Thromboembolic Prophylaxis with Heparin in Patients with Blunt Solid Organ Injuries Undergoing Non-operative Treatment

When is it safe to start venous thromboembolism prophylaxis after blunt solid organ injury? A prospective American Association for the Surgery of Trauma multi-institutional trial

BACKGROUND

The optimal time to initiate venous thromboembolism (VTE) chemoprophylaxis (VTEp) after blunt solid organ injury remains controversial, as VTE mitigation must be balanced against bleeding promulgation. Evidence from primarily small, retrospective, single-center work suggests that VTEp ≤48 hours is safe and effective. This study was undertaken to validate this clinical practice.

METHODS

Blunt trauma patients presenting to 19 participating trauma centers in North America were screened over a 1-year study period beginning between August 1 and October 1, 2021. Inclusions were age older than 15 years; ≥1 liver, spleen, or kidney injury; and initial nonoperative management. Exclusions were transfers, emergency department death, pregnancy, and concomitant bleeding disorder/anticoagulation/antiplatelet medication. A priori power calculation stipulated the need for 1,158 patients. Time of VTEp initiation defined study groups: Early (≤48 hours of admission) versus Late (>48 hours). Bivariate and multivariable analyses compared outcomes.

RESULTS

In total, 1,173 patients satisfied the study criteria with 571 liver (49%), 557 spleen (47%), and 277 kidney injuries (24%). The median patient age was 34 years (interquartile range, 25-49 years), and 67% (n = 780) were male. The median Injury Severity Score was 22 (interquartile range, 14-29) with Abbreviated Injury Scale Abdomen score of 3 (interquartile range, 2-3), and the median American Association for the Surgery of Trauma grade of solid organ injury was 2 (interquartile range, 2-3). Early VTEp patients (n = 838 [74%]) had significantly lower rates of VTE (n = 28 [3%] vs. n = 21 [7%], p = 0.008), comparable rates of nonoperative management failure (n = 21 [3%] vs. n = 12 [4%], p = 0.228), and lower rates of post-VTEp blood transfusion (n = 145 [17%] vs. n = 71 [23%], p = 0.024) when compared with Late VTEp patients (n = 301 [26%]). Late VTEp was independently associated with VTE (odd ratio, 2.251; p = 0.046).

CONCLUSION

Early initiation of VTEp was associated with significantly reduced rates of VTE with no increase in bleeding complications. Venous thromboembolism chemoprophylaxis initiation ≤48 hours is therefore safe and effective and should be the standard of care for patients with blunt solid organ injury.

LEVEL OF EVIDENCE

Therapeutic and Care Management; Level III.

Timing of venous thromboembolism prophylaxis initiation after injury: Findings from the consensus conference to implement optimal VTE prophylaxis in trauma

ABSTRACT

Optimizing prophylaxis against venous thromboembolic events (VTEs) is a critical issue in the care of injured patients. Although these patients are at significant risk of developing VTE, they also present competing concerns related to exacerbation of bleeding from existing injuries. Especially after high-risk trauma, including injuries to the abdominal solid organs, brain, and spine, trauma providers must delineate the time period in which VTE prophylaxis successfully reduces VTE rates without encouraging bleeding. Although existing data are primarily retrospective in nature and further study is required, literature supports early VTE chemoprophylaxis initiation even for severely injured patients. Early initiation is most frequently defined as <48 hours from admission but varies from <24 hours to 72 hours and occasionally refers to time from initial trauma. Prior to chemical VTE prophylaxis initiation in patients at risk for bleeding, an observation period is necessary during which injuries must show themselves to be hemostatic, either clinically or radiographically. In the future, prospective examination of optimal timing of VTE prophylaxis is necessary. Further study of specific subsets of trauma patients will allow for development of effective VTE mitigation strategies based upon collective risks of VTE and hemorrhage progression.

Thromboprophylaxis Timing After Blunt Solid Organ Injury: A Systematic Review and Meta-analysis

INTRODUCTION

Trauma patients with blunt abdominal solid organ injuries are at high risk for venous thromboembolism (VTE), but the optimal time to safely administer chemical thromboprophylaxis is controversial, especially for patients who are managed nonoperatively due to increased risk of hemorrhage. We sought to compare failure of nonoperative management (NOM) and VTE events based on timing of chemical thromboprophylaxis initiation.

METHODS

A systematic review was conducted in PubMed and Embase databases. Studies were included if they evaluated timing of initiation of chemical thromboprophylaxis in trauma patients who underwent NOM of blunt solid organ injuries. Outcomes included failure of NOM and incidence of VTE. A random-effects meta-analysis was performed comparing patients who received late (>48 h) versus early thromboprophylaxis initiation.

RESULTS

Twelve retrospective cohort studies, comprising 21,909 patients, were included. Three studies, including 6375 patients, provided data on adjusted outcomes. Pooled adjusted analysis demonstrated no difference in failure of NOM in patients receiving late versus early thromboprophylaxis (odds ratio [OR] 0.92, 95% confidence interval [CI]:0.4-2.14). When including all unadjusted studies, even those at high risk of bias, there remained no difference in failure of NOM (OR 1.16, 95% CI:0.72-1.86). In the adjusted analysis for VTE events, which had 6259 patients between two studies, patients receiving late chemical thromboprophylaxis had a higher risk of VTE compared with those who received early thromboprophylaxis (OR 1.89, 95% CI:1.15-3.12).

CONCLUSIONS

Based on current observational evidence, initiation of prophylaxis before 48 h is associated with lower VTE rates without higher risk of failure of NOM.

Timing of venous thromboembolism chemoprophylaxis using objective hemoglobin criteria in blunt solid organ injury

BACKGROUND

The purpose of this study was to evaluate the safety and efficacy of early venous thromboembolism (VTE) chemoprophylaxis following blunt solid organ injury.

METHODS

A retrospective review of patients was performed for patients with blunt solid organ injury between 2009-2019. Enoxaparin was initiated when patients had <1g/dl Hemoglobin decline over a 24 h period. These patients were then categorized by initiation: ≤48 h and >48 h.

RESULTS

There were 653 patients: 328 (50.2%) <48 h and 325 (49.8%) ≥48 h. Twenty-nine (4.4%) developed VTE. Patients in ≥48 h group suffered more frequent VTE events (6.5% vs 2.4%, p = 0.021). Non-operative failure occurred in 6 patients (1.9%) in ≥48 h group, and 5 patients (1.5%) < 48 h group. Blood transfusion following chemophrophylaxis initiation was required in 69 (21.3%) in ≥48 h group, and 46 (14.0%) in < 48 h group, occurring similarly between groups (p=0.021).

CONCLUSION

Stable hemoglobin in the first 24 h is an efficacious, objective measure that allows early initiation of VTE chemoprophylaxis in solid organ injury. This practice is associated with earlier initiation of and fewer VTE events.

Follow-up strategies for patients with splenic trauma managed non-operatively: the 2022 World Society of Emergency Surgery consensus document

Background

In 2017, the World Society of Emergency Surgery published its guidelines for the management of adult and pediatric patients with splenic trauma. Several issues regarding the follow-up of patients with splenic injuries treated with NOM remained unsolved.

Methods

Using a modified Delphi method, we sought to explore ongoing areas of controversy in the NOM of splenic trauma and reach a consensus among a group of 48 international experts from five continents (Africa, Europe, Asia, Oceania, America) concerning optimal follow-up strategies in patients with splenic injuries treated with NOM.

Results

Consensus was reached on eleven clinical research questions and 28 recommendations with an agreement rate ≥ 80%. Mobilization after 24 h in low-grade splenic trauma patients (WSES Class I, AAST Grades I–II) was suggested, while in patients with high-grade splenic injuries (WSES Classes II–III, AAST Grades III–V), if no other contraindications to early mobilization exist, safe mobilization of the patient when three successive hemoglobins 8 h apart after the first are within 10% of each other was considered safe according to the panel. The panel suggests adult patients to be admitted to hospital for 1 day (for low-grade splenic injuries—WSES Class I, AAST Grades I–II) to 3 days (for high-grade splenic injuries—WSES Classes II–III, AAST Grades III–V), with those with high-grade injuries requiring admission to a monitored setting. In the absence of specific complications, the panel suggests DVT and VTE prophylaxis with LMWH to be started within 48–72 h from hospital admission. The panel suggests splenic artery embolization (SAE) as the first-line intervention in patients with hemodynamic stability and arterial blush on CT scan, irrespective of injury grade. Regarding patients with WSES Class II blunt splenic injuries (AAST Grade III) without contrast extravasation, a low threshold for SAE has been suggested in the presence of risk factors for NOM failure. The panel also suggested angiography and eventual SAE in all hemodynamically stable adult patients with WSES Class III injuries (AAST Grades IV–V), even in the absence of CT blush, especially when concomitant surgery that requires change of position is needed. Follow-up imaging with contrast-enhanced ultrasound/CT scan in 48–72 h post-admission of trauma in splenic injuries WSES Class II (AAST Grade III) or higher treated with NOM was considered the best strategy for timely detection of vascular complications.

Conclusion

This consensus document could help guide future prospective studies aiming at validating the suggested strategies through the implementation of prospective trauma databases and the subsequent production of internationally endorsed guidelines on the issue.

Optimal timing of venous thromboembolic chemoprophylaxis initiation following blunt solid organ injury: meta-analysis and systematic review

PURPOSE

The need to prevent venous thromboembolism (VTE) following blunt solid organ injury must be balanced against the concern for exacerbation of hemorrhage. The optimal timing for initiation of VTE chemoprophylaxis is not known. The objective was to determine the safety and efficacy of early (≤ 48 h) VTE chemoprophylaxis initiation following blunt solid organ injury.

METHODS

An electronic search was performed of medical libraries for English language studies on timing of VTE chemoprophylaxis initiation following blunt solid organ injury published from inception to April 2020. Included studies compared early (≤ 48 h) versus late (> 48 h) initiation of VTE chemoprophylaxis in adults with blunt splenic, liver, and/or kidney injury. Estimates were pooled using random-effects meta-analysis. Odds ratios were utilized to quantify differences in failure of nonoperative management, need for blood transfusion and rates of VTE.

RESULTS

The search identified 2,111 studies. Of these, ten studies comprising 14,675 patients were included. All studies were non-randomized and only one was prospective. The overall odds of failure of nonoperative management were no different between early and late groups, OR 1.09 (95%CI 0.92-1.29). Similarly, there was no difference in the need for blood transfusion either during overall hospital stay, OR 0.91 (95%CI 0.70-1.18), or post prophylaxis initiation, OR 1.23 (95%CI 0.55-2.73). There were significantly lower odds of VTE when patients received early VTE chemoprophylaxis, OR 0.51 (95%CI 0.33-0.81).

CONCLUSIONS

Patients undergoing nonoperative management for blunt solid organ injury can be safely and effectively prescribed early VTE chemoprophylaxis. This results in significantly lower VTE rates without demonstrable harm.

Timing of pharmacologic venous thromboembolism prophylaxis initiation for trauma patients with nonoperatively managed blunt abdominal solid organ injury: a systematic review and meta-analysis

Background

Blunt abdominal solid organ injury is common and is often managed nonoperatively. Clinicians must balance risk of both hemorrhage and thrombosis. The optimal timing of pharmacologic venous thromboembolism prophylaxis (VTEp) initiation in this population is unclear. The objective was to evaluate early (< 48 h) compared to late initiation of VTEp in adult trauma patients with blunt abdominal solid organ injury managed nonoperatively.

Methods

Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials were searched from inception to March 2021. Studies comparing timeframes of VTEp initiation were considered. The primary outcome was failure of nonoperative management (NOM) after VTEp initiation. Secondary outcomes included risk of transfusion, other bleeding complications, risk of deep vein thrombosis (DVT) and pulmonary embolism, and mortality.

Results

Ten cohort studies met inclusion criteria, with a total of 4642 patients. Meta-analysis revealed a statistically significant increase in the risk of failure of NOM among patients receiving early VTEp (OR 1.76, 95% CI 1.01–3.05, p = 0.05). There was no significant difference in risk of transfusion. Odds of DVT were significantly lower in the early group (OR 0.36, 95% CI 0.22–0.59, p < 0.0001). There was no difference in mortality (OR 1.50, 95% CI 0.82–2.75, p = 0.19). All studies were at serious risk of bias due to confounding.

Conclusions

Initiation of VTEp earlier than 48 h following hospitalization is associated with an increased risk of failure of NOM but a decreased risk of DVT. Absolute failure rates of NOM are low. Initiation of VTEp at 48 h may balance the risks of bleeding and VTE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13017-022-00423-1.

Early initiation of thromboembolic prophylaxis in critically ill trauma patients with high-grade blunt liver and splenic lacerations is not associated with increased rates of failure of non-operative management

Background

Non-operative management (NOM) is the current standard of care of hemodynamically stable patients with traumatic blunt solid abdominal organ injuries. Guidelines do not define the optimal timing of initiation of venous thromboembolism (VTE) prophylaxis in this population, and fear of failure of NOM may lead to delayed initiation of prophylaxis specifically in patients with high-grade injuries.

Methods

This was a single-center, retrospective study of patients with high-grade (AAST grades ≥3) blunt liver and splenic lacerations presenting to our level 1 trauma center between January 2010 and October 2017. Patients were divided into groups based on timing of low-molecular weight heparin (LMWH) initiation for VTE prophylaxis. The primary outcome was rate of failure of NOM, defined as the need for interventional radiology or surgical intervention for management of abdominal organ bleeding. Secondary outcomes included rates of VTE, lengths of ICU and hospital stay, and in-hospital mortality.

Results

A total of 207 patients with high-grade blunt liver and splenic injuries undergoing an initial attempt at NOM were identified. The distribution of grades 3, 4, and 5 liver and splenic injuries were similar across all groups. Overall, 55.5% of patients received LMWH during their index admission. Early administration of LMWH was not associated with a statistically significant increased risk of failure of NOM ( p = 0.054). Rates of VTE and in-hospital mortality were similar.

Conclusions

Early initiation of VTE prophylaxis was not associated with an increased rate of failure of NOM in patients with high-grade blunt abdominal organ injuries in patients who survived 24 h post-admission and did not require massive transfusion; however, the study was likely underpowered to detect a difference among groups due to small sample size.

Effect of Prophylactic Embolization on Patients With Blunt Trauma at High Risk of Splenectomy: A Randomized Clinical Trial

Importance

Splenic arterial embolization (SAE) improves the rate of spleen rescue, yet the advantage of prophylactic SAE (pSAE) compared with surveillance and then embolization only if necessary (SURV) for patients at high risk of spleen rupture remains controversial.

Objective

To determine whether the 1-month spleen salvage rate is better after pSAE or SURV.

Design, Setting, and Participants

In this randomized clinical trial conducted between February 6, 2014, and September 1, 2017, at 16 institutions in France, 133 patients with splenic trauma at high risk of rupture were randomized to undergo pSAE or SURV. All analyses were performed on a per-protocol basis, as well as an intention-to-treat analysis for specific events.

Interventions

Prophylactic SAE, preferably using an arterial approach via the femoral artery, or SURV.

Main Outcomes and Measures

The primary end point was an intact spleen or a spleen with at least 50% vascularized parenchyma detected on an arterial computed tomography scan at 1 month after trauma, assessed by senior radiologists masked to the treatment group. Secondary end points included splenectomy and pseudoaneurysm, secondary SAE after inclusion, complications, length of hospital stay, quality-of-life score, and length of time off work or studies during the 6-month follow-up.

Results

A total of 140 patients were randomized, and 133 (105 men [78.9%]; median age, 30 years [interquartile range, 23-47 years]) were retained in the study. For the primary end point, data from 117 patients (57 who underwent pSAE and 60 who underwent SURV) could be analyzed. The number of patients with at least a 50% viable spleen detected on a computed tomography scan at month 1 was not significantly different between the pSAE and SURV groups (56 of 57 [98.2%] vs 56 of 60 [93.3%]; difference, 4.9%; 95% CI, -2.4% to 12.1%; P = .37). By the day 5 visit, there were significantly fewer splenic pseudoaneurysms among patients in the pSAE group than in the SURV group (1 of 65 [1.5%] vs 8 of 65 [12.3%]; difference, -10.8%; 95% CI, -19.3% to -2.1%; P = .03), significantly fewer secondary embolizations among patients in the pSAE group than in the SURV group (1 of 65 [1.5%] vs 19 of 65 [29.2%]; difference, -27.7%; 95% CI, -41.0% to -15.9%; P < .001), and no difference in the overall complication rate between the pSAE and SURV groups (19 of 65 [29.2%] vs 27 of 65 [41.5%]; difference, -12.3%; 95% CI, -28.3% to 4.4%; P = .14). Between the day 5 and month 1 visits, the overall complication rate was not significantly different between the pSAE and SURV groups (11 of 59 [18.6%] vs 12 of 63 [19.0%]; difference, -0.4%; 95% CI, -14.4% to 13.6%; P = .96). The median length of hospitalization was significantly shorter for patients in the pSAE group than for those in the SURV group (9 days [interquartile range, 6-14 days] vs 13 days [interquartile range, 9-17 days]; P = .002).

Conclusions and Relevance

Among patients with splenic trauma at high risk of rupture, the 1-month spleen salvage rate was not statistically different between patients undergoing pSAE compared with those receiving SURV. In view of the high proportion of patients in the SURV group needing SAE, both strategies appear defendable.

Trial Registration

ClinicalTrials.gov Identifier: NCT02021396.

Venous thromboembolism prophylaxis in the trauma intensive care unit: an American Association for the Surgery of Trauma Critical Care Committee Clinical Consensus Document

Venous thromboembolism (VTE) is a potential sequela of injury, surgery, and critical illness. Patients in the Trauma Intensive Care Unit are at risk for this condition, prompting daily discussions during patient care rounds and routine use of mechanical and/or pharmacologic prophylaxis measures. While VTE rightfully garners much attention in clinical patient care and in the medical literature, optimal strategies for VTE prevention are still evolving. Furthermore, trauma and surgical patients often have real or perceived contraindications to prophylaxis that affect the timing of preventive measures and the consistency with which they can be applied. In this Clinical Consensus Document, the American Association for the Surgery of Trauma Critical Care Committee addresses several practical clinical questions pertaining to specific or unique aspects of VTE prophylaxis in critically ill and injured patients.

Timing of thromboprophylaxis in patients with blunt abdominal solid organ injuries undergoing nonoperative management

BACKGROUND

Decision making regarding the optimal timing for initiating thromboprophylaxis in patients with blunt abdominal solid organ injuries (BSOIs) remains ill-defined, with no guidelines defining optimal timing. In this study, we aimed to evaluate the relationship of the timing of thromboprophylaxis with thromboembolic and bleeding complications in the setting of BSOIs.

METHODS

A retrospective analysis of the Trauma Quality Improvement Program database was performed between 2013 and 2016. All patients with isolated BSOIs (liver, spleen, pancreas, or kidney, Abbreviated Injury Scale score, <3 in other regions) who underwent initial nonoperative management (NOM) were included. Patients were divided into three groups (early, <48 hours; intermediate, 48-72 hours; and late, >72 hours) based on timing of thromboprophylaxis initiation. Primary outcomes were rates of thromboembolism and bleeding after thromboprophylaxis initiation.

RESULTS

Of the 25,118 patients with isolated BSOIs, 3,223 met the inclusion criteria (age, 38.7 ± 17.3 years; males, 2.082 [64.6%]), among which 1,832 (56.8%) received early thromboprophylaxis, 703 (21.8%) received intermediate thromboprophylaxis, and 688 (21.4%) received late thromboprophylaxis. Late thromboprophylaxis initiation was independently associated with a higher likelihood of both deep vein thrombosis (odds ratio [OR], 3.15; 95% confidence interval [CI], 1.68-5.91, p < 0.001) and pulmonary embolism (OR, 4.29; 95% CI, 1.95-9.42; p < 0.001). Intermediate thromboprophylaxis initiation was independently associated with a higher likelihood of deep venous thrombosis (OR, 2.38; 95% CI, 1.20-4.74; p = 0.013), but not pulmonary embolism (p = 0.960) compared with early initiation. Early (but not intermediate) thromboprophylaxis initiation was independently associated with a higher likelihood of bleeding (OR, 2.05; 95% CI, 1.11-2.18; p = 0.023), along with a history of diabetes mellitus, splenic, and high-grade liver injuries.

CONCLUSION

Early thromboprophylaxis should be considered in patients with BSOIs undergoing nonoperative management who are at low likelihood of bleeding. An intermediate delay (48-72 hours) of thromboprophylaxis should be considered for patients with diabetes mellitus, splenic injuries, and Grades 3 to 5 liver injuries.

LEVEL OF EVIDENCE

Therapeutic, Level IV.

Is early chemical thromboprophylaxis in patients with solid organ injury a solid decision?

BACKGROUND

The optimal time to initiate chemical thromboprophylaxis (CTP) in patients who have undergone nonoperative management (NOM) of blunt solid organ injuries (SOI) remains controversial. The aim of our study was to assess the impact of early initiation of CTP in patients with blunt abdominal SOIs.

METHODS

We performed a 2-year (2013-2014) retrospective analysis of American College of Surgeons Trauma Quality Improvement Program. We included all adult trauma patients (age, ≥ 18 years) with blunt SOI who underwent NOM. Patients were stratified into three groups based on timing of CTP (early, ≤48 hours of injury; late, >48 hours of injury,; and no prophylaxis group). Our primary outcomes were rates of failure of NOM, pRBC transfusion, and mortality. Our secondary outcomes were the rate of venous thromboembolic (VTE) events (i.e., deep venous thrombosis [DVT] and/or pulmonary embolism [PE]) and length of stay.

RESULTS

A total of 36,187 patients met the inclusion criteria. Mean age was 49.5 ± 19 years and 36% of patients received CTP (early, 37% (n = 4,819) versus late, 63% (n = 8,208)). After controlling for confounders, patients receiving early CTP had lower rates of DVT (p = 0.01) and PE (p = 0.01) compared with the no prophylaxis and late CTP groups. There was no difference between the three groups regarding the postprophylaxis pRBC transfusions, failure of NOM, and mortality.

CONCLUSION

Our results suggest that in patients undergoing NOM of blunt abdominal SOI, early initiation of CTP should be considered. It is associated with decreased rates of DVT and PE, with no significant difference in post prophylaxis pRBC transfusion, failure of nonoperative management, and mortality.

LEVEL OF EVIDENCE

Therapeutic, level V.

It's sooner than you think: Blunt solid organ injury patients are already hypercoagulable upon hospital admission - Results of a bi-institutional, prospective study

INTRODUCTION

The optimal time to initiate venous thromboembolism (VTE) chemoprophylaxis in blunt solid organ injury (BSOI) patients is debated. We hypothesize that 1) BSOI patients are hypercoagulable within 12 h of injury and 2) hypercoagulability dominates in patients who develop clot complications (CC).

MATERIAL AND METHODS

This is a prospective study of BSOI patients admitted to two Level-1 Trauma Centers' trauma intensive care units (ICU). Serial kaolin thrombelastography (TEG) and tissue plasminogen activator (tPA)-challenge TEGs were performed. CC included VTE and cerebrovascular accidents.

RESULTS

On ICU admission, all patients (n = 95) were hypercoagulable, 58% were in fibrinolysis shutdown, and 50% of patients were tPA-resistant. Twelve patients (13%) developed CC. Compared to those without CC, they demonstrated decreased fibrinolysis at 12 h and higher clot strength at 48 h CONCLUSIONS: BSOI patients are universally hypercoagulable upon ICU admission. VTE chemoprophylaxis should be started immediately in BSOI patients with hypercoagulability on TEG.

BET 2: Is early chemical thromboprophylaxis safe in patients with blunt trauma solid organ injury (SOI) undergoing non-operative management (NOM)?

A short cut review was carried out to establish whether chemical thromboprophylaxis was a safe early intervention in patients with solid organ injury that is being managed non-operatively. Eight papers presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. It is concluded that there is inadequate evidence assessing safety of low molecular weight heparin (LMWH) within 24 hours of trauma. The current available evidence does suggest that administration of LMWH within 48 hours is safe in non-operative management of patients who have sustained solid organ injury from blunt trauma.