Acute Management of High-Risk and Intermediate-Risk Pulmonary Embolism in Children: A Review

Management options for pediatric venous thromboembolic disease: Beyond anticoagulation with endovascular therapies

Venous thromboembolism (VTE) in pediatric patients is an uncommon but serious diagnosis that has an array of therapeutic options and challenges. An assessment of the existing literature on management of pediatric patients with VTE was conducted. The interventions reviewed include anticoagulation, thrombolysis, thrombectomy, inferior vena cava (IVC) filters, and venous stenting. For each intervention, a discussion of mechanism of action, indications, contraindications, and potential complications was performed. While anticoagulants are considered the first-line pediatric VTE treatment, many drugs remain investigational in this patient population and treatment recommendations are extrapolated from adult practice. Thrombolysis may be indicated in cases of acute thrombosis requiring more rapid clot resolution but presents a greater bleeding risk than anticoagulation. Similarly, thrombectomy also provides rapid clot resolution and offers a larger therapeutic window and usage in more mature thrombi than thrombolysis. In select patient groups, IVC filters may be indicated in the prevention of PE but present with inherent thrombogenicity and risk of migration. The data regarding pediatric VTE treatment options, monitoring, and long term outcomes is limited compared to the adult population. The relatively few clinical trials including pediatric patients have a relatively small sample size and are heterogenous with regards to predisposing factors that further exacerbate generalizability. Additional research is needed to help construct and evaluate a robust treatment algorithm for pediatric patients with VTE.

Considerations for instituting pediatric pulmonary embolism response teams: A tool kit

The incidence of pediatric pulmonary embolism (PE) has increased by 200 % in the last decade, but at a single center, it is still infrequent. Given the unique epidemiologic features of pediatric PE, diagnosis is often delayed, and the management is empiric, based on individual physician experience or preference. Thus, there is a strong need for center-specific uniform management of pediatric PE patients. In adults, the development of pulmonary embolism response teams (PERTs) or PE critical care pathways has shortened the time to diagnosis and the initiation of definitive management. Evidence to support an improvement in PE outcomes after the development of PERTs does not exist in children. Nonetheless, we have summarized the practical practice guidelines that physicians and institutions can adopt to establish their institutional PERTs or critical pathways. We also provide strategies for resource-challenged institutions for partnering with centers with expertise in the management of pediatric PE.

Anticoagulation of pediatric patients with venous thromboembolism in 2023

Venous thromboembolism (VTE) is a rare and heterozygous disease in children. Management of VTE in children is complicated by age-related differences in epidemiology, recurrent VTE and bleeding risk, hemostatic proteins and pharmacokinetics of anticoagulants. Recently, the choice of anticoagulation has expanded to oral factor IIa and Xa inhibitors, which have been authorized for children for treatment of acute VTE and extended secondary prevention. These drugs have several properties that make them extremely suitable for use in children, including oral administration, antithrombin independence, less interactions with food and drugs and no need for monitoring. Unfortunately, the phase 3 studies had many exclusion criteria, and only a few term neonates and infants were included in these studies. Additional real-world data is needed to make evidence-based recommendations in these age and patient groups, as well.

Case Report: In situ pulmonary artery thrombosis in a 12-year-old girl classified as systemic lupus erythematosus

In situ pulmonary artery thrombosis (ISPAT) is a relatively rare but potentially life-threatening complication of systemic lupus erythematosus (SLE) in children. We report the case of a 12-year-old girl who presented with fever, chest pain, and dyspnea. Immune thrombocytopenia was identified due to purpura and menorrhagia 3 months before presentation with a lowest platelet count of 12 × 109/L. The sudden onset of fever, chest pain, and dyspnea were misdiagnosed as hyperinflammatory responses caused by pneumonia; these symptoms ameliorated with glucocorticoid and antibiotic treatment. The reappearance of symptoms after dose reduction of glucocorticoids and the observation of bloody bronchoalveolar lavage fluid necessitated further evaluation. Pulmonary artery thrombosis/embolism was identified using computed tomography pulmonary angiography and high D-dimer quantitative level of 4,118 μg/L (normal <252 μg/L). Ultrasonography of the deep and superficial veins of both lower limbs and renal veins revealed no thrombosis, suggesting the diagnosis of ISPAT. Further etiological evaluation revealed positive antinuclear antibodies, lupus anticoagulant, and anti-SSA antibodies, confirming SLE. Repeated normal urine analysis indicated that lupus nephritis was unlikely. Further, the negative anticardiolipin and anti-β2 glycoprotein antibodies and temporary positive lupus anticoagulant suggested that antiphospholipid syndrome was unlikely. The patient received anticoagulants, glucocorticoids, hydroxychloroquine, and mycophenolate therapy. Her symptoms gradually improved, and she was discharged. At the 1-month follow-up, the thrombosis had resolved. During the 1-year follow-up, her condition remained well without SLE relapse. Our experience with this case emphasizes searching for SLE in the case of ISPAT and pulmonary hemorrhages. ISPAT can occur in children with SLE and may be caused by hyperinflammatory response during SLE flare.

A retrospective study of the clinical characteristics of 9 children with pulmonary embolism associated with Mycoplasma pneumoniae pneumonia

OBJECTIVE

The aim of this study was to analyze the clinical characteristics and treatment of children with Mycoplasma pneumoniae pneumonia (MPP) who also present with pulmonary embolism (PE).

METHODS

This retrospective analysis examined the demographic data, clinical manifestations, laboratory tests, imaging characteristics, therapy, and prognosis of nine cases of children with Mycoplasma pneumoniae pneumonia (MPP) complicated by pulmonary embolism (PE). The study focused on patients admitted to the respiratory department of Tianjin Children's Hospital between January 2018 and December 2021.

RESULTS

The age range of the patients was 3 to 8 years old, with a median age of 7.5 years. The median number of days from pulmonary infection to the diagnosis of embolism was 14 days. All patients had refractory Mycoplasma pneumoniae pneumonia (RMPP). Among them, three patients reported chest pain, one of whom had hemoptysis, while five patients had dyspnea, and six patients experienced radiating pain at unusual sites. Five out of the nine children tested positive for lupus anticoagulant (LA), five for anticardiolipin antibody (ACA), three for anti-2-glycoprotein antibody IgM, four for reduced protein S or protein C activity, and three for elevated coagulation factor VIII. Moreover, six out of the nine children tested positive for antinuclear antibodies. All the children underwent CT pulmonary angiograms, which revealed filling defects. After sequential low-molecular heparin anticoagulation with rivaroxaban, nine children in this study showed a good prognosis, with two of them receiving thrombolytic therapy for combined cardiac embolism. Follow-up at 0.5-9 months showed the gradual resolution of the emboli in all 9 children, with no thrombotic recurrences and normalized autoantibodies and thrombophilia markers.

CONCLUSIONS

The majority of cases involving Mycoplasma pneumoniae pneumonia (MPP) combined with pulmonary embolism (PE) were diagnosed with refractory MPP (RMPP). However, PE did not always occur in the advanced stages of the disease. Most patients presented with transient autoantibody positivity, abnormal coagulation, and fibrinolytic balance. With timely treatment, the prognosis of MPP combined with PE is generally good. Additionally, rivaroxaban treatment has been shown to be safe and effective.

Investigating the Mechanism of Intravascular Bubble Formation in Designed Arrays of Vascularized Systems on a Chip

Vascular gas embolism is a rare medical condition, resulting from the existence of air or gas in the venous or arterial system. Gas embolism is associated with a wide range of circulatory, cardiovascular, and neurological complications that can lead to sudden and unexplained death. Despite the recent increase in related studies, gas embolism remains under-reported with a poor understanding of its genesis and pathophysiology. In this work, intravascular bubble formation is investigated in an array of biomimetic microscale systems, where the endogenous generation of gas bubbles is induced by variations in the surrounding pressure. Microfluidic devices, based on polydimethylsiloxane, are designed and fabricated as vascularized systems on a chip with one main channel at two different diameters (30 µm, and 40 µm), surrounded by a pressure chamber (200 µm) on each side, at a separation of 50 µm. Two blood-equivalent solutions, at 20% and 46% hematocrit concentrations were prepared from a glycerin and xanthan gum mixture to mimic the physicochemical characteristics of the blood. As the volume of injected air increased, the events related to gas embolism were occurring at shorter timespans with more significant characteristics, i.e., length and number of bubbles. Additionally, correlations were established between the input parameters, i.e., the vascular diameter and equivalent hematocrit concentration, and the output parameters, i.e., the bubble size, velocity, frequency, and nucleation sites.Clinical Relevance- The reported results constitute a reproducible observation and quantification of intravascular bubble formation induced by global pressure variations, where the emergence of bubbles exhibits different patterns depending on biological characteristics related to gender and medical history.

Deep Vein Thrombosis of the Left Lower Limb in a Sudanese Child with Sickle Cell Disease

This is a case of an eleven-year-old female Sudanese child, a known Sickle Cell Anemia (SCA) patient, who presented with fever, as well as left thigh and leg swelling that was associated with pain and warmness, which was diagnosed as Deep Vein Thrombosis (DVT) of her left lower limb. She had a previous history of admissions to the emergency room, during which she once received blood. The patient was managed by carrying out a basic routine initial laboratory investigation. A Doppler ultrasound scan showed features consistent with DVT. Based on the clinical findings and investigation results, management began by providing the patient with intravenous fluid, analgesia, packed Red Blood Cells (RBCs), intravenous antibiotics, and low-molecular-weight heparin. Further consultations showed that there was no need for vascular surgery or surgical intervention. This case highlights the need for more studies on DVT and Venous Thromboembolism (VTE) complications in children with SCA, so as to develop strategies for diagnosis and management in order to reduce the risk of life-threatening complications of VTE in patients with Sickle Cell Disease SCD.

Practical considerations and consensus opinion for children's hospital-based inpatient hemostasis and thrombosis (HAT) consultative services: Communication from the ISTH SSC Subcommittee on Pediatric/Neonatal Thrombosis and Hemostasis

Caring for children and adolescents with disorders of hemostasis and thrombosis (HAT) has become more specialized and requires a unique skill set that many providers are not able to obtain in standard pediatric hematology/oncology/bone marrow transplant fellowship training programs. The influx of numerous therapeutic advances and increasing medical complexity has expanded the need for experienced HAT providers and subspecialty collaboration in the inpatient setting due to the nuances in the management of patients with HAT complications and concerns. While there are data highlighting the benefits of an inpatient hemostasis, thrombosis, and anticoagulation management service in adult hospitals, there are limited pediatric data supporting such programs. In this article, we summarize the current practices of various pediatric institutions in the inpatient management of HAT patients and provide a consensus opinion for the development of a pediatric inpatient HAT service at tertiary care referral centers.

Catheter-directed embolectomy for massive pulmonary embolism in a pediatric patient

Pulmonary embolisms can affect 0.9 in 100,000 children and carry high risk for mortality. However, management of pediatric pulmonary embolism is largely derived from adult studies and treatment often includes local or systemic thrombolytics or anticoagulation, which may pose unique bleeding risks in children and adolescents compared with adults. This report describes a case in which catheter-directed embolectomy was used to successfully manage a pediatric patient with high-risk/massive pulmonary embolism. This case suggests that catheter-directed embolectomy is an effective therapy in patients outside the adult population and more research is required to expand inclusion criteria for current catheter-directed embolectomy treatment paradigms. Moreover, this case emphasizes the need for dedicated pediatric pulmonary embolism response teams to best serve the pediatric population.

Thrombolysis in Children: A Case Report and Review of the Literature

Thromboembolism (TE), including venous thromboembolism (VTE), arterial TE, arterial ischemic stroke (AIS), and myocardial infarction (MI), is considered a relatively rare complication in the pediatric population. Yet, the incidence is rising, especially in hospitalized children. The vast majority of pediatric TE occurs in the setting of at least one identifiable risk factor. Most recently, acute COVID-19 and multisystem inflammatory syndrome in children (MIS-C) have demonstrated an increased risk for TE development. The mainstay for the management pediatric TE has been anticoagulation. Thrombolytic therapy is employed more frequently in adult patients with ample data supporting its use. The data for thrombolysis in pediatric patients is more limited, but the utilization of this therapy is becoming more commonplace in tertiary care pediatric hospitals. Understanding the data on thrombolysis use in pediatric TE and the involved risks is critical before initiating one of these therapies. In this paper, we present the case of an adolescent male with acute fulminant myocarditis and cardiogenic shock likely secondary to MIS-C requiring extracorporeal life support (ECLS) who developed an extensive thrombus burden that was successfully resolved utilizing four simultaneous catheter-directed thrombolysis (CDT) infusions in addition to a review of the literature on the use of thrombolytic therapy in children.