High level of venous thromboembolism in critically ill trauma patients despite early and well-driven thromboprophylaxis protocol

Racial Distribution and Associated Outcomes for Patients With and Without Severe-Isolated Traumatic Brain Injuries Following Venous Thromboembolism Prophylaxis

INTRODUCTION

Disparities in venous thromboembolism (VTE) incidence and prophylaxis have been observed across racial groups. This study investigates the relationship between race, injury type, and the timing of VTE prophylaxis in severe trauma patients, both with and without isolated traumatic brain injuries. The primary goal is to analyze how these factors interact and their potential impact on clinical outcomes.

METHODS

A retrospective cohort study of the American College of Surgeons Trauma Quality Program Participant Use File (ACS-TQIP-PUF) from 2018 to 2021. Patient demographics, injury categories, VTE prophylaxis timing, injury severity, and in-hospital complications were collected. Multivariable regression models explored associations between race, injury type, VTE prophylaxis, and in-hospital mortality. Groups were analyzed by injury profile (isolated TBI vs non-TBI) and then by VTE prophylaxis timing (early ≤24 hours, late >24 hours).

RESULTS

Of 68,504 trauma patients analyzed, the majority were non-Hispanic or Latino (83.3%), White (71.2%), and male (69.6%). Patients receiving late VTE prophylaxis had higher rates of DVT and PE across race groups than patients with early prophylaxis. Logistic regression showed Asian patients with TBI receiving early prophylaxis were significantly more likely to have in-hospital mortality (OR 16.27, CI = 1.11-237.43, P = .04) than other races.

CONCLUSION

Patients who received late prophylaxis had higher VTE rates than early prophylaxis, independent of injury pattern or race. Additionally, assessing the implications of race in early VTE prophylaxis for isolated TBI showed that adult Asian patients had 16 times higher odds of in-hospital mortality compared to other races.

Fresh Frozen Plasma Versus Solvent Detergent Plasma for Cardiopulmonary Bypass Priming in Neonates and Infants Undergoing Cardiac Surgery: A Retrospective Cohort Study

OBJECTIVE

Compared with fresh frozen plasma (FFP), Omniplasma has been attributed to an increased coagulation potential and an increased fibrinolytic potential. This study aimed to compare Omniplasma and FFP used for cardiopulmonary bypass (CPB) priming regarding the incidence of postoperative thrombotic or hemorrhagic complications and outcomes in pediatric patients undergoing cardiac surgery.

DESIGN

A retrospective observational cohort study SETTING: This single-center study was performed at the University Medical Center Groningen.

PARTICIPANT

All pediatric patients up to 10 kg undergoing cardiac surgery with CPB.

INTERVENTIONS

Procedures in which FFP was used for CPB priming were compared with those in which Omniplasma was used.

MEASUREMENTS AND MAIN RESULTS

The primary outcome parameter was a composite endpoint consisting of the following: (1) pediatric intensive care unit (PICU) mortality, (2) thromboembolic complications, and (3) hemorrhagic complications during PICU stay. The authors included 143 procedures in the analyses, 90 (63%) in the FFP group and 53 (37%) in the Omniplasma group. The occurrence of the combined primary endpoint (FFP 20% v Omniplasma 11%, p = 0.18) and its components did not differ between the used CPB priming agent). Omniplasma for CPB priming was associated with decreased unfractionated heparin administration per kg bodyweight (585 IU v 510 IU, p = 0.03), higher preoperative and postoperative activated clotting times (ACT) discrepancy (90% v 94%, p = 0.03), a lower postoperative ACT value (125 v 118 seconds, p = 0.01), and less red blood cell transfusion per kilogram bodyweight (78 v 55 mL, p = 0.02). However, none of the variables differed statistically significantly in the multivariate logistic regression analyses.

CONCLUSIONS

The authors did not find an association between the plasma used for CPB priming and thromboembolic and hemorrhagic complications and death in neonates and infants undergoing cardiac surgery. Omniplasma seems to be safe to use in this population.

Traumatic air embolism; a case report and literature review of this rare complication of trauma

Trauma management forms a significant component of any health system. It can affect any body system, and as such knowledge of the wide possible presentations and sequalae are critical. Systemic air embolism (SAE) is a rare presentation in trauma, though it can be associated with significant morbidity and mortality. We present the case of a 23-year-old gentleman with isolated penetrating trauma to the chest who developed widespread neurological insult as a result of SAE, and review historical and proposed contemporary management of SAE.

[Update on point-of-care-based coagulation treatment : Systems, reagents, device-specific treatment algorithms]

Viscoelastic test (VET) procedures suitable for point-of-care (POC) testing are in widespread clinical use. Due to the expanded range of available devices and in particular due to the development of new test approaches and methods, the authors believe that an update of the current treatment algorithms is necessary. The aim of this article is to provide an overview of the currently available VET devices and the associated reagents. In addition, two treatment algorithms for the VET devices most commonly used in German-speaking countries are presented.

Sonographic Evaluation of Deep Vein Thrombosis in Hospitalized Neurosurgical Trauma Patients in Ibadan, Nigeria

BACKGROUND

Deep vein thrombosis (DVT) is a major cause of morbidity and mortality in hospitalized trauma patients. Ultrasonography (US) has replaced venography as the initial diagnostic tool for DVT.

AIMS

The study aimed to determine the incidence of lower limb DVT in hospitalized neurosurgical trauma patients in hospitalized neurosurgical patients. It also aimed to determine the effect of combined thrombo-prophylaxis on the incidence of lower limb deep DVT relative to a single regimen.

PATIENTS AND METHODS

This was a prospective study of 154 adult neurotrauma patients who consecutively had lower limb Doppler ultrasound, initially within 72 hours of admissions and subsequently weekly or when DVT was suspected for the first 3 weeks of admission. The study spanned a 12-month period. The data generated were analyzed using the statistical package for social sciences software version 20, Chicago IL. Inc. Chi-square test was used to compare the outcome (DVT incidence) between single and combined prophylaxis groups.

RESULTS

The study participants consisted of 116 (75.3%) and 38 (24.7%) cases of head and spine injuries, respectively, with a mean age of 38.8 ± 6.3 years and 85.1% being males. A total of four cases of DVT were detected during the study period, with the majority of the cases (3) detected within the first week of admission, giving an incidence of 2.6%. All four cases of DVT were detected in patients on single thrombo-prophylaxis (4/55 = 7.3%), while none was found in those on a combined regimen (0/34, P = 0.046).

CONCLUSION

Most cases of DVT developed in the first week of hospitalization. Combined thrombo-prophylaxis was more effective than single regimen at reducing rate of DVT in neurosurgical trauma patients. Routine Doppler ultrasound DVT surveillance should be part of the management protocol for neurosurgical trauma patients on admission to increase DVT detection and prevent possible fatal pulmonary embolism.

Saudi Critical Care Society clinical practice guidelines on the prevention of venous thromboembolism in adults with trauma: Endorsement by the Scandinavian Society of Anaesthesiology and Intensive Care Medicine

The Clinical Practice Committee of the Scandinavian Society of Anaesthesiology and Intensive Care Medicine endorses the clinical practice guideline Saudi Critical Care Society clinical practice guidelines on the prevention of venous thromboembolism in adults with trauma: reviewed for evidence-based integrity and endorsed by the Scandinavian Society of Anaesthesiology and Intensive Care Medicine. This clinical practice guideline serves as a useful decision aid for Nordic anaesthesiologists managing adult trauma patients in the operating room and in the intensive care unit.

Soluble endothelial protein C receptor is an independent predictor of venous thromboembolism after severe injury: Secondary analysis of a prospective cohort study

BACKGROUND

Venous thromboembolism is a leading cause of morbidity after trauma. Endothelial cells are essential regulators of coagulation. Although endothelial cell dysregulation is widely reported after trauma, the link between endothelial injury and venous thromboembolism has not been reported.

METHODS

We conducted a secondary analysis of the Pragmatic Randomized Optimal Platelets and Plasma Ratios study. Deaths from hemorrhage or within 24 hours were excluded. Venous thromboembolism was diagnosed by duplex ultrasound or chest computed tomography. Endothelial markers soluble endothelial protein c receptor, thrombomodulin, and syndecan-1 were measured in plasma by enzyme-linked immunosorbent assay and compared over the first 72 hours from admission using the Mann-Whitney test. Multivariable logistic regression assessed the adjusted effects of endothelial markers on venous thromboembolism risk.

RESULTS

Of 575 patients enrolled, 86 developed venous thromboembolism (15%). The median time to venous thromboembolism was 6 days ([Q1, Q3], [4, 13]). No differences were identified in demographics or injury severity. Soluble endothelial protein c receptor, thrombomodulin, and syndecan-1 showed significant increases over time among patients who developed venous thromboembolism compared to those who did not. Using the last available values, patients were stratified into high and low-soluble endothelial protein c receptor, thrombomodulin, and syndecan-1 groups. Multivariable analyses revealed an independent association between elevated soluble endothelial protein c receptor and venous thromboembolism risk (odds ratio 1.63; 95% confidence interval 1.01, 2.63; P = .04). Cox proportional hazards modeling demonstrated a strong yet nonsignificant trend between elevated soluble endothelial protein c receptor and time to venous thromboembolism.

CONCLUSION

Plasma markers of endothelial injury, particularly soluble endothelial protein c receptor, are strongly associated with trauma-related venous thromboembolism. Therapeutics targeting endothelial function could mitigate the incidence of venous thromboembolism after trauma.

Safety and efficacy of artesunate treatment in severely injured patients with traumatic hemorrhage. The TOP-ART randomized clinical trial

PURPOSE

This study aimed at determining whether intravenous artesunate is safe and effective in reducing multiple organ dysfunction syndrome in trauma patients with major hemorrhage.

METHODS

TOP-ART, a randomized, blinded, placebo-controlled, phase IIa trial, was conducted at a London major trauma center in adult trauma patients who activated the major hemorrhage protocol. Participants received artesunate or placebo (2:1 randomization ratio) as an intravenous bolus dose (2.4 mg/kg or 4.8 mg/kg) within 4 h of injury. The safety outcome was the 28-day serious adverse event (SAE) rate. The primary efficacy outcome was the 48 h sequential organ failure assessment (SOFA) score. The per-protocol recruitment target was 105 patients.

RESULTS

The trial was terminated after enrolment of 90 patients because of safety concerns. Eighty-three participants received artesunate (n = 54) or placebo (n = 29) and formed the safety population and 75 met per-protocol criteria (48 artesunate, 27 placebo). Admission characteristics were similar between groups (overall 88% male, median age 29 years, median injury severity score 22), except participants who received artesunate were more shocked (median base deficit 9 vs. 4.7, p = 0.042). SAEs occurred in 17 artesunate participants (31%) vs. 5 who received placebo (17%). Venous thromboembolic events (VTE) occurred in 9 artesunate participants (17%) vs. 1 who received placebo (3%). Superiority of artesunate was not supported by the 48 h SOFA score (median 5.5 artesunate vs. 4 placebo, p = 0.303) or any of the trial's secondary endpoints.

CONCLUSION

Among critically ill trauma patients, artesunate is unlikely to improve organ dysfunction and might be associated with a higher VTE rate.

Defects in vein valve PROX1/FOXC2 antithrombotic pathway in endothelial cells drive the hypercoagulable state induced by trauma and critical illness

OBJECTIVES

Deep venous thrombosis (DVT) causes significant morbidity and mortality after trauma. Recently, we have shown that blood flow patterns at vein valves induce oscillatory stress genes, which maintain an anticoagulant endothelial phenotype that inhibits spontaneous clotting at vein valves and sinuses, is lost in the presence of DVT in human pathological samples, and is dependent on expression of the transcription factor FOXC2. We describe an assay, modifying our mouse multiple injury system, which shows evidence of clinically relevant microthrombosis and hypercoagulability applicable to the study of spontaneous DVT in trauma without requiring direct vascular injury or ligation. Finally, we investigated whether these model findings are relevant to a human model of critical illness by examining gene expression changes by quantitative polymerase chain reaction and immunofluorescence in veins collected from critically ill.

METHODS

C57/Bl6 mice were subjected to a modified mouse multiple injury model with liver crush injury, crush and pseudofracture of a single lower extremity, and 15% total blood volume hemorrhage. Serum was assayed for d-dimer at 2, 6, 24, and 48 hours after injury by enzyme-linked immunosorbent assay. For the thrombin clotting assay, veins of the leg were exposed, 100 μL of 1 mM rhodamine (6 g) was injected retro-orbitally, and 450 μg/mL thrombin was then applied to the surface of the vein with examination of real-time clot formation via in vivo immunofluorescence microscopy. Images were then examined for percentage area of clot coverage of visible mouse saphenous and common femoral vein. Vein valve specific knockout of FOXC2 was induced with tamoxifen treatment in PROX1 Ert2Cre FOXC2 fl/fl mice as previously described. Animals were then subjected to a modified mouse multiple injury model with liver crush injury, crush and pseudofracture of a single lower extremity, and 15% total blood volume hemorrhage. Twenty-four hours after injury, we examined the valve phenotype in naive versus multiple injury animals, with and without loss of the FOXC2 gene from the vein valve (FOXC2 del ) via the thrombin assay. Images were then examined for proximity of clot formation to the valve present at the junction of the mouse saphenous, tibial, and superficial femoral vein and presence of spontaneous microthrombi present in the veins before exposure to thrombin. Human vein samples were obtained from excess tissue preserved after harvest for elective cardiac surgery and from organ donors after organ procurement. Sections were submitted for paraffin embedding and then assayed by immunofluorescence for PROX1, FOXC2, thrombomodulin, endothelial protein C receptor, and von Willebrand's factor. All animal studies were reviewed and approved by the Institutional Animal Care and Use Committee, and all human studies reviewed and approved by the institutional review board.

RESULTS

After mouse multiple injuries, enzyme-linked immunosorbent assay for d-dimer showed evidence of products of fibrin breakdown consistent with formation of clot related to injury, fibrinolysis, and/or microthrombosis. The thrombin clotting assay demonstrated higher percentage area of vein covered with clot when exposed to thrombin in the multiple injury animals compared with uninjured (45% vs. 27% p = 0.0002) consistent with a phenotype of hypercoagulable state after trauma in our model system. Unmanipulated FoxC2 knockout mice manifest increased clotting at the vein valve as compared with unmanipulated wild type animals. After multiple injuries, wild type mice manifest increase clotting at the vein after thrombin exposure ( p = 0.0033), and equivalent to that of valvular knockout of FoxC2 (FoxC2del), recapitulating the phenotype seen in FoxC2 knockout animals. The combination of multiple injuries and FoxC2 knockout resulted in spontaneous microthrombi in 50% of the animals, a phenotype not observed with either multiple injuries or FoxC2 deficiency alone (χ 2 , p = 0.017). Finally, human vein samples demonstrated the protective vein valve phenotype of increased FOXC2 and PROX1 and showed decreased expression in the critically ill organ donor population by immunofluorescence imaging in organ donor samples.

CONCLUSION

We have established a novel model of posttrauma hypercoagulation that does not require direct restriction of venous flow or direct injury to the vessel endothelium to assay for hypercoagulability and can generate spontaneous microthrombosis when combined with valve-specific FOXC2 knockout. We find that multiple injuries induce a procoagulant phenotype that recapitulates the valvular hypercoagulability seen in FOXC2 knockout and, in critically ill human specimens, find evidence for loss of oscillatory shear stress-induced gene expression of FOXC2 and PROX1 in the valvular endothelium consistent with potential loss of DVT-protective valvular phenotype.

The impact of pre-existing venous pathology on lower limb free flap reconstruction and the role of preoperative screening: a systematic review

Lower limb reconstruction is performed to replace like with like and achieve tissue durability. Free flaps are a method of reconstruction commonly used to manage cases of lower limb deficits. However, the failure rate is 8.5%, with venous thrombosis and congestion playing a significant role. Despite this, preoperative venous mapping of recipient site before free flap reconstruction is not routinely practiced, often resulting in pathologies remaining unidentified until the intraoperative stage. The aim of the review was to evaluate the existing literature on the topic of lower limb preoperative venous assessment, screening, and its effect on lower limb free flap survival. Five different databases were searched from their inception to August 2021. The search terms and included studies were independently reviewed by two investigators for their eligibility. Eleven articles were eligible for inclusion, with a combined patient population of 99, and 107 flaps were identified to have lower limb pathology at the donor or recipient vein. Venous pathology was detected preoperatively in 69 veins using ultrasound duplex scanning and computed tomography angiography; of them, 3 (4.34%) resulted in failure. In comparison, 38 veins were diagnosed with venous pathology intraoperatively; of them, 5 (13.85%) failed. The studies evaluated in this review demonstrated that preoperative screening for venous pathology showed a higher flap survival rate. It can therefore be inferred that developing a standardized preoperative process for identifying venous issues in lower limb free flap reconstruction may improve outcomes. This can be explored in future research, with a focus on assessing the validity and efficacy of such screening tools, and their role in the management of patients identified with venous pathology.

Modern thromboprophylaxis protocol based on guidelines applied in a respiratory intensive care unit: a single-center prospective cohort study

BACKGROUND

Critically ill patients in intensive care units (ICUs) are at high risk of venous thromboembolism (VTE). This study aimed to explore the prophylaxis effect under a guideline-based thromboprophylaxis protocol among critically ill patients in a respiratory ICU.

METHODS

For this single-center prospective cohort study, we followed the thromboprophylaxis protocol, which was drawn up based on relevant guidelines and Chinese experts' advice. Clinical data were entered into an electronic case report form and analyzed. Multivariate logistic regression was conducted to explore independent risk factors of VTE event under this protocol.

RESULTS

From August 1, 2014, to December 31, 2020, 884 patients underwent thromboprophylaxis according to this protocol; 10.5% of them received mechanical prophylaxis, 43.8% received pharmacological prophylaxis, and 45.7% received pharmacological combined with mechanical prophylaxis. The proportion of VTE events was 14.3% for patients who received the thromboprophylaxis protocol, of which 0.1% had pulmonary thromboembolism (PTE), 2.0% had proximal deep vein thrombosis (DVT), and 12.1% had isolated distal DVT. There was no significant difference between different thromboprophylaxis measures. Cirrhosis (OR 5.789, 95% CI [1.402, 23.894], P = 0.015), acute asthma exacerbation (OR 39.999, 95% CI [4.704, 340.083], P = 0.001), and extracorporeal membrane oxygenation treatment (OR 22.237, 95%CI [4.824, 102.502], P < 0.001) were independent risk factors for proximal DVT under thromboprophylaxis.

CONCLUSIONS

The thromboprophylaxis protocol based on guidelines applied in the ICU was practicable and could help decrease the proportion of PTE and proximal DVT events. The risk factors of VTE events happening under the thromboprophylaxis protocol require more attention.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02213978.

Prevalence of Venous Thromboembolism in Intensive Care Units: A Meta-Analysis

OBJECTIVE

Venous thromboembolism (VTE) is a life threating complication in intensive care units (ICUs). This study aimed to pool the prevalence of VTE and examined the risk factors of VTE in intensive care patients worldwide.

METHODS

A systematic search in PubMed, EMBASE and Web of Science databases was performed. Studies reported that the data on the prevalence of VTE or relevant information were synthesized using a random-effects model.

RESULTS

A total of 42 studies reporting on 27,344 patients were included. The pooled prevalence of VTE was 10.0% (95% CI: 7.0-14.0%). Subgroup and metaregression analyses found that thromboprophylaxis strategy, simplified acute physiology score (SAPS II), age, study quality, sample size, malignancy, sex, spinal cord injury and injury severity score (ISS) moderated the prevalence of VTE in intensive care patients.

CONCLUSIONS

The present meta-analysis revealed a high prevalence of VTE in critically ill patients. The risk factors of VTE included thromboprophylaxis strategy, SAPS II, age, malignancy, sex, spinal cord injury and ISS. Therefore, we need to pay more attention to high-risk populations of VTE in intensive care patients.

Clinical Characteristics and Risk Factors for Early versus Late Pulmonary Embolism in Trauma Patients: A Retrospective, Observational Study

Background

We sought to evaluate the clinical characteristics and risk factors for early versus late pulmonary embolism (PE) in trauma patients.

Methods

This was a retrospective analysis of injured patients who presented with a confirmed PE between 2013 and 2019. Data were analysed and compared for patients with early PE (≤4 days) versus late PE (>4 days post-trauma).

Results

The study included 82 consecutive trauma patients with confirmed diagnosis of PE. The mean age of patients was 42.3 ± 16.2 years. The majority were males (79.3%) and the median time from injury to PE was 10 days. Of the PE cases, 24 (29.3%) had early PE, while 58 (70.7%) had late PE. The early PE group had higher rates of surgical intervention within 24 hours of admission than the late PE group (p = 0.001). Also, the rate of sub-segmental thrombi was significantly higher in the early PE group (p = 0.01). The late PE group sustained more moderate-to-severe injuries ie, GCS ED <13 (p = 0.03) and the median time from injury to PE diagnosis was 15 days (p = 0.001). After adjusting for the potential covariates, surgery within 24 hours of admission [adjusted odds ratio 37.58 (95% confidence interval 3.393-416.20), p = 0.003] was found to be significant independent predictor of early PE in trauma patients.

Conclusion

One-third of post-trauma PEs occurs early after trauma and the surgical intervention within the first 24 hours of admission is a major risk factor. A prospective study is needed to develop an objective risk assessment for the prevention and detection of early and late PE post-trauma.

Early start of thromboprophylaxis does not increase risk of intracranial hematoma progression in multiply injured patients with traumatic brain injury

BACKGROUND

Venous thromboembolism (VTE) in severely injured patients with severe traumatic brain injury (TBI) is a risk during the clinical course. Data on the safety of an early initiation of pharmacological VTE prophylaxis in severely injured patients with concomitant severe TBI is sparse.

METHODS

Admissions to our level-1-trauma center between January 2015 and December 2018 were screened. Patients suffering from severe TBI (Abbreviated Injury Scale (AIS) of the head ≥3) and at least one further AIS ≥ 3 in any other body region were included. Demographic data, thromboembolic events, and progression of the intracranial hemorrhage were extracted from the patient's charts. According to the first application of pharmacological thromboprophylaxis (VTEp), patients were categorized either to the early, the late (later than 24 h) or the no therapy group.

RESULTS

In 79 patients (early: n = 35, late: n = 29, no therapy: n = 15) the Injury Severity Score (ISS) was 36.7 ± 12.7 points (AIS_head 4.1 ± 0.8). No differences were found regarding the progression of the intracranial hemorrhage after initiation of the VTE prophylaxis (adj. p = 0.8). The VTE rate was low (n = 1, 1.6%).

CONCLUSION

In severely injured patients with severe TBI, the early administration of pharmacological thromboprophylaxis did not result in a higher rate of intracranial hematoma progression.

Association of Changes in Antithrombin Activity Over Time With Responsiveness to Enoxaparin Prophylaxis and Risk of Trauma-Related Venous Thromboembolism

Importance

Venous thromboembolism (VTE) affects 2% to 20% of recovering trauma patients, despite aggressive prophylaxis with enoxaparin. Antithrombin is a primary circulating anticoagulant and crucial component of enoxaparin thromboprophylaxis. Approximately 20% of trauma patients present with antithrombin deficiency (antithrombin activity <80%).

Objective

To examine time-dependent changes in antithrombin activity, responsiveness to enoxaparin, as measured by anti-factor Xa (anti-FXa) levels, and incidence of VTE after severe trauma and to assess the association of ex vivo antithrombin supplementation with patients' sensitivity to enoxaparin prophylaxis.

Design, Setting, and Participants

This single-center, prospective cohort study was performed at a level 1 trauma center between January 7, 2019, and February 28, 2020. Adult trauma patients admitted to the trauma service at high risk for VTE, based on injury pattern and severity, were screened and enrolled. Patients who were older than 70 years, were pregnant, had a known immunologic or coagulation disorder, or were receiving prehospital anticoagulants were excluded.

Exposures

Blood samples were collected on emergency department arrival and daily for the first 8 days of hospitalization.

Main Outcomes and Measures

Patients' antithrombin activity and anti-FXa levels were measured by a coagulation analyzer, and thrombin generation was measured by calibrated automated thrombography. Responsiveness to enoxaparin was assessed by measuring anti-FXa levels 4 to 6 hours after the first daily enoxaparin dose and compared between patients who developed VTE and who did not. In addition, the associations of ex vivo supplementation of antithrombin with plasma anti-FXa levels were assessed.

Results

Among 150 patients enrolled (median [IQR] age, 35 [27-53] years; 37 [24.7%] female and 113 [75.3%] male; 5 [3.3%] Asian, 32 [21.3%] Black, and 113 [75.3%] White; and 51 [34.0%] of Hispanic ethnicity), 28 (18.7%) developed VTE. Patients with VTE had significantly lower antithrombin activity on admission compared with patients without VTE (median [IQR], 91% [79%-104%] vs 100% [88%-112%]; P = .04), as well as lower antithrombin activity on hospital days 5 (median (IQR), 90% [83%-99%] vs 114% [99%-130%]; P = .011), 6 (median [IQR], 97% [81%-109%] vs 123% [104%-134%]; P = .003), 7 (median [IQR], 82% [74%-89%] vs 123% [110%-140%]; P < .001), and 8 (median [IQR], 99% [85%-100%] vs 123% [109%-146%]; P = .011). Anti-FXa levels were significantly lower in patients with VTE vs those without VTE at hospital day 4 (median [IQR], 0.10 [0.05-0.14] IU/mL vs 0.18 [0.13-0.23] IU/mL; P = .006), day 6 (median [IQR], 0.12 [0.08-0.14] IU/mL vs 0.22 [0.13-0.28] IU/mL; P = .02), and day 7 (median [IQR], 0.11 [0.08-0.12] IU/mL vs 0.21 [0.13, 0.28] IU/mL; P = .002). Multivariable analyses found that for every 10% decrease in antithrombin activity during the first 3 days, the risk of VTE increased 1.5-fold.

Conclusions and Relevance

The results of this cohort study suggest that after severe trauma, antithrombin deficiency is common and contributes to enoxaparin resistance and VTE. Interventional studies are necessary to determine the efficacy of antithrombin supplementation in the reduction of VTE incidence.

A retrospective cohort study assessing the incidence of inferior vena cava (IVC) occlusion following prophylactic IVC filter insertion: Is anticoagulation necessary during filter dwell?

BACKGROUND

Inferior vena cava (IVC) filters play a role in preventing venous thromboembolism after major trauma where deep venous thrombosis (DVT) risk is up to 80%. It has been suggested that IVC filters are thrombogenic and many patients are therefore placed on therapeutic anticoagulation during IVC filter dwell citing concern of in situ IVC thrombosis, even in the absence of existing DVT.

METHODS

Between 1 June 2018 and 31 December 2021, this retrospective study assessed the incidence of IVC thrombosis following prophylactic IVC filter insertion. Groups were defined according to the presence or absence of therapeutic anticoagulation during filter dwell. The primary outcome was the presence or absence of IVC thrombus at retrieval.

RESULTS

A total of 124 patients were included. Anticoagulation was prescribed in 29 and anticoagulation was not prescribed in 63. A further 32 patients developed a new thrombosis episode after the prophylactic IVC filter was placed, and 29 were prescribed anticoagulation part-way during filter dwell as a result of this diagnosis. No cases of IVC occlusion were observed in any patient group.

CONCLUSIONS

Caval thrombosis was not observed after prophylactic filter placement, with or without the prescription of anticoagulation. While prospective trials are needed to increase the level of evidence, based on these results the use of therapeutic anticoagulation during IVC filter dwell should not be dictated by the presence of an IVC filter alone but rather by the presence of a related thrombosis event.

Exploratory Investigation of the Plasma Proteome Associated with the Endotheliopathy of Trauma

BACKGROUND

The endotheliopathy of trauma (EoT) is associated with increased mortality following injury. Herein, we describe the plasma proteome related to EoT in order to provide insight into the role of the endothelium within the systemic response to trauma.

METHODS

99 subjects requiring the highest level of trauma activation were included in the study. Enzyme-linked immunosorbent assays of endothelial and catecholamine biomarkers were performed on admission plasma samples, as well as untargeted proteome quantification utilizing high-performance liquid chromatography and tandem mass spectrometry.

RESULTS

Plasma endothelial and catecholamine biomarker abundance was elevated in EoT. Patients with EoT (n = 62) had an increased incidence of death within 24 h at 21% compared to 3% for non-EoT (n = 37). Proteomic analysis revealed that 52 out of 290 proteins were differentially expressed between the EoT and non-EoT groups. These proteins are involved in endothelial activation, coagulation, inflammation, and oxidative stress, and include known damage-associated molecular patterns (DAMPs) and intracellular proteins specific to several organs.

CONCLUSIONS

We report a proteomic profile of EoT suggestive of a surge of DAMPs and inflammation driving nonspecific activation of the endothelial, coagulation, and complement systems with subsequent end-organ damage and poor clinical outcome. These findings support the utility of EoT as an index of cellular injury and delineate protein candidates for therapeutic intervention.

Comparative Risks of Fracture Among Direct Oral Anticoagulants and Warfarin: A Systematic Review and Network Meta-Analysis

Importance

Previous studies have shown the effectiveness and safety of direct oral anticoagulants (DOACs), including lower fracture risks, compared to warfarin. However, direct or indirect comparisons between different DOACs are scarce in the literature.

Objective

This study aims to compare fracture risks among different DOACs and warfarin, including apixaban, rivaroxaban, dabigatran, and edoxaban, in patients with non-valvular atrial fibrillation (NVAF) or venous thromboembolism (VTE).

Methods

We searched PubMed/MEDLINE, Embase, Cochrane CENTRAL, and Web of Science for randomized controlled trials and cohort studies comparing the fracture risks among patients who used warfarin or DOACs, up to March 2021. Two authors extracted data and appraised the risk of bias of included studies. The primary outcome was fracture risk. We performed pairwise meta-analyses to compare differences between medications and network meta-analyses using frequentist random-effects models to compare through indirect evidence. We used surface under the cumulative ranking curve (SUCRA) and mean ranks to determine the probability of a DOAC ranking best in terms of fracture risk.

Results

Thirty-one studies were included in the final analysis. Twenty-four randomized controlled trials and seven cohort studies with 455,343 patients were included in the systematic review and network meta-analysis. Compared to warfarin, the risk of any fractures was lowest with apixaban [relative risk (RR) = 0.59; 95% confidence interval (CI): 0.48-0.73], followed by rivaroxaban (RR: 0.72; 95% CI: 0.60-0.86), edoxaban (RR: 0.88; 95% CI: 0.62-1.23), and dabigatran (RR = 0.90; 95% CI: 0.75-1.07). No substantial inconsistency between direct and indirect evidence was detected for all outcomes.

Conclusions

All DOACs were safer than warfarin concerning the risk of fracture; however, apixaban had the lowest relative risk of fracture within the class of DOACs. Further head-to-head prospective studies should confirm the comparative safety profiles of DOACs regarding fractures.

THE EFFICACY OF WEIGHT-BASED ENOXAPARIN DOSING FOR VTE-PROPHYLAXIS IN TRAUMA PATIENTS: A SYSTEMATIC REVIEW AND META-ANALYSIS

BACKGROUND

Trauma patients are at high risk of developing venous thromboembolism (VTE), and standard dosing enoxaparin regimens may be inadequate for prophylaxis. This meta-analysis was performed to clarify the efficacy of alternative dosing regimens for VTE prophylaxis in this high-risk group. The objective of this systematic review was to review the evidence regarding weight-based dosing of enoxaparin for VTE prophylaxis in trauma patients.

METHODS

A systematic database search was undertaken for studies comparing standard vs weight-based dosing of enoxaparin for VTE prophylaxis in adult trauma patients, aged ≥18 years. The primary outcome was the achievement of Anti-Factor Xa (AFXa) levels within the prophylactic range. Secondary outcomes included: sub-prophylactic AFXa levels, supra-prophylactic AFXa levels, VTE incidence and bleeding events. Meta-analysis was conducted using both fixed- and random-effects models, and presented as odds ratios (OR), risk ratios (RR) and risk differences (RD) with 95% confidence intervals (CI).

RESULTS

Four cohort studies were eligible for inclusion. Compared to standard dosing, weight-based enoxaparin prophylaxis dosing was associated with increased odds of prophylactic AFXa levels (OR = 5.85., 95%CI: 3.02-11.30, p < 0.00001) and reduced risk of sub-prophylactic AFXa levels (RR = 3.97, 95%CI: 3.02-5.22, p < 0.00001). Standard dosing was associated with a reduced risk of supra-therapeutic AFXa levels (RR = 0.23, 95%CI: 0.11-0.50, P = 0.0002), but this was not associated with a difference in risk of bleeding events (RD = -0.00, 95%CI: -0.02-0.01, P = 0.55). There was no statistical difference in incidence VTE between the two groups (RD = 0.01, 95%CI: -0.02-0.03, P = 0.64).

CONCLUSIONS

Compared with standard dosing, weight-based enoxaparin dosing regimens are associated with increased odds of prophylactic range AFXa levels. Further investigation is required to determine if this translates into improved VTE prophylaxis and reduced VTE incidence.

LEVEL OF EVIDENCE

Systematic Review, level III.

Incidence and risk factors of deep vein thrombosis after extracorporeal life support

Background

Deep vein thrombosis (DVT) after decannulation of extracorporeal life support (ECLS) is not uncommon. Moreover, the impact of anticoagulation and potential risk factors is unclear. Furthermore, it is unclear if cannula‐associated DVT is more common in ECLS patients compared to critically ill patients without ECLS.

Methods

All adult patients who were successfully weaned from ECLS and were screened for DVT following decannulation were included in this observational cohort study. The incidence of post‐ECLS‐DVT was assessed and the cannula‐associated DVT rate was compared with that of patients without ECLS after central venous catheter (CVC) removal. The correlation between the level of anticoagulation, risk factors, and post‐ECLS‐DVT was determined.

Results

We included 30 ECLS patients and 53 non‐ECLS patients. DVT was found in 15 patients (50%) of which 10 patients had a DVT in a cannulated vein. No correlation between the level of anticoagulation and DVT was found. V‐V ECLS mode was the only independent risk factor for post‐ECLS‐DVT (OR 5.5; 95%CI 1.16–26.41). We found no difference between the ECLS and non‐ECLS cohorts regarding cannula‐associated DVT rate (33% vs. 32%).

Conclusion

Post‐ECLS‐DVT is a common finding that occurs in half of all patients supported with ECLS. The incidence of cannula‐associated DVT was equal to CVC‐associated DVT in critically ill patients without ECLS. V‐V ECLS was an independent risk factor for post‐ECLS‐DVT.

Trauma-induced pulmonary thromboembolism: What's update?

Trauma-induced pulmonary thromboembolism is the second leading cause of death in severe trauma patients. Primary fibrinolytic hyperactivity combined with hemorrhage and consequential hypercoagulability in severe trauma patients create a huge challenge for clinicians. It is crucial to ensure a safe anticoagulant therapy for trauma patients, but a series of clinical issues need to be answered first, for example, what are the risk factors for traumatic venous thromboembolism? How to assess and determine the status of coagulation dysfunction of patients? When is the optimal timing to initiate pharmacologic prophylaxis for venous thromboembolism? What types of prophylactic agents should be used? How to manage the anticoagulation-related hemorrhage and to determine the optimal timing of restarting chemoprophylaxis? The present review attempts to answer the above questions.

Equivalence of DOACS and LMWH for thromboprophylaxis after hip fracture surgery: Systematic review and meta-analysis

BACKGROUND

Patients with hip fractures (HF) have an increased risk of venous thromboembolism (VTE). In elective orthopedic surgery direct oral anticoagulants (DOACs) have proven to be similarly or more effective compared to low molecular weight heparin (LMWH), but DOACs are not yet approved for thromboprophylaxis in trauma patients with HF. The aim of this study was to systematically review the literature comparing the effectiveness of DOACs and LMWH for thromboprophylaxis in trauma patients with surgically treated HF.

MATERIALS AND METHODS

We searched PubMed, the Cochrane Library, Web of Science, and Embase. The primary outcome was the incidence of VTE (symptomatic and asymptomatic combined). Secondary outcomes were symptomatic VTE; a symptomatic VTE, symptomatic deep venous thrombosis (DVT); symptomatic pulmonary embolism (PE); major, clinically relevant non-major (CRNM), and minor bleeding. Meta-analysis was performed to compare the odds of VTE and secondary outcomes between DOACs and LMWH.

RESULTS

The search resulted in 738 titles. Five studies matched inclusion criteria. In total, 4748 hip fracture patients were analyzed (DOACs: 2276 patients, LMWH: 2472 patients). The pooled odds ratio for the risk of VTE for DOAC use was 0.52 (95% confidence interval 0.25-1.11, p = 0.09) compared to LMWH. No statistically significant differences between DOAC and LMWH were found for asymptomatic VTE, symptomatic DVT, PE, major or CRNM bleeding, and minor bleeding.

CONCLUSIONS

Meta-analysis of the literature suggests that DOACs are associated with equivalent effectiveness and safety compared to LMWH.

Relationship Between Anti-Xa Level Achieved with Prophylactic Low-Molecular Weight Heparin and Venous Thromboembolism in Trauma Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Trauma patients have simultaneously high venous thromboembolism (VTE) and bleeding risk. Optimal chemoprophylaxis regimens remain unclear. This study aims to answer three questions for trauma patients. Is there any association between anti-Xa and VTE? Does dose adjustment improve prophylactic anti-Xa rates? Does dose adjustment improve anti-Xa adequacy and VTE compared to standard dosing?

METHODS

Systematic search of MEDLINE, Embase, Scopus, and Web of Science occurred in May 2021.Two author review included trauma studies that: evaluated low molecular weight heparin chemoprophylaxis, reported anti-Xa level, and evaluated ≥1 outcome. Data was dually extracted and estimated effects were calculated using RevMan 5.4 applying the Mantel-Haenszel method. Analysis #1 compared patients with peak anti-Xa ≥ 0.2 IU/ml or trough ≥0.1 IU/ml to those with lower anti-Xa using VTE as the primary outcome. Analysis #2 reported the effect of dose adjustment on anti-Xa. Analysis #3 compared standard dosing to dose adjustment with the primary outcome being anti-Xa adequacy; secondary outcomes were VTE, pulmonary embolism, and bleeding complications.

RESULTS

3401 studies were evaluated with 24 being included (19 retrospective studies, 5 prospective studies). In analysis #1, achieving adequate anti-Xa was associated with reduced odds of VTE (4.0% to 3.1%, OR 0.52, p = 0.03). Analysis #2 demonstrated that 768 (75.3%) patients achieved prophylactic anti-Xa with adjustment protocols.Analysis three suggested that dose adjusted chemoprophylaxis achieves prophylactic anti-Xa more frequently (OR 4.05, p = 0.007) but without VTE (OR 0.72, p = 0.15) or PE (OR 0.48, p = 0.10) differences. In subgroup analysis, anti-Xa dose adjustment also suggested no VTE reduction (OR 0.68, p = 0.08).

CONCLUSIONS

Patients with higher anti-Xa levels are less likely to experience VTE, and anti-Xa guided chemoprophylaxis increases anti-Xa adequacy. However, dose adjustment, including anti-Xa guided dosing, may not reduce VTE.

LEVEL OF EVIDENCE

Level IV; Systematic Review Meta-Analysis.

Prevention, treatment, and risk factors of deep vein thrombosis in critically ill patients in Zhejiang province, China: a multicenter, prospective, observational study

PURPOSE

The aim of this study is to investigate the prevention and treatment patterns of deep vein thrombosis (DVT) in critically ill patients and to explore the risk factors for DVT in people from Zhejiang Province, China.

MATERIALS AND METHODS

This study prospectively enrolled patients admitted in intensive care units (ICUs) of 54 hospitals from 09/16/2019 to 01/16/2020. The risk of developing DVT and subsequent prophylaxis was evaluated. The primary outcome was DVT occurrence during ICU hospitalisation. Univariate and multivariate logistic regression were performed to determine the risk factors for DVT.

RESULTS

A total of 940 patients were included in the study. Among 847 patients who received prophylaxis, 635 (75.0%) patients received physical prophylaxis and 199 (23.5%) patients received drug prophylaxis. Fifty-eight (6.2%) patients were diagnosed with DVT after admission to the ICU, and 36 patients were treated with anticoagulants (all patients received low molecular weight heparin [LMWH]). D-dimer levels (OR = 1.256, 95% CI: 1.132-1.990), basic prophylaxis (OR = 0.092, 95% CI: 0.016-0.536), and physical prophylaxis (OR = 0.159, 95% CI: 0.038-0.674) were independently associated with DVT in ICU patients. The short-term survival was similar between DVT and non-DVT patients.

CONCLUSIONS

DVT prophylaxis is widely performed in ICU patients. Prophylaxis is an independent protective factor for DVT occurrence. The most common treatment of DVT patients is LMWH, although it might increase the rate of bleeding.Key messagesThis is the only multicenter and prospective study of DVT in ICUs in China.d-dimer levels were independently associated with DVT in ICU patients.Prophylaxis was an independent protective factor for DVT occurrence in ICU.

Thrombin Generation Following Severe Trauma: Mechanisms, Modulators, and Implications for Hemostasis and Thrombosis

ABSTRACT

Thrombin is the central coagulation enzyme that catalyzes the conversion of fibrinogen to form insoluble fibrin blood clots. In vivo, thrombin production results from the concerted effort of plasma enzymatic reactions with essential contributions from circulating and vessel wall cells. The relative amount of thrombin produced directly dictates the structure and stability of fibrin clots; therefore, sufficient thrombin generation is essential for normal hemostasis to occur. Examination of thrombin generation phenotypes among severely injury trauma patients reveals important relationships between the potential for generating thrombin and risks of bleeding and thrombotic complications. Thus, understanding determinants of thrombin generation following traumatic injury is of high clinical importance. This review will focus on patterns and mechanisms of thrombin generation in severely injured patients, the role of fluid resuscitation in modulating thrombin generation and implications for outcomes.

Intraoperative development of pulmonary thromboembolism in a bedridden patient owing to a pelvic bone fracture with negative preoperative computed tomography pulmonary angiographic findings: A case report

RATIONALE

Pulmonary thromboembolism (PTE) is a potentially life-threatening condition with high morbidity and mortality, and computed tomographic pulmonary angiography (CTPA) is an important diagnostic tool for patients in whom PTE is suspected; however, intraoperative PTE is very difficult to diagnose and often has a rapid clinical course. We experienced a case of intraoperative PTE with persistent tachycardia refractory to conventional treatments despite negative preoperative CTPA findings.

PATIENT CONCERNS

A 53-year-old man with a pelvic bone fracture who had been on bed rest for 10 days underwent open reduction and internal fixation under general anesthesia. He remained tachycardic (heart rate of 120 beats/min) despite treatments with fluid resuscitation, analgesics, and beta-blockers.

DIAGNOSES

Preoperative CTPA, computed tomography (CT) venography, and transthoracic echocardiography showed no signs of deep vein thrombosis and PTE. However, the levels of D-dimer were elevated. After the start of the surgery, tachycardia (heart rate between 100 and 110 beats/min) could not be treated with fluid resuscitation. Systolic blood pressure was maintained between 90 and 100 mm Hg using continuous infusion of phenylephrine. Ninety minutes after the surgery, systolic and diastolic blood pressures suddenly dropped from 100/60 to 30/15 mm Hg with a decrease in end-tidal carbon dioxide concentration from 29 to 13 mm Hg and development of atrial fibrillation. Arterial blood gas analysis revealed hypercapnia. Under the suspicion of PTE, cardiopulmonary resuscitation (CPR) was immediately initiated. Three CPR cycles raised the blood pressure back to 90/50 mm Hg with sinus tachycardia (115 beats/min). Transesophageal echocardiography showed right ventricular dysfunction and paradoxical septal motion. However, emboli were not found. Postoperative chest CT revealed massive PTE in both pulmonary arteries.

INTERVENTIONS

Immediately, surgical embolectomy was performed uneventfully.

OUTCOMES

The patient was discharged from the hospital 1 month later without any complications.

LESSONS

The patient with moderate risk for PTE (heart rate > 95 beats/min and immobilization, surgery under general anesthesia, and lower limb fracture within 1 month) should be closely monitored and managed intraoperatively even if preoperative CTPA findings are negative. The development of PTE needs to be expected if tachycardia is refractory to conventional treatments.

A retrospective cohort study of disease-related risk factors for central venous catheter-related symptomatic thrombosis in intensive care unit inpatients

Central venous catheters (CVC) are widely used in critically ill patients given their benefits in monitoring vital signs, treatment administration, and renal replacement therapy in intensive care unit (ICU) patients, but these catheters have the potential to induce symptomatic catheter-related venous thrombosis (CRVT). This study reported the rate of symptomatic CRVT in ICU patients receiving CVC and analyzed the disease-related risk factors for symptomatic CRVT in ICU patients.A retrospective analysis was performed on the consecutive ICU 1643 critically ill patients with CVCs inserted from January 2015 to December 2019. Symptomatic CRVT was confirmed by ultrasound. CVCs were divided into 2 groups based on the presence of symptomatic CRVT, and the variables were extracted from the electronic medical record system. Logistic univariate and multivariate regression analyses were used to determine the disease-related risk factors of symptomatic CRVT.A total of 209 symptomatic CRVT events occurred among 2114 catheters. The rate of CRVT was 9.5 per 1000 catheter days. Univariate analysis revealed that trauma, major surgery, heart failure, respiratory failure, and severe acute pancreatitis were risk factors for symptomatic CRVT in the ICU. Multivariate analysis showed that trauma (odds ratio [OR], 2.046; 95% confidence interval [CI] [1.325-3.160], P = .001), major surgery (OR, 2.457; 95% CI [1.641-3.679], P = .000), and heart failure (OR, 2.087; 95% CI [1.401-3.111], P = .000) were independent disease-related risk factors for symptomatic CRVT in ICU. The C-statistic for this model was 0.61 (95% CI [0.57-0.65], P = .000).The incidence rate of symptomatic CRVT in the ICU population was 9.5 per 1000 catheter days. Trauma, major surgery, and heart failure are independent disease-related risk factors of symptomatic CRVT.

What Do We Know about Thromboprophylaxis and Its Monitoring in Critically Ill Patients?

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is an important complication in patients hospitalized in intensive care units (ICU). Thromboprophylaxis is mainly performed with Low Molecular Weight Heparin (LMWH) and, in some specific patients, with Unfractionated Heparin (UFH). These intensive units are an environment where individual patient variability is extreme and where traditional antithrombotic protocols are frequently ineffective. This was known for a long time, but the hospitalization of many patients with COVID-19 inflammatory storms suddenly highlighted this knowledge. It is therefore reasonable to propose variable antithrombotic prevention protocols based initially on a series of individual criteria (weight, BMI, and thrombotic risks). Secondly, they should be adjusted by the monitoring of anticoagulant activity, preferably by measuring the anti-Xa activity. However, we still face unresolved questions, such as once- or twice-daily LMWH injections, monitoring at the peak and/or trough, and poorly defined therapeutic targets. Equally surprisingly, we observed a lack of standardization of the anti-Xa activity kits.

COVID-19 Sepsis: Pathogenesis and Endothelial Molecular Mechanisms Based on "Two-Path Unifying Theory" of Hemostasis and Endotheliopathy-Associated Vascular Microthrombotic Disease, and Proposed Therapeutic Approach with Antimicrothrombotic Therapy

COVID-19 sepsis is characterized by acute respiratory distress syndrome (ARDS) as a consequence of pulmonary tropism of the virus and endothelial heterogeneity of the host. ARDS is a phenotype among patients with multiorgan dysfunction syndrome (MODS) due to disseminated vascular microthrombotic disease (VMTD). In response to the viral septicemia, the host activates the complement system which produces terminal complement complex C5b-9 to neutralize pathogen. C5b-9 causes pore formation on the membrane of host endothelial cells (ECs) if CD59 is underexpressed. Also, viral S protein attraction to endothelial ACE2 receptor damages ECs. Both affect ECs and provoke endotheliopathy. Disseminated endotheliopathy activates two molecular pathways: inflammatory and microthrombotic. The former releases inflammatory cytokines from ECs, which lead to inflammation. The latter initiates endothelial exocytosis of unusually large von Willebrand factor (ULVWF) multimers and FVIII from Weibel–Palade bodies. If ADAMTS13 is insufficient, ULVWF multimers activate intravascular hemostasis of ULVWF path. In activated ULVWF path, ULVWF multimers anchored to damaged endothelial cells recruit circulating platelets and trigger microthrombogenesis. This process produces “microthrombi strings” composed of platelet-ULVWF complexes, leading to endotheliopathy-associated VMTD (EA-VMTD). In COVID-19, microthrombosis initially affects the lungs per tropism causing ARDS, but EA-VMTD may orchestrate more complex clinical phenotypes, including thrombotic thrombocytopenic purpura (TTP)-like syndrome, hepatic coagulopathy, MODS and combined micro-macrothrombotic syndrome. In this pandemic, ARDS and pulmonary thromboembolism (PTE) have often coexisted. The analysis based on two hemostatic theories supports ARDS caused by activated ULVWF path is EA-VMTD and PTE caused by activated ULVWF and TF paths is macrothrombosis. The thrombotic disorder of COVID-19 sepsis is consistent with the notion that ARDS is virus-induced disseminated EA-VMTD and PTE is in-hospital vascular injury-related macrothrombosis which is not directly  related to viral pathogenesis. The pathogenesis-based therapeutic approach is discussed for the treatment of EA-VMTD with antimicrothrombotic regimen and the potential need of anticoagulation therapy for coinciding macrothrombosis in comprehensive COVID-19 care.

Acquired antithrombin deficiency is a risk factor for venous thromboembolism after major trauma

BACKGROUND

Up to 30% of severely injured patients on prophylactic anticoagulation experience venous thromboembolism (VTE). Our previous work shows that acquired antithrombin (AT) deficiency [AT<80%] occurs in approximately 20% of trauma patients upon admission and drives poor responsiveness to enoxaparin. However, changes in AT over time and its association with VTE remain unknown. The aim of this study was to determine the relationship between acquired AT deficiency and VTE in severely injured patients.

METHODS

A secondary analysis of the Pragmatic, Randomized Optimal Platelet and Plasma Ratios (PROPPR) clinical trial was performed. Patients who died within 24 h of hemorrhage were excluded from analysis. Demographics, mechanism and severity of injury, transfusions volumes, and outcomes were compared between patients who did and did not develop VTE. Non-parametric statistical tests were used to compare patients with and without VTE. Logistic regression analyses were performed to identify predictors of VTE risk, controlling for AT deficiency (over first 72 h), age, gender, race, body mass index, study site, randomization group and injury severity. A Cox proportional hazards model was used to assess the contribution of AT deficiency to the risk of VTE, while censoring for early deaths.

RESULTS

Of the 680 patients enrolled in PROPPR, 101 died of hemorrhage. Of the remaining 579 patients, 86 (14.9%) developed VTE. The median time to VTE was 6 days (IQR 3, 13). No differences in demographics, injuries, or transfusion volumes were identified between VTE cases and controls. AT deficiency at 72 h post-admission was independently associated with VTE. Patients who experienced AT deficiency at 72 h had a 3.3 fold increased risk of VTE [p < 0.01; 95% CI 1.56, 6.98]. Lastly, patients who developed VTE had worse outcomes as displayed by significantly fewer hospital-free days compared to non-VTE patients [0 (0, 8) vs. 4 (0, 18), p < 0.01, respectively].

CONCLUSIONS

Acquired AT deficiency (AT<80%) is an important risk factor for VTE in severely injured patients. These data indicate that intervening, perhaps through AT supplementation, in the first three days after injury could mitigate the risk of VTE and improve patient outcomes.

Trauma-Induced Coagulopathy: Overview of an Emerging Medical Problem from Pathophysiology to Outcomes

Coagulopathy induced by major trauma is common, affecting approximately one-third of patients after trauma. It develops independently of iatrogenic, hypothermic, and dilutive causes (such as iatrogenic cause in case of fluid administration), which instead have a pejorative aspect on coagulopathy. Notwithstanding the continuous research conducted over the past decade on Trauma-Induced Coagulopathy (TIC), it remains a life-threatening condition with a significant impact on trauma mortality. We reviewed the current evidence regarding TIC diagnosis and pathophysiological mechanisms and summarized the different iterations of optimal TIC management strategies among which product resuscitation, potential drug administrations, and hemostatis-focused approaches. We have identified areas of ongoing investigation and controversy in TIC management.

Which Trauma Patients Require Lower Enoxaparin Dosing for Venous Thromboembolism Prophylaxis?

Trauma patients have a high risk for venous thromboembolism (VTE) such that an increased enoxaparin dose is necessary to reduce related complications. Given that most trauma patients require an enoxaparin dose of at least 40 mg every 12 hours for VTE prophylaxis, we sought to identify which patients require enoxaparin 30 mg every 12 hours and hypothesized that both weight and low creatinine clearance (CrCl) would more likely determine enoxaparin dosing than age, body mass index (BMI), or body surface area (BSA). Single institution data were collected on trauma patients between August 2014 and February 2018 to compare trauma patients who required enoxaparin 30 mg to those who required ≥40 mg every 12 hours. Of the 245 patients included, 86 (35.1%) required enoxaparin at 30 mg to achieve the goal anti-factor Xa trough level. Factors associated with low dose enoxaparin were older age (59.6 vs. 46.2 years, P ≤ .01) and lower CrCl (81.5 mL/min vs. 93.7 mL/min, P ≤ .01). Weight, BSA, and BMI did not alter the dose of enoxaparin. A regression model determined that only CrCl predicted the need for low dose enoxaparin (adjusted odds ratio .982, 95% CI: .975-.990, P < .01). Although an initial dose of enoxaparin 40 mg is appropriate for most trauma patients, patients with low CrCl should receive 30 mg. Increased age and low weight were not associated with the need for a lower enoxaparin dose.

Guidelines for the prevention of venous thromboembolism in hospitalized patients with pelvi-acetabular trauma

BACKGROUND

Venous thromboembolism is a dreaded complication leading to increased morbidity and mortality in patients having pelvi-acetabular fractures.

OBJECTIVES

These evidence based guidelines aim to provide the decision making ability in the prevention of venous thromboembolism in patients with pelvi-acetabular trauma planned for operative or non operative treatment.

METHODS

The patients were subclassified into 5 categories. The PICO framework was used to devise research questions in each category. The systematic reviews were performed for each research question. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess outcomes of critical interest. The guideline panel consisting of expert members of different subspecialties, analyzed the evidence and made recommendations.

RESULTS

The guideline panel proposed 21 recommendations. There are five recommendations in category 1 to 3, two recommendations in category 4 and four recommendations in category 5.

CONCLUSION

In pelvi-acetabular fractures there is strong evidence to suggest that thromboprophylaxis should be given. It should be initiated as early as possible after control of hemorrhage. The chemical prophylaxis is the preferred mode and LMWH is the preferred agent of choice. The mechanical methods can be used as an adjunct. The routine prophylactic use of IVC filters is not recommended. However, the use of retrievable IVC filters in high risk patients with established VTE in preoperative period can be considered. The use of newer directly acting oral anticoagulants is gaining importance.

Occult deep vein thrombosis in lower limb trauma requiring microsurgical reconstruction-A retrospective cohort study

BACKGROUND

Delayed microsurgical reconstruction of lower extremity trauma is associated with increased risk of free flap loss, frequently following failure of the venous anastomosis. This has been attributed to thrombocytosis, but occult deep vein thrombosis (DVT) may contribute to this risk.

METHODS

We performed a retrospective cohort study of consecutive patients presenting to our service with lower limb injuries requiring microsurgical reconstruction between 2013 and 2017, and examined venous Duplex ultrasound reports, operation notes and free flap outcomes.

RESULTS

A total of 165 free flap reconstructions for lower limb trauma were performed for 162 limbs in 158 patients. Seventy-two limbs (44.4%) underwent preoperative venous Duplex ultrasound identifying occult DVT in 14 (19.4%) patients. Occult DVT was identified intraoperatively in a further 7 cases. Bilateral lower limb injuries (p = 0.0002), the level of injury at or above the knee (p < 0.0001), multiple levels of injury within the affected limb (p = 0.0008) and critical care admission (p = 0.0008) were significant risk factors for DVT. All 7 cases of DVT diagnosed intraoperatively prompted a change in the surgical plan for the recipient vein; however, preoperative identification of occult DVT also lead to an adjustment in the microsurgical plan in 4 out of 14 cases.

CONCLUSIONS

Prevalence of DVT is high in severe lower limb injury, potentially increasing the risk of free flap loss. Preoperative identification of occult DVT may influence the microsurgical plan and mitigate for this risk.

A preliminary study of intensivist-performed DVT ultrasound screening in trauma ICU patients (APSIT Study)

Background

Multiple screening Duplex ultrasound scans (DUS) are performed in trauma patients at high risk of deep vein thrombosis (DVT) in the intensive care unit (ICU). Intensive care physician performed compression ultrasound (IP-CUS) has shown promise as a diagnostic test for DVT in a non-trauma setting. Whether IP-CUS can be used as a screening test in trauma patients is unknown. Our study aimed to assess the agreement between IP-CUS and vascular sonographer performed DUS for proximal lower extremity deep vein thrombosis (PLEDVT) screening in high-risk trauma patients in ICU.

Methods

A prospective observational study was conducted at the ICU of Alfred Hospital, a major trauma center in Melbourne, Australia, between Feb and Nov 2015. All adult major trauma patients admitted with high risk for DVT were eligible for inclusion. IP-CUS was performed immediately before or after DUS for PLEDVT screening. The paired studies were repeated twice weekly until the DVT diagnosis, death or ICU discharge. Written informed consent from the patient, or person responsible, or procedural authorisation, was obtained. The individuals performing the scans were blinded to the others’ results. The agreement analysis was performed using Cohen’s Kappa statistics and intraclass correlation coefficient for repeated binary measurements.

Results

During the study period, 117 patients had 193 pairs of scans, and 45 (39%) patients had more than one pair of scans. The median age (IQR) was 47 (28–68) years with 77% males, mean (SD) injury severity score 27.5 (9.53), and a median (IQR) ICU length of stay 7 (3.2–11.6) days. There were 16 cases (13.6%) of PLEDVT with an incidence rate of 2.6 (1.6–4.2) cases per 100 patient-days in ICU. The overall agreement was 96.7% (95% CI 94.15–99.33). The Cohen’s Kappa between the IP-CUS and DUS was 0.77 (95% CI 0.59–0.95), and the intraclass correlation coefficient for repeated binary measures was 0.75 (95% CI 0.67–0.81).

Conclusions

There is a substantial agreement between IP-CUS and DUS for PLEDVT screening in trauma patients in ICU with high risk for DVT. Large multicentre studies are needed to confirm this finding.

Early Detection of Deep Venous Thrombosis in Trauma Patients

Background

This study was performed to determine whether trauma patients are at an increased risk of developing deep venous thrombosis (DVT) within the first 48 hours of hospitalization.

Materials and methods

A retrospective review was performed using a prospectively maintained database of patients admitted to a trauma center during a five-year time period. Patients hospitalized for greater than 48 hours who received a screening venous duplex for DVT were included in the study.

Results

There were 1067 venous duplex scans obtained, 689 (64.5%) within the first 48 hours of admission (early DVT group), 378 (35.4%) after the first 48 hours (late DVT group). Only 142 (13.2%) patients had a positive duplex scan for DVT, 55 (early group), 87 (late group). Comorbid conditions of congestive heart failure (P = 0.02), pelvic fractures (P = 0.04), and a lower initial systolic blood pressure on presentation (p = 0.04) were associated with early DVT. Head trauma (P < 0.01), mechanical ventilation (P < 0.001), and transfusion of blood products (P < 0.001), were predictors of DVT in the late group.

Conclusions

Trauma patients are at an increased risk of developing venous thrombosis early in the hospital course due to comorbidities associated with trauma. Whereas, venous thrombosis in trauma patients diagnosed after the first 48 hours of hospitalization appears to be associated with prolonged patient immobility.

The impact of blood product ratio and procoagulant therapy on the development of thromboembolic events in severely injured hemorrhaging trauma patients

INTRODUCTION

Transfusion therapy in hemorrhaging trauma patients is associated with the development of thromboembolic events. It is unknown whether current resuscitation strategies, including large volumes of plasma and early administration of procoagulant therapy, increases this risk.

METHODS

A systematic search was conducted in MEDLINE, PubMed, and Embase. Studies were screened by two independent reviewers and included if they reported on thromboembolic events in patients with severe trauma (injury severity score ≥16) who received transfusion of at least 1 unit of red blood cells. The ratio by which blood products were transfused, as well as use of procoagulant or antifibrinolytic medication, was recorded.

RESULTS

A total of 40 studies with 11.074 bleeding trauma patients were included, in which 1.145 thromboembolic events were reported, yielding an incidence of 10% thromboembolic events. In studies performing routine screening for thromboembolic complications, the incidence ranged from 12% to 23%. The risk of thromboembolic events was increased after administration of tranexamic acid (TXA; odds ratio [OR], 2.6; 95% confidence interval [CI], 1.7-4.1; p < 0.001) and fibrinogen concentrate (OR, 2.1; 95% CI, 1.0-4.2; p = 0.04). Blood product ratio, the use of prothrombin complex concentrate or recombinant factor VIIa were not associated with thromboembolic events.

CONCLUSION

This systematic review identified an incidence of thromboembolic events of 10% in severely injured bleeding trauma patients. The use of TXA and fibrinogen concentrate was associated with the development of thromboembolic complications.

Chemoprophylaxis and Venous Thromboembolism in Traumatic Brain Injury at Different Trauma Centers

Patients with severe traumatic brain injury (TBI) are at an increased risk of venous thromboembolism (VTE). Because of concerns of worsening intracranial hemorrhage, clinicians are hesitant to start VTE chemoprophylaxis in this population. We hypothesized that ACS Level I trauma centers would be more aggressive with VTE chemoprophylaxis in adults with severe TBI than Level II centers. We also predicted that Level I centers would have a lower risk of VTE. We queried the Trauma Quality Improvement Program (2010–2016) database for patients with Abbreviated Injury Scale scores of 4 and 5 of the head and compared them based on treating the hospital trauma level. Of 204,895 patients with severe TBI, 143,818 (70.2%) were treated at Level I centers and 61,077 (29.8%) at Level II centers. The Level I cohort had a higher rate of VTE chemoprophylaxis use (43.2% vs 23.3%, P < 0.001) and a shorter median time to chemoprophylaxis (61.9 vs 85.9 hours, P < 0.001). Although Level I trauma centers started VTE chemoprophylaxis more often and earlier than Level II centers, there was no difference in the risk of VTE ( P = 0.414) after controlling for covariates. Future prospective studies are warranted to evaluate the timing, safety, and efficacy of early VTE chemoprophylaxis in severe TBI patients.

Supplementation with antithrombin III ex vivo optimizes enoxaparin responses in critically injured patients

BACKGROUND

The high incidence of venous thromboembolism (VTE) following trauma persists in spite of aggressive thromboprophylaxis strategies. Approximately half of VTE patients do not achieve the recommended anti-FXa response to enoxaparin anticoagulation (0.1-0.4 IU/mL), however, research to explain or correct this phenomenon is lacking. We hypothesized that antithrombin III (AT) deficiency is associated with poor enoxaparin responsiveness in trauma patients that develop VTE which can be reversed through supplementation with AT.

METHODS AND FINDINGS

A retrospective cohort study was performed on plasma collected from trauma patients who did and did not develop pulmonary embolism (PE) as well as healthy volunteers. AT levels, thrombin generation, and anti-FXa levels were measured in the collected plasma at baseline and in response to supplementation with AT concentrate at 120-200% or plasma (30% volume). A total of 54 PE patients and 46 non-PE patients were enrolled in this study for analysis. Compared to healthy volunteers, trauma patients had lower levels of AT, elevated thrombin generation, and lower anti-FXa levels in response to enoxaparin. Moreover, thrombin generation was higher and responses to enoxaparin were lower in patients who developed PE compared to those who did not develop PE. We found that supplementation with AT, but not plasma, increased AT levels and improved enoxaparin-mediated inhibition of thrombin generation.

CONCLUSIONS

Supplementation with AT may provide a novel adjunct therapy to increase the effectiveness of enoxaparin thromboprophylaxis and reduce the incidence of VTE in the trauma population.

Venous thromboembolism (VTE) prophylaxis in severely injured patients: an international comparative assessment

PURPOSE

Venous thromboembolisms (VTE) are a major concern after acute survival from trauma. Variations in treatment protocols for trauma patients exist worldwide. This study analyzes the differences in the number of VTE events and the associated complications of thromboprophylaxis between two level I trauma populations utilizing varying treatment protocols.

METHODS

International multicenter trauma registry-based study was performed at the University Medical Center Utrecht (UMCU) in The Netherlands (early commencement chemical prophylaxis), and Harborview Medical Center (HMC) in the United States (restrictive early chemical prophylaxis). All severely injured patients (ISS ≥ 16), aged ≥ 18 years, and admitted in 2013 were included. Primary outcomes were VTE [deep venous thrombosis (DVT) (no screening), pulmonary embolism (PE)], and hemorrhagic complications.

RESULTS

In UMCU, 279 patients were included and in HMC, 974 patients. Overall, 75% of the admitted trauma patients in UMCU and 81% in HMC (p < 0.001) received thromboprophylaxis, of which 100% in and 75% at, respectively, UMCU and HMC consisted of chemical prophylaxis. From these patients, 72% at UMCU and 47% at HMC (p < 0.001) were treated within 48 h after arrival. At UMCU, 4 patients (1.4%) (PE = 3, DVT = 1) and HMC 37 patients (3.8%) (PE = 22, DVT = 16; p = 0.06) developed a VTE. At UMCU, a greater percent of patients with VTE had traumatic brain injuries (TBI). Most VTE occurred despite adequate prophylaxis being given (75% UMCU and 81% HMC). Hemorrhagic complications occurred in, respectively, 4 (1.4%) and 10 (1%) patients in UMCU and HMC (p = 0.570). After adjustment for age, ISS, HLOS, and injury type, no significant difference was demonstrated in UMCU compared to HMC for the development of VTE, OR 2.397, p = 0.102 and hemorrhagic complications, OR 0. 586, p = 0.383.

CONCLUSIONS

A more early commencement protocol resulted in almost twice as much chemical prophylaxis being started within the first 48 h in comparison with a more delayed initiation of treatment. Interestingly, most episodes of VTE developed while receiving recommended prophylaxis. Early chemical thromboprophylaxis did not significantly increase the bleeding complications and it appears to be safe to start early.

Ultrasound Guidance for Central Venous Access: Current Evidence and Clinical Recommendations

Ultrasound-guided central line placement has been shown to decrease the number of needle puncture attempts, complication, and failure rates. In order to obtain successful central access, it is important to have adequate cognitive knowledge, workflow understanding, and manual dexterity to safely execute this invasive procedure. The operator should also be familiar with the anatomical variations, equipment operations, and potential complications and their prevention. In this article, we present a detailed review of ultrasound-guided central venous access. It includes a description of anatomy, operative technique, equipment operation, and techniques for specific situations. We describe the use of ultrasound guidance to avoid and identify various complications associated with this procedure. We have also reviewed recent recommendations and guidelines for the use of ultrasound for central venous access and the current evidence pertaining to the recommendations for the expected level of training, methodology, and metrics for establishing competency.

The Role of Chemoprophylactic Agents in Modulating Platelet Aggregability After Traumatic Brain Injury

BACKGROUND

The pathophysiology behind the subacute but persistent hypercoagulable state after traumatic brain injury (TBI) is poorly understood but contributes to morbidity induced by venous thromboembolism. Because platelets and their microvesicles have been hypothesized to play a role in post-traumatic hypercoagulability, administration of commonly used agents may ameliorate this coagulability. We hypothesized that utilization of aspirin, ketorolac, amitriptyline, unfractionated heparin, or enoxaparin would modulate the platelet aggregation response after TBI.

METHODS

Concussive TBI was induced by weight drop. Mice were then randomized to receive aspirin, ketorolac, amitriptyline, heparin, enoxaparin, or saline control at 2 and 8 h after TBI. Mice were sacrificed at 6 or 24 h after injury to determine coagulability by rotational thromboelastometry (ROTEM), platelet function testing with impedance aggregometry, and microvesicle enumeration. Platelet sphingolipid metabolites were analyzed by mass spectrometry.

RESULTS

ROTEM demonstrated increased platelet contribution to maximum clot firmness at 6 h after TBI in mice that received aspirin or amitriptyline, but this did not persist at 24 h. By contrast, adenosine diphosphate- and arachidonic acid-induced platelet aggregation at 6 h was significantly lower in mice receiving ketorolac, aspirin, and amitriptyline compared with mice receiving saline at 6 h after injury and only arachidonic acid-initiated platelet aggregation was decreased by aspirin at 24 h. There were no differences in microvesicle production at either time point. Platelet sphingosine-1-phosphate levels were decreased at 6 h in the group receiving amitriptyline and increased at 24 h along with platelet ceramide levels at 24 h in the amitriptyline group.

CONCLUSION

After TBI, amitriptyline decreased platelet aggregability and increased contribution to clot in a manner similar to aspirin. The amitriptyline effects on platelet function and sphingolipid metabolites may represent a possible role of the acid sphingomyelinase in the hypercoagulability observed after injury. In addition, inhibition of platelet reactivity may be an underappreciated benefit of low molecular weight heparins, such as enoxaparin.

Optimizing Lower Extremity Duplex Ultrasound Screening After Traumatic Injury

BACKGROUND

The risk assessment profile (RAP) score has been used to determine patients who would most benefit from lower extremity duplex ultrasound screening (LEDUS). We hypothesized that revising our LEDUS protocol to perform screening ultrasound examinations in patients with an RAP ≥8 within 48 h of admission would reduce the number of LEDUS performed without changing outcomes.

METHODS

A retrospective review was conducted on trauma patients admitted from July 1, 2014, to June 30, 2015, and July 1, 2016, to June 30, 2017. In 2014-2015, patients with an RAP score ≥5 underwent weekly LEDUS examinations starting on hospital day 4. In 2016-2017, the protocol was changed to start screening patients with an RAP score ≥8 by hospital day 2. Both protocols screened with weekly ultrasounds after the first examination. Demographic data, injury characteristics, LEDUS examination findings, chemoprophylaxis type, and venous thromboembolism incidence were collected.

RESULTS

A total of 602 patients underwent LEDUS examination in 2014-2015, whereas only 412 underwent LEDUS in 2016-2017. No significant difference was seen in the number of patients diagnosed with deep vein thrombosis (DVT) or pulmonary embolism. DVTs were most often identified on the first LEDUS examination in both cohorts. Of patients diagnosed with a DVT on an LEDUS examination, a significantly higher RAP score (12 versus 10), and a shorter time to first duplex (1 versus 3 d), and DVT diagnosis (2 versus 4 d) were observed in the 2016-2017 cohort. In patients diagnosed with a pulmonary embolism, no significant differences were demonstrated between cohorts.

CONCLUSIONS

Refinement of LEDUS protocols can decrease overutilization of hospital resources without compromising trauma patient outcomes.

Four-extremity venous duplex ultrasound for suspected deep venous thrombosis is an anachronism

BACKGROUND

Duplex ultrasound is the "gold standard" for diagnosis of acute deep venous thrombosis (DVT) because of its high specificity, sensitivity, safety, and portability. However, unnecessary testing epitomizes inefficient use of scarce health care resources. Here we hypothesize that the majority of simultaneous four-extremity duplex ultrasound (FED) examinations are unnecessary. By analyzing clinical factors of patients with acute DVT found on FED, we aimed to identify a subset of high-risk patients who may have a valid indication for four-extremity testing.

METHODS

We retrospectively reviewed all venous duplex ultrasound examinations performed in our Intersocietal Accreditation Commission-accredited vascular laboratory from January 1, 2009, to December 31, 2016. Patients with duplex ultrasound scans of all four limbs were included. DVT risk factors and indication for duplex ultrasound examination were recorded. The primary outcome was finding of acute DVT.

RESULTS

There were 188 patients who met our search criteria, of whom 31 patients (16.5%) had acute DVT (11 upper extremity, 16 lower extremity, and 4 upper and lower extremity). Fever of unknown origin (FUO) was the main indication for requesting FED (53.7%). Patients who underwent FED for FUO had a significantly lower likelihood of DVT (odds ratio, 0.21; P = .01). DVT was rarely the proximate cause (<1% of all cases) as follow-up culture results and clinical course most often revealed other sources of fever. Only patients with an upper extremity central venous catheter (CVC; n = 103) with at least two associated risk factors had an upper extremity DVT, which was usually line associated (93%). Only patients with at least two associated risk factors had a lower extremity DVT.

CONCLUSIONS

FED for FUO is inefficient, given that DVT was rarely the proximate cause of fever. Acute upper extremity DVT was found only in patients with an upper extremity CVC, demonstrating that patients without upper extremity CVC do not benefit from upper extremity duplex ultrasound examination. Upper extremity DVT is usually line associated and dependent on the number of cumulative risk factors present, suggesting that only the extremity associated with the CVC in the right clinical context should be imaged. Lower extremity DVT is also dependent on the number of cumulative risk factors present, and testing should be reserved for patients according to the clinical context. Our results indicate that a restrictive strategy can reduce testing inefficiency and health care cost without compromising patients' safety.