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

Pediatric pulmonary thromboembolism: a 3-year Canadian Pediatric Surveillance Program study

BACKGROUND

Pediatric pulmonary embolism (PE) is a rare event associated with significant morbidity and mortality. Awareness of clinical presentation and practices unique to children may aid clinicians in prompt identification and treatment.

OBJECTIVES

To describe the incidence, risk factors, clinical presentation, diagnostic and therapeutic practices, and short-term outcomes of pediatric PE.

METHODS

We conducted a 3-year national surveillance study through the Canadian Pediatric Surveillance Program. Over 2800 pediatric specialists and subspecialists were contacted monthly from 2020 to 2022 and requested to report all new cases of PE in patients up to 18 years of age. Case-specific data were obtained through voluntary completion of a detailed questionnaire.

RESULTS

Fifty-eight cases (78% female, n = 45) were reported (2.4 cases per million children), with rates highest in adolescents 15 to 18 years (6.6 cases per million). Detailed information, available for 31 (53%) cases, documented at least 1 risk factor in 28 (90%) cases; 24 (77%) patients presented with 2 or more symptoms. Computed tomography pulmonary angiography was used for diagnostic confirmation in 25 (81%) cases. Anticoagulation was initiated in 24 (77%) of 31 cases; fewer than 5 patients underwent thrombolysis or surgical interventions. Of 28 patients who received therapeutic interventions, 8 (29%) experienced treatment-related complications. Fewer than 5 mortalities were reported.

CONCLUSION

Pediatric PE is a rare event, with female adolescents at the highest risk. Although the presentation is often nonspecific, clinicians should maintain a high index of suspicion, particularly in patients with risk factors and when other diagnoses that may explain symptoms have been excluded.

Long-term outcomes of pulmonary embolism in children and adolescents

ABSTRACT

Knowledge regarding the long-term consequences of pulmonary embolism (PE) in children is limited. This cohort study describes the long-term outcomes of PE in children who were followed-up at a single-center institution using a local protocol that included clinical evaluation, chest imaging, echocardiography, pulmonary function tests, and cardiopulmonary exercise tests at follow-up, starting 3 to 6 months after acute PE. Children objectively diagnosed with PE at age 0 to 18 years, who had ≥6 months of follow-up were included. Study outcomes consisted of PE resolution, PE recurrence, death, and functional outcomes (dyspnea, impaired pulmonary or cardiac function, impaired aerobic capacity, and post-PE syndrome). The frequency of outcomes was compared between patients with/without underlying conditions. In total, 150 patients were included; median age at PE was 16 years (25th-75th percentile, 14-17 years); 61% had underlying conditions. PE did not resolve in 29%, recurrence happened in 9%, and death in 5%. One-third of patients had at least 1 documented abnormal functional finding at follow-up (ventilatory impairments, 31%; impaired aerobic capacity, 31%; dyspnea, 26%; and abnormal diffusing capacity of the lungs to carbon monoxide, 22%). Most abnormalities were transient. When alternative explanations for the impairments were considered, the frequency of post-PE syndrome was lower, ranging between 0.7% and 8.5%. Patients with underlying conditions had significantly higher recurrence, more pulmonary function and ventilatory impairments, and poorer exercise capacity. Exercise intolerance was, in turn, most frequently because of deconditioning than to respiratory or cardiac limitation, highlighting the importance of physical activity promotion in children with PE.

Return emergency department visits for recurrent pulmonary embolism symptoms in children and adolescents

Rates of pulmonary embolism (PE) in children have steadily increased over the past 2 decades. Patient outcomes after hospital discharge are poorly understood, and many patients experience recurrent or persistent chest pain or dyspnea, prompting a return to care. This retrospective cohort study of patients diagnosed with PE at a large children's hospital over a 9.5-year period was performed to evaluate rates of return to the emergency department (ED) for PE-related symptoms, and to determine the utility of repeat computed tomography angiography (CTA) in this population. Ninety-six patients were diagnosed with PE during the study period. Forty-two percent of patients (n = 40) returned to the ED for PE-related symptoms and a total of 74 repeat CTAs were performed. Among those who had return visits, the mean number of return visits was 3 and the mean number of repeat CTAs was 1.8. The median time to return to the ED was 34 days. Logistic regression analysis identified increased age and female sex as risk factors for return ED visits. Eight percent of the cohort experienced PE recurrence. Recurrent PE was observed only in those with persistent or new thrombotic risk factors and was uncommon in those who remained on appropriate anticoagulation. Future work should focus on the development of a risk stratification system to identify patients at low risk of recurrence in order to minimize repeat CTA imaging.

Pulmonary embolism in pediatrics: A 10-year experience from a tertiary center in Brazil

INTRODUCTION

Although still rare, pulmonary embolism (PE) in children has been increasing over the years. Data regarding this group of patients are still sparse, which contributes to the lack of standardized prophylaxis protocols and the misdiagnosis. This study aimed to determine the incidence of pediatric PE at a Brazilian tertiary hospital, describe clinical characteristics and identify possible risk factors. We also analyzed the diagnosis and management of PE.

METHODS

This was a retrospective review of tertiary Brazilian single-center data of all pediatric patients (0 - 18 years) with acute PE, diagnosed radiologically, from September 2009 to May 2019.

RESULTS

The incidence of PE was 3.3 cases per 10,000 hospitalized children. All the twenty-three cases had some risk factor identified and sixteen of them (69.5%) had more than one risk factor. The most important were central venous catheter (39.1%), malignancy (34.8%) and recent surgery (34.8%). Among the children with identifiable symptoms (69.5%), the most common was dyspnea (56.2%). Only one patient did not receive antithrombotic therapy because of the high bleeding risk and most patients (70.6%) were treated for 3 to 6 months. Among the nineteen patients alive at the end of the six-month follow-up, ten (52.6%) repeated the PE image control. Seven of them (70.0%) had complete or partial resolution of the thrombosis and none had worsening images.

CONCLUSION

Our lower incidence than that of the current literature may reflect underdiagnosis due to low suspicion of PE. At least one risk factor was identified in all patients, which emphasizes the importance of increasing awareness of high-risk children.

High Rates of Pediatric Venous Thromboembolism After Elective Laparoscopic Splenectomy Suggest Need for Perioperative Prophylaxis

INTRODUCTION

In adult populations, postoperative venous thromboembolism (VTE) is a reported complication of up to 8% of elective laparoscopic splenectomy (LS) cases. VTE is a rare event in the pediatric population, affecting less than 1% of all pediatric surgical patients. We hypothesized that pediatric patients are at a higher risk of postoperative VTE after undergoing elective LS relative to other laparoscopic procedures and may warrant prophylactic treatment.

MATERIALS AND METHODS

We queried the American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-P) database from 2012 to 2020. Patients were identified using the Current Procedural Terminology code 38120 and only elective cases were analyzed.

RESULTS

The incidence of VTE in all pediatric patients undergoing surgery in the American College of Surgeons NSQIP-P database was 0.13%. The incidence of VTE in pediatric patients undergoing elective laparoscopic abdominopelvic procedures was 0.17%. There were seven total cases of VTE (0.41%) in pediatric patients undergoing elective LS, more than twice the rate of the general population (P = 0.001). Eighty percent of pediatric patients undergoing elective LS had an underlying hematological disorder.

CONCLUSIONS

By analyzing the NSQIP-P database, we evaluated the largest cohort of pediatric patients undergoing elective LS to date. We identified a higher incidence of VTE following this procedure relative to the rate of VTE in the overall population in the NSQIP-P database, as well as those undergoing elective laparoscopic abdominopelvic operations. The relatively higher incidence of VTE after elective LS is likely due to the presence of underlying hematological conditions. Given the low incidence of complications associated with pharmacologic VTE prophylaxis, the results of this study suggest that further research is warranted to establish the efficacy of perioperative pharmacological VTE prophylaxis in pediatric patients undergoing elective LS.

Risk factors for the development of hospital-acquired pediatric venous thromboembolism-Dealing with potentially causal and confounding risk factors using a directed acyclic graph (DAG) analysis

Introduction

Hospital-acquired venous thromboembolism (HA-VTE) in children comprises multiple risk factors that should not be evaluated separately due to collinearity and multiple cause and effect relationships. This is one of the first case-control study of pediatric HA-VTE risk factors using a Directed Acyclic Graph (DAG) analysis.

Material and methods

Retrospective, case-control study with 22 cases of objectively confirmed HA-VTE and 76 controls matched by age, sex, unit of admission, and period of hospitalization. Descriptive statistics were used to define distributions of continuous variables, frequencies, and proportions of categorical variables, comparing cases and controls. Due to many potential risk factors of HA-VTE, a directed acyclic graph (DAG) model was created to identify confounding, reduce bias, and increase precision on the analysis. The final model consisted of a DAG-informed conditional logistic regression.

Results

In the initial conventional univariable model, the following variables were selected as potential risk factors for HA-VTE: length of stay (LOS, days), immobility, ICU admission in the last 30 days, LOS in ICU, infection, central venous catheter (CVC), number of CVCs placed, L-asparaginase, heart failure, liver failure, and nephrotic syndrome. The final model using the set of variables selected by DAG analysis revealed LOS (OR = 1.106, 95%CI = 1.021–1.198, p = 0.013), L-asparaginase (OR = 26.463, 95%CI = 1.609–435.342, p = 0.022), and nephrotic syndrome (OR = 29.127, 95%CI = 1.044–812.508, p = 0.004) as independent risk factors for HA-VTE.

Conclusion

The DAG-based approach was useful to clarify the influence of confounders and multiple causalities of HA-VTE. Interestingly, CVC placement—a known thrombotic risk factor highlighted in several studies—was considered a confounder, while LOS, L-asparaginase use and nephrotic syndrome were confirmed as risk factors to HA-VTE. Large confidence intervals are related to the sample size; however, the results were significant.

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.

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.

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.

Venous thromboembolism in children with cystic fibrosis: Retrospective incidence and intrapopulation risk factors

INTRODUCTION

Pediatric venous thromboembolism (VTE) is a rare but serious medical condition. Cystic fibrosis (CF) is a risk for recurrent pediatric VTE and has potential thrombophilic tendency. However, much remains unknown, including incidence and intrapopulation risk factors.

METHODS

A retrospective cohort of pediatric CF patients followed at Children's Hospital Colorado from January 1st 2003 through May 20th 2016 was examined. Cases were identified by informatics and validated manually. Data on CF severity, co-morbidities and treatment, central venous catheter (CVC) use, and thrombophilia were obtained from an institutional CF database and chart review.

RESULTS

Nineteen VTE occurred in 458 participants followed for 3595 person-years, yielding an incidence rate of 53 VTE per 10,000 children with CF. VTE cases had additional co-morbidities including CF-related diabetes (p=0.002) and sinus disease (p=0.04), more total admissions (p<0.001), admit days (p<0.001), positive respiratory cultures (p<0.001), pseudomonas infections (p<0.001), steroid courses (p=0.001), and total CVC days (PICC p=0.03, port p=0.007). On univariate analysis, older age (RR 1.162, p=0.007), sinus disease (RR 2.62, p=0.05), longer hospital stay (RR 1.03, p<0.001), higher ESR (RR 1.02, p=0.03) and CRP (RR 1.07, p=0.007), and an absence of systemic steroids (RR 0.19, p=0.004) increased the risk of VTE.

CONCLUSIONS

In this cohort, children with CF had a higher incidence of VTE when compared to the previously reported incidence in the overall pediatric population at Children's Hospital Colorado. Overall, those with VTE had a greater disease burden and older age, sinus disease, longer hospitalization and increased inflammation were VTE risk factors.

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.

Gene Expression Profiling of Pulmonary Artery in a Rabbit Model of Pulmonary Thromboembolism

Acute pulmonary thromboembolism (PTE) refers to the obstruction of thrombus in pulmonary artery or its branches. Recent studies have suggested that PTE-induced endothelium injury is the major physiological consequence of PTE. And it is reasonal to use PTE-induced endothelium injury to stratify disease severity. According to the massive morphologic and histologic findings, rabbit models could be applied to closely mimic the human PE. Genomewide gene expression profiling has not been attempted in PTE. In this study, we determined the accuracy of rabbit autologous thrombus PTE model for human PTE disease, then we applied gene expression array to identify gene expression changes in pulmonary arteries under PTE to identify potential molecular biomarkers and signaling pathways for PTE. We detected 1343 genes were upregulated and 923 genes were downregulated in PTE rabbits. The expression of several genes (IL-8, TNF-α, and CXCL5) with functional importance were further confirmed in transcript and protein levels. The most significantly differentially regulated genes were related to inflammation, immune disease, pulmonary disease, and cardiovascular diseases. Totally 87 genes were up-regulated in the inflammatory genes. We conclude that gene expression profiling in rabbit PTE model could extend the understanding of PTE pathogenesis at the molecular level. Our study provides the fundamental framework for future clinical research on human PTE, including identification of potential biomarkers for prognosis or therapeutic targets for PTE.

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.

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.