Preliminary report on the safety of heparin for deep venous thrombosis prophylaxis after severe head injury

Management of heterotopic ossification and venous thromboembolism following acquired brain injury

OBJECTIVE

To evaluate the effectiveness of interventional strategies for the common complications of heterotopic ossification (HO) and venous thromboembolism (VTE) following acquired brain injury (ABI).

METHODS AND MAIN OUTCOMES

A systematic review of the literature from 1980-2005 was conducted focusing on interventions for HO and VTE in the ABI population. Nineteen studies examining a variety of treatment approaches were evaluated.

RESULTS

The majority of interventions are supported by limited evidence, defined as an absence of randomized controlled trials (RCTs). All of the treatment approaches for HO are supported with limited evidence. For VTE, there is moderate evidence, defined as at least one positive RCT, indicating that low-molecular-weight heparin is more effective than low-dose unfractionated heparin in preventing VTE, low-molecular-weight heparin is as effective and safe as unfractionated heparin for the prevention of pulmonary thromboembolism, low-molecular-weight heparin combined with compression stockings is more effective than compression stockings alone for the prevention of VTE and intermittent pneumatic compression devices are as effective as low-molecular-weight heparin for the prevention of VTE.

CONCLUSIONS

There are a variety of intervention and prophylactic strategies that have been postulated to treat and reduce the incidence of these complications, with the goal of improving rehabilitation outcomes. It is therefore important to investigate the efficacy of these treatment strategies to provide guidance for clinical practice based on the best available evidence.

Early Placement of Optional Vena Cava Filter in High-Risk Patients with Traumatic Brain Injury

OBJECTIVES

Patients sustaining severe trauma are at high risk for the development of venous thromboembolic events (VTE). Pharmacologic VTE prophylaxis may be contraindicated early after trauma due to potential bleeding complications. The purpose of this study was to evaluate safety and feasibility of early prophylactic vena cava filter (VCF) placement and subsequent retrieval in multiple injured patients with traumatic brain injury (TBI).

METHODS

Analysis of single-institution case series of consecutive patients who received a prophylactic VCF after severe TBI (Abbreviated Injury Scale, AiS ≥ 3) between August 2003 and October 2006.

RESULTS

A total of 34 optional VCF were prophylactically placed with a median delay of 1 day after trauma (range, 0-7 days). All patients had sustained multiple injuries (median Injury Severity Score 41, range, 18-59) with severe TBI (median AiS 4, range 3-5). Median age was 41 years (range, 17-67 years). Two patients had succumbed before potential filter retrieval. Of the remaining patients, 27 (84%) had their filters uneventfully retrieved between 11 and 32 days (median, 18 days) after placement with no retrieval-related morbidity. Five VCF (16%) were left permanently. In one patient (3%) early inferior vena cava occlusion and deep venous thrombosis occurred 14 days after VCF placement. Symptomatic pulmonary embolism was observed in one patient (3%) 5 days after VCF retrieval. Overall trauma-related mortality was 9%.

CONCLUSIONS

Early VCF placement may be of benefit for multiple injured patients with TBI when pharmacologic VTE prophylaxis is contraindicated. VCF retrieval is safe and feasible. Filter placement- and retrieval-related morbidity is low.

Incidence of venous thromboembolism in patients with traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) may be a risk factor for venous thromboembolism (VTE). This study was designed to review the incidence of VTE in critically injured patients with an isolated TBI using a standardized venous duplex color-flow Doppler imaging program and to compare it with the overall and high-risk trauma populations.

METHODS

Trauma patients who underwent lower-extremity surveillance color-flow Doppler imaging for VTE were identified. Analyses included patient demographics, characteristics of TBI, VTE risk factors, prophylaxis, incidence, location, and patient outcome.

RESULTS

A total of 5,787 patients were admitted during the study period. Of these, 539 (9%) were deemed high risk for VTE. The incidence of VTE in patients with isolated TBI (88, 16%) was 25%. All patients and the high-risk population had incidences of 2% and 17%, respectively.

CONCLUSIONS

The incidence of VTE in isolated TBI is greatest in patients with intraparenchymal hemorrhage. Early VTE prophylaxis is warranted in TBI patients.

Utility of once-daily dose of low-molecular-weight heparin to prevent venous thromboembolism in multisystem trauma patients

INTRODUCTION

Venous thromboembolism is a preventable cause of death in the severely injured patient. Low-molecular-weight heparins (LMWHs) have been recommended as effective, safe prophylactic agents. However, LMWH use remains controversial in patients at risk for bleeding, those with traumatic brain injury, and those undergoing multiple invasive or operative procedures. We hypothesized that a protocol utilizing once-daily LMWH prophylaxis in high-risk trauma patients, regardless of the need for invasive procedures, is feasible, safe, and effective.

METHODS

From August 1998 to August 2000, all patients admitted to our American College of Surgeons-verified Level I trauma facility following injury were evaluated for deep venous thrombosis (DVT) risk and prospectively followed. Patients at high risk for DVT, including those with stable intracranial injuries, were placed on our institutional protocol and prospectively followed. Patients on the protocol received daily injections of the LMWH, dalteparin; DVT screening was performed with duplex ultrasonography within 48 hours of admission and after 7 to 10 days after injury. Regimen compliance, bleeding complications, DVT rates, and pulmonary embolus (PE) rates were analyzed.

RESULTS

During the 2-year study period, 6247 trauma patients were admitted; 743 were considered at high risk for DVT. Most of the patients were men (72%), with a mean age of 38.7 years (range 15-89 years) and a mean injury severity score (ISS) of 19.5. Compliance with the daily regimen was maintained in 74% of patients. DVT was detected in 3.9% and PE in 0.8%. The wound complications rate was 2.7%, and the need for unexplained transfusions was 3%. There were no exacerbations of head injury following dalteparin initiation due to bleeding. There were 16 patient deaths; none was caused by PE or late hemorrhage.

CONCLUSIONS

Once-daily dosing of prophylactic LMWH dalteparin is feasible, safe, and effective in high-risk trauma patients. Our protocol allows one to "operate through" systemic prophylaxis and ensures timely prophylaxis for brain-injured and multisystem trauma patients.

Head-Injured Patients Who “Talk and Die”: The San Diego Perspective

BACKGROUND

Head-injured patients who "talk and die" are potentially salvageable, making their early identification important. This study uses a large, comprehensive database to explore risk factors for head-injured patients who deteriorate after their initial presentation.

METHODS

Patients with a head Abbreviated Injury Score (AIS) score of 3+ and a preadmission verbal Glasgow Coma Scale (GCS) score of 3+ were identified from our county trauma registry during a 16-year period. Survivors and nonsurvivors were compared with regard to demographics, initial clinical presentation, and various risk factors. Logistic regression was used to explore the impact of multiple factors on outcome, including the significance of a change in GCS score from field to arrival. In addition, patients were stratified by injury severity and hospital day of death to further define the relationship between outcome and multiple clinical variables.

RESULTS

A total of 7,443 patients were identified with head AIS 3+ and verbal GCS score 3+. Overall mortality was 6.1%. About one-third of deaths occurred on the first hospital day, with more than one-third occurring after hospital day 5. Logistic regression revealed an association between mortality and older age, more violent mechanisms of injury (fall, gunshot wound, pedestrian versus automobile), greater injury severity (higher head AIS and Injury Severity Score), lower GCS score, and hypotension. In addition, mortality was associated with a decrease in GCS score from field to arrival, the use of anticoagulants, and a diagnosis of pulmonary embolus. Two important groups of "talk-and-die" patients were identified. Early deaths occurred in younger patients with more critical extracranial injuries. Anticoagulant use was also an independent risk factor in these early deaths. Later deaths occurred in older patients with less significant extracranial injuries. Pulmonary embolus also appeared to be an important contributor to late mortality.

CONCLUSIONS

More severe injuries and use of anticoagulants are independent risk factors for early death in potentially salvageable traumatic brain injury patients, whereas older age and pulmonary embolus are associated with later deaths.

Critical care issues in the early management of severe trauma

Violent trauma and road traffic injuries kill more than 2.5 million people in the world every year, for a combined mortality of 48 deaths per 100,000 population per year. Most trauma deaths occur at the scene or in the first hour after trauma, with a proportion from 34% to 50% occurring in hospitals. Preventability of trauma deaths has been reported as high as 76% and as low as 1% in mature trauma systems. Critical care errors may occur in a half of hospital trauma deaths, in most of the cases contributing to the death. The most common critical care errors are related to airway and respiratory management, fluid resuscitation, neurotrauma diagnosis and support, and delayed diagnosis of critical lesions. A systematic approach to the trauma patient in the critical care unit would avoid errors and preventable deaths.

Thromboprophylaxie en neurochirurgie et en neurotraumatologie intracrânienne

The incidence of deep vein thrombosis (DVT) is between 20 and 35% using contrast venography, with a rate of symptomatic DVT between 2.3 and 6% in neurosurgery without any prophylaxis. The risk of DVT is poorly evaluated in head injured patients but is around 5%. Specific risk factors in neurosurgery are: a motor deficit, a meningioma or malignant tumour, a large tumour, age over 60 years, surgery lasting more than 4 hours, a chemotherapy. The benefit of mechanical methods or low molecular weight heparin (LMWH) for the prevention of DVP in neurosurgery is demonstrated (grade A). Each method decreases the risk by about 50%. A postoperative prophylaxis with a LMWH does not seem to increase the risk of intracranial bleeding (grade C). There is no demonstrated benefit to begin a prophylaxis with LMWH before the intervention. The duration of the prophylaxis is 7 to 10 days but this has not been scientifically determined.

Primer on medical management of severe brain injury

OBJECTIVE

To review the current understanding of the medical management of severe brain injury.

DATA SOURCE

The MEDLINE database, bibliographies of selected articles, and current English-language texts on the subject.

STUDY SELECTION

Studies related to management of intracranial hypertension, traumatic brain injury, and brain edema.

DATA EXTRACTION

All studies relevant to the subject under consideration were considered, with a focus on clinical studies in adults.

DATA SYNTHESIS

Basic rules of resuscitation must apply, including adequate ventilation, appropriate fluid administration, and cardiovascular support. The control of intracranial pressure can be considered in three steps. The first step should be initial slight hyperventilation with a target PaCO2 of 35 mm Hg and cerebrospinal fluid drainage for intracranial pressure of >15-20 mm Hg. The second step should be mannitol or hypertonic saline and hyperventilation to target PaCO2 of 28-35 mm Hg. The third step should be barbiturate coma or decompressive craniectomy. Additional management issues, including seizure prophylaxis, sedation, nutritional support, use of hypothermia, and corticosteroids, are also discussed.

CONCLUSIONS

Brain injury is frequently associated with the development of brain edema and the development of intracranial hypertension. However, with a coordinated, stepwise, and aggressive approach to management, focusing on control of intracranial pressure without adversely affecting cerebral perfusion pressure, outcomes can be good.

Prophylaxis for deep venous thrombosis in neurosurgery: a review of the literature

The incidence of deep venous thrombosis (DVT) and subsequent pulmonary embolism (PE) in patients undergoing neurosurgery has been reported to be as high as 25%, with a mortality rate from PE between 9 and 50%. Even with the use of pneumatic compression devices, the incidence of DVT has been reported to be 32% in these patients, making prophylactic heparin therapy desirable. Both unfractionated and low-molecular-weight heparin have been shown to reduce the incidence of DVT consistently by 40 to 50% in neurosurgical patients. The baseline rate for major intracranial hemorrhage (ICH) following craniotomy has been reported to be between 1 and 3.9%, but after initiation of heparin therapy this rate has been found to be as high as 10.9%. Therefore, neurosurgeons must balance the risk of PE against the increased risk of postoperative ICH from prophylactic heparin for DVT. The authors review the literature on the incidence of DVT and PE in neurosurgical patients, focusing on the incidence of ICH related to the use of unfractionated and low-molecular-weight heparin in this patient population

Venous thromboembolism prophylaxis after head and spinal trauma: intermittent pneumatic compression devices versus low molecular weight heparin

Although there are alternative methods and drugs for preventing venous thromboembolism (VTE), it is not clear which modality is most suitable and efficacious for patients with severe (stable or unstable) head/spinal injures. The aim of this study was to compare intermittent pneumatic compression devices (IPC) with low-molecular-weight heparin (LMWH) for preventing VTE. We prospectively randomized 120 head/spinal traumatized patients for comparison of IPC with LMWH as a prophylaxis modality against VTE. Venous duplex color-flow Doppler sonography of the lower extremities was performed each week of hospitalization and 1 week after discharge. When there was a suspicion of pulmonary embolism (PE), patients were evaluated with spiral computed tomography. Patients were analyzed for demographic features, injury severity scores, associated injuries, type of head/spinal trauma, complications, transfusion, and incidence of deep venous thrombosis (DVT) and PE. Two patients (3.33%) from the IPC group and 4 patients (6.66%) from the LMWH group died, with their deaths due to PE. Nine other patients also succumbed, unrelated to PE. DVT developed in 4 patients (6.66%) in the IPC group and in 3 patients (5%) in the LMWH group. There was no statistically significant difference regarding a reduction in DVT, PE, or mortality between groups ( p = 0.04, p > 0.05, p > 0.05, respectively). IPC can be used safely for prophylaxis of VTE in head/spinal trauma patients.

Anticoagulation or Inferior Vena Cava Filter Placement for Patients With Primary Intracerebral Hemorrhage Developing Venous Thromboembolism?

Background— Most patients with primary intracerebral hemorrhage developing clinically apparent proximal deep vein thrombosis (DVT) and/or pulmonary embolism (PE) require treatment with either anticoagulants or inferior vena cava filter insertion. Although the latter probably reduces the immediate risk of incident or recurrent PE and surmounts the undefined risk of recurrent intracranial bleeding with anticoagulation, the issue of preventing further thrombus propagation is not addressed, and there are associated short- and long-term risks, including a greater incidence of recurrent DVT.

Summary of Review— There are no data from randomized trials to clarify optimum treatment in these patients; indeed, the feasibility of such studies is questionable. Hence, treatment decisions continue to be made on an individualized basis and should include assimilation of information on key factors such as time elapsed post-stroke and lobar versus deep hemispheric location of the index event, natural history studies demonstrating a two-fold risk of recurrent intracerebral hemorrhage in the former subgroup.

Conclusions— In patients selected for anticoagulation, data from nonstroke patients suggest that a 5- to 10-day course of full-dose low-molecular-weight heparin followed by 3 months of lower-dose low-molecular-weight heparin is at least as effective as warfarin and may be associated with fewer hemorrhagic complications.

Bleeding Manifestations after Early Use of Low-Molecular-Weight Heparins in Blunt Splenic Injuries

Low-molecular-weight heparins (LMWHs) have emerged as an effective method for deep venous thrombosis (DVT) prophylaxis after major trauma. The early use of LMWH in patients with splenic injuries may result in increased rates of blood transfusions and failure of nonoperative management. A retrospective review of the records of all patients ≥18 years old that sustained blunt splenic injuries from April 2000 to July 2002 was performed. Patients were divided in two groups based on whether they received LMWH during the first 48 hours (early group) or not (late group). A total of 188 patients were evaluated. One hundred fourteen patients had their splenic injuries managed nonoperatively and were included in the study. Fifty patients were assigned to the early group and 64 to the late group. There was no statistical difference between groups regarding basic demographic data, initial laboratory results, and severity of their splenic injuries. In the early group, two (4%) patients failed nonoperative management compared with four (6%) patients in the late group ( P = 0.593). The number of patients requiring blood transfusions within the first 5 days after admission was 25 (50.0%) in the early group and 36 (56.2%) in the late group ( P = 0.507). The average number of blood units given per patient within the first 5 days after admission were 3.2 ± 1.5 in the early group and 3.0 ± 1.8 in the late group ( P = 0.782). This study suggests that the early use of LMWH in trauma patients with splenic injuries is not associated with an increased rate of blood transfusion requirements or an increased rate of failure of non-operative management.