Anticoagulant prophylaxis and therapy in children: current challenges and emerging issues

Efficacy and Safety of Direct Oral Anticoagulants in Pediatric Venous Thromboembolism: A Systematic Review and Meta-Analysis

OBJECTIVES

To assess the efficacy and safety of direct oral anticoagulants (DOACs) in comparison to standard-of-care (SOC) anticoagulants in the management and prophylaxis of thromboembolic events in pediatric populations.

METHODS

A comprehensive search of electronic databases was conducted to identify relevant studies published between January 1, 2015, and December 18, 2022. A meta-analysis was undertaken to evaluate the effect of DOACs on clinically significant endpoints, employing trial-level data with harmonized endpoint definitions. The primary outcome was venous thromboembolism (VTE). Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. The study was registered with INPLASY (2022120065).

RESULTS

Three studies encompassing 934 subjects were included. The incidence of VTE was reduced in patients administered DOACs compared to those on SOC anticoagulants (OR 0.41 [95% CI 0.19-0.93], I² = 0%, P = 0.03). No significant differences were observed between the DOAC and SOC groups in all-cause mortality (OR 0.50 [95% CI 0.07-3.59], I² = 0%, P = 0.35) or serious adverse events (OR 0.75 [95% CI 0.50-1.12], I² = 0%, P = 0.16). The risk of major bleeding (OR 0.50 [95% CI 0.13-1.87], I² = 44%, P = 0.30) and clinically relevant non-major bleeding (OR 1.23 [95% CI 0.50-3.00], I² = 0%, P = 0.65) exhibited no significant differences between the groups.

CONCLUSIONS

DOACs are associated with a reduced risk of VTE in pediatric patients without increasing the risk of bleeding, all-cause mortality, or serious adverse events when compared to SOC anticoagulants. DOACs may be an alternative for the treatment and prevention of thromboembolic events in the pediatrics.

Timing of Central Venous Line Insertion During Induction in Children With Acute Lymphoblastic Leukemia

PURPOSE

Central venous lines (CVL) in children with acute lymphoblastic leukemia (ALL) provide comfortable administration of intensive chemotherapy and blood sampling. The optimal time for the insertion of CVL in patients with ALL during induction therapy is controversial. This study aimed to investigate the frequency of CVL-related complications in children with ALL concerning the time of CVL insertion.

PATIENTS AND METHODS

We reviewed the records of 52 pediatric ALL patients with CVL. CVL placement before or on treatment day 15 was defined as "early insertion", and after treatment day 15 was defined as "late insertion". Demographics, preoperative blood counts, type of central line, time of CVL placement, CVL-related complications, and blood counts during complications were all noted. All the data were collected from those with the first catheter use.

RESULTS

CVL was placed ≤15 days in 26 patients (50%) and after 15 days in 26 patients (50%). Regarding the infection rates, no statistical difference was found between early and late CVL-inserted groups ( P =n.s.). Five patients developed thrombosis, and risk was found to be similar between early and late CVL-inserted groups ( P =n.s.). Catheter-related mechanical complications were recorded in 7 patients (3 in early and 4 in late CVL-inserted group, ( P =n.s.).

CONCLUSION

The present study showed no relation between the timing of CVL placement during induction therapy and the occurrence of infection and thrombosis. Our results suggest that CVL can be placed safely at the time of diagnosis or early induction treatment to provide a comfortable administration of chemotherapy and decrease painful blood samplings.

Direct oral anticoagulants toxicity in children: an overview and practical guide

INTRODUCTION

By increasing use of direct oral anticoagulants (DOACs) in adults and children, gradual increase in the number of intentional or unintentional DOAC poisonings among children is suspected in the near future. Hence, clinicians and pharmacists need to be familiar with the clinical features and management of DOAC-toxicity among pediatric population.

AREAS COVERED

This article provides an overview and practical guide to DOAC-toxicity in pediatrics according to the available clinical evidence.

EXPERT OPINION

Based on limited available data, accidental pediatric ingestion of DOACs can be managed by supportive care in most cases. However, serious toxicity may occur following massive overdose, in presence of underlying disorders (renal or hepatic dysfunction) and concurrent anticoagulant therapy. Activated charcoal is recommended for known recent ingestion of DOACs (within 2-4 hours) to reduce the gastrointestinal absorption. Supportive interventions including local hemostatic measures and volume resuscitation are the cornerstone of management of bleeding. Vitamin K and fresh frozen plasma are ineffective for DOAC reversal and thus are not recommended. Currently, safety and efficacy data regarding the use of specific reversal agents (including idarucizumab and andexanet alfa) and 3-factor or 4-factor prothrombin complex concentrate (PCC) or activated PCC (aPCC) among children with DOAC-associated bleeding are lacking.

Endothelial Progenitor Cell-Based in vitro Pre-Endothelialization of Human Cell-Derived Biomimetic Regenerative Matrices for Next-Generation Transcatheter Heart Valves Applications

Hemocompatibility of cardiovascular implants represents a major clinical challenge and, to date, optimal antithrombotic properties are lacking. Next-generation tissue-engineered heart valves (TEHVs) made from human-cell-derived tissue-engineered extracellular matrices (hTEMs) demonstrated their recellularization capacity in vivo and may represent promising candidates to avoid antithrombotic therapy. To further enhance their hemocompatibility, we tested hTEMs pre-endothelialization potential using human-blood-derived endothelial-colony-forming cells (ECFCs) and umbilical vein cells (control), cultured under static and dynamic orbital conditions, with either FBS or hPL. ECFCs performance was assessed via scratch assay, thereby recapitulating the surface damages occurring in transcatheter valves during crimping procedures. Our study demonstrated: feasibility to form a confluent and functional endothelium on hTEMs with expression of endothelium-specific markers; ECFCs migration and confluency restoration after crimping tests; hPL-induced formation of neo-microvessel-like structures; feasibility to pre-endothelialize hTEMs-based TEHVs and ECFCs retention on their surface after crimping. Our findings may stimulate new avenues towards next-generation pre-endothelialized implants with enhanced hemocompatibility, being beneficial for selected high-risk patients.

How to use a coagulation screen

A coagulation screen is an important screening test when investigating a child who presents with easy bruising or bleeding. Interpretation of a coagulation screen can be challenging for clinicians. Evolution of the haemostasis system during childhood means normal ranges vary with age and needs to be interpreted alongside the clinical information. It is essential to consider preanalytical variables when interpreting a coagulation screen, and the reason for the investigation must always be considered. It is important that the sample is taken under optimal conditions, including sample technique, use of the correct bottle and prompt transport to the laboratory. An abnormal coagulation screen may indicate an underlying congenital bleeding disorder or an acquired bleeding disorder, or may be due to sampling error. Limitations of the coagulation screen are essential to be aware of, as some children with normal coagulation screen results may have bleeding disorders. Conversely, an abnormal coagulation screen does not always indicate a bleeding disorder.

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.

The Trilogy of SARS-CoV-2 in Pediatrics (Part 3): Thrombosis, Anticoagulant, and Antiplatelet Considerations

The hypercoagulable state induced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) affects all patients regardless of age. The incidence of venous thromboembolism in pediatric patients with SARS-CoV-2-related illnesses is not well established. Although deep vein thrombosis is rare in children in the absence of risk factors, coagulopathy and the development of thromboses have been described in pediatric patients with acute COVID-19 and multisystem inflammatory syndrome. This comprehensive review provides a detailed overview of SARS-CoV-2-associated coagulopathy as well as strategies for optimizing the evaluation, management, and prevention of thrombosis in pediatric patients.

Improving VTE prophylaxis adherence among hospitalized adolescents using Human-Centered Design

Background/problem statement

Venous thromboembolism (VTE) is the leading cause of preventable hospital mortality in the United States; however, compliance with VTE prophylaxis is poor. Most materials for education about VTE prophylaxis are oriented toward adults rather than adolescents, for whom VTE risks are lower and prophylaxis indications differ. We hypothesized that educational materials for adolescents could improve compliance with VTE prophylaxis, reduce nurse burden for initiating and maintaining VTE prevention practices, and reduce practice variation by standardizing the conversation between clinicians and patients.

Methods

A multidisciplinary team including physicians, nurses, quality experts, communication designers, service designers, and medical students applied a human-centered design (HCD) process to define, iteratively prototype, and test education tools for nurses assigned to adolescents. We piloted a suite of six educational tools for adolescent VTE prophylaxis to fit into the existing hospital workflow.

Results

An in-room poster was selected after 85% of nurses responded favorably to this intervention. Adolescent adherence with Intermittent Pneumatic Compression Device increased from 69% to 79%, attaining the benchmark goal of 78%. Staff reported greater confidence in educating adolescent patients after the intervention: 62% of nurses and 72% of residents.

Conclusion

An HCD process helped nurses improve VTE prophylaxis for adolescents with an in-room poster and messaging strategy. Engaging staff in the design increased receptivity and adoption. The piloted materials also helped to create an environment of shared priority among the clinicians.

Efficacy and Safety of Non-Vitamin K Antagonist Oral Anticoagulants in Pediatric Venous Thromboembolism Treatment and Thromboprophylaxis: A Systematic Review of the Literature

Venous thromboembolism (VTE) in children can lead to significant morbidity and mortality. Traditionally, treatment for thrombotic events in pediatric patients has been limited mainly to unfractionated heparin, low-molecular-weight heparin (LMWH), or vitamin K antagonists. Since the first non-vitamin K antagonist oral anticoagulant (NOAC) was approved for adult use, these agents have gained popularity for a variety of indications. This is largely due to their ease of administration, favorable pharmacokinetic and pharmacodynamic profile, decreased food interactions, and decreased need for therapeutic drug monitoring. Treating and preventing VTE with traditional anticoagulants in pediatric patients presents many challenges. This systematic review evaluated the current literature regarding pediatric NOAC trials. Additionally, based on an up-to-date query of clinicaltrials.gov, we detail current ongoing and as-yet unpublished clinical trials, study outcomes, and projected completion dates. Published pediatric NOAC trials have included 1,007 total children to date and have ranged from phase 1 to 4, with "indications" including both thromboembolism prophylaxis and VTE treatment. Three recent phase 3 trials, specifically involving rivaroxaban and dabigatran, have shown the agents to be at least as effective as traditional anticoagulants for acute and/or extended VTE treatment, with low frequency of recurrent thrombosis and clinically significant bleeding rates. Additionally, specially developed and tested pediatric formulations have allowed for accurate and reliable dosing, oral administration, stable pharmacokinetics and pharmacodynamics, and fewer drug or food interactions. Ongoing trials, anticipated for completion in the next few years, will reveal important information with regard to thromboembolism prophylaxis in special pediatric subpopulations and settings.

Acute Exposure to European Viper Bite in Children: Advocating for a Pediatric Approach

Viper bite is an uncommon but serious cause of envenoming in Europe, especially in children. Our study aim is to better describe and analyze the clinical course and treatment of viper bite envenoming in a pediatric population. We retrospectively reviewed 24 cases of pediatric viper bites that were admitted to the Pediatric Emergency Department and the Pediatric Intensive Care Unit of the Bambino Gesù Children Hospital in Rome between 2000 and 2020. Epidemiological characteristics of the children, localization of the bite, clinical and laboratory findings, and treatment approaches were evaluated. The median age of the patients was 4.2 years, with male predominance. Most cases of viper bite occurred in the late summer. Most patients required admission to the ward for prolonged observation. The most common presenting signs were pain, local oedema, and swelling. Patients with a high severity score also had a significantly higher white blood cell count and an increase of INR, LDH, and CRP levels. No fatality was reported. Viper bite envenomation is a rare pediatric medical emergency in Italy but may sometimes be severe. A new pediatric severity score may be implemented in the screening of children with viper bites to favor a selective and prompt administration of antivenom.

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.

Risk Assessment and Outcome of Venous Thromboembolism in Pediatric Population in an Academic Care Center of a Low-Middle Income Country

Venous thromboembolism (VTE) is a recognized complication of hospital stay in young patients in many developed countries, but such an information is largely unavailable from a low middle-income country (LMIC). This study aimed at identifying the frequency, risk factors, treatment options and outcome of deep venous thrombosis/pulmonary embolism (DVT/PE) in pediatric population in a tertiary care center from a LMIC. International classification of disease, ninth revision (ICD-9) was used to identify VTE in patients aged 0-18 years during January 2011 to September 2019. In-house computerized system was used to collect data for demographics, clinical and laboratory details. SPSS version 19 was used to analyzed data. The study was approved by Institutional ethical review committee (3872-Pat-ERC-15). During the study period, 134617 pediatric patients were hospitalized, DVT/PE was observed in 77 unique patients (47 males and 30 females) with a median (IQR) age of 14 (5-16) years equivalent to 5.9 VTE events /10,000 hospital admissions. Malignancy, community acquired infections and autoimmune diseases were the predominant risk factors (75%) in adolescent age-group while surgery for congenital heart anomalies was the primary reason (71%) in infants. Overall, lower extremity thrombosis was the most frequent (51%) followed by pulmonary embolism (25%). and upper extremity thrombosis (24%). Enoxaparin and unfractionated heparin were mainly used to treat VTE and all-cause mortality was 13% in the cohort studied. We observed substantial VTE events in pediatric patients during their hospital stay in a tertiary care center of a low-middle income country.

Diagnosis and management of cerebral venous sinus thrombosis in children: a single-center retrospective analysis

PURPOSE

Cerebral venous thrombosis (CVT) is a rare disease in children, characterized by partial or total occlusion of blood flow in the cerebral venous system. The aim of this study is to describe clinical presentation, neuroimaging features, therapeutic management, and outcome of children with CVT.

METHODS

We retrospectively analyzed the data, including clinical manifestations, laboratory data, neurological findings, and treatment of children with radiologically confirmed CVT, admitted between January 2010 and March 2020 to our hospital. Cases of CVT complicating brain surgery were excluded.

RESULTS

We enrolled 24 children with CVT. Infection was the main etiology (58.3%), followed by trauma in 16.7% of cases. In the remaining 25% of cases, the cause was identified only in one patient presenting a thrombophilic factor. The most frequent site of thrombosis was the superficial venous system (86.8%), with multiple localizations disclosed in 79% of patients. All children received anticoagulant therapy with low molecular weight heparin (LMWH). One patient died for systemic complications of an underlying disease. No patient developed hemorrhagic events during the therapy, lasting from 35 to 360 days (mean 86 days). In all but one surviving patients (22 out of 24), recanalization of the sinus was observed at AngioMRI performed during follow-up. No neurological complications of CVT were recorded (mean follow-up: 1.5 year).

CONCLUSIONS

CVT may present with subtle and unspecific clinical manifestations in children. High level of suspicion should be kept in trauma and sinusitis. Anticoagulation treatment is safe and effective and should be promptly started to improve outcome.

Predicting Anticoagulation Need for Otogenic Intracranial Sinus Thrombosis: A Machine Learning Approach

Objective  The role of anticoagulation (AC) in the management of otogenic cerebral venous sinus thrombosis (OCVST) remains controversial. Our study aims to better define when AC is used in OCVST. Methods  MEDLINE, EMBASE, and The Cochrane Library were searched from inception to February 14, 2019 for English and English-translated articles. References cited in publications meeting search criteria were searched. Titles and abstracts were screened and identified in the literature search, assessing baseline risk of bias on extracted data with the methodological index for nonrandomized studies (MINORS) scale. Random effects meta-regression followed by random forest machine learning analysis across 16 moderator variables between AC and nonanticoagulated (NAC) cohorts was conducted. Results  A total of 92% of treated patients were free of neurologic symptoms at the last follow-up (mean 29.64 months). Four percent of AC and 14% of NAC patients remained symptomatic (mean 18.72 and 47.10 months). 3.5% of AC patients experienced postoperative wound hematomas. AC and NAC recanalization rates were 81% (34/42) and 63% (five-eights), respectively. OCVST was correlated with cholesteatoma and intracranial abscess. Among the analyzed covariates, intracranial abscess was most predictive of AC and cholesteatoma was most predictive of NAC. Comorbid intracranial abscess and cholesteatoma were predictive of AC. Conclusion  The present study is the first to utilize machine learning algorithms in approaching OCVST. Our findings support the therapeutic use of AC in the management of OCVST when complicated by thrombophilia, intracranial abscess, and cholesteatoma. Patients with intracranial abscess and cholesteatoma may benefit from AC and surgery. Patients with cholesteatoma can be managed with NAC and surgery.

Venous Thromboembolism in Children: From Diagnosis to Management

Venous thromboembolism (VTE) in children is a rare occurrence, although in recent decades we have seen an increase due to several factors, such as the rise in survival of subjects with chronic conditions, the use of catheters, and the increased sensitivity of diagnostic tools. Besides inherited thrombophilia, acquired conditions such as cardiovascular diseases, infections, chronic disorders, obesity and malignancy are also common risk factors for paediatric VTE. The treatment of paediatric VTE consists of the use of heparins and/or vitamin K antagonists to prevent dissemination, embolization, and secondary VTE. Randomized clinical trials of direct oral anticoagulants in paediatric VTE are ongoing, with the aim to improve the compliance and the care of patients. We reviewed the physiological and pathological mechanisms underlying paediatric thrombosis and updated the current diagnosis and treatment options.

Participant-reported Warfarin Adherence in Community-based Pediatric Patients

Warfarin is the most commonly prescribed anticoagulant for children in the outpatient setting in Australia. Pediatric patients likely have different challenges to warfarin adherence compared with their adult counterparts; however, little is known about warfarin adherence among this population. This study aimed to understand warfarin adherence among community-based pediatric patients by using an online survey design. The survey instrument incorporated parent or patient self-reported warfarin doses missed in the preceding month, a validated warfarin adherence assessment tool, the 13-item Self-Efficacy for Appropriate Medication use Scale (SEAMS-13), and an open-ended question asking about the challenges of warfarin adherence. The indication of warfarin administration and patient's time in therapeutic range were obtained from medical records. The study recruited outpatients managed by a tertiary pediatric hospital who had previously consented to participate in warfarin research. In total, 53 families were contacted with 43 responses (81% response rate) and 41 completed surveys. The median age of the children from participating families was 10.6 years (range, 4.1 to 18.9 y). The majority of these children (n=42) used warfarin prophylactically and only 1 child used it to treat deep venous thrombosis. The time in therapeutic range achievement of this cohort was 64.4% (95% confidence interval, 58.7-70.2). The mean SEAMS-13 score was 33.5 (95% confidence interval, 31.75-35.37) and the total missed doses was 2.5%. Participants also identified barriers and enablers of warfarin adherence. This study was the first of its kind and thus it provides baseline data for future research. The warfarin adherence of this cohort was likely optimized because of frequent clinical contact and access to self-testing. Future studies are required to examine the different approaches aiming to improve the anticoagulant adherence after the emergence of direct oral anticoagulants with a wider therapeutic index and minimal monitoring that could contribute to less clinical contact.

Deep venous thrombosis of lower limbs in adolescents: a study in a tertiary hospital

BACKGROUND

Venous thromboembolism (VTE) - which includes deep venous thrombosis (DVT) and pulmonary embolism (PE) - has been increasingly recognized in the pediatric population. The estimated incidence is 0.07-0.14 cases per 10,000 children. Most cases are associated with two or more risk factors. Medium and long-term complications include recurrence and post-thrombotic syndrome (PTS).

OBJECTIVE

To characterize the adolescent population with the diagnosis of DVT of lower limbs in a tertiary hospital, regarding its clinical presentation, associated risk factors, treatment and outcome.

METHODS

Retrospective analysis of adolescents with the diagnosis of DVT of lower limbs in our hospital for a period of 7 years.

RESULTS

Eight patients were identified; seven were females; median age was 15 years. The main symptoms were local pain and edema. Left lower limb was affected in six patients. PE occurred in two cases. Positive family history of venous thromboembolism was found in five patients. Seven patients had at least two identifiable risk factors. Combined oral contraceptive pill use was the most common (seven patients). Factor V Leiden mutation was found in three patients and protein C deficiency in one. Iliac vein compression syndrome was diagnosed in one patient. The median time for discharge was 8 days. Election treatment was enoxaparin followed by warfarin, for a median period of 10.9 months. Three patients developed PTS.

CONCLUSIONS

Although uncommon, VTE is an emerging reality in adolescents, particularly in females using oral contraceptive pills. Appropriated prevention strategies and treatment are required as most orientations are extrapolated from adults.

Management of thrombosis in children and neonates: practical use of anticoagulants in children

Venous thrombosis (VTE) in children and neonates presents numerous management challenges. Although increasing in frequency, VTE in children and neonates is still uncommon compared with adults. The epidemiology of VTE is vastly different in neonates vs children vs adolescents vs adults. In reality, pediatric thrombosis should be viewed as a multitude of rare diseases (eg, renal vein thrombosis, spontaneous thrombosis, catheter-related thrombosis, cerebral sinovenous thrombosis), all requiring different approaches to diagnosis and with different short- and long-term consequences, but linked by the use of common therapeutic agents. Further, children have fundamentally different physiology in terms of blood flow, developmental hemostasis, and, likely, endothelial function. The American Society of Hematology 2017 Guidelines for Management of Venous Thromboembolism: Treatment of Pediatric VTE provides up-to-date evidence-based guidelines related to treatment. Therefore, this article will focus on the practical use of therapeutic agents in the management of pediatric VTE, especially unfractionated heparin, low-molecular-weight heparin, and oral vitamin K antagonists, as the most common anticoagulants used in children. Direct oral anticoagulants (DOACs) remain in clinical trials in children and should not be used outside of formal trials for the foreseeable future.

Warfarin: The End or the End of One Size Fits All Therapy?

Oral anticoagulants are required for both treatment and prophylaxis in many different diseases. Clinicians and patients now have a choice of oral anticoagulants, including the vitamin K antagonists (of which warfarin is the most widely used and is used as the exemplar in this paper), and direct oral anticoagulants (DOACs: dabigatran, apixaban, rivaroxaban, and edoxaban). This paper explores the recent advances and controversies in oral anticoagulation. While some commentators may favour a complete switchover to DOACs, this paper argues that warfarin still has a place in therapy, and a stratified approach that enables the correct choice of both drug and dose would improve both patient outcomes and affordability.