Dalteparin versus enoxaparin for venous thromboembolism prophylaxis in acute spinal cord injury and major orthopedic trauma patients: 'DETECT' trial

BACKGROUND: To compare the impact of switching from enoxaparin 30 mg subcutaneously (SC) twice daily to dalteparin 5,000 units SC once daily for venous thromboembolism (VTE) prophylaxis in critically-ill major orthopedic trauma and/or acute spinal cord injury (SCI) patients. METHODS: DETECT was a retrospective, cohort study at a tertiary care referral teaching center-phase 1 from December 1, 2002 to November 30, 2003 (enoxaparin); and phase 2 from January 1, 2004 to December 31, 2004 (dalteparin). Major orthopedic trauma patients with pelvic, femoral shaft, or complex lower extremity fractures, and/or acute SCI patients admitted to the intensive care unit and who received a low-molecular-weight heparin (LMWH) for VTE prophylaxis were included. RESULTS: DETECT reviewed 135 patients (63 enoxaparin, 72 dalteparin), with similar baseline demographics, clinical characteristics, injuries, severity of illness, and risk factors for VTE. Clinically symptomatic proximal deep vein thrombosis (DVT) or pulmonary embolism (PE) rates were 1.6% with enoxaparin and 9.7% with dalteparin (p=0.103, absolute risk increase [ARI] of 8.1% [-0.6% to 15.6%]), with no differences in major bleeding (6.4% versus 6.9%) or minor bleeding (64% versus 69%), or mortality (4.8% versus 6.9%). Switching from enoxaparin to dalteparin was associated with $12,485 (CAD) in LMWH acquisition cost savings. CONCLUSIONS: DETECT raises the hypothesis that dalteparin 5,000 units SC daily may not be clinically noninferior to enoxaparin 30 mg SC twice daily for VTE prophylaxis in this high-risk population. Until an adequately-powered, prospective noninferiority trial is performed, enoxaparin is supported by level 1 evidence and should be the prophylactic agent of choice.     

Prophylactic Insertion of Optional Vena Cava Filters in High-Risk Trauma Patients

Abstract Background: Vena cava interruption is a form of pulmonary embolism prophylaxis that is being used in high-risk patients who do not tolerate pharmacologic prophylaxis. Retrievable prophylactic vena cava filters (VCFs) are of particular interest for severely injured patients where the necessity for VCF is often only temporary. Methods: In a single-institution case series of consecutive patients who received prophylactic VCFs after polytrauma, between 04/1998 and 07/2004, the demographic data, injury pattern and complications were analysed. Results: Ninety-five prophylactic VCFs were placed in polytrauma patients (median ISS of 38). Median age was 38 years (range 16–80 years). Median delay between trauma and filter placement was 1 day (range 0–31 days). No complication was seen related to filter insertion or retrieval. Sixty-five VCFs (68.4%) were retrieved after 4–25 days (median 13 days). One filter migration (1.1%) was observed. Retrieval failed in two patients (3.0%). A total of 30 VCFs (31.6%) were left permanently. One non-fatal PE (1.1%) occurred 21 days after filter retrieval despite prophylaxis with LMWH. DVT developed in two patients (2.1%) including one vena caval occlusion (1.1%). Overall mortality was 7.4%. Conclusions: Early prophylactic placement of VCF in a high-risk trauma patient should be considered when anticoagulation is contraindicated. Filter insertion and retrieval is safe with a low complication rate.     

Thromboembolic prophylaxis in head trauma and multiple-trauma patients

The association between trauma and venous thromboembolism (VTE) is well recognized. VTE consists mainly of deep venous thrombosis (DVT) and pulmonary embolism, a complication that leads to mortality in nearly 50% of cases. Without thromboprophylaxis, the risk of DVT exceeds 50%, but even with routine use of prophylaxis,one third of patients may develop DVT. Despite these findings, appropriate DVT prophylaxis is often not prescribed in trauma patients, mainly because of fear that VTE prophylaxis increases bleeding in injured tissues. Pharmacological VTE prophylaxis is based on the use of low-molecular weight heparins (LMWH). Once-daily or twice-daily LMWH protocols started within 36 h of trauma and continued throughout the hospital stay, or once-daily LMWH followed by a twice-daily protocol are possible options. Mechanical VTE prophylaxis by graduated compression stockings or intermittent pneumatic compression provides suboptimal protection, and its use is recommended only in combination with LMWH prophylaxis unless active bleeding is not controlled. The routine use of VTE prophylaxis in trauma patients is a standard of care. The use of LMWH, started once primary hemostasis has been accomplished, is safe, efficacious and cost-effective in the majority of trauma patients, including TBI patients.     

Use of low-molecular-weight heparin and a deep vein thrombosis protocol to prevent DVT in elderly patients with trauma

Thromboembolic events (TEs), including pulmonary embolisms (PEs), are life threatening. Older patients with trauma are at significantly higher risk for these complications. In March 2003, a deep vein thrombosis (DVT) prophylaxis protocol was implemented for use in all trauma patients admitted to our hospital. Here we report on the results of using this protocol for patients aged 65 years or older. A risk-stratified DVT/PE prophylaxis protocol was developed, incorporating specific injuries and history and physiologic parameters, which favored aggressive therapy and included patients at highest risk for dying from PEs. Between March 2003 and June 2005, these data were collected on all trauma patients admitted to our level I hospital. Comparisons were made with historical controls (patients admitted in 2002, before implementation of this protocol). TE rates for the study period trended lower for patients aged 65 or older (6.4% vs 2.2%, P<.1). This protocol did not increase the incidence of bleeding events in this patient population. Protocol-based, risk-adjusted DVT/TE prophylaxis is safe and efficacious in elderly trauma patients who are at increased risk for TEs.     

Dalteparin Vs Low-Dose Unfractionated Heparin for Prophylaxis Against Clinically Evident Venous Thromboembolism in Acute Traumatic Spinal Cord Injury: A Retrospective Cohort Study

Background: When venous thromboembolism (VTE) includes deep-vein thrombosis (DVT) and pulmonary embolism (PE), patients with acute traumatic spinal cord injury (SCI) have the highest incidence of VTE among all hospitalized groups, with PE the third most common cause of death. Although low-molecular-weight heparin (LMWH) outperforms low-dose unfractionated heparin (LDUH) in other patient populations, the evidence in SCI remains less robust.

Objective: To determine whether the efficacy for LMWH shown in previous SCI surveillance studies (eg, routine Doppler ultrasound) would translate into real-world effectiveness in which only clinically evident VTE is investigated (ie, after symptoms or signs present).

Methods: A retrospective cohort study was conducted of 90 patients receiving LMWH dalteparin (5,000 U daily) or LDUH (5,000 U twice daily) for VTE prophylaxis after acute traumatic SCI. The incidence of radiographically confirmed VTE was primarily analyzed, and secondary outcomes included complications of bleeding and heparin-induced thrombocytopenia.

Results: There was no statistically significant association (p = 0.7054) between the incidence of VTE (7.78% overall) and the type of prophylaxis received (LDUH 3/47 vs dalteparin 4/43). There was no significant differences in complications, location of VTE, and incidence of fatal PE. Paraplegia (as opposed to tetraplegia) was the only risk factor identified for VTE.

Conclusions: There continues to be an absence of definitive evidence for dalteparin (or other LMWH) over LDUH as the choice for VTE prophylaxis in patients with SCI. Novel approaches to VTE prophylaxis are urgently required for this population, whose risk of fatal PE has not decreased over the last 25 years.     

Thromboprophylaxis in pelvic and acetabular trauma surgery. The role of early treatment with low-molecular-weight heparin

We prospectively studied the outcome of a protocol of prophylaxis for deep vein thrombosis (DVT) in 103 consecutive patients undergoing surgical stabilisation of pelvic and acetabular fractures. Low-molecular-weight heparin (LMWH) was administered within 24 hours of injury or on achieving haemodynamic stability. Patients were screened for proximal DVT by duplex ultrasonography performed ten to 14 days after surgery. The incidence of proximal DVT was 10% and of pulmonary embolus 5%. Proximal DVT developed in two of 64 patients (3%) who had received LMWH within 24 hours of injury, but in eight of 36 patients (22%) who received LMWH more than 24 hours after the injury (p < 0.01). We conclude that LMWH, when begun without delay, is a safe and effective method of thromboprophylaxis in high-risk patients with major pelvic or acetabular fractures.     

Routine prophylactic vena cava filtration is not indicated after acute spinal cord injury

BACKGROUND: Acute spinal cord injury (SCI) is a devastating problem, with over 10,000 new cases annually. Pulmonary embolism (PE) is a well-recognized risk in SCI patients, although no clear recommendations for prophylaxis exist. We therefore evaluated whether routine placement of prophylactic inferior vena cava filters is indicated in SCI patients. METHODS: The trauma registry of a regional trauma center was used to identify patients sustaining acute SCI resulting in tetraplegia or paraplegia after blunt or penetrating trauma for a 5-year period beginning in January 1995. Patients were analyzed for demographics, mechanism of injury, Injury Severity Score, associated long bone or pelvic fracture, severe closed-head injury, type of deep venous thrombosis (DVT) prophylaxis, level of SCI, and incidence of DVT and PE. DVT prophylaxis was performed in all patients with sequential compression devices (SCDs) when extremity fracture status permitted. Data are expressed as mean +/- SD and analyzed using Fisher's exact test. RESULTS: There were 8,269 admissions during the study period, with an overall incidence of DVT and PE of 11.8% and 0.9%, respectively. There were 111 (1.3%) patients who sustained SCI, with an incidence of DVT and PE of 9.0% and 1.8%, respectively, and no deaths. Of these 111 patients, 41.4% were paraplegics and 58.6% were tetraplegics, and 17.1% of patients had severe closed-head injury. Mean hospital length of stay was 23 +/- 20 days for SCI patients. Surveillance duplex ultrasound was performed an average of 2.3 +/- 2.1 times during each hospitalization. Mean Injury Severity Score was 30.0 +/- 12.2. The incidence of DVT and PE in those patients with SCDs alone was 7.1% and 2.3%; for SCDs plus subcutaneous heparin, the incidence was 11.1% and 2.8%; and for SCDs plus low-molecular-weight heparin, the incidence was 7.4% and 0%, respectively, with no statistical difference between groups. The incidence of DVT in SCI patients with long bone fractures was 37.5%, which was significantly greater than the total SCI population (p < 0.02). CONCLUSION: The incidence of DVT and PE in SCI patients was similar to that of the overall trauma population when appropriate DVT prophylaxis was used. Subgroup analysis demonstrated that SCI associated with long bone fracture significantly increases the incidence of DVT. On the basis of the low incidence of PE in the present study, routine placement of prophylactic caval filters does not appear warranted in all SCI patients. However, SCI patients with long bone fractures, patients with DVT formation despite prophylactic anticoagulation, or patients with contraindications to anticoagulation may be appropriate candidates for prophylactic caval filtration.     

Dalteparin vs low-dose unfractionated heparin for prophylaxis against clinically evident venous thromboembolism in acute traumatic spinal cord injury: a retrospective cohort study

Background:

When venous thromboembolism (VTE) includes deep-vein thrombosis (DVT) and pulmonary embolism (PE), patients with acute traumatic spinal cord injury (SCI) have the highest incidence of VTE among all hospitalized groups, with PE the third most common cause of death. Although low–molecular-weight heparin (LMWH) outperforms low-dose unfractionated heparin (LDUH) in other patient populations, the evidence in SCI remains less robust.

Objective:

To determine whether the efficacy for LMWH shown in previous SCI surveillance studies (eg, routine Doppler ultrasound) would translate into real-world effectiveness in which only clinically evident VTE is investigated (ie, after symptoms or signs present).

Methods:

A retrospective cohort study was conducted of 90 patients receiving LMWH dalteparin (5,000 U daily) or LDUH (5,000 U twice daily) for VTE prophylaxis after acute traumatic SCI. The incidence of radiographically confirmed VTE was primarily analyzed, and secondary outcomes included complications of bleeding and heparin-induced thrombocytopenia.

Results:

There was no statistically significant association (p = 0.7054) between the incidence of VTE (7.78% overall) and the type of prophylaxis received (LDUH 3/47 vs dalteparin 4/43). There was no significant differences in complications, location of VTE, and incidence of fatal PE. Paraplegia (as opposed to tetraplegia) was the only risk factor identified for VTE.

Conclusions:

There continues to be an absence of definitive evidence for dalteparin (or other LMWH) over LDUH as the choice for VTE prophylaxis in patients with SCI. Novel approaches to VTE prophylaxis are urgently required for this population, whose risk of fatal PE has not decreased over the last 25 years.     

Prophylaxis against venous thromboembolism in orthopedic surgery

Venous thromboembolism (VTE), which is manifested as deep vein thrombosis (DVT) and pulmonary embolism (PE), represents a significant cause of death, disability, and discomfort. They are frequent complications of various surgical procedures. The aging population and the survival of more severely injured patients may suggest an increasing risk of thromboembolism in the trauma patients. Expanded understanding of the population at risk challenges physicians to carefully examine risk factors for VTE to identify high-risk patients who can benefit from prophylaxis. An accurate knowledge of evidence-based risk factors is important in predicting and preventing postoperative DVT, and can be incorporated into a decision support system for appropriate thromboprophylaxis use. Standard use of DVT prophylaxis in a high-risk trauma population leads to a low incidence of DVT. The incidence of VTE is common in Asia. The evaluation includes laboratory tests, Doppler test and phlebography. Screening Doppler sonography should be performed for surveillance on all critically injured patients to identify DVT. D-Dimer is a useful marker to monitor prophylaxis in trauma surgery patients. The optimal time to start prophylaxis is between 2 hours before and 10 hours after surgery, but the risk of PE continues for several weeks. Thromboprophylaxis includes graduated compression stockings and anticoagulants for prophylaxis. Anticoagulants include Warfarin, which belongs to Vitamin K antagonists, unfractionated heparin, low molecular weight heparins, factor Xa indirect inhibitor Fondaparinux, and the oral IIa inhibitor Melagatran and ximelagatran. Recombinant human soluble thrombomodulin is a new and highly effective antithrombotic agent. Prophylactic placement of vena caval filters in selected trauma patients may decrease the incidence of PE. The indications for prophylactic inferior vena cava filter insertion include prolonged immobilization with multiple injuries, closed head injury, pelvic fracture, spine fracture, multiple long bone fracture, and attending discretion. Multiple-trauma patients are at increased risk for DVT but are also at increased risk of bleeding, and the use of heparin may be contraindicated. Serial compression devices (SCDs) are an alternative for DVT prophylaxis. Compression devices provide adequate DVT prophylaxis with a low failure rate and no device-related complications. Immobilization is one of important reasons of VTE. The ambulant patient is far less Ukely to develop complications of inactivity, not only venous thrombosis, but also contractures, decubitus ulcers, or osteoporosis ( with its associated fatigue fractures), as well as bowel or bladder complications.     

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.     

No correlation between anti-factor Xa levels, low-molecular-weight heparin, and bleeding after gastric bypass

BACKGROUND: Pulmonary embolism (PE) remains a leading cause of death after Roux-en-Y gastric bypass. Currently, various regimens of low-molecular-weight heparin (LMWH) are used for perioperative deep vein thrombosis (DVT) prophylaxis. Anti-factor Xa (AFXa) has been suggested as a potential marker of LMWH activity. We have developed a perioperative prophylactic DVT regimen for our bariatric patients in which the dosage of LMWH they receive is based on their body mass index (BMI). We looked at whether AFXa levels correlated with bleeding risk. METHODS: A retrospective, single institution review of 102 patients undergoing a gastric bypass from November 2003 to April 2004 was performed. Twelve patients received transfusions. AFXa levels were present for 7 of 12 patients requiring transfusions and 74 of 90 patients not requiring transfusions. The average AFXa level for each group was compared. RESULTS: The transfusion rate for the group was 11.7%, with an average of 2.6 units of blood given (SD 1.2). There was no statistical difference between the average AFXa value for transfused and nontransfused patients (0.13 +/- 0.08 vs. 0.16 +/- 0.19, P = .7). CONCLUSION: AFXa levels do not appear to correlate with bleeding risk in patients receiving LMWH prophylaxis following gastric bypass. Determining such risk seems to require another marker.     

Postoperative venous thrombosis in general surgery patients and perioperative prophylaxis

In a population of general surgery patients in Western countries, there was a 19% incidence of deep vein thrombosis (DVT) and a 1.6% incidence of pulmonary embolism (PE), with 0.9% of patients experiencing fatal PE. In Japan, there was a 15.8% incidence of DVT and a 0.34% incidence of PE, with 0.08% of patients experiencing fatal PE in a population of abdominal surgery patients. The incidences of PE and fatal PE in our department were 0.11% and 0.03%, respectively. We started to use intermittent pneumatic compression (IPC) for the prophylaxis of postoperative PE in 1999 and then added elastic stockings in 2002 and low-dose unfractionated heparin (LDUH) in 2003 for prophylaxis. The incidence of PE has dropped and that of fatal PE has become 0% with the use of such prophylactic measures. When the risk of venous thromboembolism of the 15 patients who experienced PE in our department were assessed using the Japanese Guidelines for Prevention of Venous Thromboembolism, 13 patients were assessed as high risk and 2 as low risk. The mean age and mean body mass index of the 15 patients were 54 yeas old and 24.8, respectively, and PE was not limited to obese or elderly patients. Such findings appear to indicate the difficulty of risk assessment for PE. Therefore we started to use IPC, elastic stockings, and LDUH for the prophylaxis of PE and DVT for all general surgery patients from April 2004. These prophylactic measures are recommended for the highest-risk patients in the Japanese Guidelines for Prevention of Venous Thromboembolism. There have so far been no serious bleeding complications with the administration of LDUH. We will continue to observe the effects of prophylaxis and the risk of bleeding.     

The role of surveillance duplex scanning in preventing venous thromboembolism in trauma patients

BACKGROUND: This study was performed to determine the role of duplex scanning in preventing pulmonary embolism (PE), the correlation of venous thromboembolism (VTE) risk score with the incidence of deep venous thrombosis (DVT), and patients who may benefit from surveillance duplex scanning. METHODS: Age, sex, Injury Severity Score (ISS), VTE score, length of stay, diagnoses, and bleeding risk were recorded from the trauma registry in patients who had a duplex scan from 1995 to 2000. RESULTS: There were 1,513 duplex scans obtained (10,141 trauma admissions), 253 (2.5%) cases of DVT (52% above-knee, 8% upper extremity), and 30 cases of PE (0.3%). Only 5 of 21 duplex scans were positive in PE patients. DVT patients were older (52.9 vs. 46.7 years), with higher ISS (24.0 vs. 20.8) than patients without DVT. Regression analysis showed poor correlation between VTE score and DVT incidence (r2 = 0.27). Univariate analysis identified age, ISS, and VTE score as risk predictors for DVT. CONCLUSION: Adherence to an evidence-based VTE prophylaxis protocol is more important than surveillance duplex scanning in preventing VTE in trauma patients.     

Profilassi antitromboembolica nel trauma scheletrico maggiore. Il punto di vista dell’ortopedico

Deep Vein Thrombosis (DVT) and pulmonary embolism (\(\mathit{PE}\)) are important complications of major skeletal trauma and polytrauma that may occur after variable time following trauma and its treatment. A variety of risk factors including the complexity of fractures and associated injuries predispose these patient to DVT and PE. Hence, early and aggressive pharmacological prophylaxis must be carried out in this setting. Thromboprophylaxis needs to be balanced against the risk of haemorrhage. It could be useful to adopt a system to stratify the risk of thromboembolism in trauma patients and select the best option for an adequate prophylaxis. The available pharmacological agents include low-dose heparin, low molecular weight heparin, and factor Xa inhibitors. Mechanical prophylaxis methods include graduated compression stockings, pneumatic compression devices, and A-V foot pumps. Caval filters are an option in high-risk patients in whom pharmacological prophylaxis is contraindicated. All these prophylactic methods are reviewed.     

A Systematic Review of Deep Venous Thrombosis Prophylaxis in Cancer Patients: Implications for Improving Quality

Introduction Deep venous thrombosis (DVT) prophylaxis is particularly important for surgical oncologists given the high rate of DVT in patients with malignancy. Additionally, DVT prophylaxis may soon be implemented by some payers as a “pay for performance” quality measure. This is a systematic review of randomized controlled trial (RCT) evidence for DVT prophylaxis in cancer patients undergoing surgery. We examine overall rates of DVT, the efficacy of high versus low-dose heparin prophylaxis, and the rate of bleeding complications. Methods The Medline database was searched for English language RCTs using key words DVT, venous thromboembolism, prophylaxis, and general surgery. Inclusion criteria were RCTs evaluating surgical oncology patients. Results Fifty-five RCTs studied DVT prophylaxis in surgery (nonorthopedic) patients. Twenty-six RCTs evaluated 7,639 cancer patients. The overall DVT rate was 12.7% for pharmacologic prophylaxis and 35.2% for controls. High-dose low-molecular weight heparin (LMWH) was more effective than low dose, lowering the DVT rate from 14.5% to 7.9% (P < 0.01). Heparin decreased the rate of proximal DVTs. Bleeding complications requiring discontinuation of prophylaxis occurred in 3% of the patients. There was no difference between LMWH and unfractionated heparin in efficacy, DVT location, or bleeding complications. Conclusion Using RCT data, this study demonstrates a greatly reduced DVT rate with pharmacologic prophylaxis in cancer patients, and higher doses appear more effective. Complication rates are low and should not prevent the use of prophylaxis in most patients. Finally, we found no difference between LMWH and unfractionated heparin in these RCTs. These results highlight the importance of routine pharmacologic prophylaxis in surgical patients with malignancy. Presented at 2006 Society of Surgical Oncology Annual Meeting, San Diego, CA.     

Evaluation of the applicability, efficacy, and safety of a thromboembolic event prophylaxis guideline designed for quality improvement of the traumatically injured patient

BACKGROUND: Thromboembolic events (TE) such as deep venous thrombosis (DVT) and pulmonary embolism (PE) are common after trauma. Our Trauma Practice Management Committee developed an evidence-based DVT/PE prophylaxis guideline using a modified Delphi approach to standardize care and reduce TE rates. Our objective was to evaluate the applicability, efficacy, and safety of this guideline in the traumatized patient, especially those admitted first to the intensive care unit (ICU). METHODS: We developed a risk-stratified DVT/PE prophylaxis guideline incorporating specific injuries, pertinent history, and physiologic parameters, favoring aggressive therapy in those at highest risk of dying from a PE. We prospectively collected data using this guideline in all patients admitted to the trauma or orthopedic-trauma services that were expected to stay for more than 48 hours (March-December 2003). Comparison was made with historical controls. Data collected included DVT, PE, prophylaxis level chosen, inferior vena cava filters, admission service and location, TRISS scores, length of stay, outcomes, adverse events, and specific risk factors. RESULTS: TE rates after implementation of the guideline were lower than historical controls for all patients (1.9% vs. 1.0%, p = 0.059) and for patients admitted first to the ICU (6.3% vs. 2%, p = 0.018). Completed sheets were collected for 46% of the targeted population. No bleeding events caused by guideline anticoagulation were noted, and one death occurred after inferior vena cava filter placement. Nine of the 12 TEs in the treatment group were in patients with spine or closed-head injury, delaying chemical prophylaxis. CONCLUSION: Form-based, risk-adjusted prophylaxis against TE leads to lower TE rates in a general and orthopedic ICU trauma population. Protocol compliance should be enforced.     

A retrospective analysis of the effectiveness of low molecular weight heparin for venous thromboembolism prophylaxis in trauma patients

Background

In trauma patients, Enoxaparin (a low molecular weight heparin, LMWH) prophylaxis for venous thromboembolism (VTE) risk reduction is unproven.

Methods

Cohort analysis conducted consisting of all trauma patients age >13 admitted to Level-I trauma center and hospitalized >48 hours. VTE risk determined by the Risk Assessment Profile. High risk patients received LMWH unless contraindicated, while low and moderate risk patients received LMWH at attending surgeon's discretion. Odds ratio for VTE by logistic regression. VTE incidence, relative risk (RR), and number needed to treat (NNT) to prevent deep vein thrombosis (DVT) or pulmonary embolism determined by risk category.

Results

Cohort consisted of 2,281 patients (1,211 low, 979 moderate, 91 high risks). VTE occured in 254 patients (11.1%). High-risk patients had significantly higher VTE incidence, odds ratio = 31.8 (P < .001). VTE was significantly reduced in high-risk patients receiving LMWH versus those who did not (.26 vs .53, P = .02). Among moderate and high risk, prophylactic LMWH reduced the incidence of pulmonary embolism (RR = .19, NNT = 40.4, P = .01), and trended toward reduced DVT incidence (RR = .81, NNT = 27.3, P = .15). LMWH lowered DVT incidence (RR = .52, NNT = 4.1, P = .03) in high risk patients.

Conclusion

Prophylactic LMWH is associated with reduction of VTE in trauma patients.     

Early experience with retrievable inferior vena cava filters in high-risk trauma patients

BACKGROUND: This study describes the use of retrievable IVC filters in a select group of trauma patients at high risk for deep vein thrombosis (DVT) and pulmonary embolism (PE). STUDY DESIGN: Retrievable IVC filters were placed in selected trauma patients who met high-risk criteria for deep vein thrombosis and PE according to institutional clinical management guidelines. All filters were placed percutaneously in the interventional radiology suite. Indications for filter placement were based on injury complex, weight-bearing status, and contraindications to enoxaparin or pneumatic compression devices. IVC filters were either removed or maintained. RESULTS: Retrievable IVC filters were placed in 35 patients after blunt trauma. Twenty-six patients (74%) sustained at least one orthopaedic injury; 17 patients (49%) were diagnosed with a pelvis fracture. Activity was limited to bed rest or spinal precautions in 18 patients (51%). Enoxaparin was contraindicated in 32 patients (91%) and injuries precluded the use of pneumatic compression devices in 11 (31%). IVC filters were removed in 18 patients (51%), with no reported complications. Patients with orthopaedic injuries and pelvis fractures were less likely to have their filters maintained (p = 0.040). CONCLUSIONS: Retrievable IVC filters offer a versatile option for prophylaxis in trauma patients at high risk for PE. Filter retrieval potentially spares the longterm complications of permanent filters in younger trauma patients. Retrievable filters warrant consideration in patients who meet high-risk criteria for deep vein thrombosis or PE who cannot receive effective mechanical prophylaxis and in whom contraindications to anticoagulation are expected to be temporary.     

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

BackgroundPatients 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 MethodsWe 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.ResultsThe 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.ConclusionsMeta-analysis of the literature suggests that DOACs are associated with equivalent effectiveness and safety compared to LMWH.     

Prolonged thromboprophylaxis with dalteparin after surgical treatment of achilles tendon rupture: a randomized, placebo-controlled study

OBJECTIVES: Prophylaxis against thromboembolic complications has become routine after major orthopedic surgery. In contrast, it remains an issue for debate whether prophylaxis after minor surgery and immobilization is necessary, even though these treatments are well-known risk factors for deep-vein thrombosis (DVT). The objective of this study was to evaluate the efficacy of dalteparin during lower-limb immobilization after surgical treatment of Achilles tendon rupture. DESIGN SETTING, AND PATIENTS: Randomized, placebo-controlled, double-blind study of 105 consecutive patients surgically treated for Achilles tendon rupture in a trauma hospital. DVT screening with color duplex sonography was conducted 3 weeks and 6 weeks after surgery. All DVTs were confirmed with phlebography. Intervention was placebo or dalteparin (5000 U) given subcutaneously once daily for 6 weeks postoperatively. MAIN OUTCOME MEASURE: DVT incidence. RESULTS: Primary endpoint analysis was available for 91 patients. DVT was diagnosed in 16 of 47 patients (34%) in the dalteparin group and in 16 of 44 patients (36%) in the placebo group. These figures are not significantly different (P = 0.8). Proximal DVT was diagnosed in 1 patient (2%) in the dalteparin group and in 3 patients (6%) in the placebo group (P = 0.6). No pulmonary emboli or major bleeding occurred in either of the groups. CONCLUSIONS: DVT is common after surgical treatment of Achilles tendon rupture, and therefore effective thromboprophylaxis is desirable. In our study, thromboprophylaxis with dalteparin, however, does not affect the incidence of DVT during immobilization after Achilles tendon rupture surgery. Long-term effects of immobilization, such as the risk for postthrombotic syndrome, need to be investigated further.