Risk factors for venous thromboembolism after pediatric trauma

Incidence of acute Deep Vein Thrombosis in pediatric and adolescent orthopedic trauma hospitalized patients and effect of rivaroxaban treatment

OBJECTIVE

Deep vein thrombosis (DVT) provoked by orthopedic trauma is increasing in pediatric hospitalized patients. The purpose of our study is to identify the prevalence of acute DVT in pediatric and adolescent orthopedic trauma hospitalized patients and focus on evaluating the anticoagulation strategies and the clinical outcomes after a confirmed acute DVT.

METHODS

Patients (age ≤18 years) with a confirmed acute DVT admitted for orthopedic trauma between September 2017 and December 2023 were included. Patients were classified into the non-anticoagulation (NA), the in-hospital anticoagulation (IHA), and the in-and-out-of-hospital anticoagulation (IOHA) groups based on their anticoagulation regimen. Efficacy outcomes were the venous thromboembolism (VTE) recurrence within 3 months and change in thrombus burden by repeat imaging at 2 weeks after discharge compared with baseline. Safety outcomes were major bleeding (MB) and clinically relevant non-major bleeding (CRNMB) within 3 months.

RESULTS

Of the 11,206 pediatric and adolescent orthopedic trauma inpatients, 94(median age,16 [15, 18] years) were diagnosed with acute DVT, with an incidence of 0.84 %, of which 8(8.5 %) received NA, 41(43.6 %) received IHA, and 45(47.9 %) received IOHA. After the diagnosis of DVT, of patients who received anticoagulation, 97.9 % were treated with rivaroxaban as an oral anticoagulant, and 71.7 % received an LMWH course of ≥5 days before starting rivaroxaban therapy. With a median anticoagulation course of 22(8, 37.3) days, the duration in the IOHA was significantly longer than the IHA (37 days vs. 8 days, p = 0.000). No patients experienced recurrent VTE and MB at 3 months, and 1 received IOHA had a CRNMB event (0 % vs. 0 % vs. 2.2 %, p = 1.000). Thrombus resolution was significantly higher in patients who received anticoagulation therapy (IOHA 91.1 % vs. IHA 80.5 % vs. NA 37.5 %, P = 0.002), and thrombus-no relevant change was significantly lower in patients who received the IOHA strategy compared with the other groups (4.4 % vs. 19.5 % vs. 62.5 %, P = 0.000).

CONCLUSIONS

A rivaroxaban-predominant IOHA strategy significantly reduced the thrombotic burden without increasing the risk of bleeding for the treatment of DVT in adolescents with orthopedic trauma. Duration of anticoagulation therapy <6 weeks appears appropriate for adolescent orthopedic trauma-related DVT.

Incidence of venous thromboembolism in pediatric orthopedics: A systematic review

BACKGROUNDS

Children undergoing orthopedic procedures often present numerous risk factors for thromboembolism. A recent survey, conducted by the Pediatric Orthopaedic Society of North America (POSNA), indicates that pediatric orthopedic surgeons are unaware of venous thromboembolism (VTE) prevention protocols and feel that certain procedures should require thromboprophylaxis. The aim of this systematic review was to properly assess the incidence of VTE in pediatric orthopedics. By using a thorough and broad search of the literature, the incidence according to different subspecialties of pediatric orthopedics was evaluated.

METHODS

A systematic review on VTE in pediatric orthopedics was conducted. Four databases were searched for articles reporting these events. Three major search concepts: "pediatrics", "orthopedic surgery/trauma" and "VTE complications" were used and broken down in MeSH, EmTree and their free vocabulary synonyms for proper literature review. Two independent authors screened 8467 titles and abstracts. Seventy articles reporting VTE in children treated by orthopedic surgeons were selected for data extraction. We reported median incidences by orthopedic subtypes and by study characteristics with a semi-quantitative review model.

RESULTS

The 70 articles yielded a total of 845,010 participants. Spine articles (33/70) provided 25,2% of the children included in the review. Trauma studies (16/70) accounted for 47.5% of the participants. The overall VTE median incidence was 0.16% [95% CI: 0.0-1.01%]. Musculoskeletal infections had a noticeably higher median incidence of 3.5% [CI: 0.0-13.8%]. Small variations were seen for the other subtypes: trauma, spine and elective surgeries. Subgroups by article characteristics did not differ significantly either.

CONCLUSION

Thrombotic complications are rare events in pediatric orthopedics, but knowledge epidemiologic is important because its potential severity. In this review, VTE median incidence for all orthopedic subtypes was around 0.16% [CI: 0.0-1.01%]. According to subspecialty assessment, musculoskeletal infections were associated with greater risk of VTE occurrence.

LEVEL OF EVIDENCE

III - Systematic review.

Pediatric Orthopaedic Venous Thromboembolism: A Systematic Review Investigating Incidence, Risk Factors, and Outcome

Background

There is growing evidence of increased venous thromboembolism (VTE) incidence in children with trauma or infection. The purpose of this study was to conduct a systematic review of existing literature related to VTE in the pediatric orthopaedic population, to estimate the overall incidence of VTE and identify risk factors associated with this condition.

Methods

A systematic review of the available literature was performed to identify articles that described VTE in pediatric orthopaedic surgery or admission. Literature queries were performed to identify articles published from 1980 to 2021 that included patients ≤21 years of age. A stepwise search strategy of 5 electronic databases yielded 1,426 articles, which were filtered by 2 reviewers to identify 30 articles for full-text review. The primary aim was to determine the rate of VTE, and the secondary aim was to identify risk factors for VTE. The pooled incidence of VTE was estimated and reported in cases per 10,000. Studies were stratified by study size, by trauma versus elective surgery, and by orthopaedic subspecialty.

Results

The 30 articles reported 3,113 VTE events in 2,467,764 pediatric patients (including those with non-orthopaedic conditions), for a pooled VTE incidence of 20 events (95% confidence interval [CI] = 10.8 to 37.2) per 10,000. Four of the studies were excluded for incomplete data or high heterogeneity. The remaining 26 studies had 850,268 orthopaedic patients with 1,108 cases of VTE, for a pooled VTE incidence of 16.6 events (95% CI = 9.1 to 30.5) per 10,000. Studies with <10,000 patients and those involving a diagnosis of trauma had the highest VTE incidence when stratification was performed. The most frequently analyzed risk factors in 15 available studies included age, sex, obesity/body mass index, type of surgery, and use of a central venous catheter.

Conclusions

This systematic review indicated that the risk of VTE associated with pediatric orthopaedic surgery or admission remains low, at <17 events per 10,000 cases. However, orthopaedic surgeons should be aware of the most common risk factors associated with pediatric orthopaedic VTE and should pay special attention to traumatic etiologies, as these yielded the highest incidence.

Levels of Evidence

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Venous thromboembolic screening in pediatric trauma: A prospective cohort study of risk-stratified ultrasonography

BACKGROUND

This prospective observational cohort study evaluates risk-stratified venous thromboembolism (VTE) screening in injured children. While the reported incidence of VTE is 6% to 10% among critically injured children, there is no standard for screening. Venous thromboembolism may have long-term sequelae in children, including postthrombotic syndrome.

METHODS

Patients admitted to a level 1 pediatric trauma center were risk stratified for VTE using a validated prediction algorithm. Children at high risk (risk scores ≥523; i.e., ≥1% risk) received screening duplex ultrasonography. Children at moderate risk (risk scores 410-522; i.e., 0.3-0.99% risk) were screened as a comparison/control.

RESULTS

Three-hundred fifty-five children were consecutively risk stratified from October 2019 to May 2021. Forty-seven children received screening duplex ultrasounds: 21 from a high-risk cohort and 26 from a moderate-risk cohort. Four children were diagnosed with VTE in the high-risk cohort compared with seven in the moderate-risk cohort ( p = 0.53). Total incidence of VTE among screened children was 23.4% (11 of 47). Asymptomatic VTE accounted for 81.8% of all events (9 of 11). Fifty-four percent (6 of 11) of VTE were central venous catheter associated. Venous thromboembolism in surviving children resolved by 3 to 6 months with no symptoms of postthrombotic syndrome after 1 year. No cases of VTE were identified in unscreened children, yielding an institutional VTE incidence of 3.1% (11 of 355).

DISCUSSION

Risk-stratified screening demonstrates a significant incidence of asymptomatic VTE in injured children. These results may guide reevaluation of prediction algorithms developed from symptomatic VTE risk and longitudinal study of the sequelae of asymptomatic VTE.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.

Venous thromboembolic risk stratification in pediatric trauma: A Pediatric Trauma Society Research Committee multicenter analysis

BACKGROUND

Venous thromboembolism (VTE) in injured children is rare, but its consequences are significant. Several risk stratification algorithms for VTE in pediatric trauma exist with little consensus, and all are hindered in development by relying on registry data with known inaccuracies. We performed a multicenter review to evaluate trauma registry fidelity and confirm the effectiveness of one established algorithm across diverse centers.

METHODS

Local trauma registries at 10 institutions were queried for all patients younger than 18 years admitted between 2009 and 2018. Additional chart review was performed on all "VTE" cases and random non-VTE controls to assess registry errors. Corrected data were then applied to our prediction algorithm using 10 real-time variables (Glasgow Coma Scale, age, sex, intensive care unit admission, transfusion, central line placement, lower extremity/pelvic fracture, major surgery) to calculate VTE risk scores. Contingency table classifiers and the area under a receiver operator characteristic curve were calculated.

RESULTS

Registries identified 52,524 pediatric trauma patients with 99 episodes of VTE; however, chart review found that 13 cases were misclassified for a corrected total of 86 cases (0.16%). After correction, the algorithm still displayed strong performance in discriminating VTE-fated encounters (sensitivity, 69%; area under the receiver operating characteristic curve, 0.96). Furthermore, despite wide institutional variability in VTE rates (0.04-1.7%), the algorithm maintained a specificity of >91% and a negative predictive value of >99.7% across centers. Chart review also revealed that 54% (n = 45) of VTEs were directly associated with a central line, usually femoral (n = 34, p < 0.001 compared with upper extremity), and that prophylaxis rates were underreported in the registries by about 50%; still, only 19% of the VTE cases had been on prophylaxis before diagnosis.

CONCLUSION

The VTE prediction algorithm performed well when applied retrospectively across 10 diverse pediatric centers using corrected registry data. These findings can advance initiatives for VTE screening/prophylaxis guidance following pediatric trauma and warrant prospective study.

LEVEL OF EVIDENCE

Clinical decision rule evaluated in a single population, level III.

Identification of genes, pathways and transcription factor-miRNA-target gene networks and experimental verification in venous thromboembolism

Venous thromboembolism (VTE) is a complex, multifactorial life-threatening disease that involves vascular endothelial cell (VEC) dysfunction. However, the exact pathogenesis and underlying mechanisms of VTE are not completely clear. The aim of this study was to identify the core genes and pathways in VECs that are involved in the development and progression of unprovoked VTE (uVTE). The microarray dataset GSE118259 was downloaded from the Gene Expression Omnibus database, and 341 up-regulated and 8 down-regulated genes were identified in the VTE patients relative to the healthy controls, including CREB1, HIF1α, CBL, ILK, ESM1 and the ribosomal protein family genes. The protein-protein interaction (PPI) network and the transcription factor (TF)-miRNA-target gene network were constructed with these differentially expressed genes (DEGs), and visualized using Cytoscape software 3.6.1. Eighty-nine miRNAs were predicted as the targeting miRNAs of the DEGs, and 197 TFs were predicted as regulators of these miRNAs. In addition, 237 node genes and 4 modules were identified in the PPI network. The significantly enriched pathways included metabolic, cell adhesion, cell proliferation and cellular response to growth factor stimulus pathways. CREB1 was a differentially expressed TF in the TF-miRNA-target gene network, which regulated six miRNA-target gene pairs. The up-regulation of ESM1, HIF1α and CREB1 was confirmed at the mRNA and protein level in the plasma of uVTE patients. Taken together, ESM1, HIF1α and the CREB1-miRNA-target genes axis play potential mechanistic roles in uVTE development.

Venous thromboembolism prophylaxis after pediatric trauma

In recent years, there has been an increased focus on developing and validating venous thromboprophylaxis guidelines in the pediatric trauma population. We review the current literature regarding the incidence of and risk factors for venous thromboembolism (VTE) and the use of prophylaxis in the pediatric trauma population. Risk factors such as age, injury severity, central venous catheters, mental status, injury type, surgery, and comorbidities can lead to a higher incidence of VTE. Risk stratification tools have been developed to determine whether mechanical and/or pharmacologic prophylaxis should be implemented depending on the degree of VTE risk. When VTE risk is high, pharmacologic prophylaxis, such as with low molecular weight heparin, is often initiated. However, the timing and duration of VTE prophylaxis is dependent on patient factors including ambulatory status and contraindications such as bleeding. In addition, the utility of screening ultrasound for VTE surveillance has been evaluated and though they are not widely recommended, no formal guidelines exist. While more research has been done in recent years to assess the most appropriate type, timing, and duration of VTE prophylaxis, further studies are warranted to create optimal guidelines for decreasing the risk of VTE after pediatric trauma.

Venous Thromboembolism among Critically Ill Children: A Narrative Review

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality among hospitalized patients, including children. In recent years, it has become clear that hospitalization and critical illness bestow an increased VTE risk in pediatrics and relate to mortality and life-limiting comorbidities. For critically ill children, reported rates of VTE vary by study sampling techniques, presence of inherited or acquired thrombophilia, acute and chronic immobility, underlying illness prompting hospitalization, and clinical factors related to illness severity such as central venous catheterization, length of stay, mechanical ventilation, and patient age. Accordingly, critically ill children with new signs of venous congestion, acute inflammation, or unexplained acute organ dysfunction should be routinely evaluated for VTE. This narrative review summarizes recent and historical literature regarding risk factors, prevention, presentation, treatment, and outcomes of VTE in critically ill children. In addition, we identify knowledge gaps and priorities for future collaborative research on this vital condition. Special attention is given to the clinical trial opportunities, challenges, and ongoing efforts in thromboprophylaxis in critically ill children, including those hospitalized for disease related to novel coronavirus (COVID-19) and multisystem inflammatory disease in children.

Anti-Xa levels in critically ill children receiving enoxaparin for venothromboembolism prophylaxis

Venothrombolism (VTE) prophylaxis is increasingly utilized in pediatric intensive care units (PICUs). Enoxaparin, a low-molecular weight heparin, is frequently used for this purpose. Enoxaparin can also be used for therapeutic anticoagulation in cases of known thrombus. In such cases, monitoring involves obtaining serum anti- Xa levels with a target value of 0.5-1 units/mL. No monitoring recommendations currently exist for enoxaparin when intended for pediatric VTE prophylaxis. We hypothesize that a clinically important number of patients on VTE prophylaxis with enoxaparin have serum anti-Xa levels consistent with values targeted for therapeutic anticoagulation. We found that over 20% of patients on VTE prophylaxis with enoxaparin had serum anti-Xa levels consistent with true therapeutic anticoagulation (anti-Xa level 0.5-1 units/mL) during their enoxaparin course and 5% achieved values of supratherapeutic anticoagulation (anti-Xa level >1 units/mL). Serum anti-Xa level did not correlate with once versus twice daily dosing, body mass index (BMI), or creatinine level. Blood urea nitrogen (BUN) was found to have a positive odds ratio for an anti-Xa level ≥ 0.5 units/mL. We believe that this incidence of unintended therapeutic anticoagulation indicates a clinically significant number and therefore routine anti-Xa evaluation while on VTE prophylaxis is warranted within our population.

Intraoperative Pulmonary Embolism in an Adolescent Patient with Type III Spinal Muscular Atrophy: A Case Report

CASE

We present the case of an 11-year-old girl with spinal muscular atrophy (SMA) type III who suffered an intraoperative venous thromboembolism (VTE), leading to death during bilateral extremity contracture releases for deformity correction.

CONCLUSION

Given the increasing incidence of VTE in pediatric patients, further consideration should be given to broadening the patient population offerring preoperative deep vein thrombosis screening or thromboprophylaxis. Specifically, patients with previous trauma, neuromuscular disorders, and prolonged immobilization or contractures should receive special attention. In addition, SMA may cause hypercoagulability independent of its status as a neuromuscular disorder, and this link should be investigated further.

Incidence of venous thromboembolism in hospitalized pediatric neurosurgical patients: a retrospective 25-year institutional experience

PURPOSE

Venous thromboembolism (VTE) refers to both deep venous thrombosis (DVT) and pulmonary embolism (PE). The risk of VTE in adult neurosurgical patients is thoroughly studied. However, the incidence and risk of VTE in a comprehensive pediatric neurosurgical population is not well-defined. The available pediatric data consists of reviews of specific high-risk groups, such as trauma, critical care, or cancer patients. This may not be reflective of the entire spectrum of a high-volume pediatric neurosurgery practice. This study was undertaken to analyze the incidence and risk factors of VTE in all hospitalizations evaluated by a pediatric neurosurgery service over a 25-year period.

METHODS

A retrospective review of electronic medical records was performed for 9149 hospitalizations in 6374 unique patients evaluated by the pediatric neurosurgery service at Riley Hospital for Children (Indianapolis, IN, USA) from 1990-2014. During this time period, there was no standardized VTE prevention protocol. The study group included all patients less than 18 years of age. Patients with a known pre-existing VTE or pregnancy were excluded.

RESULTS

VTE was diagnosed in 20 of the 9149 (0.22%) hospitalizations, in 18 unique patients. All DVTs were diagnosed via Doppler ultrasound and/or computed tomography. Anatomic clot locations included 9 in the upper extremity (0.098% of hospitalizations), 8 in the lower extremity (0.087%), and 4 (0.044%) pulmonary emboli. Ten of the 20 occurred in hospitalizations where the patient underwent surgery, although the need for surgery was not a statistically significant risk factor. Sixteen of the 20 (80%) occurred in patients with at least one form of central venous line (p < 0.00001). There was one VTE-related death (0.01%).

CONCLUSIONS

In all pediatric neurosurgical patients, a VTE was found in 0.22% of hospitalizations over a 25-year span. Statistically significant risk factors for VTE included central venous line placement, paralysis, malignancy, intubation greater than 48 h, and hypercoagulable state.

Venous thromboembolism in children undergoing surgery: incidence, risk factors and related adverse events

Background

Although less common in adults, venous thromboembolism (VTE) in children is a highly morbid, preventable adverse event. While VTE has been well studied among pediatric hospitalized and trauma patients, limited work has been done to examine postoperative VTE in children undergoing surgery.

Methods

Using data from National Surgical Quality Improvement Project Pediatric database (NSQIP-P) from 2012 to 2016, a retrospective cohort analysis was performed to determine the incidence of, and risk factors for, VTE in children undergoing surgery. Additionally, the relationships between VTE and other postoperative adverse outcomes were evaluated.

Results

Of 361 384 pediatric surgical patients, 378 (0.10%) were identified as experiencing postoperative VTE. After controlling for patient and surgical factors, we found that American Society of Anesthesiologists (ASA) class of II or greater, aged 16–18 years, non-elective surgery, general surgery (compared with several other surgical specialties), cardiothoracic surgery (compared with general surgery) and longer operative time were significantly associated with VTE in pediatric patients (p<0.001 for each comparison). Furthermore, a majority of adverse events were found to be associated with increased risk of subsequent VTE (p<0.001).

Conclusion

In a large pediatric surgical population, an incidence of postoperative VTE of 0.10% was observed. Defined patient and surgical factors, and perioperative adverse events were found to be associated with such VTE events.

Elevated risk of venous thromboembolism among post-traumatic brain injury patients requiring pharmaceutical immobilization

Traumatic brain injury (TBI) patients are known to have a high rate of venous thromboembolism (VTE), and additional neuromuscular blockade or barbiturate coma therapy has the theoretical risk of exacerbating baseline hemostasis and elevating the incidence of thromboembolic events. We conducted a single-institution retrospective review of patients surviving severe TBI, as determined by need for intracranial pressure (ICP) monitoring, who further required paralytics or barbiturate therapy to maintain ICP control. Patients were administered VTE prophylaxis as clinically appropriate. Predictors for VTE were subsequently determined with univariate and logistic multivariate regression analyses. The main cohort includes 144 patients, 34 of whom received pharmaceutical immobilization for ICP control. Mean ISS and GCS at intake were 31.9 and 5.2, respectively. Among those receiving vs not-receiving paralytics and/or barbiturate therapy, there was a statistical difference of 12/34 (35.3%) vs 18/110 (16.4%, p = 0.0280) in VTE events, at a mean time greater than two weeks from the time of trauma. Multivariate logistics regression indicated 3.2 times increased odds of developing a VTE (log odds = 1.17, p = 0.023). No pediatric patients were positive for an event (0/12 vs 7/22, p = 0.0356), and infections were only documented among those with VTE (0/22 vs 4/12, p = 0.0107). Overall, paralytics and barbiturate therapy were correlated with a higher incidence of VTE among TBI patients. Although the need for ICP control will outweigh an increase in thromboembolic risk, there is value for increased surveillance and screening during the prolonged inpatient stay of these patients.

Association of Blood Component Ratios With 24-Hour Mortality in Injured Children Receiving Massive Transfusion

OBJECTIVES

To determine if higher fresh frozen plasma and platelet to packed RBC ratios are associated with lower 24-hour mortality in bleeding pediatric trauma patients.

DESIGN

Retrospective cohort study using the Pediatric Trauma Quality Improvement Program Database from 2014 to 2016.

SETTING

Level I and II pediatric trauma centers participating in the Trauma Quality Improvement Program PATIENTS:: Injured children (≤ 14 yr old) who received massive transfusion (≥ 40 mL/kg total blood products in 24 hr). Of 123,836 patients, 590 underwent massive transfusion, of which 583 met inclusion criteria.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Ratios of fresh frozen plasma:packed RBC and platelet:packed RBC. Of the 583 patients, 60% were male and the median age was 5 years (interquartile range, 2-10 yr). Overall mortality was 19.7% (95% CI, 16.6-23.2%) at 24 hours. There was 51% (adjusted relative risk, 0.49; 95% CI, 0.27-0.87; p = 0.02) and 40% (adjusted relative risk, 0.60; 95% CI, 0.39-0.92; p = 0.02) lower risk of death at 24 hours for the high (≥ 1:1) and medium (≥ 1:2 and < 1:1) fresh frozen plasma:packed RBC ratio groups, respectively, compared with the low ratio group (< 1:2). Platelet:packed RBC ratio was not associated with mortality (adjusted relative risk, 0.94; 95% CI, 0.51-1.71; p = 0.83).

CONCLUSIONS

Higher fresh frozen plasma ratios were associated with lower 24-hour mortality in massively transfused pediatric trauma patients. The platelet ratio was not associated with mortality. Although these findings represent the largest study evaluating blood product ratios in pediatric trauma patients, prospective studies are necessary to determine the optimum blood product ratios to minimize mortality in this population.

The Importance of a Standardized Screening Tool to Identify Thromboembolic Risk Factors in Pediatric Lower Extremity Arthroscopy Patients

INTRODUCTION

Deep vein thrombosis and pulmonary embolism are major complications that can occur in common orthopaedic procedures such as knee arthroscopy. The purpose of this study is to determine the incidence of venous thromboembolism (VTE) risk factors in adolescent patients undergoing elective lower extremity arthroscopy. A second objective is to determine whether a targeted, standardized screening tool is both cost- and clinically effective in the identification of VTE risk factors in adolescents.

METHODS

A standardized VTE screening tool was prospectively administered to all elective arthroscopic procedures in a pediatric sports medicine practice. A comparison cohort that did not complete the screening tool was isolated through a retrospective chart review identifying VTE risk factors. The incidence and cost between the two cohorts were compared.

RESULTS

Of 332 subjects who did not receive a targeted screening (TS) tool, 103 risk factors were noted. One pulmonary embolism case was identified with a total incidence of 0.15% over 3 years. With TS, we identified 325 subjects with 134 identifiable risk factors. Six patients (1.8%) were noted to be very high risk, requiring consultation with hematology. No VTEs were reported. When compared with the retrospective review, TS identified 30% more risk factors. A significant increase in the identification of family history of blood clots (P < 0.001), history of previous blood clot (P = 0.059), recurrent miscarriages in the family (P = 0.010), and smoking exposure (P = 0.062) was found. Additionally, the total cost of screening was less than the cost of prophylaxis treatment with no screening ($20.98 versus $23.51 per person, respectively).

DISCUSSION

Risk factors for VTE may be present in 32.5% of elective adolescent arthroscopic patients. A TS model for VTE identified 30% more risk factors, especially a significant family history, and was shown to be a cost-effective way to safely implement a VTE prevention program.

LEVEL OF EVIDENCE

Level II.

Venous thromboembolism risk factors in a pediatric trauma population

PURPOSE

New guidelines have been proposed for venous thromboembolism (VTE) prophylaxis in pediatric trauma patients. This paper seeks to evaluate risk factors associated with VTE that might further guide patient selection for prophylaxis.

METHODS

Review of a tertiary children's academic hospital's trauma database for VTE events and associated risk factors from 2005 to 2016.

RESULTS

15,306 pediatric trauma patients were identified and reviewed. During this time period there were 6191 admissions (40.4%), of which 20 developed a VTE (0.3%) including two pulmonary emboli. Primary outcome was comparison of risk factors for developing a VTE that were identified in the literature. Age stratification revealed the highest incidence of VTE in children under the age of 2 (0.7%), which increased with CVC placement when compared to children aged 2-12 and 13-15 (0.036 Fisher's exact test).

CONCLUSIONS

VTE after pediatric trauma is rare, and may be more uncommon than previously reported. CVC placement was the strongest predictor of VTE, particularly in infant and toddler patients which can explain their higher overall incidence compared to other pediatric age groups. Identifying high-risk patients is important to optimize screening and prophylaxis of VTE in pediatric trauma patients while minimizing risks of anticoagulation.

Venous thromboembolism following inpatient pediatric surgery: Analysis of 153,220 patients

PURPOSE

To evaluate venous thromboembolism (VTE) rates and risk factors following inpatient pediatric surgery.

METHODS

153,220 inpatient pediatric surgical patients were selected from the 2012-2015 NSQIP-P database. Demographic and perioperative variables were documented. Primary outcome was VTE requiring treatment within 30 postoperative days. Secondary outcomes included length of stay (LOS) and 30-day mortality. Prediction models were generated using logistic regression. Mortality and time to VTE were assessed using Kaplan-Meier survival analysis.

RESULTS

305 patients (0.20%) developed 296 venous thromboses and 12 pulmonary emboli (3 cooccurrences). Median time to VTE was 9 days. Most VTEs (81%) occurred predischarge. Subspecialties with highest VTE rates were cardiothoracic (0.72%) and general surgery (0.28%). No differences were seen for elective vs. urgent/emergent procedures (p = 0.106). All-cause mortality VTE patients was 1.2% vs. 0.2% in patients without VTE (p < 0.001). After stratifying by American Society of Anesthesiologists (ASA) class, no mortality differences remained when ASA < 3. Preoperative, postoperative, and total LOSs were longer for patients with VTE (p < 0.001 for each). ASA ≥ 3, preoperative sepsis, ventilator dependence, enteral/parenteral feeding, steroid use, preoperative blood transfusion, gastrointestinal disease, hematologic disorders, operative time, and age were independent predictors (C-statistic = 0.83).

CONCLUSIONS

Pediatric postsurgical patients have unique risk factors for developing VTE.

LEVEL OF EVIDENCE

Level II.

Efficacy of surveillance ultrasound for venous thromboembolism diagnosis in critically ill children after trauma

INTRODUCTION

Venous thromboembolism (VTE) is increasingly prevalent in injured children admitted to the intensive care unit (ICU). Few data exist to support VTE pharmacologic prophylaxis or ultrasound (US) surveillance in children with high bleeding risk. After implementation of screening US guidelines, we sought to describe our experience, hypothesizing that screening US of children at highest risk for VTE results in earlier detection and management.

STUDY DESIGN

A retrospective analysis was conducted on prospectively collected data of injured children admitted to an American College of Surgeons Verified level 1 Pediatric Trauma Center from 2010 to 2015. In patients at high risk for both VTE and bleeding (HRHR), guidelines recommended deferral of pharmacologic prophylaxis and a screening US at ≥7 ICU days if bleeding risk remained. Outcomes analyzed included VTE rates, guideline compliance, and US timing. The rate of deep vein thrombosis (DVT) detection (number of DVT captured/number of US obtained) was examined.

RESULTS

Of 4061 trauma patients, 588 (14.5%) were critically injured including 112 patients who met HRHR criteria. The rate of VTE in the HRHR group ≥7 ICU days was 25% (14/56). Of 23 VTE diagnosed in the ICU, 17 were detected by 49 US performed (34.7%), with the remaining 6 diagnosed by computed tomography. DVT was detected earlier than the US guideline recommended 7 days, independent of symptoms. Guideline compliance was 86%.

CONCLUSION

Critically injured children at risk for bleeding frequently develop VTE. Surveillance ultrasound in patients at high risk for both VTE and bleeding allows earlier detection and treatment.

LEVEL OF EVIDENCE

Therapeutic study, level II.

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.

Multicenter Review of Current Practices Associated With Venous Thromboembolism Prophylaxis in Pediatric Patients After Trauma

OBJECTIVES

Frequency of venous thromboembolism in pediatric trauma patients admitted to PICUs is not insignificant, ranging up to 6%. Risk factors have been identified in this population. However, there is little consensus of actual venous thromboembolism prophylaxis practice. We examined factors associated with venous thromboembolism prophylaxis in PICUs.

DESIGN

A retrospective study evaluating associations with mechanical venous thromboembolism prophylaxis, pharmacologic venous thromboembolism prophylaxis, or dual therapy (DUAL) prophylaxis compared with no venous thromboembolism prophylaxis. Multivariable logistic regression explored the relationship between prophylaxis type and selected covariates with stepwise selection method to identify the independent predictors of venous thromboembolism prophylaxis utilization.

SETTING

Five level I/II pediatric trauma centers in the United States.

PATIENTS

Children less than 18 years from January 1, 2013, to December 31, 2013, admitted to the PICU after a trauma, identified through combined trauma registry and Virtual Pediatric Systems database.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Six hundred ninety-two patients were included in the database, with 55 excluded for missing data. Of the remaining 637 patients, 538 (84.5%) had no venous thromboembolism prophylaxis by 48 hours, 77 (12.1%) had only mechanical venous thromboembolism prophylaxis, 11 (1.7%) had DUAL, and 11 (1.7%) had pharmacologic venous thromboembolism prophylaxis alone. Multivariable analysis showed increased age, and orthopedic procedure was associated with all forms of prophylaxis. Orthopedic procedures were associated with higher utilization of dual prophylaxis use (odds ratio, 5.2; 95% CI, 1.2-21.8), pharmacologic venous thromboembolism prophylaxis (odds ratio, 8.5; 95% CI, 2.3-31.7), and mechanical venous thromboembolism prophylaxis (odds ratio, 2.2; 95% CI, 1.1-4.2) alone. Brain/spinal cord procedures (odds ratio, 3.7; 95% CI, 1.9-7.3) and abdominal procedures (odds ratio, 6.6; 95% CI, 2.5-17.1) were associated with mechanical venous thromboembolism prophylaxis. Head injury was associated with a decreased use of any prophylaxis (odds ratio, 0.5; 95% CI, 0.3-0.9). Patient comorbidities were associated with decreased use of mechanical venous thromboembolism prophylaxis (odds ratio, 0.5; 95% CI, 0.3-1.0).

CONCLUSIONS

Pharmacologic venous thromboembolism prophylaxis is not common in critically ill children after trauma. Patient age, orthopedic and vascular procedures, and higher injury severity are associated with pharmacologic venous thromboembolism prophylaxis.

Evaluation of guidelines for injured children at high risk for venous thromboembolism: A prospective observational study

BACKGROUND

Pharmacologic prophylaxis for venous thromboembolism (VTE) is a widely accepted practice in adult trauma patients to prevent associated morbidity and mortality. However, VTE prophylaxis has not been standardized in injured pediatric patients. Our institution identified factors potentially associated with a high risk of VTE in critically injured children that led to prospective implementation of VTE prophylaxis guidelines. We hypothesize that the guidelines are accurate in predicting children at risk for VTE.

METHODS

Data were prospectively collected on injured children from August 2010 to August 2015. Pharmacologic prophylaxis was indicated for patients identified by the guidelines as high risk for VTE. Prophylaxis was deferred and a screening ultrasound was performed if the high-risk VTE patients were also at high risk for bleeding. To assess the accuracy of predicting confirmed cases of VTE, stepwise logistic regression analysis was used to measure the association of individual risk factors with VTE controlling for age (≥13 years). A receiver operating characteristic curve measured the accuracy of the final model to predict a VTE.

RESULTS

Of 4,061 trauma patients, 588 were admitted to the ICU, with the guidelines identifying 199 as high risk for VTE. VTE occurred in 3.9% (23/588) of the ICU population and 10% (20/199) of the high risk group. The median age of VTE patients in the ICU was 9.7 years. Statistically significant predictors (p < 0.05) of VTE in the multivariate model included presence of a central venous catheter (OR = 5.2), inotropes (OR = 7.7), immobilization (OR = 5.5), and a Glasgow Coma Scale of <9 (OR = 1.3). The area under receiver operating characteristic curve of this model was 0.92, demonstrating its excellent predictive ability.

CONCLUSION

Specific clinical factors in critically injured children are associated with a high risk for VTE. Incorporating these risk factors in VTE prophylaxis guidelines facilitates more accurate risk stratification and may allow for improved VTE prevention in pediatric trauma.

LEVEL OF EVIDENCE

Prognostic study, level II.

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).

Obesity in pediatric trauma

BACKGROUND/PURPOSE

The implications of childhood obesity on pediatric trauma outcomes are not clearly established. Anthropomorphic data were recently added to the National Trauma Data Bank (NTDB) Research Datasets, enabling a large, multicenter evaluation of the effect of obesity on pediatric trauma patients.

METHODS

Children ages 2 to 19years who required hospitalization for traumatic injury were identified in the 2013-2014 NTDB Research Datasets. Age and gender-specific body mass indices (BMI) were calculated. Outcomes included injury patterns, operative procedures, complications, and hospital utilization parameters.

RESULTS

Data from 149,817 pediatric patients were analyzed; higher BMI percentiles were associated with significantly more extremity injuries, and fewer injuries to the head, abdomen, thorax and spine (p values <0.001). On multivariable analysis, higher BMI percentiles were associated with significantly increased likelihood of death, deep venous thrombosis, pulmonary embolus and pneumonia; although there was no difference in risk of overall complications. Obese children also had significantly longer lengths of stay and more frequent ventilator requirement.

CONCLUSIONS

Among children admitted after trauma, increased BMI percentile is associated with increased risk of death and potentially preventable complications. These findings suggest that obese children may require different management than nonobese counterparts to prevent complications.

LEVEL OF EVIDENCE

Level III; prognosis study.

Venous thromboembolism prophylaxis in the pediatric trauma patient

Although venous thromboembolism (VTE) occurs in less than 1% of hospitalized pediatric trauma patients, care providers must make decisions about VTE prophylaxis on a daily basis. The consequences of VTE are significant; the risks of developing VTE are variable; and the effectiveness of prophylaxis against VTE is not conclusive in children. While the value of VTE prophylaxis is well defined in adult trauma care, it is unclear how this translates to the care of injured children. This review evaluates the incidence and risks of VTE in pediatric trauma and assesses the merits of prophylaxis in children. Pharmacologic prophylaxis against VTE is a reasonable strategy in critically injured adolescent trauma patients. Further study is needed to establish the risks and benefits of VTE prophylaxis across the spectrum of injured children.

Venous Thromboembolism in Critical Illness and Trauma: Pediatric Perspectives

Critically ill children and those sustaining severe traumatic injuries are at higher risk for developing venous thromboembolism (VTE) than other hospitalized children. Multiple factors including the need for central venous catheters, immobility, surgical procedures, malignancy, and dysregulated inflammatory state confer this increased risk. As well as being at higher risk of VTE, this population is frequently at an increased risk of bleeding, making the decision of prophylactic anticoagulation even more nuanced. The use of pharmacologic and mechanical prophylaxis remains variable in this high-risk cohort. VTE pharmacologic prophylaxis is an accepted practice in adult trauma and intensive care to prevent VTE development and associated morbidity, but it is not standardized in critically ill or injured children. Given the lack of pediatric specific guidelines, prevention strategies are variably extrapolated from the successful use of mechanical and pharmacologic prophylaxis in adults, despite the differences in developmental hemostasis and thrombosis risk between children and adults. Whether the burden of VTE can be reduced in the pediatric critically ill or injured population is not known given the lack of robust data. There are no trials in children showing efficacy of mechanical compression devices or prophylactic anticoagulation in reducing the rate of VTE. Risk stratification using clinical factors has been shown to identify those at highest risk for VTE and allows targeted prophylaxis. It remains unproven if such a strategy will mitigate the risk of VTE and its potential sequelae.

A simplified stratification system for venous thromboembolism risk in severely injured trauma patients

BACKGROUND

The objective of this study was to re-evaluate and simplify the Greenfield risk assessment profile (RAP) for venous thromboembolism (VTE) in trauma using information readily available at the bedside.

METHODS

Retrospective review of 1233 consecutive admissions to the trauma intensive care unit from August 2011-January 2015. Univariate analyses were performed to determine which RAP risk factors were significant contributors to VTE. Multivariable logistic regression was used to develop models for risk stratification. All results were considered statistically significant at P ≤ 0.05.

RESULTS

The study population was as follows: age 44 ± 19, 75% male, 72% blunt, injury severity score 21 ± 13, RAP score 9 ± 5, and 8% mortality. Groups were separated into +VTE (n = 104) and -VTE (n = 1129). They were similar in age, gender, mechanism, and mortality, but injury severity and RAP scores were higher in the +VTE group (all P < 0.0001). The +VTE group had more transfusions and longer time to prophylaxis (all P < 0.05). Receiving four or more transfusions in the first 24 h (odds ratio [OR], 2.60; 95% confidence interval [CI], 1.64-4.13), Glasgow coma score <8 for >4 h (OR, 2.13; 95% CI, 1.28-3.54), pelvic fracture (OR, 2.26; 95% CI, 1.44-3.57), age 40-59 y (OR, 1.70; 95% CI, 1.10-2.63), and >2-h operation (OR, 1.80; 95% CI, 1.14-2.85) predicted VTE with an area under the receiver operator curve of 0.729, which was comparable with 0.740 for the RAP score alone.

CONCLUSIONS

VTE risk in trauma can be easily assessed using only five risk factors, which are all readily available at the bedside (transfusion, Glasgow coma scale, pelvic fracture, prolonged operation, and age). This simplified model provides similar predictive ability to the more complicated RAP score. Prospective validation of a simplified risk assessment score is warranted.