Pediatric venous thromboembolism in relation to adults

Evaluating thromboprophylaxis in the sickle cell disease population: Navigating the evidence gap

Sickle cell disease (SCD) arises from beta-globin gene mutations, with global estimates indicating around 500 000 affected neonates in 2021. In the United States, it is considered rare, impacting fewer than 200 000 individuals. The key pathogenic flaw lies in mutant haemoglobin S, prone to polymerization under low oxygen conditions, causing erythrocytes to adopt a sickled shape. This leads to complications like vascular occlusion, haemolytic anaemia, inflammation and organ damage. Beyond erythrocyte abnormalities however, there is a body of literature highlighting the hypercoagulable state that is likely a contributor to many of the complications we see in SCD. The persistent activation of the coagulation cascade results in thromboembolic events, notably venous thromboembolism (VTE) which is independently associated with increased mortality in both adults and children with SCD. While the increased risk of VTE in the SCD population seems well established, there is a lack of guidelines for thromboprophylaxis in this population. This Wider Perspective will describe the hypercoagulable state and increased thrombosis risk in the SCD population, as well as advocate for the development of evidence-based guidelines to aid in the prevention of VTE in SCD.

Risk factors for venous thromboembolism in a single pediatric intensive care unit in China

BACKGROUND

Analyses of extensive, nationally representative databases indicate a rising prevalence of venous thromboembolism (VTE) among critically ill children. However, the majority of studies on childhood VTE have primarily concentrated on Caucasian populations in the United States and European countries. There is a lack of epidemiological studies on VTE in Chinese children.

METHODS

We conducted a retrospective cohort study of data from the Pediatric Intensive Care (PIC) database. Data were obtained and extracted by using Structured Query Language (SQL) and the administrative platform pgAdmin4 for PostgreSQL. Bivariate analyses were conducted in which categorical variables were analyzed by a chi-square test and continuous variables were analyzed by a Student's t-test. Separate multivariable logistic regressions were employed to investigate the associations between VTE and sociodemographic factors as well as clinical factors.

RESULTS

Our study included 12,881 pediatric patients from the PIC database, spanning the years 2010 to 2018. The incidence rate of pediatric VTE was 0.19% (24/12,881). The venous thrombotic locations were deep venous thrombosis extremities (n = 18), superior vena cava (n = 1), cerebral sinovenous (n = 1), and other deep venous thrombosis (n = 4). Univariate analysis showed that age, weight, shock, sepsis, cancer and vasopressor receipt were statistically significant risk factors for pediatric VTE (all p ≤ 0.05). After multivariable logistic regression analysis, only shock (aOR: 6.77, 95%CI: 1.33-34.73, p = 0.019) and admission for sepsis (aOR: 6.09, 95%CI: 1.76-21.09, p = 0.004) were statistically significant associated with pediatric VTE.

CONCLUSIONS

In conclusion, data obtained from the Pediatric Intensive Care (PIC) database revealed a prevalence of VTE in pediatric patients of 0.19%. The most common location for venous thrombi was deep venous thrombosis (DVT) in the extremities. We identified that shock and sepsis were statistically significant factors associated with pediatric VTE.

Similar rate of venous thromboembolism (VTE) and failure of non-operative management for early versus delayed VTE chemoprophylaxis in adolescent blunt solid organ injuries: a propensity-matched analysis

BACKGROUND

Early initiation of venous thromboembolism (VTE) chemoprophylaxis in adults with blunt solid organ injury (BSOI) has been demonstrated to be safe but this is controversial in adolescents. We hypothesized that adolescent patients with BSOI undergoing non-operative management (NOM) and receiving early VTE chemoprophylaxis (eVTEP) (≤ 48 h) have a decreased rate of VTE and similar rate of failure of NOM, compared to similarly matched adolescents receiving delayed VTE chemoprophylaxis (dVTEP) (> 48 h).

METHODS

The 2017-2019 Trauma Quality Improvement Program database was queried for adolescents (12-17 years of age) with BSOI (liver, kidney, and/or spleen) undergoing NOM. We compared eVTEP versus dVTEP using a 1:1 propensity score model, matching for age, comorbidities, BSOI grade, injury severity score, hypotension on arrival, and need for transfusions. We performed subset analyses in patients with isolated spleen, kidney, and liver injury.

RESULTS

From 1022 cases, 417 (40.8%) adolescents received eVTEP. After matching, there was no difference in matched variables (all p > 0.05). Both groups had a similar rate of VTE (dVTEP 0.6% vs. eVTEP 1.7%, p = 0.16), mortality (dVTEP 0.3% vs. eVTEP 0%, p = 0.32), and failure of NOM (eVTEP 6.7% vs. dVTEP 7.3%, p = 0.77). These findings remained true in all subset analyses of isolated solid organ injury (all p > 0.05).

CONCLUSIONS

The rate of VTE with adolescent BSOI is exceedingly rare. Early VTE chemoprophylaxis in adolescent BSOI does not increase the rate of failing NOM. However, unlike adult trauma patients, adolescent patients with BSOI receiving eVTEP had a similar rate of VTE and death, compared to adolescents receiving dVTEP.

Deep vein thrombosis screening in pediatric orthopedic patients

Background

Deep vein thrombosis (DVT) is an important clinical condition that leads to subsequent morbidity and mortality in children, particularly those who involved operative procedures. The preoperative assessment for DVT in children may vary among different population risk factors and types of surgery. This study aimed to evaluate the screening methods for DVT in pediatric orthopedic patients.

Method

We performed a retrospective cohort study of orthopedic patients aged <18 years at Ramathibodi Hospital, Bangkok, Thailand, from 2015 to 2019. The inclusion criteria were children scheduled for orthopedic surgery; who performed a D-dimer test, Wells score, and Caprini score; and who underwent Doppler ultrasonography for DVT screening. The exclusion criteria were incomplete data or inconclusive ultrasonographic results. Age and results of the D-dimer test, Wells score, and Caprini score were collected from all patients. The outcome assessment was ultrasound-proven DVT. The screening abilities of each test were analyzed in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), likelihood ratio (LR) for positive and negative tests, and area under the receiver operating characteristic curve (AUC).

Results

A total of 419 children were included in the study. Five (1.19%) patients were diagnosed with DVT. The mean age was 10.16 ± 4.83 years. D-dimer ≥500 ng/mL had a sensitivity of 100% (95% CI: 47.8%–100%), a specificity of 36.7% (95% CI: 32.1%–41.6%), a PPV of 1.9% (95% CI: 0.6%–4.3%), and an NPV of 100% (95% CI: 97.6%–100%). Wells score ≥3 demonstrated a sensitivity of 0% (95% CI: 0%–52.2%), a specificity of 99.3% (95% CI: 97.9%–99.9%), and an LR for a negative test of 1.00 (95% CI: 1.00–1.01). Caprini score ≥11 had a sensitivity of 0% (95% CI: 0%–52.2%) and a specificity of 99.8% (95% CI: 98.7%–100%). The parallel test included D-dimer ≥500 ng/mL, Wells score ≥3, or Caprini score ≥11 points, generating a sensitivity of 100% (95% CI: 47.8%–100%), a specificity of 36.7% (95% CI: 32.1%–41.6%), an LR for a positive test of 1.58 (95% CI: 1.47–1.70), and an AUC of 0.68 (95% CI: 0.66–0.71).

Conclusions

The D-dimer test exhibited moderate ability in predicting the development of DVT among pediatric orthopedic patients requiring surgery. The Wells score and Caprini score had low performance in identifying hospitalized children at increased risk of DVT events.

Thrombosis and hemorrhage experienced by hospitalized children with SARS-CoV-2 infection or MIS-C: Results of the PICNIC registry

INTRODUCTION

Coagulopathy and thrombosis associated with SARS-CoV-2 infection are well defined in hospitalized adults and leads to adverse outcomes. Pediatric studies are limited.

METHODS

An international multicentered (n = 15) retrospective registry collected information on the clinical manifestations of SARS-CoV-2 and multisystem inflammatory syndrome (MIS-C) in hospitalized children from February 1, 2020 through May 31, 2021. This sub-study focused on coagulopathy. Study variables included patient demographics, comorbidities, clinical presentation, hospital course, laboratory parameters, management, and outcomes.

RESULTS

Nine hundred eighty-five children were enrolled, of which 915 (93%) had clinical information available; 385 (42%) had symptomatic SARS-CoV-2 infection, 288 had MIS-C (31.4%), and 242 (26.4%) had SARS-CoV-2 identified incidentally. Ten children (1%) experienced thrombosis, 16 (1.7%) experienced hemorrhage, and two (0.2%) experienced both thrombosis and hemorrhage. Significantly prevalent prothrombotic comorbidities included congenital heart disease (p-value .007), respiratory support (p-value .006), central venous catheter (CVC) (p = .04) in children with primary SARS-CoV-2 and in those with MIS-C included respiratory support (p-value .03), obesity (p-value .002), and cytokine storm (p = .012). Comorbidities prevalent in children with hemorrhage included age >10 years (p = .04), CVC (p = .03) in children with primary SARS-CoV-2 infection and in those with MIS-C encompassed thrombocytopenia (p = .001) and cytokine storm (p = .02). Eleven patients died (1.2%), with no deaths attributed to thrombosis or hemorrhage.

CONCLUSION

Thrombosis and hemorrhage are uncommon events in children with SARS-CoV-2; largely experienced by those with pre-existing comorbidities. Understanding the complete spectrum of coagulopathy in children with SARS-CoV-2 infection requires ongoing research.

Successful Secondary Endovascular Intervention in Pediatric Patients with Venous Thromboembolic Events

BACKGROUND

 In the past, pediatric patients with venous thromboembolic events (VTE) were treated with low-molecular-weight heparin (LMWH) which was successful in around 70% of the cases. However, anticoagulation alone might not restore patency in all patients, and advanced therapeutic options to prevent postthrombotic syndrome are needed. During recent years, endovascular interventions have become a treatment option for pediatric patients with persistent thrombotic occlusion, not only in life- or limb-threatening VTE.

METHODS

 We evaluated 12 consecutive patients (11-17 years) with newly diagnosed VTE being treated at our department during the last 4 years (2017-2020). In case follow-up examination showed persistent venoocclusion under anticoagulation, patients received secondary interventional therapy like recanalization, percutaneous transluminal angioplasty with or without catheter-directed thrombolysis, and stenting. Patients with no clinical signs of venoocclusion or regredient thrombosis in imaging examination received anticoagulation alone.

RESULTS

 Six of 12 (50%) patients underwent catheter intervention. Median time from diagnosis to intervention was 4 months (0-12 months). Reintervention was necessary in one (8%) case and complete recanalization failed in one (8%) case. There were no major bleeding events or other major postinterventional complications, no acute or late local recurrence, and all patients reported clinical improvement after the procedure.

CONCLUSION

 If endovascular intervention is used in teenage patients with persistent symptomatic VTE, reduction of postthrombotic symptoms is possible, even if intervention is performed secondary to failure of anticoagulation. Multidisciplinary treatment decisions can be based on the clinical course and follow-up imaging.

Assessment of provider practices regarding venous thromboembolism management and prevention in pediatric acute leukemia patients

Despite the known occurrence of venous thromboembolism (VTE) in the pediatric oncology population, there are no leukemia-specific VTE treatment guidelines. The primary objective of this study was to assess current practices regarding the management and prevention of VTE in the pediatric acute lymphoblastic leukemia (ALL) population. We performed a cross sectional, anonymous, electronic survey of members of the American Society of Hematology and the pediatric subcommittee of VENUS (VTE Network US of the Hemostasis and Thrombosis Research Society). Survey items included questions on demographics and clinical practice. Of 870 surveys distributed, 154 were submitted, giving a 17.7% response rate. Treatment duration, re-imaging timeline, and class of anticoagulants used were reported for catheter-associated deep vein thrombus, pulmonary embolism, and cerebral venous sinus thrombosis. While there are some common themes regarding VTE management, there is notable variation in the overall practice as well as with the decision to continue anticoagulation in the presence of thrombocytopenia. Given the variation seen, a multi-center, prospective clinical trial is urgently needed for developing consensus guidelines for the management of VTE in children with ALL.

Pediatric Venous Thromboembolism: Different Rates of Incidence, Anatomic Locations, and Risk Factors Between Orthopaedic and Nonorthopaedic Related Patients

BACKGROUND

The prevalence of venous thromboembolism (VTE) may be increasing in children; however, scarce literature exists comparing incidence rates between pediatric orthopaedic patients and other pediatric patients. The purpose of this study was to compare the incidence, anatomic locations, and risk factors of VTEs between orthopaedic and nonorthopaedic pediatric related patients to determine if important differences exist.

METHODS

Computed tomography and ultrasound data were reviewed for children (below 19 y old) with a diagnosed VTE between January 1, 2009 and December 31, 2016. Demographic and clinical data, including VTE anatomic location and risk factors, were recorded. Two major cohorts were identified: orthopaedic-related (ORTH) and nonorthopaedic-related (NORTH) VTEs. Incidence rates were estimated and risk factors were compared using χ2 testing.

RESULTS

There were 373 children diagnosed with a VTE (average age 10.3 y) of a total of 810,097 treated as in-patients for an incidence rate of 4.60 per 10,000 cases (95% confidence interval=4.15 to 5.10 per 10,000 cases). The rate of ORTH VTEs (28 of 188,669 orthopaedic patients, 1.48 per 10,000 cases) was significantly lower than that of NORTH VTEs (345 of 621,428 nonorthopaedic patients, 5.55 per 10,000 cases; P<0.001). For the ORTH cohort, there was a significant difference in the proportion of deep vein thrombosis in the lower extremity (91%) compared with the upper extremity (9%) (P<0.001), while a more even distribution of NORTH deep vein thrombosis in the upper (50%) and lower (41%) extremities was appreciated. The primary risk factors for ORTH VTEs included surgery (93%; P<0.001), change in ambulatory status (61%; P<0.001), and trauma (18%; P<0.001), while the primary risk factors for NORTH VTEs included intravenous peripheral inserted central catheter/central line (61%; P<0.001) and cancer (27%; P=0.001).

CONCLUSIONS

Pediatric ORTH VTEs have a significantly lower incidence rate and different primary risk factors than those of NORTH VTEs. This information is useful for health care providers when making decisions regarding risk and prophylaxis in pediatric patients with orthopaedic and nonorthopaedic conditions.

LEVEL OF EVIDENCE

Level III.

An expert spotlight on inferior vena cava filters

Introduction: Inferior vena cava (IVC) filters are mechanical filtration devices designed as an alternative to surgical ligation/plication of the IVC. Their use has been controversial, especially with the introduction of retrievable filters and expanded/prophylactic indications.Areas covered: Authors discuss the types of available IVC filters, indications for placement, evidence on their effectiveness in general and specific patient populations, procedural considerations, off-label use, complications, and filter retrieval. This review is based on manuscripts/abstracts published from 1960 to 2021 on venous thromboembolism and IVC filters.Expert opinion: Despite the limited data on their effectiveness and survival benefit, IVC filters continue to play an important role in the treatment of patients with venous thromboembolism (VTE) who cannot receive standard anticoagulation. There is no role of IVC filters in patients without VTE. While retrievable filters are desirable for short-term use, a dedicated team-based approach, and advanced training are required for their successful removal. Newer devices are promising in improving patient safety . The device manufacturers and regulatory agencies should consider specific approaches to track device-related adverse events. Population-based studies are required to establish optimal patient population who would benefit from these devices. .

Catheter-directed thrombolysis for in situ pulmonary artery thrombosis in children

In situ pulmonary artery thrombosis (ISPAT) is a unique form of pulmonary embolism characterized by local formation of thrombus in the pulmonary arteries. We present here a baby with hypoplastic left heart syndrome who developed ISPAT after Glenn surgery. The patient underwent catheter-directed thrombolysis, followed by systemic anticoagulation with excellent results.

Central venous catheters are an important factor in paediatric thrombosis

AIM

To establish the incidence and characteristics of paediatric thrombosis (PT) in a Canadian tertiary care centre during the era of low molecular weight heparin (LMWH).

METHODS

A retrospective observational case study of all patients <18 years of age evaluated for arterial and venous thrombosis from May 2008 to July 2018 at McMaster Children's Hospital was conducted through the electronic medical record.

RESULTS

The incidence of PT was 52.2 per 10 000 hospital admissions (n = 477/91 462). Provoked thrombosis was more prevalent (88.9%, n = 424/477) than unprovoked (2.9%, n = 14/477) or idiopathic thrombosis (4%, n = 19/477). Half of PT were in children <2 years (51.2%, n = 244/477). Central vascular catheterisation was a contributory factor in more than half of thrombotic events (56.2%, n = 268/477), while trauma (1.1%, n = 5/477), oral contraceptives (4%, n = 19/477), infection (4%, n = 19/477), surgery (6.9%, n = 33/477) and malignancy (8.4%, n = 40/477) were also risk factors. Arterial ischaemic stroke was diagnosed in 11.1% of cases (n = 53/477), while pulmonary embolism was identified in 7.1% (n = 34/477) and 1.7% of cases were fatal (n = 8/477). LMWH was the first-line therapeutic of choice (47.8%, n = 228/477), with 28.1% (n = 134/477) requiring no intervention.

CONCLUSION

These data reiterate the elevated thrombosis risk to which infants and children with central vascular access are exposed.

FDA approval summary: Dalteparin for the treatment of symptomatic venous thromboembolism in pediatric patients

On May 16, 2019, the U.S. Food and Drug Administration (FDA) approved dalteparin sodium for the treatment of symptomatic venous thromboembolism (VTE) to reduce the risk of recurrence in pediatric patients 1 month of age and older. Approval was primarily based on FDA review of a single-arm trial evaluating dalteparin administered subcutaneous twice daily in 38 pediatric patients with symptomatic VTE. Efficacy was based on the achievement of therapeutic plasma anti-Xa levels. The FDA concluded that dalteparin has efficacy and acceptable safety for pediatric patients.

Severe Acute Respiratory Syndrome Coronavirus 2 Infection and Thrombosis: Phlegmasia Cerulea Dolens Presenting with Venous Gangrene in a Child

A 12-year-old girl with severe acute respiratory syndrome coronavirus 2 infection presented as phlegmasia cerulea dolens with venous gangrene. Emergent mechanical thrombectomy was complicated by a massive pulmonary embolism and cardiac arrest, for which extracorporeal cardiopulmonary resuscitation and therapeutic hypothermia were used. Staged ultrasound-assisted catheter-directed thrombolysis was used for treatment of bilateral pulmonary emboli and the extensive lower extremity deep vein thrombosis while the patient received extracorporeal membrane oxygenation support. We highlight the need for heightened suspicion for occult severe acute respiratory syndrome coronavirus 2 infection among children presenting with unusual thrombotic complications.

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.

Coagulation disorders in Duchenne muscular dystrophy? Results of a registry-based online survey

Different complications of hemostasis have been reported in patients with Duchenne Muscular Dystrophy (DMD). These comprise an increased rate of bleeding-symptoms during scoliosis surgery but also thromboembolic complications such as pulmonary embolism, cerebral infarction, deep vein thrombosis or cardiac thrombus.

For this cross-sectional study, personalized online survey-links were forwarded to 682 registered patients with a genetically confirmed diagnosis of DMD via the German-Austrian DMD patient registry (www.dmd-register.de). The questionnaire enquired data regarding the degree of mobility, disposition to hematoma, epistaxis and gum bleeding, occurrence of peri- and postsurgical hemorrhage, stroke, deep vein thrombosis, and cardiac thromboembolism. Further data on regular medication and age were recorded.

Three-hundred-fifty-one DMD-patients completed the questionnaire (response rate of 51.5%). Of those, 164 (46.7%) were ambulatory and 187 (53.3%) were non-ambulatory. Age distribution was homogeneous. Two participants had a history of thromboembolic events (0.6%). Correlations analysis revealed no coherence with the degree of mobility, age or regular medication. A bleeding tendency was reported by 76 participants (21.7%). No significant correlations with age or degree of mobility were found. We found no association with underlying genetic variants.

Results of this patient registry-based survey do not indicate a distinct DMD-specific risk for thromboembolic events that exceeds the risk by typical comorbidities of chronic immobility and cardiac insufficiency in advanced stages of the disease. The results of this survey suggest a mild bleeding tendency in this DMD cohort, whereas a selection bias cannot be excluded.

Thrombotic risk in children undergoing orthopedic surgery

Children are physiologically protected against venous thromboembolism (VTE). Specific triggering events or contributing factors have been identified in the majority of reported cases, which differs from the adult pathology where 50% of the thromboses are considered "idiopathic". This is a rare disease in children with an estimated frequency of less than 1/1000. The risk is highest in neonates, then decreases and increases again around 13 years to reach the same level as adults at 16 years. The risk of VTE is clearly higher in certain situations: significant trauma, prolonged immobilization, central venous catheter, stay in intensive care unit, inherited thrombophilia, cancer, obesity, oral contraceptives, etc. Thromboprophylaxis should not be used systematically, even in adolescents. Proper hydration and early mobilization form the basis of mechanical thromboprophylaxis. A prescription is only given after careful analysis of the child's risk factors and the orthopedic context. Thrombotic risk assessment scores - which are based on expert opinion and large VTE registers but have not been evaluated in clinical studies - are currently the most reliable method to evaluate the thrombotic risk in children and to prescribe thromboprophylaxis. Low-molecular weight heparin are the most commonly used thromboprophylaxis agents in children, with good tolerance and efficacy.

The Developing Balance of Thrombosis and Hemorrhage in Pediatric Surgery: Clinical Implications of Age-Related Changes in Hemostasis

Bleeding and thrombosis in critically ill infants and children is a vexing clinical problem. Despite the relatively low incidence of bleeding and thrombosis in the overall pediatric population relative to adults, these critically ill children face unique challenges to hemostasis due to extreme physiologic derangements, exposure of blood to foreign surfaces and membranes, and major vascular endothelial injury or disruption. Caring for pediatric patients on extracorporeal support, recovering from solid organ transplant or invasive surgery, and after major trauma is often complicated by major bleeding or clotting events. As our ability to care for the youngest and sickest of these children increases, the gaps in our understanding of the clinical implications of developmental hemostasis have become increasingly important. We review the current understanding of the development and function of the hemostatic system, including the complex and overlapping interactions of coagulation proteins, platelets, fibrinolysis, and immune mediators from the neonatal period through early childhood and to young adulthood. We then examine scenarios in which our ability to effectively measure and treat coagulation derangements in pediatric patients is limited. In these clinical situations, adult therapies are often extrapolated for use in children without taking age-related differences in pediatric hemostasis into account, leaving clinicians confused and impacting patient outcomes. We discuss the limitations of current coagulation testing in pediatric patients before turning to emerging ideas in the measurement and management of pediatric bleeding and thrombosis. Finally, we highlight opportunities for future research which take into account this developing balance of bleeding and thrombosis in our youngest patients.

Venous thromboembolism in childhood: where is Brazil after 20 years?

Due to the longer survival of critically ill children, venous thromboembolism is a problem which is becoming increasingly recognized in pediatric practice. In the last decades, several international studies have been published, shedding a light upon the epidemiology of this disease during childhood. These data show peculiarities in the clinical presentation and the significant morbidity and mortality. The new "epidemic of thrombosis" in pediatric hospitals points toward the urgent need for specific treatment and prevention protocols targeting this population. In Brazil, knowledge regarding this disease remains scarce. The lack of epidemiological data impacts both the clinical care and the design of specific public policies in the field. Thus, a national registry of pediatric venous thromboembolism is relevant to the proposal of an appropriate plan of action to create a qualified net of assistance. The improvement in educational initiatives related to the field of Pediatric Hemostasis is also very important. In this review, we have updated the epidemiological, clinical and therapeutic aspects of the disease, as well as the prevention strategies.

Venous thromboembolism in young adults: Findings from the RIETE registry

BACKGROUND

Little is known on the clinical characteristics, risk factors and outcomes during anticoagulation in young patients with acute venous thromboembolism (VTE).

METHODS

We used data from the RIETE (Registro Informatizado Enfermedad TromboEmbólica) registry to assess the clinical characteristics, risk factors and outcomes during anticoagulation in VTE patients aged 10-24 years. Data were separately analyzed according to initial presentation and gender.

RESULTS

Of 76,719 patients with VTE, 1571 (2.0%) were aged 10-24 years. Of these, 989 (63%) were women and 669 (43%) presented with pulmonary embolism (PE). Most women were using estrogens (680, 69%) or were pregnant (101, 10%), while 59% of men had unprovoked VTE. Women were more likely to present with PE (48% vs. 34%). The majority (87%) of PE patients had Sat O₂ levels ≥90% at baseline. The vast majority (97%) of PE patients were at low risk according to the PESI score, many (90%) at very low risk. During the course of anticoagulation (median, 192 days), 40 patients had VTE recurrences, 17 had major bleeding and 10 died (3 died of PE). Women had as many VTE recurrences as major bleeds (15 vs. 14 events), while men had many more VTE recurrences than major bleeding (25 vs. 3 events).

CONCLUSIONS

VTE is associated with low risk of short-term mortality in young adults. Noticeable gender differences exist in the risk factor profile and the risk of VTE recurrences and major bleeding in the course of anticoagulation.

Thrombosis in Children: Approach to Anatomic Risks, Thrombophilia, Prevention, and Treatment

Pediatric venous thromboembolism (VTE) is increasing in incidence but minimal data exist for best practices regarding therapy, use of thrombophilia testing, and management of long-term complications. Classification schema use anatomic location and presence of clinical or thrombophilic inciting factors. There are a small number of risk-assessment and risk-modeling systems for incident VTE, but all suffer from low numbers, single-institution design, and lack of prospective validation. Acute treatment is limited to heparin products and thrombolysis may be indicated in specific situations. In addition, chronic postthrombotic comorbidities are expected to increase in incidence and lack evidence-based treatment paradigms.

Overcoming challenges of venous thromboembolism in sickle cell disease treatment

INTRODUCTION

Venous thromboembolism (VTE) is a common comorbid condition found in sickle cell disease (SCD) and is associated with increased mortality for adults with SCD. The pathophysiology that leads to the thrombophilic state in SCD has been previously reviewed; however, evidence-based guidelines to aid in diagnosis, prevention, and management of VTE are lacking. Areas covered: This review article will cover the pathophysiology underlying the hypercoagulable state, the epidemiology of VTE, and management strategies of VTE in SCD. Expert opinion: Providers should have a high suspicion for diagnosing VTE to help reduce morbidity and mortality in the SCD population. Unlike other thrombophilias, the risk of life-threatening anemia while being treated with anticoagulation is compounded with the potential complications surrounding red blood cell transfusions in this population (i.e. alloimmunization, hyperhemolysis) and this provides another complexity to managing VTE in this population. Clinical trials evaluating the risk and benefit of treatment and treatment duration are needed.

Diagnostic challenge of the newborn patients with heritable protein C deficiency

ABSTARCT

OBJECTIVE: The diagnosis of neonatal-onset protein C (PC) deficiency is challenging. This study aimed to establish the neonatal screening of heritable PC deficiency in Japan.

STUDY DESIGN

We determined the changes in plasma activity levels of PC and protein S (PS) in healthy neonates, and studied newborn patients with PROC mutation in the Japanese registry.

RESULT

Physiological PC and PS levels increased with wide range. The PC/PS-activity ratios converged after birth. The PC/PS-activity ratios of 19 patients with biallelic mutations, but not, 9 with monoallelic mutation, were lower than those of 13 without mutation. The logistic regression analyses established a formula including two significant variables of PC activity (cut-off < 10%, odds ratio = 30.0) and PC/PS-activity ratio (cut-off < 0.35, odds ratio = 22.7), with 93% sensitivity and 44% specificity for determining patients with mutation(s).

CONCLUSION

The PC/PS-activity ratio is an effective parameter for the genetic screening of neonatal-onset PC-deficiency in Japanese population.

Central Venous Catheter-associated Venous Thromboembolism in Children With Hematologic Malignancy

In pediatric oncology, the diagnosis of a hematologic malignancy and presence of a central venous catheter (CVC) have been identified as significant risk factors for the development of a venous thromboembolism (VTE). There remain little data regarding CVC factors associated with CVC-related VTE. Using the VTE and oncology database in a quaternary care center, a retrospective cohort study was conducted in children below 18 years old with hematologic cancer from November 5, 2012 to April 4, 2016. Patient, CVC factors, and VTE occurrence were analyzed to identify significant patient and CVC factors associated with the development of clinically identified CVC-related VTE. Utilizing the χ, Mann-Whitney, and the Fisher exact tests, patient factors were compared across VTE yes/no groups. Of the 198 study patients, 22 VTE cases were identified. Eighteen VTE events were CVC-associated, occurring in 9% of study population. Peripherally inserted central catheter lines and older ages were associated with VTE. The use of tissue-plasminogen activator for CVC occlusion was associated with decreased VTE rates, suggesting a protective potential.

Epidemiology of Lower Extremity Deep Venous Thrombosis in Critically Ill Adolescents

OBJECTIVE

To determine the epidemiology of lower extremity deep venous thrombosis (DVT) in critically ill adolescents, which currently is unclear.

STUDY DESIGN

We performed a multicenter, prospective, cohort study. Adolescents aged 13-17 years who were admitted to 6 pediatric intensive care units and were anticipated to receive cardiopulmonary support for at least 48 hours were eligible, unless they were admitted with DVT or pulmonary embolism or were receiving or anticipated to receive therapeutic anticoagulation. While patients were in the unit, serial sonograms of the lower extremities were performed, then centrally adjudicated. Bayesian statistics were used to leverage the similarities between adults and adolescents.

RESULTS

A total of 88 adolescents were enrolled, from whom 184 lower extremity sonograms were performed. Of these, 9 adolescents developed DVT, with 1 having bilateral DVT. The frequency of DVT was 12.4% (95% credible interval: 6.1%, 20.1%), which ranged from 6.3% to 19.8% with a variability of 41.0% across units. All cases of DVT occurred in adolescents who received invasive mechanical ventilation (frequency: 16.5%; 95% credible interval 8.1%, 26.6%). DVT was associated with femoral central venous catheterization (OR 15.44; 95% credible interval 1.62, 69.05) and severe illness (OR for every 0.1 increase in risk of mortality 3.11; 95% credible interval 1.19, 6.85). DVT appears to be associated with prolonged days on support.

CONCLUSIONS

Our findings highlight the similarities and differences in the epidemiology of DVT between adults and adolescents. They support the conduct and inform the design of a trial of pharmacologic prophylaxis in critically ill adolescents.

Risk factors for venous thromboembolic events in pediatric surgical patients: Defining indications for prophylaxis

BACKGROUND

Venous thromboembolism (VTE) in pediatric surgical patients is a rare event. The risk factors for VTE in pediatric general surgery patients undergoing abdominopelvic procedures are unknown.

STUDY DESIGN

The American College of Surgeon's National Surgical Quality Improvement Program-Pediatric (NSQIP-P) database (2012-2015) was queried for patients with VTE after abdominopelvic general surgery procedures. Patient and operative variables were assessed to identify risk factors associated with VTE and develop a pediatric risk score.

RESULTS

From 2012-2015, 68 of 34,813 (0.20%) patients who underwent abdominopelvic general surgery procedures were diagnosed with VTE. On multivariate analysis, there was no increased risk of VTE based on concomitant malignancy, chemotherapy, inflammatory bowel disease, or laparoscopic surgical approach, while a higher rate of VTE was identified among female patients. The odds of experiencing VTE were increased on stepwise regression for patients older than 15 years and those with preexisting renal failure or a diagnosis of septic shock, patients with American Society of Anesthesia (ASA) classification ≥ 2, and for anesthesia time longer than 2 h. The combination of age > 15 years, ASA classification ≥ 2, anesthesia time > 2 h, renal failure, and septic shock was included in a model for predicting risk of VTE (AUC = 0.907, sensitivity 84.4%, specificity 88.2%).

CONCLUSION

VTE is rare in pediatric patients, but prediction modeling may help identify those patients at heightened risk. Additional studies are needed to validate the factors identified in this study in a risk assessment model as well as to assess the efficacy and cost-effectiveness of prophylaxis methods.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Phase 3, single-arm, multicenter study of dabigatran etexilate for secondary prevention of venous thromboembolism in children: Rationale and design

BACKGROUND

Anticoagulant therapy for venous thromboembolism (VTE) in children is largely based on treatment recommendations for adults. However, differences in both physiology (ie, renal maturation and drug excretion) and developmental hemostasis must be considered when treating children, as such differences could affect dose appropriateness, safety and efficacy.

OBJECTIVES

To address these concerns, a study was designed to evaluate the safety of dabigatran etexilate in children requiring secondary thrombus prevention in whom an initial VTE was associated with an identified risk factor that persisted after the acute VTE treatment period. We report herein the rationale and design of the study.

PATIENTS/METHODS

This phase 3, open-label, single-arm, multicenter, multinational, prospective cohort study will be conducted in ≥100 children aged 0 to <18 years at ~100 specialist sites worldwide. Children will be treated with dabigatran etexilate for 12 months, or for a shorter duration if their identified VTE risk factor resolves, as per current American College of Chest Physicians recommendations. A nomogram will be used to determine starting doses for each patient.

RESULTS

The primary outcomes of the study will be VTE recurrence, bleeding events, overall mortality, and VTE-related mortality. Secondary outcomes will include occurrence of post-thrombotic syndrome, the pharmacokinetics of dabigatran, and the need for dose adjustments during treatment. Data on adverse events during the study will also be collected.

CONCLUSION

This study will evaluate the safety of dabigatran etexilate for the secondary prevention of VTE in children, in addition to providing further data to guide pediatric dosing with dabigatran.

Design and rationale for the DIVERSITY study: An open-label, randomized study of dabigatran etexilate for pediatric venous thromboembolism

BACKGROUND

The current standard of care (SOC) for pediatric venous thromboembolism (VTE) comprises unfractionated heparin (UFH), or low-molecular-weight heparin (LMWH) followed by LMWH or vitamin K antagonists, all of which have limitations. Dabigatran etexilate (DE) has demonstrated efficacy and safety for adult VTE and has the potential to overcome some of the limitations of the current SOC. Pediatric trials are needed to establish dosing in children and to confirm that results obtained in adults are applicable in the pediatric setting.

OBJECTIVES

To describe the design and rationale of a planned phase IIb/III trial that will evaluate a proposed dosing algorithm for DE and assess the safety and efficacy of DE versus SOC for pediatric VTE treatment.

PATIENTS/METHODS

An open-label, randomized, parallel-group noninferiority study will be conducted in approximately 180 patients aged 0 to <18 years with VTE, who have received initial UFH or LMWH treatment and who are expected to require ≥3 months of anticoagulation therapy. Patients will receive DE or SOC for 3 months. DE will be administered twice daily as capsules, pellets, or an oral liquid formulation according to patient age. Initial doses will be calculated using a proposed dosing algorithm.

RESULTS

There will be two coprimary endpoints: a composite efficacy endpoint comprising the proportion of patients with complete thrombus resolution, freedom from recurrent VTE and VTE-related mortality, and a safety endpoint: freedom from major bleeding events.

CONCLUSION

Findings will provide valuable information regarding the efficacy and safety of DE for the treatment of pediatric VTE. ClinicalTrials.gov registration number: NCT01895777.

Venous thromboembolism among pediatric orthopedic trauma patients: a database analysis

Using the 2012 Kids Inpatient Database, we assessed records of pediatric patients (<21 years old) with fractures of the upper limb, lower limb, spine, pelvis, and multiple locations and calculated the overall prevalence of venous thromboembolism (VTE) and associated potential risk factors. 387 (0.68%) of 57 183 patients with one or more fractures were diagnosed with VTE. Children sustaining fractures of the axial skeleton and those with multiple fractures had a higher prevalence of VTE than those with isolated extremity fractures. Associated risk factors included the presence of a central venous catheter. A prospective, multicenter study is needed to confirm our findings.

Serratia Marcescens Sepsis in a Child with Deep Venous Thrombosis - A Case Report

Introduction

Venous thromboembolism is a rare condition in paediatrics that included both deep venous thrombosis and pulmonary embolism. Serratia marcescens is a gram-negative bacterium that belongs to the Enterobacteriaceae family and tends to affect immunocompromised hosts.

Case report

We report the case of an 11-year-old boy, admitted in the Pediatric Clinic I from Emergency County Hospital Tîrgu Mureş, Romania with intense pain, swelling, cyanosis and claudication of the left foot. His personal history revealed a recent appendectomy. A close family was reported to have had a deep venous thrombosis. The laboratory tests, performed on the day of admission, revealed increased inflammatory biomarkers and D-dimer. Coagulation tests gave a low activated partial thromboplastin time (APTT). Doppler venous ultrasound and CT-exam established a diagnosis of deep venous thrombosis. Anticoagulant therapy was initiated, but on the tenth day of admission, the patient developed signs and symptoms of sepsis, and the blood culture revealed Serratia marcescens. After antibiotic and anticoagulant therapy, the patient progressed favourably. The patient was a carrier of the heterozygous form of Factor V Leiden.

Conclusions

The association between deep venous thrombosis and Serratia marcescens sepsis can compromise a condition in pediatric patients.

Serratia marcescens Sepsis in a Child with Deep Venous Thrombosis – A Case Report

Introduction: Venous thromboembolism is a rare condition in paediatrics that included both deep venous thrombosis and pulmonary embolism. Serratia marcescens is a gram-negative bacterium that belongs to the Enterobacteriaceae family and tends to affect immunocompromised hosts.

Case report: We report the case of an 11-year-old boy, admitted in the Pediatric Clinic I from Emergency County Hospital Tîrgu Mureș, Romania with intense pain, swelling, cyanosis and claudication of the left foot. His personal history revealed a recent appendectomy. A close family was reported to have had a deep venous thrombosis. The laboratory tests, performed on the day of admission, revealed increased inflammatory biomarkers and D-dimer. Coagulation tests gave a low activated partial thromboplastin time (APTT). Doppler venous ultrasound and CT-exam established a diagnosis of deep venous thrombosis. Anticoagulant therapy was initiated, but on the tenth day of admission, the patient developed signs and symptoms of sepsis, and the blood culture revealed Serratia marcescens. After antibiotic and anticoagulant therapy, the patient progressed favourably. The patient was a carrier of the heterozygous form of Factor V Leiden.

Conclusions: The association between deep venous thrombosis and Serratia marcescens sepsis can compromise a condition in pediatric patients.

IVC filter placements in children: nationwide comparison of practice patterns at adult and children's hospitals using the Kids' Inpatient Database

BACKGROUND

Inferior vena cava (IVC) filter placement in children has been described in literature, but there is variability with regard to their indications. No nationally representative study has been done to compare practice patterns of filter placements at adult and children's hospitals.

OBJECTIVE

To perform a nationally representative comparison of IVC filter placement practices in children at adult and children's hospitals.

MATERIALS AND METHODS

The 2012 Kids' Inpatient Database was searched for IVC filter placements in children <18 years of age. Using the International Classification of Diseases, 9th Revision (ICD-9) code for filter insertion (38.7), IVC filter placements were identified. A small number of children with congenital cardiovascular anomalies codes were excluded to improve specificity of the code used to identify filter placement. Filter placements were further classified by patient demographics, hospital type (children's and adult), United States geographic region, urban/rural location, and teaching status. Statistical significance of differences between children's or adult hospitals was determined using the Wilcoxon rank sum test.

RESULTS

A total of 618 IVC filter placements were identified in children <18 years (367 males, 251 females, age range: 5-18 years) during 2012. The majority of placements occurred in adult hospitals (573/618, 92.7%). Significantly more filters were placed in the setting of venous thromboembolism in children's hospitals (40/44, 90%) compared to adult hospitals (246/573, 43%) (P<0.001). Prophylactic filters comprised 327/573 (57%) at adult hospitals, with trauma being the most common indication (301/327, 92%). The mean length of stay for patients receiving filters was 24.5 days in children's hospitals and 18.4 days in adult hospitals.

CONCLUSION

The majority of IVC filters in children are placed in adult hospital settings. Children's hospitals are more likely to place therapeutic filters for venous thromboembolism, compared to adult hospitals where the prophylactic setting of trauma predominates.

Reduced dosing of enoxaparin for venous thromboembolism in overweight and obese adolescents: a single institution retrospective review

BACKGROUND

The global obesity epidemic has created new challenges, including venous thromboembolisms (VTE) in obese adolescents. The data on whether to reduce the dose of low-molecular heparin in obese adults is conflicting, and information on adolescent patients is scarce.

OBJECTIVES

Our primary goal was to describe dosing, anti-Xa levels, and outcomes of overweight and obese adolescents who received reduced doses of enoxaparin at the initiation of therapy. The secondary goal was to compare their outcomes to overweight and obese adolescents who received standard 1 mg/kg dosing to determine if future trials for dose reduction are warranted.

PATIENTS/METHODS

We performed a retrospective cohort study of overweight and obese patients between the ages of 12 and 18 years old diagnosed with VTE who were treated with reduced dosing (RD) of enoxaparin, comparing their dosing, anti-Xa levels, and outcomes to overweight and obese adolescents who received standard dosing (SD).

RESULTS

RD patients (n=19) achieved therapeutic mean initial anti-Xa levels that were similar to SD patients (n=11). Of the RD patients, 53% did not require dose adjustments during treatment. Two RD patients had thrombus progression. A total of 25 patients ultimately completed therapy with RD.

CONCLUSIONS

Future trials are warranted to evaluate the efficacy and safety of reduced dosing of enoxaparin to treat overweight and obese adolescents with VTE.

Risk of deep venous thrombosis in elective neurosurgical procedures: a prospective, Doppler ultrasound-based study in children 12 years of age or younger

OBJECTIVE The risk of venous thromboembolism (VTE) from deep venous thrombosis (DVT) is significant in neurosurgical patients. VTE is considered a leading cause of preventable hospital deaths and preventing DVT is a closely monitored quality metric, often tied to accreditation, hospital ratings, and reimbursement. Adult protocols include prophylaxis with anticoagulant medications. Children's hospitals may adopt adult protocols, although the incidence of DVT and the risk or efficacy of treatment is not well defined. The incidence of DVT in children is likely less than in adults, although there is very little prospectively collected information. Most consider the risk of DVT to be extremely low in children 12 years of age or younger. However, this consideration is based on tradition and retrospective reviews of trauma databases. In this study, the authors prospectively evaluated pediatric patients undergoing a variety of elective neurosurgical procedures and performed Doppler ultrasound studies before and after surgery. METHODS A total of 100 patients were prospectively enrolled in this study. All of the patients were between the ages of 1 month and 12 years and were undergoing elective neurosurgical procedures. The 91 patients who completed the protocol received a bilateral lower-extremity Doppler ultrasound examination within 48 hours prior to surgery. Patients did not receive either medical or mechanical DVT prophylaxis during or after surgery. The ultrasound examination was repeated within 72 hours after surgery. An independent, board-certified radiologist evaluated all sonograms. We prospectively collected data, including potential risk factors, details of surgery, and details of the clinical course. All patients were followed clinically for at least 1 year. RESULTS There was no clinical or ultrasound evidence of DVT or VTE in any of the 91 patients. There was no clinical evidence of VTE in the 9 patients who did not complete the protocol. CONCLUSIONS In this prospective study, no DVTs were found in 91 patients evaluated by ultrasound and 9 patients followed clinically. While the study is underpowered to give a definitive incidence, the data suggest that the risk of DVT and VTE is very low in children undergoing elective neurosurgical procedures. Prophylactic protocols designed for adults may not apply to pediatric patients. Clinical trial registration no.: NCT02037607 (clinicaltrials.gov).

Post thrombotic syndrome following deep vein thrombosis in paediatric patients

Background Although well characterised in adults, less is known about post-thrombotic syndrome in children. In this review, current knowledge regarding paediatric post-thrombotic syndrome is summarised, with particular emphasis on pathophysiology, aetiology, diagnosis and management. Methods A Medline literature review was performed using search terms 'post thrombotic syndrome', 'post phlebitic syndrome', paediatric and children. Relevant articles were identified and included for summation analysis. Results The incident of paediatric venous thromboembolism is rising. Deep vein thrombosis can cause venous hypertension through a combination of venous reflux, venous obstruction and impairment of the calf muscle pump, leading to development of post-thrombotic syndrome. In children, this is more likely to occur if deep vein thrombosis diagnosis and treatment are delayed, if a higher number of vessels are involved, and if factors such as D-dimer are elevated at diagnosis and throughout treatment. Post-thrombotic syndrome occurs in about 26% of paediatric deep vein thrombosis, though the results of individual studies vary widely. A number of tools exist to diagnose paediatric post-thrombotic syndrome, including the modified Villalta scale and Manco-Johnson instrument. Once post-thrombotic syndrome develops, the mainstay of treatment remains supportive, with little evidence of benefit from pharmacological measures. Conclusion Surgical or interventional treatment is not advised except in exceptional cirumstances, due to variable prognosis of PTS in paediatric populations with rising incidence of paediatric venous thromboembolism, it follows that the prevalence of post-thrombotic syndrome in children may also increase. Evidence-based venous thromboembolism prevention strategies need to be implemented for prevention of deep vein thrombosis, but when it does occur, deep vein thrombosis requires prompt and effective treatment to prevent post-thrombotic syndrome. Optimum treatment strategies for post-thrombotic syndrome require further investigation.

Epidemiology and Risk Assessment of Pediatric Venous Thromboembolism

The incidence of diagnosed venous thromboembolism (VTE) has been increasing concurrent with advances in technology and medical care that enhance our ability to treat pediatric patients with critical illness or complex multiorgan system dysfunction. Although the overall incidence of VTE is estimated at 0.07-0.49 per 10,000 children, higher rates are observed in specific populations including hospitalized children, those with central venous catheters (CVCs) or patients convalescing from a major surgery. While the absolute number of pediatric VTE events may seem trivial compared to adults, the increasing incidence, associated with increased mortality and morbidity, the availability of novel therapies, and the impact on the cost of care have made investigation of VTE risk factors and prevention strategies a high priority. Many putative risk factors for pediatric VTE have been reported, primarily from single-institution, retrospective studies which lack appropriate methods for verifying independent risk factors. In addition, some risk factors have inconsistent definitions, which vex meta-analyses. CVCs are the most prevalent risk factors but have not consistently been assigned the highest level of risk as defined by odds ratios from retrospective, case-control studies. Few risk-assessment models for hospital-acquired pediatric VTE have been published. Some models focus exclusively on hospitalized pediatric patients, while others target specific populations such as patients with cancer or severe trauma. Multicenter, prospective studies are needed to identify and confirm risk factors in order to create a pediatric risk-assessment tool and optimize preventive measures and reduce unintended harm.

Venous thromboembolism in pediatric patients: a single institution experience in Korea

Background

While venous thromboembolism (VTE) is uncommon, its incidence is increasing in children. We aimed to evaluate the incidence, risk factors, treatment, and outcome of pediatric VTE cases at a single tertiary hospital in Korea.

Methods

We retrospectively analyzed the records of consecutive pediatric VTE patients admitted to the Seoul National University Bundang Hospital between April 2003 and March 2016.

Results

Among 70,462 hospitalizations, 25 pediatric VTE cases were identified (3.27 cases per 10,000 admissions). Fifteen patients (60%) were male, 8 were neonates (32%), and the median age at diagnosis was 10.9 years (range, 0 days‒17 yr). Doppler ultrasonography was the most frequently used imaging modality. Thrombosis occurred in the intracerebral (20%), upper venous (64%), lower venous (12%), and combined upper and lower venous systems (4%). Twenty patients (80%) had underlying clinical conditions including venous catheterization (24%), malignancy (20%), and systemic diseases (12%). Protein C, protein S, and antithrombin deficiencies occurred in 2 of 13, 4 of 13, and 1 of 14 patients tested, respectively. Six patients were treated with heparin followed by warfarin, while 4 were treated with heparin or warfarin. Thrombectomy and inferior vena cava filter and/or thrombolysis were performed in 5 patients. Two patients died of pulmonary embolism, and 2 developed a post-thrombotic syndrome.

Conclusion

Compared with the reports from Western countries, VTE occurrence was lower in the Korean pediatric population under study, although similar clinical characteristics including bimodal age distribution, underlying diseases, treatment pattern, and outcomes were observed.

Coagulation Profile Dynamics in Pediatric Patients with Cushing Syndrome: A Prospective, Observational Comparative Study

OBJECTIVE

To evaluate the association between Cushing syndrome and hypercoagulability in children.

STUDY DESIGN

A prospective, observational study was performed of 54 patients with Cushing syndrome, 15.1 ± 3.9 years, treated at the National Institutes of Health Clinical Center. Coagulation profiles were taken before and 6-12 months after surgery and compared with18 normocortisolemic children, 13.7 ± 3.6 years.

RESULTS

At baseline, patients with Cushing syndrome had greater levels of the procoagulant factor VIII (FVIII) vs controls (145 IU/dL ± 84 vs 99 ± 47, P = .04); 6-12 months after surgery, FVIII levels decreased to 111 ± 47, P = .05. Patients with Cushing syndrome had greater levels of the antifibrinolytic α2-antiplasmin, 96 ± 17% vs 82 ± 26%, P = .015. After surgery, antifibrinolytic α2-antiplasmin levels decreased to 82 ± 24%, P < .001. Anticoagulants were greater in patients with Cushing syndrome vs controls at baseline, including protein C (138 ± 41% vs 84 ± 25%, P < .001), protein S (94 ± 19% vs 74 ± 19%, P = .001), and antithrombin III (96 ± 18% vs 77 ± 13%, P < .0001). The 24-hour urinary free cortisol levels correlated positively with FVIII levels, r = 0.43, P = .004.

CONCLUSION

Children with Cushing syndrome had elevated procoagulants, antifibrinolytics, and anticoagulants at baseline compared with controls; normalization of coagulation measures was seen after surgical cure. Despite the increase in anticoagulants, hypercortisolemia is associated with a hypercoagulable state in children, as is the case in adults. This finding has potential implications for prevention of venous thromboembolism in children with Cushing syndrome.

TRIAL REGISTRATION

ClinicalTrials.gov:NCT00001595.

Incidence of Deep Vein Thrombosis and Pulmonary Embolism in the Elective Pediatric Orthopaedic Patient

BACKGROUND

Although venous thromboembolism (VTE) has been well studied in the pediatric trauma population, rates of VTE associated with elective pediatric orthopaedic procedures have not been addressed in current literature. The purpose of this retrospective study was to identify the incidence of VTE in the elective pediatric orthopaedic surgical population and delineate subsets of this population at greatest risk. This study may provide valuable data to begin the process of resolving the controversy surrounding deep vein thrombosis prophylaxis in the pediatric orthopaedic population.

METHODS

The Pediatric Health Information System was queried for patients admitted on an ambulatory or inpatient basis, aged below 18 years, from January 2006 to March 2011 during which an elective orthopaedic surgery was the principal procedure performed. Patients with diagnoses or procedures related to infection, trauma, malignancy, or coagulopathies were excluded. Patients admitted through the emergency department or whose orthopaedic procedure was not performed on the admission date were excluded. Age, sex, ethnicity, race, admission year, and all procedures/diagnoses were recorded. The presence of VTE at the index admission or any subsequent readmission within 90 days was recorded. All criteria were coded using ICD-9-CM codes. Generalized logistic regression analyses were used to identify factors related to VTE.

RESULTS

A total of 143,808 admissions (117,676 patients) matched the inclusion criteria. Thirty-three had a VTE during the index admission with an additional 41 at subsequent readmissions, for a total incidence of 0.0515% by admission and 0.0629% by patient. In the multivariable model, variables significantly (P<0.05) related to VTE included increasing age, admission type, diagnosis of metabolic conditions, obesity, and/or syndromes, and complications of implanted devices and/or surgical procedures. No procedure variables were significantly related to VTE in the multivariable model.

CONCLUSIONS

The incidence of VTE in this cohort of pediatric patients undergoing elective orthopaedic surgery was 0.0515%. In children, underlying diagnosis seems to be a stronger predictor of VTE than procedures performed. Diagnosis with a metabolic condition, syndrome, and/or obesity, complications of implanted devices and/or surgical procedures, older age, and admission as an inpatient were significantly related to the development of a VTE.

LEVEL OF EVIDENCE

Level IV—case series.

Age-specific onset and distribution of the natural anticoagulant deficiency in pediatric thromboembolism

BACKGROUND

The early diagnosis of inherited thrombophilia in children is challenging because of the rarity and hemostatic maturation.

METHODS

We explored protein C (PC), protein S (PS), and antithrombin (AT) deficiencies in 306 thromboembolic patients aged ≤20 y using the screening of plasma activity and genetic analysis.

RESULTS

Reduced activities were determined in 122 patients (40%). Low PC patients were most frequently found in the lowest age group (0-2 y, 45%), while low PS or low AT patients were found in the highest age group (16-20 y; PS: 30% and AT: 20%). Genetic study was completed in 62 patients having no other causes of thromboembolism. Mutations were determined in 18 patients (8 PC, 8 PS, and 2 AT genes). Six of eight patients with PC gene mutation were found in age 0-2 y (75%), while six of eight patients with PS gene mutation were in 7-20 y. Two AT gene-mutated patients were older than 4 y. Four PC-deficient and two PS-deficient patients carried compound heterozygous mutations. All but one PC gene-mutated patient suffered from intracranial thromboembolism, while PS/AT gene-mutated patients mostly developed extracranial venous thromboembolism.

CONCLUSION

Stroke in low PC infants and deep vein thrombosis in low PS/AT school age children could be targeted for genetic screening of pediatric thrombophilias.

Risk factors for venous thromboembolism after pediatric trauma

BACKGROUND/PURPOSE

The purposes of this study were to identify independent predictors of venous thromboembolism (VTE), to evaluate the relative impact of adult VTE risk factors, and to identify a pediatric population at high-risk for VTE after trauma.

METHODS

1934 consecutive pediatric admissions (≤ 17 years) from 01/2000 to 12/2012 at a level 1 trauma center were reviewed. Logistic regression was used to identify predictors of VTE.

RESULTS

Twenty-two patients (1.2%) developed a VTE, including 5% of those requiring orthopedic surgery, 14% of those with major vascular injury (MVI), and 36% of those with both. Most (84%) were diagnosed at the primary site of injury. 86% of those who developed a VTE were receiving thromboprophylaxis at the time of diagnosis. Independent predictors were age (odds ratio (OR): 1.59, 95% confidence interval (CI): 1.11-2.25), orthopedic surgery (OR: 8.10, CI: 3.10-21.39), transfusion (OR: 3.37, CI: 1.26-8.99), and MVI (OR: 15.43, CI: 5.70-41.76). When known risk factors for VTE in adults were adjusted, significant factors were age ≥ 13 years (OR: 9.16, CI: 1.08-77.89), indwelling central venous catheter (OR: 4.41, CI: 1.31-14.82), orthopedic surgery (OR: 6.80, CI: 2.47-18.74), and MVI (OR: 14.41, CI: 4.60-45.13).

CONCLUSION

MVI and orthopedic surgery are synergistic predictors of pediatric VTE. Most children who developed a VTE were receiving thromboprophylaxis at the time of diagnosis.

Inferior vena cava (IVC) filters in children: A 10-year single center experience

BACKGROUND

Venous thromboembolism (VTE) is an increasingly recognized problem among children and adolescents. Although inferior vena cava (IVC) filter placement for pulmonary embolism prevention is well reported in adults, data regarding safety and efficacy in the pediatric age group are lacking.

PROCEDURE

At a large university hospital with a level I trauma center, medical records of children and adolescents who underwent IVC filter insertion were reviewed. Appropriateness of referral for retrieval was assessed in each case.

RESULTS

Fifty-nine children and adolescents (mean age 16 years) successfully underwent IVC filter insertion. All filters placed were retrievable. In 47 patients (79.7%), prophylactic filters were placed in the absence of acute VTE in the setting of trauma. In eight patients (13.5%), filters were placed due to contraindication to anticoagulation therapy with concomitant lower extremity deep vein thrombosis or pulmonary embolism. Filters were successfully retrieved in only 12 patients (20.3%), although an attempt at removal was appropriate and feasible in over 90% of cases. Mean duration of follow-up was 2.1 (range 0.4-7.3) years. A significantly higher retrieval rate was found in patients followed at our thrombosis clinic (P < 0.01). Ten patients (17%) experienced at least one filter-related complication.

CONCLUSIONS

Although in most cases, IVC filters were placed for prophylactic indications, the evidence to support their role in this setting is limited. Their low retrieval rate and high filter-related complication rate question their extensive utilization in children. Dedicated follow-up is necessary to detect complications and to ensure that an attempt at retrieval is made when feasible.

Phlegmasia Cerulea Dolens in the Pediatric Population: A Life-threatening Condition

BACKGROUND

Phlegmasia cerulea dolens is a rare complication of deep venous thromboembolism that can have life-threatening consequences. It is more commonly reported in the adult population, and rarely in the pediatric population, especially in a healthy child.

CASE REPORT

We report a case of a healthy 7-year-old girl who presented with right leg pain and fever, found to have a thrombus involving her inferior vena cava and right lower extremity. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case illustrates the importance of early recognition and a multimodal approach to treatment of phlegmasia cerulea dolens.