A Stitch in Time Saves Clots: Venous Thromboembolism Chemoprophylaxis in Traumatic Brain Injury

Risk factors for thromboembolic complications in isolated severe head injury

PURPOSE

Patients with traumatic brain injury (TBI) are at high risk for venous thromboembolism (VTE). The aim of the present study is to identify factors independently associated with VTE events. Specifically, we hypothesized that the mechanism of penetrating head trauma might be an independent factor associated with increased VTE events when compared with blunt head trauma.

METHODS

The ACS-TQIP database (2013-2019) was queried for all patients with isolated severe head injuries (AIS 3-5) who received VTE prophylaxis with either unfractionated heparin or low-molecular-weight heparin. Transfers, patients who died within 72 h and those with a hospital length of stay < 48 h were excluded. Multivariable analysis was used as the primary analysis to identify independent risk factors for VTE in isolated severe TBI.

RESULTS

A total of 75,570 patients were included in the study, 71,593 (94.7%) with blunt and 3977 (5.3%) with penetrating isolated TBI. Penetrating trauma mechanism (OR 1.49, CI 95% 1.26-1.77), increasing age (age 16-45: reference; age > 45-65: OR 1.65, CI 95% 1.48-1.85; age > 65-75: OR 1.71, CI 95% 1.45-2.02; age > 75: OR 1.73, CI 95% 1.44-2.07), male gender (OR 1.53, CI 95% 1.36-1.72), obesity (OR 1.35, CI 95% 1.22-1.51), tachycardia (OR 1.31, CI 95% 1.13-1.51), increasing head AIS (AIS 3: reference; AIS 4: OR 1.52, CI 95% 1.35-1.72; AIS 5: OR 1.76, CI 95% 1.54-2.01), associated moderate injuries (AIS = 2) of the abdomen (OR 1.31, CI 95% 1.04-1.66), spine (OR 1.35, CI 95% 1.19-1.53), upper extremity (OR 1.16, CI 95% 1.02-1.31), lower extremity (OR 1.46, CI 95% 1.26-1.68), craniectomy/craniotomy or ICP monitoring (OR 2.96, CI 95% 2.65-3.31) and pre-existing hypertension (OR 1.18, CI 95% 1.05-1.32) were identified as independent risk factors for VTE complications in isolated severe head injury. Increasing GCS (OR 0.93, CI 95% 0.92-0.94), early VTE prophylaxis (OR 0.48, CI 95% 0.39-0.60) and LMWH compared to heparin (OR 0.74, CI 95% 0.68-0.82) were identified as protective factors for VTE complications.

CONCLUSION

The identified factors independently associated with VTE events in isolated severe TBI need to be considered in VTE prevention measures. In penetrating TBI, an even more aggressive VTE prophylaxis management may be justified as compared to that in blunt.

Analysis of fibrinolytic shutdown in trauma patients with traumatic brain injury

BACKGROUND

Coagulation profiles following major trauma vary depending on injury pattern and degree of shock. The physiologic mechanisms involved in coagulation function at any given time are varied and remain poorly understood. Thromboelastography (TEG) has been used evaluate coagulation profiles in the trauma population with some reports demonstrating a spectrum of fibrinolysis to fibrinolytic shutdown on initial presentation. The objective of this study was to evaluate the fibrinolytic profile of patients with TBI using thromboelastography (TEG). We hypothesized that patients with TBI would demonstrate low fibrinolytic activity.

METHODS

All trauma activations at an ACS-verified level 1 trauma center received a TEG analysis upon arrival from December 2019 to June 2021. A retrospective review of the results and outcomes was conducted, and TBI patients were compared to patients without TBI. Linear regression was used to evaluate the effect of patient and injury factors on fibrinolysis. Hyperfibrinolysis was defined as LY30 ​> ​7.7%, physiologic fibrinolysis as LY30 0.6-7.7%, and fibrinolytic shutdown as LY30 ​< ​0.6%.

RESULTS

A total of 1369 patients received an admission TEG analysis. Patients with TBI had a significantly higher median ISS (16 vs. 8, p ​< ​0.001), lower median admission Glasgow Coma Scale (14 vs. 15, p ​< ​0.001), longer intensive care unit length of stay (3 vs. 2 days, p ​< ​0.0001), increased ventilator days (216 vs. 183, p ​< ​0.001), higher mortality (14.6% vs. 5.1%, p ​< ​0.001), but lower shock index (0.6 vs. 0.7, p ​< ​0.0001) compared to those without TBI. Median LY30 was found to be decreased in the TBI group (0.1 vs. 0.2, p ​= ​0.0006). Patients with TBI were found to have a higher rate of fibrinolytic shutdown compared those without TBI (68.7% vs. 63.5%, p ​= ​0.054). ISS, sex, and shock index were found to be predictive of LY30 on linear regression, but TBI was not (Β: 0.09, SE: 0.277, p ​= ​0.745). The rate of DVT/PE did not appear to be elevated in patients with TBI (0.8%) and without TBI (1.2%).

CONCLUSIONS

Trauma patients with and without TBI were found to have high rates of fibrinolytic shutdown. Although there was a high incidence of fibrinolytic shutdown, it did not appear to have an impact on the rate of thrombotic complications. The clinical significance of these results is unclear and differs significantly from recent reports which demonstrated that TBI is associated with a 25% rate of fibrinolytic shutdown. Further investigation is needed to better define the fibrinolytic pathway in patients with trauma and TBI to develop optimal treatment algorithms.

Early venous thromboembolism prophylaxis in patients with trauma intracranial hemorrhage: Analysis of the prospective multicenter Consortium of Leaders in Traumatic Thromboembolism study

BACKGROUND

The optimal time to initiate venous thromboembolism prophylaxis (VTEp) for patients with intracranial hemorrhage (ICH) is controversial and must balance the risks of VTE with potential progression of ICH. We sought to evaluate the efficacy and safety of early VTEp initiation after traumatic ICH.

METHODS

This is a secondary analysis of the prospective multicenter Consortium of Leaders in the Study of Thromboembolism study. Patients with head Abbreviated Injury Scale score of > 2 and with immediate VTEp held because of ICH were included. Patients were divided into VTEp ≤ or >48 hours and compared. Outcome variables included overall VTE, deep vein thrombosis (DVT), pulmonary embolism, progression of intracranial hemorrhage (pICH), or other bleeding events. Univariate and multivariate logistic regressions were performed.

RESULTS

There were 881 patients in total; 378 (43%) started VTEp ≤48 hours (early). Patients starting VTEp >48 hours (late) had higher VTE (12.4% vs. 7.2%, p = 0.01) and DVT (11.0% vs. 6.1%, p = 0.01) rates than the early group. The incidence of pulmonary embolism (2.1% vs. 2.2%, p = 0.94), pICH (1.9% vs. 1.8%, p = 0.95), or any other bleeding event (1.9% vs. 3.0%, p = 0.28) was equivalent between early and late VTEp groups. On multivariate logistic regression analysis, VTEp >48 hours (odds ratio [OR], 1.86), ventilator days >3 (OR, 2.00), and risk assessment profile score of ≥5 (OR, 6.70) were independent risk factors for VTE (all p < 0.05), while VTEp with enoxaparin was associated with decreased VTE (OR, 0.54, p < 0.05). Importantly, VTEp ≤48 hours was not associated with pICH (OR, 0.75) or risk of other bleeding events (OR, 1.28) (both p = NS).

CONCLUSION

Early initiation of VTEp (≤48 hours) for patients with ICH was associated with decreased VTE/DVT rates without increased risk of pICH or other significant bleeding events. Enoxaparin is superior to unfractionated heparin as VTE prophylaxis in patients with severe TBI.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Effectiveness of a Patient Education Bundle on Venous Thromboembolism Prophylaxis Administration by Sex

INTRODUCTION

Venous thromboembolism (VTE) is a frequent cause of preventable harm among hospitalized patients. Many prescribed prophylaxis doses are not administered despite supporting evidence. We previously demonstrated a patient-centered education bundle improved VTE prophylaxis administration broadly; however, patient-specific factors driving nonadministration are unclear. We examine the effects of the education bundle on missed doses of VTE prophylaxis by sex.

METHODS

We performed a post-hoc analysis of a nonrandomized controlled trial to evaluate the differences in missed doses by sex. Pre-intervention and intervention periods for patients admitted to 16 surgical and medical floors between 10/2014-03/2015 (pre-intervention) and 04/2015-12/2015 (intervention) were compared. We examined the conditional odds of (1) overall missed doses, (2) missed doses due to patient refusal, and (3) missed doses for other reasons.

RESULTS

Overall, 16,865 patients were included (pre-intervention 6853, intervention 10,012), with 2350 male and 2460 female patients (intervention), and 6373 male and 5682 female patients (control). Any missed dose significantly reduced on the intervention floors among male (odds ratio OR 0.55; 95% confidence interval CI, 0.44-0.70, P < 0.001) and female (OR 0.59; 95% CI, 0.47-0.73, P < 0.001) patients. Similar significant reductions ensued for missed doses due to patient refusal (P < 0.001). Overall, there were no sex-specific differences (P-interaction >0.05).

CONCLUSIONS

Our intervention increased VTE prophylaxis administration for both female and male patients, driven by decreased patient refusal. Patient education should be applicable to a wide range of patient demographics representative of the target group. To improve future interventions, quality improvement efforts should be evaluated based on patient demographics and drivers of differences in care.

Effects of Early Chemoprophylaxis in Traumatic Brain Injury and Risk of Venous Thromboembolism

BACKGROUND

The optimal timing to initiate venous thromboembolism (VTE) prophylaxis in patients with a traumatic brain injury (TBI) is still unknown. We designed a study to determine the effect that timing of initiation of VTE prophylaxis has on VTE rates in TBI patients.

METHODS

Patient records were obtained from 32 level 1 and 2 trauma centers in the Michigan Trauma Quality Improvement Program from 2008 to 2018. Overall, 5589 patients with a TBI were included and split into cohorts based on VTE prophylaxis initiation time. Outcomes included rate of VTE, mortality, and serious in-hospital complications.

RESULTS

There were nine patients (1.3%) in the <24 hour group with a VTE as compared to 36 (2.6%) in the 24-48 hour group, 51 (4.1%) in the 48-72 hour group, and 181 (8.1%) in the >72 hour group (P < .001). The adjusted odds of VTE were significantly greater in patients initiated within 48-72 hours (AOR 2.861, 95% CI 1.271-6.439) and >72 hours (AOR 3.963, 95% CI 1.824-8.612) compared to <24 hours. Patients that received VTE prophylaxis within 24 hours had similar rates of serious in-hospital complication as patients initiated within 24-48 hours (AOR .956, 95% CI .637-1.434) and 48-72 hour (AOR 1.132, 95% CI .757-1.692) but less than the >72 hour group (AOR 1.662, 95% CI 1.154-2.393) groups.

DISCUSSION

Patients initiated on VTE prophylaxis within 48 hours of presentation had lower incidence of VTE without a significant increase in serious complications.

TRAUMATIC BRAIN INJURY PROVOKES LOW FIBRINOLYTIC ACTIVITY IN SEVERELY INJURED PATIENTS

BACKGROUND

Traumatic brain injury (TBI) in combination with shock has been associated with hypocoagulability. However, recent data suggest that TBI itself can promote a systemic procoagulant state via the release of brain-derived extracellular vesicles. The objective of our study was to identify if TBI was associated with differences in thrombelastography (TEG) indices when controlling for other variables associated with coagulopathy following trauma. We hypothesized that TBI is independently associated with a less coagulopathic state.

METHODS

Prospective study including all highest-level trauma activations at an urban level 1 trauma center, from 2014-2020. TBI was defined as AIS Head ≥3. Blood samples were drawn at ED admission. Linear regression was used to assess the role of independent predictors on TIC. Models adjusted for ISS, shock (defined as ED SBP < 70, or ED SBP < 90 and ED HR > 108, or first hospital base deficit ≥10), and prehospital GCS.

RESULTS

Of the 1,023 patients included, 291 (28%) suffered a TBI. TBI patients more often were female (26% vs. 19%, p = 0.01), had blunt trauma (83% vs. 43%, p < 0.0001), shock (33% vs. 25%, p = 0.009), and higher median ISS (29 vs. 10, p < 0.0001). Fibrinolysis shutdown (25% vs. 18%) was more common in the TBI group (p < 0.0001). When controlled for the confounding effects of ISS and shock, the presence of TBI independently decreases LY30 (Beta estimate: - 0.16 ± 0.06, p = 0.004). This effect of TBI on LY30 persisted when controlling for sex and mechanism of injury in addition to ISS and shock (Beta estimate: -0.13 ± 0.06, p = 0.022).

CONCLUSIONS

TBI is associated with lower LY30 independent of shock, tissue injury, sex, and mechanism of injury. These findings suggest a propensity toward a less coagulopathic state in patients with TBI, possibly due to fibrinolysis shutdown. Tranexamic acid has been reported to improve outcomes following TBI. Our data suggest the mechanism may be independent of changes in fibrinolysis.

LEVEL OF EVIDENCE

Level III, Prognostic and Epidemiological.

Timing of venous thromboembolic pharmacological prophylaxis in traumatic combined subdural and subarachnoid hemorrhage

BACKGROUND

The combination of subdural and subarachnoid hemorrhage is the most common intracranial bleeding. The present study evaluated the timing and type of venous thromboembolic chemoprophylaxis (VTEp) for efficacy and safety in patients with blunt head trauma with combined acute subdural and subarachnoid hemorrhage.

METHODS

Patients with isolated combined acute subdural and subarachnoid hemorrhage were extracted from the ACS-TQIP database (2013-2017). After 1:1 cohort matching of patients receiving early prophylaxis (EP, ≤48 h) versus late prophylaxis (LP, >48 h) outcomes were compared with univariable and multivariable regression analysis.

RESULTS

Multivariable regression analysis identified EP as an independent protective factor for VTE complications (OR 0.468, CI 0.293-0.748) but not mortality (p = 0.485). The adjusted risk for delayed craniectomy was not associated with EP compared to LP (p = 0.283). The type of VTEp was not associated with VTE complications (p = 0.301), mortality (p = 0.391) or delayed craniectomy (p = 0.126).

CONCLUSIONS

Early VTEp (≤48 h) was associated with fewer VTE complications in patients and did not increase the risk for craniectomies in patients with combined acute subdural and subarachnoid hemorrhage.