Clinical features and outcome of pulmonary embolism in children

Catheter-directed therapy for acute pulmonary embolism in children

BACKGROUND

Acute pulmonary embolism is a life-threatening condition and rarely occurs in children. In adults, catheter-directed therapy emerges as a potentially safer and effective therapeutic option. However, there is a paucity of data on the safety and efficacy of catheter-directed therapy for pulmonary embolism in children. We report a single-centred experience of catheter-directed therapy for acute pulmonary embolism in children.

METHODS

This is a retrospective study of children who had no CHD and underwent catheter-directed therapy at Detroit Medical Center during a 12-year period from 2005 to 2017. Demographic and clinical data associated with pulmonary embolism were collected along with the outcome.

RESULTS

A total of nine patients of median age 16 years with the range from 12 to 20 received catheter-directed therapy for sub-massive (n = 6) and massive pulmonary embolism (n = 3). Among nine patients, one patient received Angiojet thrombectomy and balloon angioplasty, whereas eight patients received catheter-directed thrombolysis using tissue plasminogen activator through infusion catheters (n = 3) or EkoSonic ultrasound-accelerated thrombolysis system (n = 5). In four out of five patients treated with EkoSonic, significant clinical improvement was noticed within 24 hours. Among seven patients who survived, two patients had minor gastrointestinal bleeding with median hospital stay of 8 days with the range from 5 to 24 days, and two patients with massive pulmonary embolism died possibly due to delayed institution of catheter-directed therapy.

CONCLUSION

Catheter-directed therapy with/without EkoSonic is an emerging alternative therapy for sub-massive and massive pulmonary embolism in children. A timely institution of catheter-directed therapy appeared important to improve the outcome.

Pulmonary Embolism in Children

Pulmonary embolism is an uncommon but potentially life-threatening event in children. There has been increasing awareness of pulmonary embolism in children with improved survival in children with systemic disease and advancements in diagnostic modalities. However, literature regarding pulmonary embolism in children is sparse, and thus current guidelines for management of pulmonary embolism in children are extrapolated from adult literature and remain controversial. This article reviews the background and pathophysiology of venous thromboembolism, as well as current diagnostic approach and recommended management of pulmonary embolism in children.

Lessons from a patient with cardiac arrest due to massive pulmonary embolism as the initial presentation of Wilms tumor: a case report and literature review

Background

Finding an abdominal mass or hematuria is the initial step in diagnosing Wilms tumor. As the first manifestation of Wilms tumor, it is exceedingly rare for pulmonary tumor embolism to present with cardiac arrest. A case of a patient whose sudden cardiac arrest due to massive pulmonary tumor embolism of Wilms tumor was not responsive to resuscitation is presented.

Case presentation

The patient was a five-year-old girl who collapsed suddenly during activity in nursery school and went into cardiac arrest in the ambulance. Unfortunately, she was not responsive to conventional resuscitation. A judicial autopsy conducted at the local police department showed the main cause of her sudden cardiac arrest was attributed to multiple pulmonary tumor embolisms of stage IV Wilms tumor.

Conclusions

Except for one reported case, treatments were not successful in all eight cardiac arrest cases with pulmonary tumor embolism of Wilms tumor. These results indicate that it is challenging not only to make an accurate diagnosis, but also to provide proper specific treatment in the cardiac arrest setting. We propose that flexible triage and prompt transfer to a tertiary hospital are necessary as an oncologic emergency to get such patients to bridging therapy combined with extracorporeal membrane oxygenation or immediate surgical intervention under cardiopulmonary bypass.

D-dimer in Adolescent Pulmonary Embolism

BACKGROUND

D-dimer is used to aid in diagnosing adult pulmonary embolism (PE). D-dimer has not been validated in adolescents. Clinicians must balance the risk of overtesting with that of a missed PE. D-dimer may be useful in this context. This study evaluates D-dimer in PE-positive and PE-negative adolescents.

METHODS

PE-positive patients < 22 years were diagnosed with PE by computed tomography (CT) or high-probability ventilation/perfusion, seen at emergency departments (EDs)/hospitals within a 16-hospital system across two states, January 1998 through December 2016. Of the 189 PE-positive patients, 88 (46.5%) had a D-dimer and were matched 1:1 by age, sex, and race to patients suspected of PE but confirmed negative by CT angiogram.

RESULTS

Ages of PE-positive patients ranged from 13 to 21 years, 64 (73%) were female, and 52 (60%) were Caucasian. Mean D-dimer was significantly higher (3,256 ng/mL, 95% confidence interval [CI] = 2,505-4,006 ng/mL) in PE-positive versus PE-negative patients (1,244 ng/mL, 95% CI = 493-1,995 ng/mL; p < 0.001). Mean D-dimer was higher in patients with massive or submassive PE (8,742 ng/mL, 95% CI = 5,994-11,491 ng/mL), followed by PE in central (4,795 ng/mL [95% CI = 3,465-6,125 ng/mL), lobar (3,758 ng/mL [95% CI = 1,841-5,676), and distal (2,327 ng/mL [95% CI = 1,273-3,381 ng/mL]) arteries. When comparing thresholds of positive D-dimer (≥500, ≥750, and ≥1,000 ng/mL), D-dimer had sensitivities of 90, 82, and 67% and specificities of 16, 53, and 67%, respectively. Negative predictive values were 61, 75, and 71% while positive likelihood ratios were 1.1, 1.8, and 2.2, respectively.

CONCLUSIONS

This study represents the largest available cohort of adolescent patients examining the diagnostic value of D-dimer for PE. Our results indicate that depending on the threshold selected, D-dimer can be a sensitive test for PE in adolescents and that discriminative value is higher for a cutoff of 750 ng/mL than that for 500 ng/mL. Prospective studies investigating the diagnostic value of D-dimer and a clinical decision rule for PE in pediatrics are needed.

Pulmonary Embolism Mimicking Infectious Pleuritis

The diagnosis of pulmonary thromboembolism (PE) is often delayed because it is usually misdiagnosed as pneumonia or deep vein thrombosis. We report an unusual case of PE misdiagnosed as viral pleuritis on the first arrival at the emergency department (ED) in our hospital. A 14-year-old girl with no previous significant medical history was referred to the ED with pleuritic and chest pain with low-grade fever 4 days before admission. Echography showed a small amount of left pleural effusion. A 12-lead electrocardiogram was normal. She received a diagnosis of viral pleuritis. Two days before admission, she revisited ED with dyspnea and exacerbated pain. Echography showed slight increase in left pleural effusion. She had the same diagnosis. The chest pain remained at the same level. On the day of admission, she presented to ED with vomiting, watery diarrhea, abdominal pain, chest pain, and respiratory distress. Laboratory findings showed hypoalbuminemia and proteinuria. Echography showed a moderate amount of pleural effusion on both sides and no dilatation of the right cardiac ventricle. Contrast-enhanced chest computed tomography was performed to search the cause of the respiratory distress, which showed filling defects with contrast material in pulmonary arteries. A 12-lead electrocardiogram showed an S1Q3T3 pattern. She received a diagnosis of PE caused by nephrotic syndrome. Pulmonary thromboembolism can mimic infectious pleuritis and lead to misdiagnosis and/or delayed diagnosis. Thus, risk factors of PE should be considered in pediatric patients presenting with symptoms suggesting infectious pleuritis.

Clinical characteristics of children evaluated for suspected pulmonary embolism with D-dimer testing

BACKGROUND

We sought to determine clinical variables in children tested for suspected pulmonary embolism (PE) that predict PE+ outcome for the development of paediatric PE prediction rule.

METHODS

Data were collected by query of a laboratory database for D-dimer from January 2004 to December 2014 for a large multicentre hospital system and the radiology database for pulmonary vascular imaging in children aged 5-17. Using explicit, predefined methods, trained abstractors, determined if D-dimer was sent in the evaluation of PE and then recorded predictor data which was tested for association with PE+ outcome using univariate techniques.

RESULTS

D-dimer was ordered in 526 children for clinical suspicion of PE. Thirty-four of 526 were PE+ (6.4%, 95% CI 4.3% to 8.7%). The radiology database identified 17 additional patients with PE (n=51 PE+ total). Children evaluated for PE were primarily in the ED setting (80%), teenagers (88%) and 2:1 female:male. Children with PE had higher mean heart and higher respiratory rate and a lower pulse oximetry and haemoglobin concentration. On univariate analysis, five conditions were more frequent in PE+ compared with no PE: surgery, central line, limb immobility, prior PE or deep vein thrombosis and cancer.

CONCLUSIONS

The rate of PE diagnosis in children with D-dimer was 6.4%, similar to that seen in adults; most children with PE are over 13 years and had clinical predictors known to increase probability of PE in symptomatic adults. Future studies should use these criteria to develop a clinical decision rule for PE in children.

Pulmonary Embolism in Children

Pulmonary embolism (PE) in children is a rare condition with potential for high mortality. PE incidence is increasing owing to increased survival of children with predisposing conditions, increased use of central venous catheters, and improved awareness and recognition. Although pediatric PE is distinct from adult PE, management guidelines in children are extrapolated from the adult data. Treatment includes thrombolysis or thrombectomy, and pharmacologic anticoagulation. Ongoing clinical trials are evaluating the use of direct oral anticoagulants in children. Further research is required to develop pediatric-specific evidence-based guidelines for diagnosis and management of PE.

Magnetic resonance imaging of cardiovascular thrombi in children

Cardiovascular thrombosis is rare in children and usually occurs in the presence of predisposing conditions, such as indwelling vascular catheters, tumors, aneurysms, ventricular dysfunction, or after surgery. Clots can occur in the cardiac chambers, arteries or veins, or inside conduits. Detection of thrombi is feasible with a variety of magnetic resonance imaging (MRI) techniques, including unenhanced methods but also contrast-enhanced MR angiography. In this essay we illustrate the MRI appearance of cardiovascular thrombosis in children and suggest an imaging protocol based on our clinical experience.

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.

Pediatric issues in thrombosis and hemostasis: The how and why of venous thromboembolism risk stratification in hospitalized children

Multiple observational studies have identified risk factors for venous thromboembolism (VTE) in hospitalized children, but very few interventional studies have assessed the safety and efficacy of thromboprophylaxis in this population. In recent years, however, evidence in pediatric VTE risk stratification has grown considerably. This has led to the conception of a pediatric subpopulation-specific risk-based paradigm for mechanical and pharmacological thromboprophylaxis in hospitalized children. More research is required to validate and further refine pediatric subpopulation-specific risk models and to subsequently investigate risk-stratified thromboprophylaxis strategies for hospitalized children.

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

This review is aimed at describing the unique challenges of anticoagulant prophylaxis and treatment in children, and highlighting areas for research for improving clinical outcomes of children with thromboembolic disease. The evidence presented demonstrates the challenges of advancing the evidence base informing optimal management of thromboembolic disease in children. Recent observational studies have identified risk factors for venous thromboembolism in children, but there are few interventional studies assessing the benefit-risk balance of using thromboprophylaxis in risk-stratified clinical subgroups. A risk level-based framework is proposed for administering mechanical and pharmacological thromboprophylaxis. More research is required to refine the assignment of risk levels. The anticoagulants currently used predominantly in children are unfractionated heparin, low molecular weight heparin, and vitamin K antagonists. There is a paucity of robust evidence on the age-specific pharmacology of these agents, and their efficacy and safety for prevention and treatment of thrombosis in children. The available literature is heterogeneous, reflecting age-specific differences, and the various clinical settings for anticoagulation in children. Monitoring assays and target ranges are not well established. Nevertheless, weight-based dosing appears to achieve acceptable outcomes in most indications. Given the limitations of the classical anticoagulants for children, there is great interest in the direct oral anticoagulants (DOACs), whose properties appear to be particularly suitable for children. All DOACs currently approved for adults have Pediatric Investigation Plans ongoing or planned. These are generating age-specific formulations and systematic dosing information. The ongoing pediatric studies still have to establish whether DOACs have a positive benefit-risk balance in the various pediatric indications and age groups.

Pulmonary embolism and in situ pulmonary artery thrombosis in paediatrics

Data on paediatric pulmonary embolism (PE) are scarce. We sought to systematically review the current literature on childhood PE and conducted a search on paediatric PE via PubMed (1946–2013) and Embase (1980–2013). There was significant heterogeneity in reported data. Two patterns were noted: classic thromboembolic PE (TE-PE) and in situ pulmonary artery thrombosis (ISPAT). Mean age of presentation for TE-PE was 14.86 years, and 51% of cases were males. The commonest method for diagnosis of TE-PE was contrast CT with angiography (74% of patients). The diagnosis of TE-PE was often delayed. Although 85% of children with TE-PE had an elevated D-dimer at presentation, it was non-discriminatory for the diagnosis. In paediatric TE-PE, the prevalence of central venous catheters was 23%, immobilisation 38%, systemic infection 31% and obesity 13%, elevated Factor VIII or von Willebrand factor levels 27%, Protein C deficiency 17%, Factor V Leiden 14% and Protein S deficiency 7%. In patients with TE-PE, pharmacologic thrombolysis was used in 29%; unfractionated heparin was the most common initial anticoagulant treatment in 64% and low-molecular-weight heparins the most common follow-up treatment in 83%. Duration of anticoagulant therapy was variable and death was reported in 26% of TE-PE patients. In contrast to TE-PE, patients with ISPAT were not investigated systematically for presence of thrombophilia, had more surgical interventions as the initial management and were often treated with anti-platelet medications. This review summarises important data and identifies gaps in the knowledge of paediatric PE, which may help to design future studies.

Quality Initiative to Introduce Pediatric Venous Thromboembolism Risk Assessment for Orthopedic and Surgery Patients

BACKGROUND AND OBJECTIVES

Pediatric hospital-acquired venous thromboembolism (VTE) is costly, has high morbidity, and is often preventable. The objective of this quality-improvement effort was to increase the percentage of general surgery and orthopedic patients ≥10 years of age screened for VTE risk from 0% to 80%.

METHODS

At a freestanding children's hospital, 2 teams worked to implement VTE risk screening for postoperative inpatients. The general surgery team used residents and nurse practitioners to perform screening whereas the orthopedic team initially used bedside nursing staff. Both groups employed multiple small tests of change. Shared key interventions included refinement of a screening tool, provider education, mitigation of failures, and embedding the risk assessment task into staff workflow. The primary outcome measure, the percentage of eligible patients with a completed VTE risk assessment, was plotted on run charts. Secondary outcome measures for screened patients included the level of risk, the use of appropriate prophylaxis, and VTE events.

RESULTS

Median weekly percentage of general surgery patients screened for VTE risk increased from 0% to 86% within 12 months, and median weekly percentage of orthopedic patients screened for VTE risk increased from 0% to 46% within 8 months. Among screened patients, the majority were at low or moderate risk for VTE and received prophylaxis in accordance with or beyond guideline recommendations. No screened patients developed VTE.

CONCLUSIONS

Quality-improvement methods were used to implement a VTE risk screening process for postoperative patients. Using providers as screeners, as opposed to bedside nurses, led to a greater percentage of patients screened.

Development of a Surveillance System for Pediatric Hospital-Acquired Venous Thromboembolism

BACKGROUND

Pediatric hospital-acquired (HA) venous thromboembolism (VTE) is a vexing problem with improvement efforts hampered by lack of robust surveillance methods to establish accurate rates of HA-VTE.

METHODS

At a freestanding children's hospital, a multidisciplinary team worked to develop a comprehensive surveillance strategy for HA-VTE. Starting with diagnosis codes, we implemented complementary detection methods, including clinical and radiology data, to develop a robust surveillance system. HA-VTE events were tracked by using descriptive statistics and a statistical process control chart. Detection methods were evaluated via retrospective application of each method to every identified HA-VTE. Initial detection method was tracked.

RESULTS

A total of 68 HA-VTE events were identified and the median number of events per 1000 patient days increased from 0.18 to 0.34. No single detection method would have identified all events. Each detection method initially identified HA-VTE events.

CONCLUSIONS

Implementation of multiple detection methods has optimized timely detection of HA-VTE. This allows the establishment of a reliable baseline rate, enabling quality improvement efforts to address HA-VTE.

[Bilateral pulmonary embolism mimicking acute chest syndrome in an adolescent with sickle cell disease]

Pulmonary embolism is a life-threatening and potentially lethal disease. Its incidence in children with sickle cell disease is probably underestimated and pediatric case reports in the literature are rare. Moreover, symptoms can mimic an acute chest syndrome. We report on the case of a 17-year-old boy with SS sickle cell disease, admitted for chest pain with dyspnea and tachycardia. Pulmonary angiography revealed a partial bilateral obstructive pulmonary embolism. We did not find any deep venous thrombosis or thrombophilia. The progression was rapidly favorable with anticoagulant therapy. We recommend a pulmonary angiography for any chest pain that does not evolve favorably in a child with sickle cell disease. Large series of pediatric patients would be useful to establish diagnostic and therapeutic guidelines.

New anticoagulants for the treatment of venous thromboembolism

Worldwide, venous thromboembolism (VTE) is among the leading causes of death from cardiovascular disease, surpassed only by acute myocardial infarction and stroke. The spectrum of VTE presentations ranges, by degree of severity, from deep vein thrombosis to acute pulmonary thromboembolism. Treatment is based on full anticoagulation of the patients. For many decades, it has been known that anticoagulation directly affects the mortality associated with VTE. Until the beginning of this century, anticoagulant therapy was based on the use of unfractionated or low-molecular-weight heparin and vitamin K antagonists, warfarin in particular. Over the past decades, new classes of anticoagulants have been developed, such as factor Xa inhibitors and direct thrombin inhibitors, which significantly changed the therapeutic arsenal against VTE, due to their efficacy and safety when compared with the conventional treatment. The focus of this review was on evaluating the role of these new anticoagulants in this clinical context.

Pulmonary Embolism in Children

Pulmonary embolism (PE) in the pediatric population is relatively rare when compared to adults; however, the incidence is increasing and accurate and timely diagnosis is critical. A high clinical index of suspicion is warranted as PE often goes unrecognized among children leading to misdiagnosis and potentially increased morbidity and mortality. Evidence-based guidelines for the diagnosis, management, and follow-up of children with PE are lacking and current practices are extrapolated from adult data. Treatment options include thrombolysis and anticoagulation with heparins and oral vitamin K antagonists, with newer direct oral anticoagulants currently in clinical trials. Long-term sequelae of PE, although studied in adults, are vastly unknown among children and adolescents. Additional research is needed in order to provide pediatric focused care for patients with acute PE.

Detection of Pulmonary Embolism in High-Risk Children

OBJECTIVE

To evaluate 2 commonly used adult-based pulmonary embolism (PE) algorithms in pediatric patients and to derive a pediatric-specific clinical decision rule to evaluate children at risk for PE, given the paucity of data to guide diagnostic imaging in children for whom PE is suspected.

STUDY DESIGN

We performed a single-center retrospective study among 561 children <22 years of age undergoing either D-dimer testing or radiologic evaluation (computed tomography or ventilation-perfusion scan) in the emergency department setting for concern of PE. A diagnosis of PE required radiologic confirmation and anticoagulant treatment. We evaluated the test characteristics of the Wells criteria and Pulmonary Embolism Rule-out Criteria (PERC) low-risk rule and used recursive partition analysis to derive a clinical decision rule.

RESULTS

Among the 561 patients included in the study, 36 (6.4%) were diagnosed with PE. The Wells criteria demonstrated a sensitivity and specificity of 86% and 60%, respectively. The sensitivity and specificity of the PERC were 100% and 24%, respectively. A clinical decision rule including the presence of oral contraceptive use, tachycardia, and oxygen saturation <95% demonstrated a sensitivity and specificity of 90% and 56%, respectively, a positive and negative likelihood ratio of 2.0 and 0.2, and a positive and negative predictive value of 0.12 and 0.99, respectively.

CONCLUSIONS

The risk of PE is low among children not receiving estrogen therapy and without tachycardia and hypoxia in those with an initial suspicion of PE. Application of the PERC rule and Wells criteria should be used cautiously in the pediatric population.

Pediatric Pulmonary Embolism: Diagnostic and Management Challenges

A rare case of massive pulmonary embolism is presented in an oligosymptomatic teenager with predisposing factors. Computed tomography pulmonary angiography supported by three-dimensional reconstruction was diagnostic. The embolus qualified as massive by conventional anatomical guidelines, but as low risk by more recent functional criteria. Functional assessment has complemented morphologic assessment for risk stratification in adult patients. Such evidence is scarce in pediatrics. The patient underwent surgical embolectomy, followed by prophylactic anticoagulation, without further events. Diagnostic and management challenges are discussed.

Association of Obesity and Pediatric Venous Thromboembolism

BACKGROUND

The incidence of venous thromboembolism (VTE) is increasing among pediatric patients in the United States. Previous studies on obesity as a risk factor have produced mixed results.

METHODS

We completed a retrospective chart review of patients aged 2 to 18 years with VTE identified by using International Classification of Diseases, Ninth Revision, codes and confirmed by imaging. Patients were admitted between January 2000 and September 2012. Control subjects were matched on age, gender, and the presence of a central venous catheter. Data were collected on weight, height, and risk factors, including bacteremia, ICU admission, immobilization, use of oral contraceptives, and malignancy. Underweight patients and those without documented height and weight data were excluded. Independent predictors of VTE risk were identified by using univariate and multivariate analyses.

RESULTS

We identified 88 patients plus 2 matched control subjects per case. The majority of cases were nonembolic events (77%) of the lower extremity (25%) or head and neck (22%) confirmed by ultrasound (43%) or computed tomography scan (41%). A statistically significant association was found between VTE and increased BMI z score (P = .002). In multivariate analysis, BMI z score (odds ratio [OR]: 3.1; P = .007), bacteremia (OR: 4.9; P = .02), ICU stay (OR: 2.5; P = .02), and use of oral contraceptives (OR: 17.4; P < .001) were significant predictors.

CONCLUSIONS

In this single-institution study, the diagnosis of VTE was significantly associated with overweight and obesity. Further study is needed to fully define this association.

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.

[Recombinant tissue plasminogen activator for the management of intracardiac thrombi in newborns]

INTRODUCTION

The incidence of cardiac thrombi in newborns has increased with the use of central venous catheters. Thrombolysis with recombinant tissue plasminogen activator (rTPA) has been used as an alternative to heparin in life threatening giant thrombus and embolization. The aim of this study is to describe the response and complications related to the use of rTPA in the management of life- threatening cardiac thrombi in newborns.

PATIENTS AND METHOD

The medical records of 8 newborn were reviewed in a retrospective study, of whom 7 were preterm with cardiac thrombi, and rTPA was used in all of them.

RESULTS

The patients included 4 males with a mean weight of 1580 gr. The principal pathology was sepsis (7/8), all of them used venous central catheter. The superior vena cava was the most frequent location, with a mean time of installation before the diagnosis of 12 days. RN 7/8 thrombi were located in the right atrium with a size between 7 to 20 mm. Three patients received low molecular weight heparin prior to using rTPA. They received between 1 to 5 cycles with rTPA. In 4 patients complete resolution of the thrombus was achieved in a mean of 3.5 days. Four patients had intracranial haemorrhage grade I, without sequelae at follow-up. There were no deaths or embolism.

CONCLUSION

This study is the first series of infants treated with rTPA in Chile, and where its use has quickly achieved complete resolution of the thrombus in 50% of cases, and partially in the others, thus reducing the secondary life-threatening risk of this disease.

A case of panic to pulmonary embolism

Pulmonary embolism (PE) is a rare paediatric diagnosis, but its presence is likely to be underestimated due to the subtle and non-specific nature of its symptoms. Common clinical features of PE include shortness of breath, pleuritic chest pain and acute cardiovascular collapse. Less common symptoms can include persistent unexplained tachycardia, fever or deep vein thrombosis. Rarely do patients present with abdominal pain and self-resolving shortness of breath; symptoms our patient experienced. However, in contrast to popular belief, having normal vital signs does not necessarily lower the probability of PE. D-dimer, a specific fibrin degradation product, has a good negative predictive value for venous thromboembolism diagnosis but its use in children is less clear, with up to 40% of children with PE having a normal D-dimer level. CT pulmonary angiography remains the gold standard in diagnosis.

Successful pulmonary embolectomy of a saddle pulmonary thromboembolism in a preterm neonate

Symptomatic pulmonary thromboembolism (PTE) is rare in neonates, and the diagnosis is often made only postmortem. The true incidence is probably underestimated because of its varying presentations, ranging from mild respiratory distress to acute right-heart failure and cardiovascular collapse. We report a sudden cardiorespiratory collapse on day 10 of life in a preterm neonate who was subsequently diagnosed as having a saddle pulmonary embolus. The patient underwent an emergency surgical embolectomy as a salvage procedure. Considering the potentially lethal complications of PTE, neonatologists and pediatricians should maintain a high degree of suspicion in infants with sudden inexplicable deterioration in cardiorespiratory status. Surgical removal of the thrombus is an invasive procedure and potentially carries a high mortality rate. Two term neonatal survivors of surgical intervention have been reported in the medical literature so far. However, we believe that this is the first documented preterm neonatal survivor after surgical intervention for a massive saddle PTE.

Chondrosarcoma presenting with pulmonary embolism in a 9-year-old girl: a case report

Chondrosarcoma is a malignant bone tumour common in adults, third to myeloma and osteosarcoma, but is exceptionally rare in children. Here we discuss a 9-year-old girl presenting with occlusive right pulmonary artery neoplastic embolus, resulting from a primary right proximal humerus chondrosarcoma. To the best of our knowledge, this the first pediatric and only second overall case reported in the United States of a neoplastic pulmonary embolus resulting from a primary chondrosarcoma.

Venous thromboembolism at uncommon sites in neonates and children

We retrospectively analyzed the data of 24 children (whereof 11 neonates), with non-central venous line-related and nonmalignancy-related venous thromboembolism (VTE) at uncommon sites, referred to our Unit from January 1999 to January 2012. Thirty patients who also suffered deep vein thrombosis, but in upper/low extremities, were not included in the analysis. The location of rare site VTE was: portal (n=7), mesenteric (n=2) and left facial vein (n=1), spleen (n=3), lung (n=3), whereas 10 neonates developed renal venous thrombosis. The majority of patients (91.7%) had at least 1 risk factor for thrombosis. Identified thrombophilic factors were: antiphospholipid antibodies (n=2), FV Leiden heterozygosity (n=6), MTHFR C677T homozygosity (n=4), protein S deficiency (n=2), whereas all neonates had age-related low levels of protein C and protein S. All but 6 patients received low-molecular-weight heparin, followed by warfarin in 55% of cases, for 3 to 6 months. Prolonged anticoagulation was applied in selected cases. During a median follow-up period of 6 years, the clinical outcome was: full recovery in 15 patients, evolution to both chronic portal hypertension and esophageal varices in 2 children, and progression to renal failure in 7 of 10 neonates. Neonates are greatly vulnerable to complications after VTE at uncommon sites, particularly renal. Future multicentre long-term studies on neonatal and pediatric VTE at unusual sites are considered worthwhile.

Development of a new risk score for hospital-associated venous thromboembolism in noncritically ill children: findings from a large single-institutional case-control study

OBJECTIVE

To determine risk factors for pediatric hospital-associated venous thromboembolism (HA-VTE) in noncritically ill children to derive a novel HA-VTE risk model for this population.

STUDY DESIGN

Patients with HA-VTE were identified retrospectively via the electronic health record at All Children's Hospital Johns Hopkins Medicine from April 10, 2013 through January 1, 2006. Seven contemporaneous, noncritically ill control children were randomly selected for each case of HA-VTE. The association between putative risk factors and HA-VTE was estimated with ORs and 95% CIs, which were calculated using the Wald method. A P-value threshold ≤.2 was used in univariate analysis for inclusion into a multivariate (adjusted) model.

RESULTS

Fifty cases of HA-VTE occurred in noncritically ill children. The presence of a central venous catheter (OR 27.67, 95% CI, 8.40-91.22), infection (OR 10.40, 95% CI, 3.46-31.25), and length of stay ≥4 days (OR 5.26, 95% CI, 1.74-15.88) were found to be statistically significant risk factors for HA-VTE. An 8-point risk score was derived in which scores of 8 points, 7 points, and ≤6 points corresponded to venous thromboembolism risks of 12.5%, 1.1%, and 0.1%, respectively.

CONCLUSION

The presence of a central venous catheter, infection, and length of stay ≥4 days are significant risk factors for HA-VTE in noncritically ill children, forming the basis for a new risk score that could inform venous thromboembolism prophylaxis decision-making. These findings warrant prospective validation.

Transcatheter treatment for pulmonary artery occlusion secondary to pulmonary embolism in an infant

We report a case of successful recanalisation of the left pulmonary artery after occlusion due to embolic thrombi in a 9-month-old infant after surgical repair of a common atrioventricular canal with tetralogy of Fallot. A transhepatic approach was used because of caval vein thrombosis. After the failure of high-pressure balloon angioplasty, the left pulmonary artery was successfully recanalised with cutting balloons, followed by stent implantation with an excellent result.

Pulmonary artery thrombus in a premature neonate treated with recombinant tissue plasminogen activator

Pulmonary artery thrombus is a rarely reported complication in premature neonates. The management of life-threatening thrombotic events in neonates is controversial, especially regarding the use of thrombolytics versus anticoagulation alone for treatment. We report a case of a premature neonate with symptomatic pulmonary artery thrombus treated with recombinant tissue plasminogen activator who survived without bleeding complications.

Risk factors for venous thromboembolism in hospitalized children and adolescents: a systemic review and pooled analysis

We performed a systematic review of published studies that evaluated the potential risk factors and outcomes of venous thromboembolism (VTE) in hospitalized children. A total of 761 VTE patients from six published studies were identified. The mean prevalence of VTE in children admitted to the hospital was 9.7/10 000 admissions. The presence of a central venous catheter was found to be the single most important predisposing cause of VTE, with a pooled percentage of 29%. Infection was the second most common cause of the disease (20%). Pulmonary embolism occurred in 15% (113/745) of the patients. The overall recurrence rate of VTE was 16% (74/464) and the mortality rate was 8% (59/704). Although uncommon, orthopedic surgeons need to be aware of the unique risk factors for VTE among pediatric inpatients. Hospitalized children and adolescents with known risk factors for VTE should be considered candidates for VTE screening or prophylaxis.

A multinational study of thromboprophylaxis practice in critically ill children

OBJECTIVES

Although critically ill children are at increased risk for developing deep venous thrombosis, there are few pediatric studies establishing the prevalence of thrombosis or the efficacy of thromboprophylaxis. We tested the hypothesis that thromboprophylaxis is infrequently used in critically ill children even for those in whom it is indicated.

DESIGN

Prospective multinational cross-sectional study over four study dates in 2012.

SETTING

Fifty-nine PICUs in Australia, Canada, New Zealand, Portugal, Singapore, Spain, and the United States.

PATIENTS

All patients less than 18 years old in the PICU during the study dates and times were included in the study, unless the patients were 1) boarding in the unit waiting for a bed outside the PICU or 2) receiving therapeutic anticoagulation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 2,484 children in the study, 2,159 (86.9%) had greater than or equal to 1 risk factor for thrombosis. Only 308 children (12.4%) were receiving pharmacologic thromboprophylaxis (e.g., aspirin, low-molecular-weight heparin, or unfractionated heparin). Of 430 children indicated to receive pharmacologic thromboprophylaxis based on consensus recommendations, only 149 (34.7%) were receiving it. Mechanical thromboprophylaxis was used in 156 of 655 children (23.8%) 8 years old or older, the youngest age for that device. Using nonlinear mixed effects model, presence of cyanotic congenital heart disease (odds ratio, 7.35; p < 0.001) and spinal cord injury (odds ratio, 8.85; p = 0.008) strongly predicted the use of pharmacologic and mechanical thromboprophylaxis, respectively.

CONCLUSIONS

Thromboprophylaxis is infrequently used in critically ill children. This is true even for children at high risk of thrombosis where consensus guidelines recommend pharmacologic thromboprophylaxis.

Venous thromboembolism in critically ill children

PURPOSE OF REVIEW

To review the current literature on venous thromboembolism (VTE) in critically ill children.

RECENT FINDINGS

There is an increasing concern for VTE and its complications in critically ill children. Critically ill children are at increased risk of thromboembolism because of the treatment that they are receiving and their underlying condition. A complex relationship exists between thrombosis and infection. A thrombus is a nidus for infection, while infection increases the risk of thrombosis. Pediatric-specific guidelines for the prevention and treatment of thromboembolism are lacking. Current guidelines are based on the data from adults. Novel anticoagulants are now available for use in adults. Studies are ongoing to determine their safety in children. Risk assessment tools have recently been developed to determine the risk of thromboembolism in critically ill children. Certain molecules are associated with thromboembolism in adults.

SUMMARY

Pediatric critical care practitioners should be cognizant of the importance of VTE in critically ill children to allow early identification and treatment. Adequately powered clinical trials are critically needed to generate evidence that will guide the treatment and prevention of thromboembolism in critically ill children. Risk assessment tools that incorporate biomarkers may improve our ability to predict the occurrence of thromboembolism in critically ill children.

Venous thromboembolism in children: preliminary results of a survey of POSNA members

BACKGROUND

The term venous thromboembolism (VTE) includes deep venous thrombosis of the extremity and pulmonary embolism, a potentially fatal clinical entity. Although the prevalence of VTE may be lower in children compared with adults, recent reports suggest a possible rise in this diagnosis among pediatric patients, especially in association with certain risk factors. We assessed the clinical experience and practice of members of the Pediatric Orthopaedic Society of North America (POSNA) related to VTE among their pediatric patients.

METHODS

A 36-question online survey was sent to all 636 active POSNA members. The proportion of surgeons who had encountered at least 1 child with VTE and the respondents' practice of using thromboprophylaxis in children (<18 y old) was assessed. The relationship of responders' experience with VTE among pediatric patients with various practice characteristics was evaluated.

RESULTS

The response rate was 56% (354/636). More than half (55%) [95% confidence interval (CI), 50%-60%] of the respondents could recall at least 1 (median, 2 cases/member) pediatric patient with deep venous thrombosis and 29% (95% CI, 24%-34%) could recall ≥1 child with pulmonary embolism. Approximately one quarter (23%) (95% CI, 18%-27%) of all respondents reported never using mechanical prophylaxis and almost one half (45%) (95% CI, 40%-50%) of respondents reported never using pharmacologic prophylaxis against VTE in children. Only 16% (95% CI, 12%-20%) of the respondents had a thromboprophylaxis protocol for pediatric patients. Respondent characteristics such as being in clinical practice <5 years (P=0.01) and having a surgical volume of <100 cases/y (P=0.03) were associated with a lower likelihood of encountering a pediatric patient with VTE.

CONCLUSIONS

More than half of responding active POSNA members reported having come across at least 1 case of VTE among pediatric patients during their practice. The routine use of VTE prophylaxis for children is uncommon among pediatric orthopaedists. Further studies aimed at determining the prevalence of VTE and developing specific guidelines for prophylaxis among pediatric patients seeking orthopaedic care are warranted.

LEVEL OF EVIDENCE

IV.

Pulmonary embolism in the pediatric emergency department

OBJECTIVE

To describe patients who present to the pediatric emergency department (PED) and are subsequently diagnosed with pulmonary embolism (PE).

METHODS

Electronic medical records from 2003 to 2011 of a tertiary care pediatric health care system was retrospectively reviewed to identify patients <21 years who had a final International Classification of Diseases, Ninth Revision diagnosis of PE. Patient demographics, and hospital course were recorded. Adult validated clinical decision rules Wells criteria and Pulmonary Embolism Rule-out Criteria (PERC) were retrospectively applied. PERC identified 8 clinical criteria for adult patients using logistic regression modeling to exclude PE without additional diagnostic evaluation. If all criteria are met, further evaluation is not indicated.

RESULTS

Of 1 185 794 PED visits, 105 patients had an ultimate diagnosis of PE. Twenty-five met study criteria, and all were admitted. Forty percent of these patients had PE diagnosed in the PED. The most common risk factors were BMI ≥25 (50%, 10 of 20), oral contraceptive use (38% 5 of 13 female patients), and history of previous thrombus without PE (28%, 7 of 25). When the PERC rule was applied retrospectively, 84% of patients could not be ruled out, indicating additional evaluation for PE was needed.

CONCLUSIONS

Pulmonary embolism is rare in children but does occur. This study emphasizes risk factors among children that should raise the suspicion of PE. Additional studies are needed to further evaluate risk factors and signs and symptoms of PE to develop pediatric specific clinical decision rules to provide reliable and reproducible means of determining pretest probability of PE.

Papillary fibroelastoma of tricuspid valve in a pediatric patient

We are reporting a rare case of papillary fibroelastoma of the tricuspid valve in an 8-year-old child who presented with pulmonary embolism. Echocardiography was instrumental in determining the source of the pulmonary embolism, but not in delineating between tumor and thrombus. Successful surgical resection of the mass was accomplished and good outcome was attained despite the delay in diagnosis and failure of medical management. A high index of suspicion for tumor involving the tricuspid valve is emphasized despite its rarity in children.

Cardiac findings and long-term thromboembolic outcomes following pulmonary embolism in children: a combined retrospective-prospective inception cohort study

In paediatric pulmonary embolism, cardiac findings and thromboembolic outcomes are poorly defined. We conducted a mixed retrospective-prospective cohort study of paediatric pulmonary embolism at the Children's Hospital Colorado between March, 2006 and January, 2011. A total of 58 consecutive children - age less than or equal to 21 years - with acute pulmonary embolism were enrolled. Data collection included clinical and laboratory characteristics, treatments, serial echocardiographic and electrocardiographic findings, and outcomes of pulmonary embolism non-resolution and recurrence. The median age was 16.5 years ranging from 0 to 21 years. The most prevalent clinical risk factors were oral contraceptive pill use (52% of female patients), presence of a non-infectious inflammatory condition (21%), and trauma (21%). Thrombophilias included heterozygous factor V Leiden in 21%; antiphospholipid antibody syndrome was established in 31% overall. Proximal pulmonary artery involvement was present in 34%. At presentation, nearly half of the patients had hypoxaemia and 37% had tachycardia. The classic electrocardiographic finding of S1Q3T3 was present in 12% acutely; tricuspid regurgitation greater than 3 metres per second, septal flattening, and right ventricular dilation were each present on acute echocardiogram in 25%. Nearly all patients received therapeutic anticoagulation, with initial systemic tissue plasminogen activator administered in 16% for occlusive iliofemoral deep venous thrombosis and/or massive pulmonary embolism. Pulmonary embolism resolution was observed in 82% by 6 months. Recurrent pulmonary embolism occurred in 9%. There were no pulmonary embolism-related deaths. Right ventricular dysfunction was rare in follow-up. These data indicate that acute heart strain is common, but chronic cardiac dysfunction is rare, following aggressive management of acute pulmonary embolism in children.

Neonatal and infant pulmonary thromboembolism: a literature review

Pulmonary thromboembolism (PTE) is rare in neonates and infants; however evidence suggests it is underdiagnosed. The primary objective is to conduct a scientific review to determine if the presentation, diagnosis, treatment and outcomes of neonates and infants with PTE are consistent across studies. Secondly, to develop an algorithm to establish the diagnosis and management of the condition based on current information. Two authors searched the literature independently using existing databases and verified that identical articles were assembled. Infants aged less than 1 year with PTE were included and further categorized into neonates 28 days or less and infants 29 days to 1 year or less. Forty-five articles with 157 cases (121 neonates; 36 infants) were identified with PTE. All of the reports were descriptive and neither randomized controlled trials nor prospective or case-control studies were identified. The reports are sub-classified into cases of pulmonary air embolism (PAE) with a higher mortality rate and patients with PTE. Diagnostic and treatment strategies varied widely and were individually case-based, dependent on clinical findings, which influenced patient outcomes. Scientific data to guide an evidence-based, diagnostic and treatment approach to PTE is limited because of the absence of rigorous clinical trials. Large scale, multicenter collaborative studies are required to firmly establish the management of PTE in this population.

Pulmonary emboli associated with isolated lower-extremity venous malformation: a case report

Pulmonary thromboembolism is a relatively rare entity in the pediatric population; however, it should always be part of the differential diagnosis in patients with the appropriate clinical presentation. We report the case of a 13-year-old girl with a history of a lower-extremity venous malformation status post sclerotherapy 2 years prior but otherwise healthy who presented with painless hemoptysis. She was found to have multiple bilateral pulmonary emboli on computed tomographic angiography of the chest. Magnetic resonance venography of the lower extremities showed stable venous changes from prior studies and no obvious source of emboli. She was started on anticoagulation and was discharged home.