Central venous catheter-related thrombosis and thromboprophylaxis in children: a systematic review and meta-analysis

Prevention of complications for hospitalized patients receiving parenteral nutrition: A narrative review

Hospitalized patients may benefit from parenteral nutrition to address their compromised nutrition status attributed to limited oral/enteral intake and increased nutrient/energy requirement during acute illness. Parenteral nutrition, however, can be associated with many complications that can negatively impact patient outcomes. In this review, we focus on potential metabolic and catheter-related complications associated with parenteral nutrition use. We report on potential risk factors for such complications and highlight strategies for prevention and early recognition. To optimize outcomes, key findings include the creation and implementation of evidence-based protocols with proven efficacy. For each hospital unit delivering parenteral nutrition to patients, tracking compliance with established protocols and patient outcomes is crucial for ongoing improvement through identification of gaps, proper reeducation and training, and ongoing refinement of care protocols. Establishment of specialized inpatient nutrition support teams should be considered.

Case Report: Vascular access in paediatric haemodialysis patients-creating and maintaining the patency of an arteriovenous fistula

Introduction

Paediatric vascular access is a demanding field. The need for a multidisciplinary team is mandatory in children with end-stage kidney disease (ESKD). Central venous catheters (CVCs) remain the preferred option worldwide. Recent emerging data demonstrated the benefits of using arteriovenous fistulas (AVFs) in the paediatric population for long-term vascular access. The small vessel size in children represents a surgical challenge for vascular access.

Case presentation

We report three cases from our haemodialysis department and the difficulty in maintaining permanent vascular access. The first case is an adolescent girl who required a change in vascular approach after multiple central venous catheter (CVC) infections and catheter thrombosis secondary to thrombophilia. Three AVFs were performed but failure occurred early. The patient was also diagnosed with a complex vascular thrombosis with total occlusion of the inferior vena cava and completed distal thrombosis of the superior vena cava. A permanent CVC was placed in the right jugular vein with the tip in the azygos vein. The second case is of an adolescent boy with systemic vasculitis with multiple CVC infections secondary to immunosuppression. The first thrombosis of two right AVFs occurred early with the development of a pseudo-aneurysm that required surgical intervention. The left brachial-cephalic fistula required surgery for closing the collaterals, repositioning and superficialisation. The third case is an adolescent boy with one surgical stage brachial-basilic left AVF and difficulties in venous puncturing.

Conclusion

Vascular access in paediatric haemodialysis remains a demanding field. There is a need for a multidisciplinary team, consisting of a vascular surgeon and an interventional radiologist specialising in children.

Evaluation of non-infectious complications in children receiving parenteral nutrition

BACKGROUND

Parenteral nutrition may lead to inevitable complications.

AIMS

To determine the indications, metabolic and mechanical complications of parenteral nutrition in children.

METHODS

One hundred fifty-eight children (91 males; 57.8%) who received 179 episodes of individualized parenteral nutrition for ≥ 5 days within 2 years were analyzed. Indications and duration of parenteral nutrition, effect on growth, and metabolic and central venous catheter-related non-infectious complications were evaluated.

RESULTS

Parenteral nutrition was administered in 179 different episodes (109 males; 60.9%), and the median age during these episodes was 64.0 (14.0-129.0) months. The most common indications were hematological malignancies, gastrointestinal surgery, and hematopoietic stem cell transplantation. Most of the electrolyte imbalances occurred in the first 3 days. Hypophosphatemia (44.7%), hypomagnesemia (43.0%), hypokalemia (43.0%), hyponatremia (40.8%), and hypertriglyceridemia (38.2%) were the most common metabolic complications. Liver transaminases elevated in 32/145 (22.1%) episodes and bilirubin in 30/149 (21.0%). Ursodeoxycholic acid treatment was added to 25 patients with hypertransaminasemia and/or hyperbilirubinemia. Transaminase levels improved in 16 (64%) and bilirubin levels in 15 (60%) patients receiving ursodeoxycholic acid. Catheter thrombosis was seen in 4.5% of the episodes. The targeted energy could be given more efficiently via central catheters rather than peripheral venous accesses. Patients' bodyweights increased in 39.1% of the episodes.

CONCLUSIONS

Close monitoring of electrolyte levels, especially in the first 3 days, is crucial to prevent complications of parenteral nutrition. When individualized PN preparations are used for metabolically unstable patients, it can be easier to maintain the blood glucose, lipids, and electrolyte levels within the normal range.

Thrombosis incidence in major paediatric burns

BACKGROUND

Major burns are associated with multiple risk factors for thrombosis such as decreased mobilization and systemic inflammation. It is unclear if these factors are offset by the inherent lower thrombosis risk in the paediatric patient. As such there is no consensus on thromboprophylaxis for paediatric burns patients, in contrast to this being a mainstay of treatment in the adult population. This retrospective cohort study examines the incidence of, and risk factors for, thrombotic events in major paediatric burns with a view to establish guidelines for prevention.

METHOD

Review of major paediatric burns, defined as % total body surface area (%TBSA) ≥30%, at the Adelaide Women's and Children's Hospital (WCH) over a 16-year period. Coding data and the local burns database were used to identify participants with subsequent review of case files.

RESULTS

Of the cohort (n = 23), six cases (26%) were complicated by thrombotic events. These patients had the most extensive burns averaging 68.5% TBSA, longer PICU admissions and associated interventions. These data points were more than doubled in the cohort diagnosed with a thrombus. Of the six events, five were secondary to central venous catheters (CVC) and one deep venous thrombosis (DVT) to the left calf.

CONCLUSION

The incidence of thrombotic events in our study was significant albeit in a small population. There is a strong association between large %TBSA and thrombus, with clots mostly forming around CVCs. While further research is required, this study demonstrates screening and targeted thromboprophylaxis may be required for major paediatric burns.

Complications Associated with Subsequent Vascular Access in Pediatric ECMO Patients

INTRODUCTION

Following ECMO decannulation, intensivists and surgeons must consider whether to reuse the cannulation site for central venous catheters (CVC) or seek remote access. This study investigates the risk of infectious complication associated with the reuse of peripheral ECMO cannulation sites for subsequent central venous access.

METHODS

A retrospective review was conducted for patients aged 0-18 years, who underwent peripheral ECMO cannulation between 2009 and 2021 at a single children's hospital.

RESULTS

Of the 227 charts reviewed, after ECMO decannulation, 53 patients received a CVC at the same location, 25 received a CVC at a different location, 62 received a peripherally inserted central catheter (PICC), and 87 had no subsequent vascular access placed within 30 days of decannulation. Patients with secondary access placed at the same site experienced 1 CLABSI, or 0.94 CLABSIs per 1000 line days. Patients with PICC lines after ECMO decannulation had 1 CLABSI, or 0.43 CLABSIs per 1000 line days. In comparison, the institution's hospital-wide CLABSI rate was 1.46 per 1000 line days during this same period. Although the rate of CLABSI among patients with secondary access at the site of decannulation was higher than the rate among patients with PICC lines (p = 0.79) it was lower than the institutional rate (p = 0.54), these differences did not rise to the level of statistical significance.

CONCLUSION

Compared with ECMO patients with subsequent CVCs placed at an alternative access site or via PICC after decannulation, patients with contemporaneous CVC placement at the site of decannulation do not experience a significantly higher rate of CLABSIs.

LEVEL OF EVIDENCE

Level III.

TYPE OF STUDY

Retrospective comparative study.

The Effect of Serum Electrolyte Levels and Infusion Treatments on the Development of Femoral Central Venous Catheter-Associated Deep Vein Thrombosis in Pediatric Intensive Care Unit

In this study, we aimed to determine the frequency of symptomatic central venous catheters-associated deep vein thrombosis (CVC-a DVT) among critically ill children with femoral vein implantation in our pediatric intensive care unit (PICU), and to compare the demographic factors, serum electrolyte levels, and types of the infusion treatments performed. A total of 215 patients aged 1 month to 18 years who had femoral CVC implanted between 2019 and 2021 were included in this study. The cases that were clinically symptomatic and had thrombosis diagnosed ultrasonography were accepted as CVC-a DVT (+), and the other cases were considered as CVC-a DVT (-). Of the total 215 cases, 57.2% (n = 123) were female and 42.8% (n = 92) were male. Catheters-associated deep vein thrombosis diagnosis were made in 9.8% of the cases (n = 21). The mean time to diagnose thrombosis in CVC-a DVT (+) cases was 8.33 ± 5.65 days. With regard to gender, age, blood type, intubation status, length of stay on mechanical ventilator, presence of extra hemodialysis catheter, acute and chronic disease status, number of days of PICU hospitalization, and Pediatric Risk of Mortality-3 scoring, no significant differences between CVC-a DVT (-) and CVC-a DVT (+) cases were observed (P > .05). The incidence of thrombosis in refugee cases was found to be significantly higher than in Turkish cases (P = .047; P < .05). There was no statistically significant difference between the groups in baseline, mean, and peak glucose, sodium, and magnesium values and who received magnesium, blood product, inotrope, and 3% hypertonic saline (HTS) infusion (P > .05). No effect of serum glucose, sodium, and magnesium levels on the development of CVC-a DVT was found. Magnesium, blood product, inotrope, and 3% HTS infusion treatments have not been shown to have an effect on the development of CVC-a DVT.

The association of vitamin-D level with catheter-related-thrombosis in hemodialysis patients: A data mining model

PURPOSE

This study aims to investigate the association of different risk factors including vitamin-D level with catheter-related-thrombosis in hemodialysis patients by applying data mining techniques.

METHODS

This study used the retrospectively approach and was done based on the CRISP-DM framework. The data of 1048 hemodialysis patients of Hasheminejad Kidney Center whose first catheterization was between 2014 and 2019 was used for analysis. In this study, patients with a previous history of deep venous thrombosis, thrombophilic condition, and undergone anticoagulant therapy were excluded. The decision tree J48 in WEKA software was used for modeling. The K-fold cross-validation method was also used to evaluate the classification performance. Finally, the model was evaluated by using Confusion Matrix and F-Measure.

RESULTS

The approved model was accurate in 70.3% of the predictions, and it demonstrated an association between patients' vitamin-D range and catheter-related-thrombosis.

CONCLUSION

The results indicated that in hemodialysis patients without the history of cancer or high blood pressure, vitamin-D had a significant impact on catheter related thrombosis.

Epidemiology and risk factors for thrombosis in children and newborns: systematic evaluation and meta-analysis

BACKGROUND

Thrombosis is a serious condition in children and neonates. However, the risk factors for thrombosis have not been conclusively determined. This study aimed to identify the risk factors for thrombosis in children and neonates in Intensive Care Unit (ICU) through a meta-analysis to better guide clinical treatment.

METHODS

A systematic search of electronic databases (PubMed, Embase, Cochrane Library, WOS, CNKI, Wanfang, VIP) was conducted to retrieve studies from creation on 23 May 2022. Data on the year of publication, study design, country of origin, number of patients/controls, ethnicity, and type of thrombus were extracted. The publication bias and heterogeneity between studies were assessed, and pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed or random effects models.

RESULTS

A total of 18 studies met the inclusion criteria. The incidence of thrombosis in children was 2% per year (95% CI 1%-2%, P < 0.01). Infection and sepsis (OR = 1.95, P < 0.01), CVC (OR = 3.66, [95%CL 1.78-7.51], P < 0.01), mechanical ventilation (OR = 2.1, [95%CL1.47-3.01], P < 0.01), surgery (OR = 2.25, [95%CL1.2-4.22], P < 0.01), respiratory distress (OR = 1.39, [95%CL0.42-4.63], P < 0.01), ethnicities (OR = 0.88, [95%CL 0.79-0.98], P = 0.78), gestational age (OR = 1.5, [95%CL1.34-1.68], P = 0.65)were identified as risk factors for thrombosis.

CONCLUSIONS

This meta-analysis suggests that CVC, Surgery, mechanical ventilation, Infection/sepsis, gestational age, Respiratory distress, and different ethnicities are risk factors for thrombosis in children and neonates in ICU. These findings may help clinicians to identify high-risk patients and develop appropriate prevention strategies.

TRIAL REGISTRATION

PROSPERO (CRD 42022333449).

Catheter-related atrial thrombosis: prevalence and risk factors in the pediatric age group—a retrospective study

Background

Catheter-related right atrial thrombosis (CRAT) is an under-studied complication of a long-term implantable venous access devices (IVAD), particularly in children with incidence rates extrapolated from the adult literature ranging between 2 and 29%. This is a single-center retrospective review of electronic medical records of children who underwent insertion of IVADs and had at least one echocardiogram performed prior to catheter removal between 2008 and 2018. Data collection included demographic information, development of CRAT, systemic infection, and administration of thrombogenic chemotherapeutic agents. We identified six patients who developed CRAT and compared them to 120 control patients. We also performed a detailed chart review for the patients who developed CRAT. Data was entered and analyzed using SPSS.

Results

A total of 764 patients underwent IVAD placement between 2008 and 2018. Six (0.79%) patients developed CRAT, and 120 patients were identified as controls that match the CRAT patients based on definitive criteria that include age, gender, chemotherapy type, steroid therapy, reason of line insertion, site of catheter insertion, tip-location at insertion, and history of systemic infections. In the CRAT group, 3 (50%) patients had their catheter tips placed in the superior vena cava-right atrial junction and 3 (50%) in the right atrium, whereas in the control group, all patients had their catheter tips placed in the superior vena cava-right atrial junction (p=0.000). Five (83.3%) patients in the CRAT group received L-asparaginase as compared to 75 (62.5%) patients in the control group (p=0.301). In the CRAT group, all patients had a history of systemic infection compared to 47 (39.2%) in the control group (p=0.180).

Conclusion

We identified 6 (0.79%) children with CRAT. Catheter-tip location within the right atrium is a potential risk factor for CRAT development in children.

Appendix to the Society of Interventional Radiology Consensus Guidelines for the Periprocedural Management of Thrombotic and Bleeding Risk in Patients Undergoing Percutaneous Image-Guided Interventions: Pediatric Considerations

PURPOSE

To provide guidance on the use of anticoagulant and antithrombotic agents in pediatric patients undergoing interventional radiology procedures.

MATERIALS AND METHODS

A multidisciplinary writing group conducted a comprehensive literature search to identify studies on the topic of interest. Recommendations were developed for procedural risk and medication dosage and withholding. A modified Delphi technique was used to achieve consensus agreement on the recommendations.

RESULTS

A total of 24 studies, including systematic reviews and meta-analyses, randomized controlled trials, and prospective and retrospective cohort studies, were identified as relevant. The expert writing group agreed on procedural risk categorization, laboratory testing thresholds, and medication dosage and withholding recommendations specific to pediatric practice. They additionally described the nuances of anticoagulation in clinical conditions specific to pediatrics.

CONCLUSIONS

The Society of Interventional Radiology recommends following the guidance provided in the document when developing multidisciplinary management protocols for anticoagulation and antithrombotic treatment in pediatric patients undergoing interventional radiology procedures.

Thromboprophylaxis for children hospitalized with COVID-19 and MIS-C

Background

Limited data exist about effective regimens for pharmacological thromboprophylaxis in children with acute coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C).

Objectives

Study the outcomes of institutional thromboprophylaxis protocol for primary venous thromboembolism (VTE) prevention in children hospitalized with acute COVID-19/MIS-C.

Methods

This single-center retrospective cohort study included consecutive children (aged less than 21 years) with COVID-19/MIS-C who received tailored intensity thromboprophylaxis, primarily with low-molecular-weight heparin, from April 2020 through October 2021. Thromboprophylaxis was given to those with moderate to severe disease based on the World Health Organization scale and exposure to two or more VTE risk factors. Therapeutic intensity was considered for severe illness. Clinical recovery along with D-dimer improvement determined thromboprophylaxis duration. Outcomes were incident VTEs, bleeding, and mortality.

Results

Among 211 hospitalizations, 45 (21.3%) received thromboprophylaxis (COVID-19, 16; MIS-C, 29). Median age was 14.8 years (interquartile range [IQR], 8.9-16.1). Among 35 (77.8%) with severe illness, 27 (60.0%) required respiratory support, and 19 (42.2%) required an intensive care unit stay. Median hospitalization was 6 days (IQR, 5.0-10.5). Median thromboprophylaxis duration was 19 days (IQR, 6.0-31.0) with therapeutic intensity in 24 (53.3%) and prophylactic in 21 (46.7%). Outcomes were as follows: VTE, 1 (2.2%); death, 1 (2.2%, unrelated to bleeding/thrombosis); major/clinically relevant nonmajor bleeding, 0; and minor bleeding, 7 (15.5%). D-dimer was elevated in a majority at diagnosis (median, 2.3; IQR, 1.2-3.3 mg/ml fibrinogen-equivalent units) and was noninformative in assessing disease severity. D-dimer normalized at thromboprophylaxis discontinuation.

Conclusions

Our experience of using clinically directed thromboprophylaxis with tailored intensity approach for children hospitalized with COVID-19 and MIS-C favors its inclusion in current standard of care. The role of D-dimer in directing thromboprophylaxis management deserves further evaluation.

Management of Central Venous Catheters in Children and Adults on Home Parenteral Nutrition: A French Survey of Current Practice

Although central venous catheter (CVC)-related thrombosis (CRT) is a severe complication of home parenteral nutrition (HPN), the amount and quality of data in the diagnosis and management of CRT remain low. We aimed to describe current practices regarding CVC management in French adult and pediatric HPN centers, with a focus on CVC obstruction and CRT. Current practices regarding CVC management in patients on HPN were collected by an online-based cross-sectional survey sent to expert physicians of French HPN centers. We compared these practices to published guidelines and searched for differences between pediatric and adult HPN centers’ practices. Finally, we examined the heterogeneity of practices in both pediatric and adult HPN centers. The survey was completed by 34 centers, including 21 pediatric and 13 adult centers. We found a considerable heterogeneity, especially in the responses of pediatric centers. On some points, the centers’ responses differed from the current guidelines. We also found significant differences between practices in adult and pediatric centers. We conclude that the management of CVC and CRT in patients on HPN is a serious and complex situation for which there is significant heterogeneity between HPN centers. These findings highlight the need for more well-designed clinical trials in this field.

Prophylaxis of Venous Thromboembolism in Children: A Systematic Review

Venous thromboembolism (VTE) in children is a rare but serious event. Current guidance on pharmacological thromboprophylaxis in children is mostly based on adult studies and expert opinions. The aim of this systematic review was to examine under which conditions children (age ≤ 18 years) would benefit from pharmacological thromboprophylaxis with low molecular weight heparin or unfractionated heparin. Eligible studies included children, who did not receive pharmacological thromboprophylaxis as comparator, and VTE events were radiologically verified. MEDLINE and Embase were searched up to October 3, 2021. Ten studies were included presenting data for 976 children receiving pharmacological thromboprophylaxis. We divided the studies into three categories based on the population studied: children in the intensive care unit (n = 2), children with fractures and/or undergoing surgery (n = 5), and children with systemic disease (n = 3). A lower incidence of VTE was found when pharmacological thromboprophylaxis was used compared with no prophylaxis in children in intensive care unit with central venous catheter and mechanical ventilation (7/27 vs. 13/24), children in the intensive care unit admitted after trauma with a very high risk of VTE based on several risk factors (0/21 vs. 13/96), and children with acute lymphoblastic leukemia treated with L-asparaginase concomitant with steroid and presence of central venous catheter (0/82 vs. 8/121). Pharmacological thromboprophylaxis was not associated with an increased bleeding risk. In conclusion, pharmacological thromboprophylaxis in children is sparsely investigated. Only children with several risk factors for VTE are likely to benefit from pharmacological thromboprophylaxis.

Use of Pharmacologic Prophylaxis Against Venous Thromboembolism in Hospitalized Injured Children

Despite a practice management guideline and risk prediction model for venous thromboembolism (VTE), pediatric-specific evidence on pharmacologic prophylaxis is lacking. In a retrospective study, we characterized receipt of prophylaxis and explored its effectiveness in hospitalized injured patients below 18 years old using data from the Trauma Quality Improvement Program. Concordance of receipt of prophylaxis with guideline and predicted risk of VTE was estimated using κ statistic. Effectiveness was explored using cohorts matched based on the risk prediction model. A total of 11,165 (6.2%) of 180,932 patients received prophylaxis. Those who received prophylaxis were more commonly post-pubertal and more severely injured. Receipt of prophylaxis was fairly concordant with the guideline (κ=0.32) and predicted risk of VTE (κ=0.29). Receipt of prophylaxis was associated with higher rates of VTE likely due to confounding by indication. Low molecular weight heparin seemed more effective against VTE than unfractionated heparin (incidence rate ratio: 0.52; 95% confidence interval: 0.36, 0.75), but less effective when received ≥72 hours after admission to the hospital. We showed that hospitalized injured children did not commonly receive prophylaxis. We also showed that prophylaxis may be effective in hospitalized injured children, but it needs to be proven definitively in a randomized clinical trial.

Anticoagulation in Pediatric Patients

Special aspects of anticoagulation in children include the different epidemiology of thrombosis, developmental changes in the coagulation system, age-dependent pharmacokinetics of anticoagulants, risk of bleeding, and practical hurdles to anticoagulation. The classical anticoagulants so far used in children have several limitations, resulting in the need for regular monitoring. The pharmacological properties of direct oral anticoagulants (DOACs) and the special challenges of anticoagulation in children make the DOACs particularly attractive for children. All DOACs have pediatric development programs, targeting various indications for prevention and treatment of thrombosis. Child-appropriate formulations have been developed, age-specific dosing information generated, and safety and efficacy evaluated in ongoing phase 3 trials. Rivaroxaban and dabigatran have already been authorized for children for treatment of acute venous thrombosis and for extended secondary prevention. Their safety and efficacy have been demonstrated comparable to that of standard-of-care anticoagulants, without need for monitoring. Further studies are ongoing, which are expected to lead to pediatric authorizations of DOACs for primary venous thromboembolic event prevention in some high-risk settings. More real-life data will be necessary from postmarketing studies and registries to complement the evidence base for DOAC use in children, particularly in the youngest age groups and special disease populations.

Incidence of venous thromboembolic events not related to vascular catheters in a prospective cohort of critically ill children

The risk for venous thromboembolism (VTE) is considered to be low in the general paediatric intensive care unit (PICU) population, and pharmacological thromboprophylaxis is not routinely used. PICU patients considered at high-risk of VTE could possibly benefit from pharmacological thromboprophylaxis, but the incidence of VTE in this group of patients is unclear. This was an observational, prospective study at a tertiary multi-disciplinary paediatric hospital. We used comprehensive ultrasonography screening for VTE in critically ill children with multiple risk factors for VTE. Patients admitted to PICU ≥ 72 h and with ≥ two risk factors for VTE were included. Patients receiving pharmacological thromboprophylaxis during their entire PICU stay were excluded. The primary outcome of the study was VTEs not related to the use of a CVC. Ultrasonography screening of the great veins was performed at PICU discharge. Seventy patients with median (interquartile range) 3 (2-4) risk factors for VTE were evaluated. Median age was 0.3 years (0.03-4.3) and median PICU length of stay 9 days (5-17). Regarding the primary outcome, no symptomatic VTEs occurred and no asymptomatic VTEs were found on ultrasonography screening, resulting in an incidence of VTEs not related to a vascular catheter of 0% (95% CI: 0-5.1%).

CONCLUSION

Our results indicate that VTEs not related to a vascular catheter are a rare event even in a selected group of severely ill small children considered to be at high risk of VTE.

WHAT IS KNOWN

• Children in the PICU often have several risk factors for venous thromboembolism (VTE). • The incidence of VTE in PICU patients is highly uncertain, and there are no evidence-based guidelines regarding VTE prophylaxis.

WHAT IS NEW

• This study found an incidence of VTEs not related to a vascular catheter of 0% (95% CI: 0-5.1%). • This indicates that such VTE events are rare even in PICU patients with multiple risk factors for VTE.

Outcomes of Catheter-Related Arterial and Venous Thrombosis After Enoxaparin Therapy in Neonates and Infants With Congenital Heart Disease

OBJECTIVES

Outcomes of catheter-related arterial and venous thrombosis after enoxaparin therapy in neonates and infants with congenital heart disease.

DESIGN

A single-center retrospective cohort study.

SETTING

Cardiac ICU.

PATIENTS

Patients under 1 year old cared for in the cardiac ICU at Nicklaus Children's Hospital from January 2015 to January 2019 and treated with enoxaparin for central vascular catheter-related arterial and venous thrombosis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One-hundred fifty-six events of central catheter-related arterial and venous thrombosis were included in the study. Arterial thrombi accounted for 109 (69.9%) and venous thrombi for 47 (30.1%) of the events. Femoral vessels were the most commonly affected site (88.5%). Therapeutic outcomes were analyzed in 106 events, excluding those without follow-up imaging. The analysis was stratified by age into neonates and infants and catheter types into arterial and venous catheter groups. Therapeutic dose of enoxaparin was higher in neonates (median 1.8 mg/kg/dose) compared with infants (1.6 mg/kg/dose; p = 0.001). Complete resolution was seen in 68%, partial resolution in 19%, nonresolution in 13% of the events. The complete resolution was higher for arterial than venous (85% vs 65.6%; p = 0.032) thrombi with a shorter duration of enoxaparin treatment (23 vs 43 d; p = 0.014). Complete resolution was lowest in neonates with venous thrombosis (42.9%). The median time to complete resolution by Kaplan-Meier analysis was 24.9 days in the overall cohort, 34.3 days in neonates, 24.9 days in infants, 20 days in arterial, and 44.9 days in venous catheter group.

CONCLUSIONS

A high proportion of vascular catheter-related thrombi identified in infants with congenital heart disease resolve with enoxaparin treatment. In all patients with thrombosis, arterial versus venous thrombosis is associated with greater odds of resolution.

Venous thromboembolic risk stratification in pediatric trauma: A Pediatric Trauma Society Research Committee multicenter analysis

BACKGROUND

Venous thromboembolism (VTE) in injured children is rare, but its consequences are significant. Several risk stratification algorithms for VTE in pediatric trauma exist with little consensus, and all are hindered in development by relying on registry data with known inaccuracies. We performed a multicenter review to evaluate trauma registry fidelity and confirm the effectiveness of one established algorithm across diverse centers.

METHODS

Local trauma registries at 10 institutions were queried for all patients younger than 18 years admitted between 2009 and 2018. Additional chart review was performed on all "VTE" cases and random non-VTE controls to assess registry errors. Corrected data were then applied to our prediction algorithm using 10 real-time variables (Glasgow Coma Scale, age, sex, intensive care unit admission, transfusion, central line placement, lower extremity/pelvic fracture, major surgery) to calculate VTE risk scores. Contingency table classifiers and the area under a receiver operator characteristic curve were calculated.

RESULTS

Registries identified 52,524 pediatric trauma patients with 99 episodes of VTE; however, chart review found that 13 cases were misclassified for a corrected total of 86 cases (0.16%). After correction, the algorithm still displayed strong performance in discriminating VTE-fated encounters (sensitivity, 69%; area under the receiver operating characteristic curve, 0.96). Furthermore, despite wide institutional variability in VTE rates (0.04-1.7%), the algorithm maintained a specificity of >91% and a negative predictive value of >99.7% across centers. Chart review also revealed that 54% (n = 45) of VTEs were directly associated with a central line, usually femoral (n = 34, p < 0.001 compared with upper extremity), and that prophylaxis rates were underreported in the registries by about 50%; still, only 19% of the VTE cases had been on prophylaxis before diagnosis.

CONCLUSION

The VTE prediction algorithm performed well when applied retrospectively across 10 diverse pediatric centers using corrected registry data. These findings can advance initiatives for VTE screening/prophylaxis guidance following pediatric trauma and warrant prospective study.

LEVEL OF EVIDENCE

Clinical decision rule evaluated in a single population, level III.

Efficacy of Early Prophylaxis Against Catheter-Associated Thrombosis in Critically Ill Children: A Bayesian Phase 2b Randomized Clinical Trial

OBJECTIVES

We obtained preliminary evidence on the efficacy of early prophylaxis on the risk of central venous catheter-associated deep venous thrombosis and its effect on thrombin generation in critically ill children.

DESIGN

Bayesian phase 2b randomized clinical trial.

SETTING

Seven PICUs.

PATIENTS

Children less than 18 years old with a newly inserted central venous catheter and at low risk of bleeding.

INTERVENTION

Enoxaparin adjusted to anti-Xa level of 0.2-0.5 international units/mL started at less than 24 hours after insertion of central venous catheter (enoxaparin arm) versus usual care without placebo (usual care arm).

MEASUREMENTS AND MAIN RESULTS

At the interim analysis, the proportion of central venous catheter-associated deep venous thrombosis on ultrasonography in the usual care arm, which was 54.2% of 24 children, was significantly higher than that previously reported. This resulted in misspecification of the preapproved Bayesian analysis, reversal of direction of treatment effect, and early termination of the randomized clinical trial. Nevertheless, with 30.4% of 23 children with central venous catheter-associated deep venous thrombosis on ultrasonography in the enoxaparin arm, risk ratio of central venous catheter-associated deep venous thrombosis was 0.55 (95% credible interval, 0.24-1.11). Including children without ultrasonography, clinically relevant central venous catheter-associated deep venous thrombosis developed in one of 27 children (3.7%) in the enoxaparin arm and seven of 24 (29.2%) in the usual care arm (p = 0.02). Clinically relevant bleeding developed in one child randomized to the enoxaparin arm. Response profile of endogenous thrombin potential, a measure of thrombin generation, was not statistically different between trial arms.

CONCLUSIONS

These findings suggest the efficacy and safety of early prophylaxis that should be validated in a pivotal randomized clinical trial.

Vascular access device securement for oncology patients and those with chronic diseases

This article presents three case studies, each discussing securement issues as they relate to the use of long-term vascular access devices from the perspectives of the clinician and the patient. The choice of securement should be weighed against the patient's activity level, duration of the line placement, infection risks and inevitable skin irritation caused by repeated replacement of adhesive securement. Living with a chronic illness requiring frequent infusions is difficult enough-worrying about the device being dislodged should not be an additional stressor.

Thromboembolic Complications of Vascular Catheters Used for Pediatric Continuous Renal Replacement Therapy: Prevalence in a Single-Center, Retrospective Cohort

OBJECTIVES

Pediatric venous thromboembolic events are commonly associated with in situ central venous catheters. The risk for severe venous thromboembolism increases if a larger portion of the vessel lumen is occupied by the central venous catheter. A functioning vascular catheter is required when the continuous renal replacement therapy is used in critically ill children. Due to the high blood flow required for continuous renal replacement therapy, the external diameter of the catheter needs to be larger than a conventional central venous catheter used for venous access, potentially increasing the risk of venous thromboembolism. However, children on continuous renal replacement therapy often receive systemic anticoagulation to prevent filter clotting, possibly also preventing venous thromboembolism. The frequency of catheter-related venous thromboembolic events in this setting has not been described. Our main objective was to determine the prevalence of catheter-related venous thromboembolism in pediatric continuous renal replacement therapy.

DESIGN

Retrospective cohort study.

SETTING

Tertiary multidisciplinary academic pediatric hospital.

PATIENTS

Patients 0-18 years old with a vascular catheter used for continuous renal replacement therapy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In our series of 80 patients, we used 105 vascular catheters. The median age of the patients was 10 months and PICU mortality rate was 21%. Venous thromboembolic events were considered to be catheter related if located in the same vein as the vascular catheter and radiologically verified. Six (5.7%) catheter-related venous thromboembolic events were found. The clinically relevant complications of venous thromboembolism included superior vena cava syndrome and catheter dysfunction. In one patient, severe and life-threatening pulmonary embolism occurred. In comparison with patients without venous thromboembolism, venous thromboembolic events were associated with lower body weight (p = 0.03) and longer durations of continuous renal replacement therapy (p < 0.01), mechanical ventilation (p = 0.03), and PICU stay (p < 0.01). Five out of six venous thromboembolisms appeared in neonates.

CONCLUSIONS

Catheter-related venous thromboembolism is a clinically relevant complication of pediatric continuous renal replacement therapy, with a prevalence of 5.7% in our cohort. Clinicians involved in pediatric continuous renal replacement therapy need to be vigilant for symptoms of venous thromboembolisms and initiate appropriate treatment as soon as possible.

Venous Thromboembolism among Critically Ill Children: A Narrative Review

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality among hospitalized patients, including children. In recent years, it has become clear that hospitalization and critical illness bestow an increased VTE risk in pediatrics and relate to mortality and life-limiting comorbidities. For critically ill children, reported rates of VTE vary by study sampling techniques, presence of inherited or acquired thrombophilia, acute and chronic immobility, underlying illness prompting hospitalization, and clinical factors related to illness severity such as central venous catheterization, length of stay, mechanical ventilation, and patient age. Accordingly, critically ill children with new signs of venous congestion, acute inflammation, or unexplained acute organ dysfunction should be routinely evaluated for VTE. This narrative review summarizes recent and historical literature regarding risk factors, prevention, presentation, treatment, and outcomes of VTE in critically ill children. In addition, we identify knowledge gaps and priorities for future collaborative research on this vital condition. Special attention is given to the clinical trial opportunities, challenges, and ongoing efforts in thromboprophylaxis in critically ill children, including those hospitalized for disease related to novel coronavirus (COVID-19) and multisystem inflammatory disease in children.

Enoxaparin Reduces Catheter Associated Venous Thrombosis Following Infant Cardiac Surgery

BACKGROUND

Central venous catheter (CVC) related venous thrombosis (VT) following pediatric cardiac surgery increases the morbidity and mortality. Although VT prevention using low dose anticoagulation has proven ineffective, anticoagulation using high dose enoxaparin to achieve a therapeutic anti-xa level has not been studied. We hypothesized that high dose enoxaparin would reduce VT after pediatric cardiac surgery.

METHODS

Enoxaparin was administered to infants < 150 days when post-operative CVC duration was anticipated to extend beyond 5 days. The primary outcome was the rate of VT, re-exploration for bleeding, and post-operative red blood cell (RBC) transfusions per 1,000 CVC days.

RESULTS

From 2012-2019, 157 infants were treated with enoxaparin. Infants were divided into two groups: 1) SubTherapeutic (SubTher) (N = 51) - therapeutic anti-xa level (0.5-1.0 IU/mL) was not achieved, 2) Therapeutic (Ther) (N = 106) - therapeutic anti-xa level was achieved. Baseline demographics demonstrated a lower age at operation within the Ther group. The SubTher group had a higher VT rate/1,000 CVC days (8.2) compared to the Ther group (2.6; p=0.005). Re-exploration for bleeding was similar between groups. The number of post-operative RBC transfusions/1,000 CVC days was significantly greater in the SubTher group (109.4 vs. 81.6; p=0.008). Multivariate analysis demonstrated that higher median anti-xa levels reduced the risk of VT (OR 0.02, CI: 0.001, 0.63; p = 0.02).

CONCLUSIONS

This data suggests that enoxaparin treatment resulting in a therapeutic anti-xa level reduces post-operative CVC associated VT without increasing bleeding complications.

Safety and efficacy of anticoagulant therapy in pediatric catheter-related venous thrombosis (EINSTEIN-Jr CVC-VTE)

Anticoagulant treatment of pediatric central venous catheter-related venous thromboembolism (CVC-VTE) has not been specifically evaluated. In EINSTEIN-Jr, 500 children with any VTE received rivaroxaban or standard anticoagulants. A predefined analysis of the CVC-VTE cohort was performed. Children with CVC-VTE (age, birth to 17 years) were administered rivaroxaban or standard anticoagulants during the 1-month (children <2 years) or 3-month (all other children) study period. Predefined outcomes were recurrent VTE, change in thrombotic burden on repeat imaging, and bleeding. Predictors for continuation of anticoagulant therapy beyond the study period were evaluated. One hundred twenty-six children with symptomatic (n = 76, 60%) or asymptomatic (n = 50, 40%) CVC-VTE received either rivaroxaban (n = 90) or standard anticoagulants (n = 36). There was no recurrent VTE (0%; 95% confidence interval [CI], 0.0%-2.8%). Three children had the principal safety outcome: none had major bleeding and 3 children had clinically relevant nonmajor bleeding (2.4%; 95% CI, 0.7%-6.5%), all in the rivaroxaban arm. Complete or partial vein recanalization occurred in 57 (55%) and 38 (37%) of 103 evaluable children, respectively. Results were similar for symptomatic and asymptomatic CVC-VTE. Continuation of anticoagulant therapy beyond the study period occurred in 61 (48%) of children and was associated with residual VTE but only in children <2 years (odds ratio [OR], 20.9; P = .003) and continued CVC use (OR, 6.7; P = .002). Anticoagulant therapy appeared safe and efficacious and was associated with reduced clot burden in most children with symptomatic or asymptomatic CVC-VTE. Residual VTE and continued CVC use were associated with extended anticoagulation. This trial was registered at www.clinicaltrials.gov as #NCT02234843.

Age-Dependent Heterogeneity in the Efficacy of Prophylaxis With Enoxaparin Against Catheter-Associated Thrombosis in Critically Ill Children: A Post Hoc Analysis of a Bayesian Phase 2b Randomized Clinical Trial

OBJECTIVES

We explored the age-dependent heterogeneity in the efficacy of prophylaxis with enoxaparin against central venous catheter-associated deep venous thrombosis in critically ill children.

DESIGN

Post hoc analysis of a Bayesian phase 2b randomized clinical trial.

SETTING

Seven PICUs.

PATIENTS

Children less than 18 years old with newly inserted central venous catheter.

INTERVENTIONS

Enoxaparin started less than 24 hours after insertion of central venous catheter and adjusted to anti-Xa level of 0.2-0.5 international units/mL versus usual care.

MEASUREMENTS AND MAIN RESULTS

Of 51 children randomized, 24 were infants less than 1 year old. Risk ratios of central venous catheter-associated deep venous thrombosis with prophylaxis with enoxaparin were 0.98 (95% credible interval, 0.37-2.44) in infants and 0.24 (95% credible interval, 0.04-0.82) in older children greater than or equal to 1 year old. Infants and older children achieved anti-Xa level greater than or equal to 0.2 international units/mL at comparable times. While central venous catheter was in situ, endogenous thrombin potential, a measure of thrombin generation, was 223.21 nM.min (95% CI, 8.78-437.64 nM.min) lower in infants. Factor VIII activity, a driver of thrombin generation, was also lower in infants by 45.1% (95% CI, 15.7-74.4%). Median minimum platelet count while central venous catheter was in situ was higher in infants by 39 × 103/mm3 (interquartile range, 17-61 × 103/mm3). Central venous catheter:vein ratio was not statistically different. Prophylaxis with enoxaparin was less efficacious against central venous catheter-associated deep venous thrombosis at lower factor VIII activity and at higher platelet count.

CONCLUSIONS

The relatively lesser contribution of thrombin generation on central venous catheter-associated thrombus formation in critically ill infants potentially explains the age-dependent heterogeneity in the efficacy of prophylaxis with enoxaparin.

Abdominal aortic thrombus formation in a neonate with an interrupted aortic arch

We note the risk of paradoxical embolism in patients with congenital heart defects with a right-to-left shunt. These patients should be managed to ensure that abdominal aortic thrombi are not overlooked when their clinical conditions change.

Venous thromboembolism in children with central nervous system tumors: Comparison of an institutional cohort to a national administrative database

BACKGROUND

Central nervous system (CNS) tumors are the second most common malignancy of childhood, and published data on venous thromboembolism (VTE) rate and risk factors for these patients are outdated or incomplete. Here, we determine the cumulative incidence and risk factors for VTE in this population.

PROCEDURE

VTE diagnosis and associated clinical risk factors were abstracted and analyzed for two cohorts of children (0-21 years) diagnosed with CNS tumors between January 1, 2010 to September 30, 2018. The first study was a retrospective single institution cohort study. The initial observations were confirmed across multiple pediatric hospitals using the Pediatric Health Information System (PHIS) administrative database.

RESULTS

The single-institution cohort included 338 patients aged 3 days to 20.9 years (median age, 8.6 years); VTE developed in eight (2.4%) patients. The PHIS cohort included 17 634 patients aged from 0 to 21.9 years (median: 9.5 years); VTE developed in 354 (2.0%) patients. Univariate analysis for the single-institution cohort identified central venous catheter (CVC) placement as a risk factor for VTE (odds ratio [OR] 8.40, 95% confidence interval [CI] 1.43-49.41, P = .0186). Multivariable analysis of the PHIS dataset identified CVC placement (OR 1.97, 95% CI 1.57-2.46; P < .0001), obesity (OR 2.96, 95% CI 1.21-7.26; P = .0177), and more than one hospital admission (OR 3.54, 95% CI 2.69-4.64; P < .0001) as significant predictors of VTE. VTE diagnosis was not associated with increased mortality in either cohort.

CONCLUSIONS

The VTE rate in children with CNS tumors is low (2%). CVC placement was identified as a modifiable risk factor in both cohorts.

Accuracy of Bedside Ultrasound Femoral Vein Diameter Measurement by PICU Providers

OBJECTIVES

Perform a needs assessment by evaluating accuracy of PICU provider bedside ultrasound measurement of femoral vein diameter prior to utilization of the catheter-to-vein ratio for central venous catheter size selection.

DESIGN

Prospective observational cohort study.

SETTING

PICU within a quaternary care children's hospital.

PATIENTS

PICU patients greater than 30 days and less than 6 years without a femoral central venous catheter.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Gold-standard femoral vein diameter measurements were made by a radiologist, sonographer, or bedside ultrasound expert. PICU providers then repeated the femoral vein diameter measurements, and results were compared by Bland-Altman analysis with a priori accuracy goal of limits of agreement ± 15%. Among recruited patients (n = 27), the median age was 1.1 years (interquartile range 0.5-2.3 yr), weight was 9.0 kg (interquartile range 7.0-11.5 kg), and reference femoral vein diameter was 0.36 cm (interquartile range 0.28-0.45 cm). Providers performed 148 femoral vein diameter measurements and did not meet goal accuracy when compared with the reference measurement with a bias of 4% (95% of limits of agreement -62% to 70%). A majority of patients would have a catheter-to-vein ratio greater than 0.5 using either age-based central venous catheter size selection criterion (14/27) or the provider bedside ultrasound femoral vein diameter measurement (18/27).

CONCLUSIONS

PICU provider measurement of femoral vein diameter by bedside ultrasound is inaccurate when compared with expert reference measurement. Central venous catheter size selection based on age or PICU provider femoral vein diameter measurement can lead to a catheter-to-vein ratio greater than 0.5 and potentially increase the risk of catheter-associated venous thromboembolism. Structured bedside ultrasound training with assessment of accuracy is necessary prior to implementation of venous thromboembolism reduction efforts based on catheter-to-vein ratio recommendations.

Risk Factors for Central Venous Access Device-Related Thrombosis in Hospitalized Children: A Systematic Review and Meta-Analysis

OBJECTIVE

 To identify the potential associations of patient-, treatment-, and central venous access device (CVAD)-related factors with the CVAD-related thrombosis (CRT) risk in hospitalized children.

METHODS

 A systematic search of PubMed, EMBASE, Web of Science, the Cochrane Library, China National Knowledge Infrastructure, Wanfang, and VIP database was conducted. RevMan 5.3 and Stata 12.0 statistical software were employed for data analysis.

RESULTS

 In terms of patient-related factors, the patient history of thrombosis (odds ratio [OR] = 3.88, 95% confidence interval [CI]: 2.57-5.85), gastrointestinal/liver disease (OR = 1.85, 95% CI: 0.99-3.46), hematologic disease (OR = 1.45, 95% CI: 1.06-1.99), and cancer (OR = 1.58, 95% CI: 1.01-2.48) were correlated with an increased risk of CRT. In terms of treatment-related factors, parenteral nutrition (PN)/total PN (OR = 1.70, 95% CI: 1.21-2.39), hemodialysis (OR = 2.17, 95% CI: 1.34-3.51), extracorporeal membrane oxygenation (OR = 1.51, 95% CI: 1.31-1.71), and cardiac catheterization (OR = 3.92, 95% CI: 1.06-14.44) were associated with an increased CRT risk, while antibiotics (OR = 0.46, 95% CI: 0.32-0.68) was associated with a reduced CRT risk. In terms of the CVAD-related factors, CRT risk was more significantly increased by peripherally inserted central catheter than tunneled lines (OR = 1.81, 95% CI: 1.15-2.85) or totally implantable venous access port (OR = 2.81, 95% CI: 1.41-5.60). And subclavian vein catheterization significantly contributed to a lower CRT risk than femoral vein catheterization (OR = 0.36, 95% CI: 0.14-0.88). Besides, multiple catheter lines (OR = 4.06, 95% CI: 3.01-5.47), multiple catheter lumens (OR = 3.71, 95% CI: 1.99-6.92), central line-associated bloodstream infection (OR = 2.66, 95% CI: 1.15-6.16), and catheter malfunction (OR = 1.65, 95% CI: 1.07-2.54) were associated with an increased CRT risk.

CONCLUSION

 The exact identification of the effect of risk factors can boost the development of risk assessment tools with stratifying risks.

Bayesian analysis of the epidemiology of bleeding in critically ill children

PURPOSE

We updated our findings on the epidemiology of clinically relevant bleeding (CRB) in critically ill children. We also determined the concordance of CRB as defined by the International Society of Thrombosis and Haemostasis, i.e., ISTH definition, and characteristics identified by pediatric intensivists in a recent survey, i.e., survey definition.

METHODS

In a prospective cohort study, we included children <18 years old who were admitted to the pediatric intensive care unit for >1 day. We followed them daily for bleeding. Bayesian inference was used as the primary analytic tool to incorporate our prior findings.

RESULTS

Using the ISTH definition, the estimated frequency of CRB was 10.0% (95% credible interval, CrI: 7.6%, 12.8%) from 41 of 405 children who had CRB. The estimated frequency from 4 of 12 adolescents >13 years old who received mechanical ventilation or vasopressor support and had CRB was 32.9% (95% CrI: 12.0%, 58.8%). Using the survey definition, the estimated frequency of CRB for the entire cohort was 10.8% (95% CrI: 8.3%, 13.8%). Concordance between definitions for each bleeding event was 0.40 (95% confidence interval: 0.27, 0.52).

CONCLUSIONS

Our updated findings highlight the high frequency of CRB regardless of definition used for CRB.

Low molecular weight heparin for prevention of central venous catheter-related thrombosis in children

BACKGROUND

The prevalence of children diagnosed with thrombotic events has been increasing in the last decades. The most common thrombosis risk factor in neonates, infants and children is the placement of a central venous catheter (CVC). It is unknown if anticoagulation prophylaxis with low molecular weight heparin (LMWH) decreases CVC-related thrombosis in children. This is an update of the Cochrane Review published in 2014.

OBJECTIVES

To determine the effect of LMWH prophylaxis on the incidence of CVC-related thrombosis and major and minor bleeding complications in children. Further objectives were to determine the effect of LMWH on occlusion of CVCs, number of days of CVC patency, episodes of catheter-related bloodstream infection (CRBSI), other side effects of LMWH (allergic reactions, abnormal coagulation profile, heparin-induced thrombocytopaenia and osteoporosis) and mortality during therapy.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 7 May 2019. We undertook reference checking of identified trials to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-randomised trials comparing LMWH to no prophylaxis (placebo or no treatment), or low-dose unfractionated heparin (UFH) either as continuous infusion or flushes (low-dose UFH aims to ensure the patency of the central line but has no systemic anticoagulation activity), given to prevent CVC-related thrombotic events in children. We selected studies conducted in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified eligible studies, which were assessed for study methodology including bias, and extracted unadjusted data where available. In the data analysis step, all outcomes were analysed as binary or dichotomous outcomes. The effects of interventions were summarised with risk ratios (RR) and their respective 95% confidence intervals (CI). We assessed the certainty of evidence for each outcome using the GRADE approach.

MAIN RESULTS

One additional study was included for this update bringing the total to two included studies (with 1135 participants). Both studies were open-label RCTs comparing LMWH with low-dose UFH to prevent CVC-related thrombosis in children. We identified no studies comparing LMWH with placebo or no treatment. Meta-analysis found insufficient evidence of an effect of LMWH prophylaxis in reducing the incidence of CVC-related thrombosis in children with CVC, compared to low-dose UFH (RR 0.68, 95% CI 0.27 to 1.75; 2 studies; 787 participants; low-certainty evidence). One study (158 participants) reported symptomatic and asymptomatic CVC-related thrombosis separately and detected no evidence of a difference between LMWH and low-dose UFH (RR 1.03, 95% CI 0.21 to 4.93; low-certainty evidence; RR 1.17, 95% CI 0.45 to 3.08; low-certainty evidence; for symptomatic and asymptomatic participants respectively). There was insufficient evidence to determine whether LMWH impacts the risk of major bleeding (RR 0.27, 95% CI 0.05 to 1.67; 2 studies; 813 participants; low-certainty evidence); or minor bleeding. One study reported minor bleeding in 53.3% of participants in the LMWH arm and in 44.7% of participants in the low-dose UFH arm (RR 1.20, 95% CI 0.91 to 1.58; 1 study; 158 participants; very low-certainty evidence), and the other study reported no minor bleeding in either group (RR: not estimable). Mortality during the study period was reported in one study, where two deaths occurred during the study period. Both were unrelated to thrombotic events and occurred in the low-dose UFH arm. The second study did not report mortality during therapy per arm but showed similar 5-year overall survival (low-certainty evidence). No additional adverse effects were reported. Other pre-specified outcomes (including CVC occlusion, patency and CRBSI) were not reported.

AUTHORS' CONCLUSIONS

Pooling data from two RCTs did not provide evidence to support the use of prophylactic LWMH for preventing CVC-related thrombosis in children (low-certainty evidence). Evidence was also insufficient to confirm or exclude a difference in the incidence of major and minor bleeding complications in the LMWH prophylaxis group compared to low-dose UFH (low and very low certainty respectively). No evidence of a clear difference in overall mortality was seen. Studies did not report on the outcomes catheter occlusion, days of catheter patency, episodes of CRBSI and other side effects of LMWH (allergic reactions, abnormal coagulation profile, heparin-induced thrombocytopaenia and osteoporosis). The certainty of the evidence was downgraded due to risk of bias of the included studies, imprecision and inconsistency, preventing conclusions in regards to the efficacy of LMWH prophylaxis to prevent CVC-related thrombosis in children.

Epidemiology and outcomes of clinically unsuspected venous thromboembolism in children: A systematic review

BACKGROUND

Clinically unsuspected venous thromboembolic events (uVTE) detected during routine imaging pose a management challenge due to limited knowledge about their clinical significance. Unsuspected VTE are often referred as "asymptomatic," "incidental," or "clinically silent/occult" VTE.

OBJECTIVE

To understand the epidemiology, management, and outcomes of uVTE in children.

METHODS

A systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The search criteria included controlled vocabulary and keywords for VTE, incidental findings, and children (ages ≤ 21 years).

RESULTS

Among 10 875 articles, 51 studies (8354 children with 758 uVTE) were selected. The studies were heterogeneous, I2 96%; P < .0001. Unsuspected VTE were diagnosed in two settings: first, asymptomatic VTE (aVTE) diagnosed through surveillance imaging for VTE (46 studies; n = 5894; aVTE: 715, pooled frequency: 19%, 95% confidence interval [CI]: 13%-24%); second, incidental VTE (iVTE) diagnosed during imaging performed for indications without primary suspicion for VTE (6 studies; n = 2460; iVTE: 43). The majority (94%) of aVTE were associated with central venous lines (CVL). Non-CVL settings included post-spinal surgery, post-splenectomy, trauma, nephrotic syndrome, and newborns. In general, aVTE were reported to have a benign clinical course, were mostly transient, and resolved without intervention and with few immediate or long-term functional complications. Incidental VTE were primarily detected in children with cancer and ranged from tumor-associated thrombi to pulmonary embolism (PE) with insufficient evidence to draw meaningful conclusions about their management.

CONCLUSION

Clinically uVTE were predominantly diagnosed with CVL and their outcomes were generally favorable implying limited benefit of routine surveillance and thromboprophylaxis. Prospective research is needed to clarify the optimal management of iVTE.

Protein biomarkers for incident deep venous thrombosis in critically ill adolescents: An exploratory study

BACKGROUND

There are no tests to identify critically ill children at high risk of deep venous thrombosis (DVT). In this exploratory study, we aimed to identify proteins that are associated with incident DVT in critically ill adolescents.

PROCEDURE

Plasma samples were obtained from critically ill adolescents within 24 hours after initiation of cardiopulmonary support. The adolescents were followed with ultrasound to detect the development of DVT of the lower extremity and clinically for bleeding. Thrombin-antithrombin complex and prothrombin fragment 1+2 were measured using immunosorbent assays, whereas procoagulation and anticoagulation factors were measured using multiplex assays. Plasma samples were also analyzed using SOMAscan, an aptamer-based capture assay. The associations between DVT and the log-transformed level of the proteins were assessed using logistic regression adjusting for the presence of femoral venous catheter and severity of illness. Associations were expressed as odds ratio (OR) for every log-fold increase in level of the protein with 95% confidence interval (CI).

RESULTS

Plasma from 59 critically ill adolescents, of whom 9 developed incident DVT, was analyzed. The median age of the adolescents was 15.1 years (interquartile range, 14.0-16.7 years). Higher levels of thrombin-antithrombin complex (OR: 31.54; 95% CI: 2.09-475.92) and lower levels of factor XIII (OR: 0.03; 95% CI: 0.002-0.44) were associated with DVT. CD36, MIC-1, and EpoR were marginally associated with DVT. Only factor XIII was associated with clinically relevant bleeding (OR: 0.27; 95% CI: 0.08-0.97).

CONCLUSIONS

We identified candidate protein biomarkers for incident DVT. We plan to validate our findings in adequately powered studies.

Pediatric trauma venous thromboembolism prediction algorithm outperforms current anticoagulation prophylaxis guidelines: a pilot study

PURPOSE

Venous thromboembolism (VTE) in injured children is rare, but sequelae can be morbid and life-threatening. Recent trauma society guidelines suggesting that all children over 15 years old should receive thromboprophylaxis may result in overtreatment. We sought to evaluate the efficacy of a previously published VTE prediction algorithm and compare it to current recommendations.

METHODS

Two institutional trauma registries were queried for all pediatric (age < 18 years) patients admitted from 2007 to 2018. Clinical data were applied to the algorithm and the area under the receiver operating characteristic (AUROC) curve was calculated to test algorithm efficacy.

RESULTS

A retrospective review identified 8271 patients with 30 episodes of VTE (0.36%). The VTE prediction algorithm classified 51 (0.6%) as high risk (> 5% risk), 322 (3.9%) as moderate risk (1-5% risk) and 7898 (95.5%) as low risk (< 1% risk). AUROC was 0.93 (95% CI 0.89-0.97). In our population, prophylaxis of the 'moderate-' and 'high-risk' cohorts would outperform the sensitivity (60% vs. 53%) and specificity (96% vs. 77%) of current guidelines while anticoagulating substantially fewer patients (373 vs. 1935, p < 0.001).

CONCLUSION

A VTE prediction algorithm using clinical variables can identify injured children at risk for venous thromboembolic disease with more discrimination than current guidelines. Prospective studies are needed to investigate the validity of this model.

LEVEL OF EVIDENCE

III-Clinical decision rule evaluated in a single population.

Acquired systemic-to-pulmonary shunts in a 6-month-old child: case report and review of the literature

The incidence of paediatric venous thromboembolism has steadily increased in the past decade, by nearly 10% per year. Deep venous thrombosis may remain completely asymptomatic during the acute phase and symptoms may occur later, due to complications. We related the case of a 9-month-old child with increasing cyanosis. A computed tomography (CT) angiography showed a thrombosis of the superior vena cava (SVC) with the development of collateral flow from the systemic to the pulmonary veins. Transcatheter shunt occlusion after SVC recanalization was successfully performed. We discussed the characteristics of these cases and the consequence on our practice in term of treatment (anticoagulation, transcatheter, intervention) and screening.

Epidemiology of Clinically Relevant Bleeding in Critically Ill Adolescents

OBJECTIVES

The epidemiology of clinically relevant bleeding in critically ill adolescents, particularly those who are at high risk of venous thromboembolism, is unclear. In preparation for a randomized clinical trial of pharmacologic prophylaxis against venous thromboembolism, we characterized the epidemiology of clinically relevant bleeding in critically ill adolescents.

DESIGN

Post hoc analysis of data from a pediatric multicenter observational study of venous thromboembolism.

SETTING

Six PICUs.

PATIENTS

Adolescents 13-17 years old who received cardiac or pulmonary support for at least 48 hours were eligible. Those admitted with venous thromboembolism or receiving therapeutic anticoagulation were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Adolescents (n = 88) were followed daily for the development of any bleeding event. The severity of the event was categorized based on the definitions by the International Society on Thrombosis and Haemostasis. The frequency of clinically relevant bleeding was 29.5% (95% CI, 20.3-40.2%) or 3.7 events (95% CI, 2.5-5.4 events) per 100 patient-days. Adolescents with venous thromboembolism were more likely to develop clinically relevant bleeding (hazard ratio, 2.06; 95% CI, 1.08-3.94). Age was negatively associated with clinically relevant bleeding (hazard ratio for every 1-year increase in age: 0.68; 95% CI, 0.58-0.79). In contrast, predicted risk of mortality (hazard ratio for every 0.10 increase in risk: 1.35; 95% CI, 1.05-1.74) and admission for trauma or surgery (hazard ratio: 2.04; 95% CI, 1.21-3.44) were positively associated with clinically relevant bleeding. The association of clinically relevant bleeding with medications, interventions, or laboratory tests, including mechanical ventilation and pharmacologic prophylaxis with anticoagulation, did not reach statistical significance. Adolescents with clinically relevant bleeding stayed in the hospital longer than those without clinically relevant bleeding.

CONCLUSIONS

Clinically relevant bleeding is common in critically ill adolescents who are at high risk of venous thromboembolism. Admission for trauma or surgery can be used to stratify the risk of clinically relevant bleeding in these adolescents.

Central Venous Line Associated Deep Vein Thrombosis in Hospitalized Children

An increase in the incidence of deep vein thrombosis (DVT) has been reported in pediatric patients over the past decade. The presence of central venous line (CVL) is a major contributing risk factor with conflicting data on the relative risk of DVT with various types of central lines. We aimed to assess the incidence of and identify potential risk factors for DVT overall and with different types of CVL individually. A retrospective chart review of pediatric patients with a CVL placed at Cleveland Clinic Children's from 2011 to 2016 was conducted. Data collected included demographics, potential risk factors, CVL characteristics and related thrombotic events. The study cohort consisted of 376 CVLs in 325 patients between 0 and 26 years of age. There were 1.6 thrombi per 10,000 line-days (95% confidence interval: 1.0, 2.5), and the overall incidence of DVT was 5.1%. The incidence of DVT was highest with tunneled catheters (5/16=31%) versus with peripherally inserted central catheters (4/111=3.6%) or with ports (10/249=4%, P<0.001), and whereas there were overarching significant risk factors for CVL-associated thrombi, these risk factors differed in significance when analyzed by the CVL type. The study supports the need for continued improvement in pediatric hospital practices for early identification of patients at a higher thrombosis risk.

Comparison of heparinized saline and 0.9% sodium chloride for maintaining central venous catheter patency in healthy dogs

BACKGROUND

The purpose of this study was to determine whether heparinized saline (HS) would be more effective in maintaining the patency of central venous catheters (CVCs) in dogs compared to 0.9% sodium chloride. This was a prospective randomized blinded study conducted at a University Veterinary Teaching Hospital.

METHODS

A total of 24 healthy purpose-bred dogs were randomized into two groups: a treatment and a control group. A CVC was placed in the jugular vein of each dog. Each dog in the treatment group had their CVC flushed with 10 IU/mL HS, while dogs in the control group had their CVC flushed with 0.9% sodium chloride every 6 h for 72 h. Immediately prior to flushing, each catheter was evaluated for patency by aspiration of blood. The catheter site was also evaluated for phlebitis, and a rectal temperature was obtained in each dog every 6 h. Prothrombin (PT) and activated partial thromboplastin (aPTT) times were evaluated prior to the administration of any flush solution. Results were then compared to values obtained 72 h later.

RESULTS

All CVCs in both groups were patent after 72 h, which was demonstrated by aspiration of blood and ease of flushing the catheter. Two CVCs in the 0.9% sodium chloride group had a negative aspiration at hour 12 and 36, respectively. One CVC in the HS group had a negative aspiration at hour 18. Signs of phlebitis occurred in three dog: two in the 0.9% sodium chloride group and one in the HS group. No dog was hyperthermic (>103 °F). Two catheters were inadvertently removed by dogs in the HS group during the study. There were no significant differences in catheter patency, incidence of phlebitis, or incidence of negative aspirations between both groups. aPTT and PT values remained within the normal reference range for all dogs in both groups. Ultimately, 0.9% sodium chloride was as effective as 10 IU/mL HS in maintaining the patency of CVCs for up to 72 h in healthy dogs. Further evaluation in clinical patients is warranted.

Deep Vein Thrombosis in a Young, Healthy Baseball Catcher: A Case Report and Review of the Literature

Venous thromboembolism is becoming increasingly recognized as a significant cause of morbidity and mortality in the hospitalized pediatric population. However, young healthy athletes can present with unique risk factors for deep vein thrombosis (DVT) that can be overlooked. Here we report a case of an adolescent male with no inherited risk factors or prior history of DVTs who developed a right femoral vein DVT in the context of playing catcher in baseball after recovering from a bout of streptococcal pharyngitis. We review the evidence that suggests that repetitive squatting-induced compression of the femoral vein can cause the venous stasis and endothelial microtrauma that contributed to the formation of this thrombus.

Central Venous Catheter-Related Deep Vein Thrombosis in the Pediatric Cardiac Intensive Care Unit

BACKGROUND

Central venous catheter (CVC) use is common in the management of critically ill children, especially those with congenital heart disease. CVCs are known to augment the risk of deep vein thrombosis (DVT), but data on CVC-associated DVTs in the pediatric cardiac intensive care unit (CICU) are limited. In this study, we aim to identify the incidence of and risk factors for CVC-related DVT in this high-risk population, as its complications are highly morbid.

MATERIALS AND METHODS

The PC4 database and a radiologic imaging database were retrospectively reviewed for the demographics and outcomes of patients admitted to the Texas Children's Hospital CICU requiring CVC placement, as well as the incidence of DVT and its complications.

RESULTS

Between January 2017 and December 2017, 1215 central lines were placed over 851 admissions. DVT was diagnosed in 8% of admissions with a CVC, 29% of which demonstrated thrombus in the inferior vena cava. The risk factors significantly associated with DVT included the presence of >1 line, higher total line hours, longer intubation times, and extended CICU stay. A diagnosis of low cardiac output syndrome, sepsis, central line-associated bloodstream infection, and cardiac catheterization were also significant risk factors. Interestingly, cardiac surgery with cardiopulmonary bypass appeared to be protective of clot development. DVT was a highly significant risk factor for mortality in these patients.

CONCLUSIONS

CVC-related DVTs in critically ill children with congenital heart disease are associated with higher risks of morbidity and mortality, highlighting the need for well-designed studies to determine the best preventative and treatment strategies and to establish guidelines for appropriate monitoring and follow-up of these patients.

Effect of impregnated central venous catheters on thrombosis in paediatric intensive care: Post-hoc analyses of the CATCH trial

Purpose

The CATheter infections in CHildren (CATCH) trial reported reduced risks of bloodstream infection with antibiotic impregnated compared with heparin-bonded or standard central venous catheters (CVC) in paediatric intensive care. CVC impregnation did not increase the risk of thrombosis which was recorded in 24% of participants. This post-hoc analysis determines the effect of CVC impregnation on the risk of thrombosis leading to CVC removal or swollen limb.

Methods

We analysed patients in the CATCH trial, blind to CVC allocation, to define clinically relevant thrombosis based on the clinical sign most frequently recorded in patients where the CVC was removed because of concerns regarding thrombosis. In post-hoc, three-way comparisons of antibiotic, heparin and standard CVCs, we determined the effect of CVC type on time to clinically relevant thrombosis, using Cox proportional hazards regression.

Results

Of 1409 participants with a successful CVC insertion, the sign most frequently resulting in CVC removal was swollen limb (37.6%; 41/109), with lower rates of removal of CVC following 2 episodes of difficulty withdrawing blood or of flushing to unblock the CVC. In intention to treat analyses (n = 1485), clinically relevant thrombosis, defined by 1 or more record of swollen limb or CVC removal due to concerns about thrombosis, was recorded in 11.9% (58/486) of antibiotic CVCs, 12.1% (60/497) of heparin CVCs, and 10.2% (51/502) of standard CVCs. We found no differences in time to clinically relevant thrombosis according to type of CVC.

Conclusions

We found no evidence for an increased risk of clinically relevant thrombosis in antibiotic impregnated compared to heparin-bonded or standard CVCs in children receiving intensive care.

Central Venous Access Devices (CVAD) in Pediatric Oncology Patients-A Single-Center Retrospective Study Over More Than 9 Years

Background: Central venous access devices (CVAD) provide important benefits in the management of oncological pediatric patients. However, these catheters are responsible for severe complications. Methods: In this context, we aimed to analyze all patients receiving a CVAD in the Department of Pediatric Hematology and Oncology of the University hospital of Mainz over a period of 9 years, focused on CVAD related complications. Data on demographics, as well as intraoperative and postoperative complications were extracted. Results: A total of 296 patients with a mean age 93.2 ± 62.4 months were analyzed. The majority suffered from leukemia (n = 91, 30.7%), lymphomas (n = 50, 16.9%), and brain tumors (n = 48, 16.2%). In 63 (21.3) patients, complications were observed. No death caused by complications of CVADs was found in our series. Catheter-related blood stream infections (BSI) (7.4%) were most prevalent, followed by dislodgements (5.4%), occlusions (2.7%), thrombosis (2.4%), and catheter leakage (2.4%). Insertion site infections were observed in three patients (1.0%). Fifty-nine percent of all patients with catheter-related BSI suffered from Leukemia. In patients with Catheter-related BSIs we detected the condition leukemia as the underlying disease as a risk factor compared to solid tumors as the underlying disease. Overall, totally implanted devices (ports) have a lower complication rate than tunneled catheter. Conclusion: Implantation of CVADs seems to be safe and reliable in this large pediatric patient cohort. Even if complications occur in the long-term management of CVADs, they can be treated successfully and long-term catheter survival rates are excellent.