

Recovery of cefazolin and clindamycin in in vitro pediatric CPB systems.

Cardiopulmonary bypass (CPB) is often necessary for congenital cardiac surgery, but CPB can alter drug pharmacokinetic parameters resulting in underdosing. Inadequate plasma levels of antibiotics could lead to postoperative infections with increased morbidity. The influence of pediatric CPB systems on cefazolin and clindamycin plasma levels is not known. We have measured plasma levels of cefazolin and clindamycin in in vitro pediatric CPB systems. We have tested three types of CPB systems. All systems were primed and spiked with clindamycin and cefazolin. Samples were taken at different time points to measure the recovery of cefazolin and clindamycin. Linear mixed model analyses were performed to assess if drug recovery was different between the type of CPB system and sampling time point. The experiments were conducted at a tertiary university hospital. 81 samples were analyzed. There was a significant difference in the recovery over time between CPB systems for cefazolin and clindamycin (P < .001). Cefazolin recovery after 180 minutes was 106% (95% CI: 91-123) for neonatal, 99% (95% CI: 85-115) for infant, and 77% (95% CI: 67-89) for pediatric systems. Clindamycin recovery after 180 minutes was 143% (95% CI: 116-177) for neonatal, 111% (95% CI: 89-137) for infant, and 120% (95% CI: 97-149) for pediatric systems. Clindamycin recovery after 180 minutes compared to the theoretical concentration was 0.4% for neonatal, 1.2% for infants, and 0.6% for pediatric systems. The recovery of cefazolin was high in the neonatal and infant CPB systems and moderate in the pediatric system. We found a large discrepancy between the theoretical and measured concentrations of clindamycin in all tested CPB systems.

Drug Disposition and Pharmacotherapy in Neonatal ECMO: From Fragmented Data to Integrated Knowledge.

Extracorporeal membrane oxygenation (ECMO) is a lifesaving support technology for potentially reversible neonatal cardiac and/or respiratory failure. As the survival and the overall outcome of patients rely on the treatment and reversal of the underlying disease, effective and preferentially evidence-based pharmacotherapy is crucial to target recovery. Currently limited data exist to support the clinicians in their every-day intensive care prescribing practice with the contemporary ECMO technology. Indeed, drug dosing to optimize pharmacotherapy during neonatal ECMO is a major challenge. The impact of the maturational changes of the organ function on both pharmacokinetics (PK) and pharmacodynamics (PD) has been widely established over the last decades. Next to the developmental pharmacology, additional non-maturational factors have been recognized as key-determinants of PK/PD variability. The dynamically changing state of critical illness during the ECMO course impairs the achievement of optimal drug exposure, as a result of single or multi-organ failure, capillary leak, altered protein binding, and sometimes a hyperdynamic state, with a variable effect on both the volume of distribution (Vd) and the clearance (Cl) of drugs. Extracorporeal membrane oxygenation introduces further PK/PD perturbation due to drug sequestration and hemodilution, thus increasing the Vd and clearance (sequestration). Drug disposition depends on the characteristics of the compounds (hydrophilic vs. lipophilic, protein binding), patients (age, comorbidities, surgery, co-medications, genetic variations), and circuits (roller vs. centrifugal-based systems; silicone vs. hollow-fiber oxygenators; renal replacement therapy). Based on the potential combination of the above-mentioned drug PK/PD determinants, an integrated approach in clinical drug prescription is pivotal to limit the risks of over- and under-dosing. The understanding of the dose-exposure-response relationship in critically-ill neonates on ECMO will enable the optimization of dosing strategies to ensure safety and efficacy for the individual patient. Next to in vitro and clinical PK data collection, physiologically-based pharmacokinetic modeling (PBPK) are emerging as alternative approaches to provide bedside dosing guidance. This article provides an overview of the available evidence in the field of neonatal pharmacology during ECMO. We will identify the main determinants of altered PK and PD, elaborate on evidence-based recommendations on pharmacotherapy and highlight areas for further research.

The Sublingual Microcirculation Throughout Neonatal and Pediatric Extracorporeal Membrane Oxygenation Treatment: Is It Altered by Systemic Extracorporeal Support?

Background: Extracorporeal membrane oxygenation (ECMO) treatment alleviates systemic cardiorespiratory failure. However, it is unclear whether ECMO also improves microcirculatory function, as the microcirculation can be disturbed despite normal systemic hemodynamics. We therefore aimed to study the sublingual microcirculation (SMC) throughout neonatal and pediatric ECMO treatment. We hypothesized that the SMC improves after starting ECMO, that the SMC differs between venovenous (VV) and venoarterial (VA) ECMO, and that insufficient recovery of microcirculatory disturbances during ECMO predicts mortality. Methods: This single-center prospective longitudinal observational study included 34 consecutive children (April 2016-September 2018). The SMC was assessed daily with a handheld vital microscope (integrated with incident dark field illumination) before, during, and after ECMO. Validated parameters of vessel density, perfusion, and flow quality were assessed for all vessels (diameter <100 µm) and small vessels (<20 µm). Linear mixed models and logistic regression models were built to assess changes over time and identify significant covariates. Using ROC curves, the predictive values of microcirculatory parameters were assessed for mortality on ECMO and overall mortality. Results: The study population comprised 34 patients (median age 0.27 years, 16 neonates, 16 females). Twelve patients were treated with VV and 22 with VA ECMO. Twelve patients died during ECMO (stopped due to futility) and 3 died after ECMO but before discharge. Microcirculatory parameters did not change significantly before, during or after ECMO. Except between microcirculatory flow index (MFI) and mean arterial pressure (MAP), no significant associations were found between microcirculatory parameters and global systemic hemodynamics. The probability of an undisturbed MFI (>2.6) increased with higher MAP (OR: 1.050, 95%CI: 1.008-1.094). Microcirculatory parameters did not significantly differ between VV and VA ECMO or between survivors and non-survivors. None of the microcirculatory parameters could predict mortality on ECMO or overall mortality. Conclusion: In this heterogeneous study population, we were not able to demonstrate an effect of ECMO on the sublingual microcirculation. Microcirculatory parameters did not change throughout ECMO treatment and did not differ between VV and VA ECMO or between survivors and non-survivors. Future research should focus on determining which neonatal and pediatric ECMO patients would benefit from microcirculatory monitoring and how.

Morphine treatment for neonatal abstinence syndrome: huge dosing variability underscores the need for a better clinical study design.

INTRODUCTION: At present, morphine is the most commonly used first-line therapy to treat Neonatal Abstinence Syndrome (NAS). Unfortunately, there is still lack of evidence and consensus to guide pharmacologic therapy for NAS. In this review, we provide an overview on dosing regimens of morphine currently reported to treat NAS, with the aim to stimulate discussion on the need for a standardized dosing through better study design. EVIDENCE ACQUISITION: A search strategy was performed in PubMed to identify studies that provide a dosing regimen used, or advised by a review or guideline for morphine to treat NAS. In addition, dosing regimens from labels and formularies were collected. EVIDENCE SYNTHESIS: On 138 articles identified, 33 were retained after reading the full-text. In addition, 10 articles were included based on reference check. Extensive variability was observed for dosing advice, threshold in the initiating phase, dosing advice and maximum dose in the escalating phase. The same applies for dosing advice and detail during weaning, dosing interval and stabilization phase. CONCLUSIONS: This review shows a large variability in dosing regimens of morphine used to treat NAS. This is likely a reflection of the heterogeneous populations included in NAS studies, the lack of standardization in assessment tools and study outcomes. We suggest that the development and validation of a core outcome set, subsequently applied in pragmatic point-of-care clinical trials or specific subgroups (e.g. iatrogenic postnatal NAS) are useful approaches to improve the current setting.