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Heparin, a sulfated polysaccharide belonging to the glycosaminoglycan family, has been widely used as an anticoagulant drug for decades and remains the most commonly used parenteral anticoagulant in adults and children. However, heparin has important clinical limitations and is derived from animal sources which pose significant safety and supply problems. The ever growing shortage of the raw material for heparin manufacturing may become a very significant issue in the future. These global limitations have prompted much research, especially following the recent well-publicized contamination scandal, into the development of alternative anticoagulants derived from non-animal and/or totally synthetic sources that mimic the structural features and properties of heparin. Such compounds, termed heparin mimetics, are also needed as anticoagulant materials for use in biomedical applications (e.g., stents, grafts, implants etc.). This review encompasses the development of heparin mimetics of various structural classes, including synthetic polymers and non-carbohydrate small molecules as well as sulfated oligo- and polysaccharides, and fondaparinux derivatives and conjugates, with a focus on developments in the past 10 years.

Currently there are three commercially available thrombin generation methods. These methods help detect the levels of thrombin generated in patient samples by the use of chromogenic or fluorogenic substrates in plasma or whole blood. Determining the rate of thrombin generation can help indicate if patients are at risk of clotting or bleeding. This review discusses two fluorogenic and one chromogenic method and focuses on similarities and differences of these three methods. The review specifically focuses on the accuracy of commercial substrates used in thrombin generation, and interference that can occur by various plasma proteins, as well as on evaluating the advantages and disadvantages of each method. The commercial chromogenic assay and both fluorogenic assays are able to monitor the rate of thrombin generation and can give indications towards potential coagulation abnormalities. Overall, the main differences between the thrombin generation methods are based on the type of substrate used, sample preparation, and data processing. Despite advancement in this field there are still technical challenges that preclude the widespread use of thrombin generation in clinical applications.

BACKGROUND: Venous thromboembolism (VTE) is a relatively rare condition in childhood with treatment mainly based on extrapolation from studies in adults. Therefore, clinical trials of anticoagulation in children require novel approaches to deal with numerous challenges. The EINSTEIN-Jr program identified pediatric rivaroxaban regimens commencing with in vitro dose finding studies followed by evaluation of children of different ages through phase I and II studies using extensive modeling to determine bodyweight-related doses. Use of this approach resulted in drug exposure similar to that observed in young adults treated with rivaroxaban 20 mg once-daily. METHODS: EINSTEIN-Jr phase III is a randomized, open-label, study comparing the efficacy and safety of rivaroxaban 20 mg-equivalent dose regimens with those of standard anticoagulation for the treatment of any types of acute VTE in children aged 0-18 years.A total of approximately 500 children are expected to be included during the 4-year study window. Flexibility of treatment duration is allowed with study treatment to be given for 3 months with the option to continue treatment in 3-month increments, up to a total of 12 months. However, based on most common current practice, children younger than 2 years with catheter-related thrombosis will have a main treatment period of 1 month with the option to prolong treatment in 1-month increments, up to a total of 3 months. CONCLUSIONS: EINSTEIN-Jr will compare previously established 20 mg-equivalent rivaroxaban dosing regimens with standard anticoagulation for the treatment of VTE in children. Demonstration of similarity of disease, as well as equivalent rivaroxaban exposure and exposure-response will enable extrapolation of efficacy from adult trials, which is critical given the challenges of enrollment in pediatric anticoagulation trials. TRIAL REGISTRATION: Clinicaltrials.gov NCT02234843, registered on 9 September 2014.

BACKGROUND: The EINSTEIN-Jr program will evaluate rivaroxaban for the treatment of venous thromboembolism (VTE) in children, targeting exposures similar to the 20 mg once-daily dose for adults. METHODS: This was a multinational, single-dose, open-label, phase I study to describe the pharmacodynamics (PD), pharmacokinetics (PK) and safety of a single bodyweight-adjusted rivaroxaban dose in children aged 0.5-18 years. Children who had completed treatment for a venous thromboembolic event were enrolled into four age groups (0.5-2 years, 2-6 years, 6-12 years and 12-18 years) receiving rivaroxaban doses equivalent to 10 mg or 20 mg (either as a tablet or oral suspension). Blood samples for PK and PD analyses were collected within specified time windows. RESULTS: Fifty-nine children were evaluated. In all age groups, PD parameters (prothrombin time, activated partial thromboplastin time and anti-Factor Xa activity) showed a linear relationship versus rivaroxaban plasma concentrations and were in line with previously acquired adult data, as well as in vitro spiking experiments. The rivaroxaban pediatric physiologically based pharmacokinetic model, used to predict the doses for the individual body weight groups, was confirmed. No episodes of bleeding were reported, and treatment-emergent adverse events occurred in four children and all resolved during the study. CONCLUSIONS: Bodyweight-adjusted, single-dose rivaroxaban had predictable PK/PD profiles in children across all age groups from 0.5 to 18 years. The PD assessments based on prothrombin time and activated partial thromboplastin time demonstrated that the anticoagulant effect of rivaroxaban was not affected by developmental hemostasis in children. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT01145859.

BACKGROUND: Venous thromboembolism (VTE) in young children is not well documented. METHODS: Clinicians from 12 institutions retrospectively evaluated the presentation, therapeutic management, and outcome of VTE in children younger than 2 years seen in 2011-2016. Feasibility of recruiting these children in EINSTEIN-Jr. phase III, a randomized trial evaluating rivaroxaban versus standard anticoagulation for VTE, was assessed. RESULTS: We identified 346 children with VTE, of whom 227 (65.6%) had central venous catheter-related thrombosis (CVC-VTE), 119 (34.4%) had non-CVC-VTE, and 156 (45.1%) were younger than 1 month. Of the 309 children who received anticoagulant therapy, 86 (27.8%) had a short duration of therapy (i.e. < 6 weeks for CVC-VTE and < 3 months for non-CVC-VTE) and 17 (5.5%) had recurrent VTE during anticoagulation (n = 8, 2.6%) or shortly after its discontinuation (n = 9, 2.9%). A total of 37 (10.7%) children did not receive anticoagulant therapy and 4 (10.5%) had recurrent VTE.The average number of children aged < 0.5 years and 0.5-2 years who would have been considered for enrolment in EINSTEIN-Jr is approximately 1.0 and 0.9 per year per site, respectively. CONCLUSIONS: Young children with VTE most commonly have CVC-VTE and approximately one-tenth and one-fourth received no or only short durations of anticoagulant therapy, respectively. Recurrent VTE rates without anticoagulation, during anticoagulation or shortly after its discontinuation seem comparable to those observed in adults. Short and flexible treatment durations could potentially increase recruitment in EINSTEIN-Jr. phase III.

AIM: To estimate the strengths of association between clinical features and migraine or arterial ischaemic stroke (AIS) in children presenting to the emergency department. METHOD: Eighty-four children with migraine, prospectively recruited from 2009 to 2010, were compared with 55 children with AIS, prospectively/retrospectively recruited from 2003 to 2010. Odds ratios were calculated via logistic regression to measure associations between clinical features and process-of-care factors, and migraine and AIS. RESULTS: Median age was 13 years 5 months (interquartile range 12y 11mo-13y 10mo) for migraine and 5 years (interquartile range 3y 7mo-8y) for patients with AIS. All cases of AIS and 30% of migraine cases underwent neuroimaging. Over 40% of children with migraine had vomiting, numbness, or visual disturbance; other symptoms were uncommon. Fifty-five per cent had no signs on physician assessment. Weakness or speech disturbance were common in patients with AIS. Significant clinical features associated with increased odds of AIS included sudden symptom onset, weakness, seizures, speech disturbance, and ataxia, and signs of face, arm, or leg weakness, inability to walk, dysarthria, dysphasia, and altered consciousness (p<0.05). Significant features associated with decreased odds of AIS included older age, vomiting, visual, sensory, other symptoms, and absent focal signs on assessment (p<0.05). INTERPRETATION: Presenting features can discriminate childhood AIS from migraine. These differences inform decisions about urgency and type of neuroimaging in children presenting to the emergency department with brain attack symptoms. WHAT THE PAPER ADDS: Weakness, seizures, ataxia, speech, or walking difficulties are more frequent in arterial ischaemic stroke (AIS). Vomiting, visual, or sensory disturbance and absent focal signs are more frequent in migraine. Identifying features of AIS and migraine guides neuroimaging in children with brain attack symptoms.

Error pattern analysis is a teaching technique that emphasizes identifying, classifying, and keeping a frequency count on only those errors actually occurring in students' writing. Application of error pattern analysis in a workshop format requires three steps: preparing an error pattern analysis, teaching from this analysis, and integrating it into the workshop format. Three samples from a student are usually enough to determine his or her error patterns; in a whole class, there probably will not be more than 20 to 30 types of errors. After compiling error pattern analysis charts for the class as a whole, the teacher can focus work in mechanics precisely where the students need it. Error pattern analysis can be integrated into the workshop format at the point where students edit each other's rough drafts. In this way, rudimentary editing skills and mechanics are learned simultaneously, while students also learn to interact cooperatively. In effect, students become their own teachers. (JL)

The use of error pattern analysis can reduce the time and money spent on editing and correcting manuscripts. What is required is noting, classifying, and keeping a frequency count of errors. First an editor should take a typical page of writing and circle each error. After the editor has done a sufficiently large number of pages to identify an error pattern, the errors can be arranged in categories, alphabetically, and assigned numbers such as (1) awkward syntax, (2) choice of word, (3) lack of colon for lists and definitions, and so forth. While it is possible for authors to make a wide variety of errors, they actually make only a few, and these they repeat. Commas may be a special problem because of the large number of subcategories and rules governing them. In this instance the editor can simplify terms and produce subcategories such as (4a), (4b), and so on. Once a pattern and numbering system are established, the editor can simply circle an error and place a number above it. The authors can then refer to the rules cited on a master sheet of the most common errors that would accompany their papers. This list becomes a nameless and faceless expert, a "third part," that can prevent some of the confrontations that occasionally arise between a writer and an editor. The most important aspect of error pattern analysis is that it reduces what seems to be a thicket of possible errors to a relatively small list of those that people actually make. (HOD)

BACKGROUND: Neuromotor impairments are common after pediatric stroke, but little is known about functional motor outcomes. We evaluated motor function and how it changed over the first 12 months after diagnosis. We also examined differences in outcome according to age at diagnosis and whether fine motor (FM) or gross motor (GM) function at 12 months was associated with adaptive behavior. METHOD(S): This prospective, longitudinal study recruited children (N = 64) from The Royal Children's Hospital, Melbourne who were diagnosed with acute arterial ischemic stroke (AIS) between December 2007 and November 2013. Motor assessments were completed at 3 time points after the diagnosis of AIS (1, 6, and 12 months). Children were grouped as follows: neonates (n = 27), preschool-aged (n = 19), and school-aged (n = 18). RESULT(S): A larger lesion size was associated with poorer GM outcomes at 12 months (P = .016). Neonatal AIS was associated with better FM and GM function initially but with a reduction in z scores over time. For the preschool- and school-aged groups, FM remained relatively stable over time. For GM outcomes, the preschool- and the school-aged age groups displayed similar profiles, with gradual recovery over time. Overall, poor FM and GM outcomes at 12 months were associated with poorer adaptive behavior scores. CONCLUSION(S): Motor outcomes and the trajectory of recovery post-AIS differed according to a child's age at stroke onset. These findings indicate that an individualized approach to surveillance and intervention may be needed that is informed in part by age at diagnosis.Copyright © 2017 by the American Academy of Pediatrics.

Aim: Childhood stroke disrupts brain development and emerging neural networks. Motor, cognitive, and language deficits are well recognized, yet little is known about psychosocial function after childhood stroke. This study aims to describe psychosocial function within the first year after childhood stroke, and to identify factors associated with outcome. Method(s): Thirty-seven children were involved in a prospective, longitudinal study investigating recovery over the first year after childhood stroke. Children's social functioning was assessed at 6-months and 12-months poststroke and psychological function at 12-months poststroke, using standardized measures. Result(s): Mean social function was poorer at both 6-months and 12-months poststroke, compared to prestroke. Psychological problems were more common than expected, with emotional difficulties and hyperactivity-inattention most significantly affected. Poorer social function was associated with older age at onset, acute neurological impairment, and prestroke social impairment. Social and psychological problems were associated with parent mental health. Interpretation(s): While not all children are affected, psychosocial impairment affects a significant minority after childhood stroke. Older age at onset, acute neurological impairment, prestroke social problems, and poorer parent mental health were associated with deficits. Identifying early predictors of poorer outcome will facilitate early intervention. Of particular importance is parent mental health, suggesting support for families may improve child outcome.Copyright © 2017 Mac Keith Press

Aim: Little is known about psychological and social outcomes after paediatric stroke. This study aimed to evaluate psychosocial outcomes in children 5 years after paediatric stroke and explore the contribution of early presenting factors. Method(s): Thirty-one children (19 males, 12 females) with arterial ischemic stroke were involved in this prospective, longitudinal study. Children underwent intellectual assessment at 12 months poststroke and parents completed questionnaires rating their own mental health and their child's functioning at 12 months and 5 years poststroke. Result(s): At 5-year follow-up, psychological and social function were significantly poorer than normative expectations. Exploration of early predictive factors showed poorer cognitive and psychological function at 12 months poststroke and older age at stroke onset was associated with poorer psychosocial function at 5 years. Larger lesion size was also associated with poorer psychological function at 5 years poststroke. Interpretation(s): These early predictors of poorer psychosocial outcome suggest that screening children within the first year after stroke may identify children most at risk of later problems and facilitate early intervention.Copyright © 2017 Mac Keith Press

AIM: Little is known about psychological and social outcomes after paediatric stroke. This study aimed to evaluate psychosocial outcomes in children 5 years after paediatric stroke and explore the contribution of early presenting factors. METHOD: Thirty-one children (19 males, 12 females) with arterial ischemic stroke were involved in this prospective, longitudinal study. Children underwent intellectual assessment at 12 months poststroke and parents completed questionnaires rating their own mental health and their child's functioning at 12 months and 5 years poststroke. RESULTS: At 5-year follow-up, psychological and social function were significantly poorer than normative expectations. Exploration of early predictive factors showed poorer cognitive and psychological function at 12 months poststroke and older age at stroke onset was associated with poorer psychosocial function at 5 years. Larger lesion size was also associated with poorer psychological function at 5 years poststroke. INTERPRETATION: These early predictors of poorer psychosocial outcome suggest that screening children within the first year after stroke may identify children most at risk of later problems and facilitate early intervention.

AIM: Childhood stroke disrupts brain development and emerging neural networks. Motor, cognitive, and language deficits are well recognized, yet little is known about psychosocial function after childhood stroke. This study aims to describe psychosocial function within the first year after childhood stroke, and to identify factors associated with outcome. METHOD: Thirty-seven children were involved in a prospective, longitudinal study investigating recovery over the first year after childhood stroke. Children's social functioning was assessed at 6-months and 12-months poststroke and psychological function at 12-months poststroke, using standardized measures. RESULTS: Mean social function was poorer at both 6-months and 12-months poststroke, compared to prestroke. Psychological problems were more common than expected, with emotional difficulties and hyperactivity-inattention most significantly affected. Poorer social function was associated with older age at onset, acute neurological impairment, and prestroke social impairment. Social and psychological problems were associated with parent mental health. INTERPRETATION: While not all children are affected, psychosocial impairment affects a significant minority after childhood stroke. Older age at onset, acute neurological impairment, prestroke social problems, and poorer parent mental health were associated with deficits. Identifying early predictors of poorer outcome will facilitate early intervention. Of particular importance is parent mental health, suggesting support for families may improve child outcome.

Background and aims Current clinical decision rules for pulmonary embolism are based on adult populations and have not been validated in children. The objective was to identify and evaluate clinical features for a first lifetime episode of pulmonary embolism in children presenting to the emergency department. Materials and methods We present a case-control study of children (<= 18 years) presenting to the emergency department of the Royal Children's Hospital, Melbourne between November 2007 and February 2015. Children with radiologically proven pulmonary embolism formed the case group, whilst children in whom there was a clinical suspicion of pulmonary embolism but negative diagnostic imaging formed the control group. Charts, electronic medical and imaging records of both cases and controls were reviewed and analysed. Results There were a total of 50 patients in this study (11 cases and 39 controls). Current or recent (within three months) use of the oral contraceptive pill was the most significant risk factor in our study (odds ratio 14.667, 95% confidence interval 3.001-71.678, P < 0.001). Most other features failed to discriminate between cases and controls, although there was a trend towards increased heart rate in cases. Conclusions Pulmonary embolism is perhaps the most common presenting spontaneous venous thromboembolism in the community and teenage girls on the oral contraceptive pill are most at-risk amongst children. The clinical signs and symptoms are often non-specific. Additional larger studies are required to determine the significance and magnitude of potential clinical predictors identified in this study. This may lead to derivation of a paediatric-specific pre-test probability tool.Copyright © 2015 Elsevier Ltd. All rights reserved.

BACKGROUND AND PURPOSE: Clinical identification of stroke in the pediatric emergency department is critical for improving access to hyperacute therapies. We identified key clinical features associated with childhood stroke or transient ischemic attack compared with mimics. METHODS: Two hundred and eighty consecutive children presenting to the emergency department with mimics, prospectively recruited over 18 months from 2009 to 2010, were compared with 102 children with stroke or transient ischemic attack, prospectively/retrospectively recruited from 2003 to 2010. RESULTS: Cerebrovascular diagnoses included arterial ischemic stroke (55), hemorrhagic stroke (37), and transient ischemic attack (10). Mimic diagnoses included migraine (84), seizures (46), Bell's palsy (29), and conversion disorders (18). Being well in the week before presentation (odds ratio [OR] 5.76, 95% confidence interval [CI] 2.25-14.79), face weakness (OR 2.94, 95% CI 1.19-7.28), arm weakness (OR 8.66, 95% CI, 2.50-30.02), and inability to walk (OR 3.38, 95% CI 1.54-7.42) were independently associated with increased odds of stroke diagnosis. Other symptoms were independently associated with decreased odds of stroke diagnosis (OR 0.28, 95% CI 0.10-0.77). Associations were not observed between seizures or loss of consciousness. Factors associated with stroke differed by arterial and hemorrhagic subtypes. CONCLUSIONS: Being well in the week before presentation, inability to walk, face and arm weakness are associated with increased odds of stroke. The lack of positive or negative association between stroke and seizures or loss of consciousness is an important difference to adults. Pediatric stroke pathways and bedside tools need to factor in differences between children and adults and between stroke subtypes.

Emergency physicians are often the first point of contact in children presenting with acute neurological disorders. Differentiating serious disorders, such as stroke, from benign disorders, such as migraine, can be challenging. Clinical assessment influences decision-making, in particular the need for emergent neuroimaging to confirm diagnosis. This review describes the spectrum of disorders causing 'brain attack' symptoms, or acute onset focal neurological dysfunction, with particular emphasis on childhood stroke, because early recognition is essential to improve access to thrombolytic treatments, which have improved outcomes in adults. Clues to diagnosis of specific conditions are discussed. Symptoms and signs, which discriminate stroke from mimics, are described, highlighting differences to adults. Haemorrhagic and ischaemic stroke have different presenting features, which influence choice of the most appropriate imaging modality to maximise diagnostic accuracy. Improvements in the care of children with brain attacks require coordinated approaches and system improvements similar to those developed in adults.

BACKGROUND: Unfractionated heparin (UFH) is the anticoagulant of choice in paediatric patients undergoing a variety of cardiac procedures. There are currently no population pharmacokinetic-pharmacodynamic (PKPD) models for UFH in paediatrics. OBJECTIVE: The aim of the present study was to develop and evaluate a PKPD model of UFH in paediatrics. METHODS: Data from 64 children who received 75-100 IU kg(-1) of UFH during cardiac angiography were analysed. Five blood samples were collected at baseline and at 15, 30, 45 and 120 min postdose. The UFH concentration was quantified using a protamine titration assay. The UFH effect was quantified using activated partial thromboplastin time (aPTT). A PKPD model was fitted using nonlinear mixed-effects modelling. Patient covariates such as gender, weight (WT) and fat-free mass (FFM) were tested. The final model was evaluated using the likelihood ratio test and visual predictive checks (VPCs). RESULTS: A one-compartment model with linear elimination provided the best fit for the dose-concentration data. FFM was a significant covariate on clearance. A linear model provided the best fit for the concentration-effect data using aPTT as a biomarker for effect. The models performed well using VPCs. However, when used to simulate UFH infusion (at a much lower dose), the model overpredicted target aPTT responses. CONCLUSIONS: A PKPD model to describe the time course of the UFH effect was developed in a paediatric population. FFM was shown to describe drug disposition well. However, when applied to smaller UFH infusion doses, the model overpredicted target aPTT responses. This unsuccessful extrapolation may be attributed to a possible nonlinear relationship for heparin PKPD.

Pre-eclampsia (PE) is a serious pregnancy complication which affects 3-5% of the pregnant population. To date there is no 'cure' for PE. However, the placenta seems to play an important role in the pathogenesis of this disease. Human placenta is an abundant source of proteoglycans to which glycosaminoglycan (GAG) side chains are attached. Heparan sulphate proteoglycans (HSPGs) have been implicated in many biological processes including, anticoagulation, angiogenesis and inflammation. However, their role in human placentae is largely unknown. The aim of this study was to determine the mRNA expression and protein abundance of HSPGs as well as the structure and relative abundance of GAGs in PE-affected placentae compared to gestation-matched controls.

Background: Pediatric stroke outcome studies are often cross sectional in design. Prospective information regarding the clinical course following diagnosis is lacking, but may inform clinical management beyond the acute period. Aim(s): To describe the outcome of arterial ischemic stroke in infants, children and adolescents at one-month and six-months post-stroke across health domains, and explore the relationship between lesion characteristics and early outcome with six-month adaptive behavior. Method(s): A single center prospective longitudinal study at a tertiary level children's hospital. Recruitment was undertaken from December 2007 to January 2012. Participants were children aged birth to 18 years presenting acutely with first diagnosed arterial ischemic stroke. Lesion characteristics on brain imaging were classified. Children were grouped according to age at diagnosis for analysis (neonates vs. those aged >30 days). Result(s): In 50 children with a median age of 47 months at diagnosis, sensorimotor impairments were most evident upon neurological examination acutely, especially in the older children. At both one-month and six-months motor functioning was significantly impaired in the older age group but no significant cognitive or language sequelae were identified. Lesion characteristics alone were not associated with six-month adaptive behavior outcomes. Conclusion(s): For patients surviving arterial ischemic stroke, the most significant clinical consequences both acutely and at six-months, are sensorimotor impairments, particularly evident in the older children. In contrast cognitive or language sequelae were not identified. Long-term surveillance is required to describe clinical course and rehabilitation needs, particularly for neonates and infants.Copyright © 2015 World Stroke Organization.

BACKGROUND: Long-term central venous catheters are essential for the management of chronic medical conditions, including childhood cancer. Catheter occlusion is associated with an increased risk of subsequent complications, including bloodstream infection, venous thrombosis, and catheter fracture. Therefore, predicting and pre-emptively treating occlusions should prevent complications, but no method for predicting such occlusions has been developed. METHODS: We conducted a prospective trial to determine the feasibility, acceptability, and efficacy of catheter-resistance monitoring, a novel approach to predicting central venous catheter occlusion in pediatric patients. Participants who had tunneled catheters and were receiving treatment for cancer or undergoing hematopoietic stem cell transplantation underwent weekly catheter-resistance monitoring for up to 12 weeks. Resistance was assessed by measuring the inline pressure at multiple flow-rates via a syringe pump system fitted with a pressure-sensing transducer. When turbulent flow through the device was evident, resistance was not estimated, and the result was noted as "non-laminar." RESULTS: Ten patients attended 113 catheter-resistance monitoring visits. Elevated catheter resistance (>8.8% increase) was strongly associated with the subsequent development of acute catheter occlusion within 10 days (odds ratio = 6.2; 95% confidence interval, 1.8-21.5; p <0.01; sensitivity, 75%; specificity, 67%). A combined prediction model comprising either change in resistance greater than 8.8% or a non-laminar result predicted subsequent occlusion (odds ratio = 6.8; 95% confidence interval, 2.0-22.8; p = 0.002; sensitivity, 80%; specificity, 63%). Participants rated catheter-resistance monitoring as highly acceptable. CONCLUSIONS: In this pediatric hematology and oncology population, catheter-resistance monitoring is feasible, acceptable, and predicts imminent catheter occlusion. Larger studies are required to validate these fin

BACKGROUND: Remote ischemic preconditioning (RIPC) has been applied in paediatric cardiac surgery. We have demonstrated that RIPC induces a proteomic response in plasma of healthy volunteers. We tested the hypothesis that RIPC modifies the proteomic response in children undergoing Tetralogy of Fallot (TOF) repair. METHODS AND RESULTS: Children (n=40) were randomized to RIPC and control groups. Blood was sampled at baseline, after cardiopulmonary bypass (CPB) and 6, 12 and 24h post-CPB. Plasma was analysed by liquid chromatography mass spectrometry (LC-MS) in an untargeted approach. Peptides demonstrating differential expression (p<0.01) were subjected to tandem LC-MS/MS and protein identification. Corresponding proteins were identified using the NCBI protein database. There was no difference in age (7.3±3.5vs6.8±3.6 months)(p=0.89), weight (7.7±1.8vs7.5±1.9 kg)(p=0.71), CPB time (104±7vs94±7 min)(p=0.98) or aortic cross-clamp time (83±22vs75±20 min)(p=0.36). No peptides were differentially expressed at baseline or immediately after CPB. There were 48 peptides with higher expression in the RIPC group 6h post-CPB. This was no longer evident at 12 or 24h, with one peptide down-regulated in the RIPC group. The proteins identified were: inter-alpha globulin inhibitor (42.0±11.8 vs 820.8±181.1, p=0.006), fibrinogen preproprotein (59.3±11.2 vs 1192.6±278.3, p=0.007), complement-C3 precursor (391.2±160.9 vs 5385.1±689.4, p=0.0005), complement C4B (151.5±17.8 vs 4587.8±799.2, p=0.003), apolipoprotein B100 (53.4±8.3 vs 1364.5±278.2, p=0.005) and urinary proteinase inhibitor (358.6±74.9 vs 5758.1±1343.1, p=0.009). These proteins are involved in metabolism, haemostasis, immunity and inflammation. CONCLUSIONS: We provided the first comprehensive analysis of RIPC-induced proteomic changes in children undergoing surgery. The proteomic changes peak 6h post-CPB and return to baseline within 24h of surgery. TRIAL REGISTRATION: ACTR.org.au ACTRN12610000496011.