Routine use of LMWH prophylaxis is associated with a lower incidence of venous thromboembolic events following an ankle fracture

BackgroundVenous thromboembolic events (VTE) are well-known and serious complications following a trauma to the lower extremities. There is an ongoing debate on the benefit of low-molecular-weight heparin (LMWH) as prophylaxis following ankle fracture treatment. We examined the association between the incidence of VTE and the use of LMWH-prophylaxis following an ankle fracture, as well as factors affecting the risk of VTE.MethodsIn this retrospective cohort study, data on ankle fractures and fracture treatment from the Swedish Fracture Register was linked to data from the Swedish National Patient Register and the Swedish Prescribed Drug Register. Patients with VTE and patients who received LMWH prophylaxis were identified. The treating orthopedic departments were sent a questionnaire about their guidelines regarding the use of LMWH prophylaxis.Results222 cases of diagnosed VTE were identified among 14,954 ankle fractures. Orthopedic departments with higher-than-average use of LMWH prophylaxis among non-operatively treated ankle fractures had a lower incidence of VTE (OR 0.60, CI 0.39–0.92). Among operatively treated patients, departments with a guideline for the routine use of LMWH prophylaxis also had lower incidence of VTE (OR 0.56, CI 0.37–0.86). A later onset of VTE was seen among patients prescribed LMWH prophylaxis, with a mean of 56 days to onset (CI 44–67), compared to 39 days (CI 33–45) in patients without prescribed prophylaxis. During the first two weeks following injury, there was only one case of VTE in patients with prescribed LMWH, compared to 39 cases of VTE among patients without prescribed prophylaxis.ConclusionsRoutine use of LMWH in patients with operatively treated ankle fractures was associated with a lower incidence of VTE. A more frequent use of LMWH among patients with non-operatively treated ankle fractures were associated with a lower incidence of VTE. The onset occurred later among patients with LMWH-prophylaxis who still suffered a VTE.     

The survival benefit of low molecular weight heparin over unfractionated heparin in pediatric trauma patients

IntroductionVenous thromboembolism (VTE) prophylaxis in pediatric patients is controversial and is mainly dependent on protocols derived from adult practices. Our study aimed to compare outcomes among pediatric trauma patients who received low molecular weight heparin (LMWH) compared to those who received unfractionated heparin (UFH).MethodsWe performed 2 years (2015–2016) retrospective analysis of the Pediatrics ACS-TQIP database. Pediatric trauma patients (age ≤ 17) who received thromboprophylaxis with either LMWH or UFH were included. Patients were stratified into three age groups. Analysis of each subgroup and the entire cohort was performed. Outcome measures included VTE events (deep vein thrombosis [DVT] and pulmonary embolism [PE]), hospital and ICU length of stay (LOS) among survivors, and mortality. Propensity score matching was used to match the two cohorts LMWH vs UFH.ResultsA matched cohort of 1,678 pediatric trauma patients was analyzed. A significant difference in survival, DVT events, and in-hospital LOS was seen in the age groups above 9 years. Overall, the patients who received LMWH had lower mortality (1.4% vs 3.6%, p < 0.01), DVT (1.7% vs 3.7%, p < 0.01), and hospital LOS among survivors (7 days vs 9 days, p < 0.01) compared to those who received UFH. There was no significant difference in the ICU LOS among survivors and the incidence of PE between the two groups.ConclusionLMWH is associated with increased survival, lower rates of DVT, and decreased hospital LOS compared to UFH among pediatric trauma patients age 10–17 years.Level of EvidenceLevel III Prophylactic.Study TypeProphylactic.     

Chemoprophylaxis for venous thromboembolism in pelvic and/or acetabular fractures: A systematic review

BackgroundIt is unclear which pharmacological agents, and at what dosage and timing, are most effective for venous thromboembolism (VTE) prophylaxis in patients with pelvic/acetabular fractures.MethodsWe searched the Cochrane Database of Systematic Reviews, Embase, Web of Science, EBSCO, and PubMed on October 3, 2020, for English-language studies of VTE prophylaxis in patients with pelvic/acetabular fractures. We applied no date limits. We included studies that compared efficacy of pharmacological agents for VTE prophylaxis, timing of administration of such agents, and/or dosage of such agents. We recorded interventions, sample sizes, and VTE incidence, including deep vein thrombosis (DVT) and pulmonary embolism.ResultsTwo studies (3604 patients) compared pharmacological agents, reporting that patients who received direct oral anticoagulants (DOACs) were less likely to develop DVT than those who received low molecular weight heparin (LMWH) (p < 0.01). Compared with unfractionated heparin (UH), LMWH was associated with lower odds of VTE (odds ratio [OR] = 0.37, 95% confidence interval [CI]: 0.22–0.63) and death (OR = 0.27, 95% CI: 0.10–0.72). Three studies (3107 patients) compared timing of VTE prophylaxis, reporting that late prophylaxis was associated with higher odds of VTE (OR = 1.9, 95% CI: 1.2–3.2) and death (OR = 4.0, 95% CI: 1.5–11) and higher rates of symptomatic DVT (9.2% vs. 2.5%, p = 0.03; and 22% vs. 3.1%, p = 0.01). One study (31 patients) investigated dosage of VTE prophylaxis, reporting that a higher proportion of patients with acetabular fractures were underdosed (23% of patients below range of anti–Factor Xa [aFXa] had acetabular fractures vs. 4.8% of patients within adequate range of aFXa, p<0.01).Conclusions: Early VTE chemoprophylaxis (within 24 or 48 h after injury) was better than late administration in terms of VTE and death. Many patients with acetabular fractures are underdosed with LMWH, with inadequate aFXa levels. Compared with UH, LMWH was associated with lower odds of VTE and death. DOACs were associated with lower risk of DVT compared with LMWH.Level of Evidence: III, systematic review of retrospective cohort studies.     

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.     

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.     

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.     

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.     

Timing of venous thromboprophylaxis in isolated severe pelvic fracture: Effect on mortality and outcomes

Introduction: Optimal timing of pharmacological thromboprophylaxis (VTEp) in patients with severe pelvic fractures remains unclear. The high risk of venous thromboembolic (VTE) complications after severe pelvic fractures supports early VTEp however concern for fracture-associated hemorrhage can delay initiation. Patients with pelvic fractures also frequently have additional injuries that complicate the interpretation of the VTEp safety profiles. To minimize this problem, the study included only patients with isolated severe pelvic fractures.Materials and methods: The Trauma Quality Improvement Program was used to collect patients with blunt severe pelvic fractures (AIS?>?3) who received VTEp with unfractionated heparin (UH) or low-molecular-weight heparin (LMWH). Patients with head, chest, spine, and abdominal injuries AIS?>?3, or those with angio or operative intervention prior to VTEp were excluded. The study population was stratified according to timing of VTEp, early (<48?h) and late (>48?h). Outcomes included in-hospital mortality and VTE.Results: 2752 patients were included in the study. Overall, 2007 patients (72.9%) received early VTEp, while 745 (27.1%) received late VTEp. LMWH was administered in 2349 (85.4%) and UH in 403 (14.6%).Late VTEp was associated with significantly higher incidence of VTE (4.3% vs. 2.2%, p?=?0.004). Logistic regression identified late VTEp as an independent risk factor for VTE (OR 1.93, p?=?0.009) and mortality (OR 4.03, p?=?0.006). LMWH was an independent factor protective for both VTE and mortality (OR 0.373, p?<?0.001, OR 0.266, p?=?0.009, respectively).Conclusion: In isolated severe pelvic fractures, early VTEp is independently associated with improved survival and fewer VTE. LMWH may be preferred over UH for this purpose.     

Early versus delayed thromboprophylaxis with LMWH in pelvic-acetabular trauma- a prospective study

BackgroundDelayed presentation of pelvic-acetabular fractures is a common scenario in developing countries and there is usually a delay of more than 24 h in their presentation.ObjectivesWe aim to comparatively analyse early(<24 h) versus delayed (>24 h) thromboprophylaxis with low molecular weight heparin (LMWH) in prevention of deep venous thrombosis (DVT) in Pelvic Acetabular fractures.MethodsPatients of pelvic-acetabular fractures who presented during 1 year of study period were divided into 2 groups after exclusion of patients with contraindications for thromboprophylaxis. Group A included patients who received LMWH prophylaxis within 24 h of injury. Group B included patients who received LMWH prophylaxis after 24 h of injury. All patients underwent CT venography at day 14 and were followed up with doppler ultrasound on 4th and 8th week.Results110 patients with pelvic-acetabular fractures were included after exclusion of 61 patients. 4 out of 29 patients in group A (13.8%) and 12 out of 81 patients (14.8%) in group B developed DVT. There was no significant difference in incidence of DVT between Group A and B (P value-0.893).ConclusionThere was no difference between early and delayed thromboprophylaxis with LMWH in pelvic-acetabular trauma.     

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.     

IgG-class anti-PF4/heparin antibodies and symptomatic DVT in orthopedic surgery patients receiving different anti-thromboembolic prophylaxis therapeutics

Background  

Heparin-induced thrombocytopenia (HIT) is a thromboembolic complication that can occur with unfractionated heparin (UFH) or low molecular weight heparin (LMWH). Our objective was to determine and compare the incidence of IgG-class HIT antibodies in patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) with different antithrombotic prophylaxis therapies and their contributions to the occurrence of venous thromboembolism (VTE).     

Preoperative low molecular weight heparin reduces heparin responsiveness during cardiac surgery

PURPOSE: Cardiac surgery with cardiopulmonary bypass requires systemic anticoagulation, defined by an activated clotting time (ACT) of 400-480 sec. Patients with altered heparin responsiveness require disproportionately higher doses of heparin to achieve this target ACT. A common risk factor for heparin resistance is preoperative heparin therapy. Recently, therapy with low molecular weight heparin (LMWH) has become an acceptable substitute for prolonged heparin therapy. The current study examines the effect of preoperative LMWH therapy on subsequent heparin responsiveness during cardiac surgery. METHODS: Records of patients undergoing cardiac surgery with cardiopulmonary bypass over a period of four months were reviewed. We identified patients who, during the week preceding surgery, had received prolonged (>24 hr) therapy with either sc LMWH (LMWH group) or continuous iv unfractionated heparin (Heparin group). A Control group consisted of patients who received neither heparin nor LMWH preoperatively. The heparin sensitivity index (calculated as the first change in ACT from baseline divided by the first intraoperative heparin dose, normalized to body weight), was compared among groups using ANOVA. RESULTS: One hundred and thirty-nine patients were included in the analysis. The heparin sensitivity index was 33-45% higher in the Control group (1.6+/-0.7 sec.IU-1.kg-1; P<0.0001) compared to the LMWH (1.2+/-0.4 sec.IU-1.kg-1) and Heparin (1.1+/-0.5 sec.IU-1.kg-1) groups. In a multivariable model, the use of preoperative LMWH remained a significant predictor of reduced intraoperative heparin responsiveness (P=0.002). CONCLUSION: Prolonged preoperative LMWH therapy, similar to the known effect of prolonged unfractionated heparin infusion, reduces subsequent intraoperative response to heparin.     

Venous thromboembolism in trauma patients: Standardized risk factors

Purpose: This study was done to evaluate the use of published standardized risk factors for venous thromboembolism (VTE) in patients admitted to a trauma intensive care unit (ICU) and to derive guidelines for the use of low molecular weight heparin (LMWH) and surveillance venous Doppler ultrasound scanning (VDUS). Methods: Patients were admitted to a regional trauma center ICU. Two periods were studied. Period 1 was a retrospective analysis of documented cases of VTE in the trauma registry from 1993 to 1995 (n = 39). The period was also a review of all patients admitted to a trauma ICU in 1994 without VTE who met the following criteria: age greater than 11 years, ICU stay of more than 36 hours, and survival of more than 72 hours (n = 227). Period 2 was a concurrent analysis of 1996 documented cases of VTE and similarly selected ICU admissions (VTE, n = 10; no VTE, n = 224). Risk factor scores (R1, admitting; R2, total) were calculated from the International Society for Cardiovascular Surgery/Society for Vascular Surgery reporting standards. The scores were cumulative by category and over time. The suitability of such standards was determined in period 1. The resulting therapeutic and surveillance guidelines were evaluated in period 2. Results: Period 1 risk factor scores, R1 and R2, were correlated with the occurrence of VTE from χ² test (P < .05 and P < .01, respectively). Risk categories were grouped as low, moderate, and high. VTE was not observed in the low-risk group (0 to 2). Among all VTE (n = 49), 11 cases occurred in patients with moderate-risk scores and 38 in patients with high-risk scores. In 1994 and 1996, the selected groups were analyzed and the incidence rate of VTE was 4.7% in both years for the moderate-risk group and 2.5% and 4.8% for the high-risk group, respectively. Most VTE cases (78%) received some form of prophylaxis (PRx), and 26% of cases had multiple methods of prophylaxis (MPRx). This included 80% of the cases that received unfractionated heparin. In period 2, no pulmonary emboli (PE) occurred, in contrast to period 1, in which 16 of 39 cases of VTE (41%) were first seen with PE. In period 2, no patient receiving MPRx, including compression and LMWH, had VTE develop. Surveillance VDUS discovered 6〈$〉0% of 1996 cases in period 2. No PE were seen in period 2. Conclusion: Standard risk factors were easily applied to the trauma patient at the bedside. Patients at low risk needed no PRx. Patients at high risk did best with both compression devices and LMWH. VDUS was recommended selectively in patients at high risk in whom multiple-method PRx could not be achieved. Patients at moderate risk required further study to define optimal PRx and need for surveillance VDUS. Intracaval devices were used prophylactically only twice. (J Vasc Surg 1998;28:250-9.)     

Early antithrombotic prophylaxis with low molecular weight heparin in neurosurgery

Summary> ¶Background. Despite the high risk of venous thromboembolic events (VTE) in neuro-surgical patients, heparin prophylaxis has not been routinely established due to concern about bleeding complications. After initiating early low molecular weight heparin (LMWH) prophylaxis, we reviewed our patients in order to examine the viability of this practice. Method. Over a 3 year period, the records of patients admitted for elective neuro-surgery (ES), head injury (HI) or spontaneous intracranial haemorrhage (ICH) were analysed. Prophylaxis was performed with certoparin (3000 U anti-factor Xa s.c.) on the evening before ES and within 24 hours after surgery or admission whenever a CT did not show a progress-sive haematoma. Contraindications for LMWH were prothrombin time <70%, partial thrombo-plastin time >40s, platelet count <100.000/ml, and platelet aggregation test sum <60%. The incidence of bleeding complications, VTE, and resulting morbidity/mortality was assessed. Findings. 294 patients were admitted for ES, 344 for HI, and 302 for ICH. 155 of these were excluded because of contraindications. Intracranial bleeding was recorded in 1.5% (ES 1.1%, HI 3.5%, ICH 0%) and operative revision was performed in 1.1% (ES 0.7%, HI 2.8%) of patients. One case of moderate disability and no mortality occurred. The incidence of VTE and pulmonary embolism was documented in 0.2% and 0.1% of patients, with no associated mortality. No heparin induced thrombocytopenia was observed. Interpretation. In neurosurgical patients, antithrombotic prophylaxis with certoparin was determined to be safe and efficacious when contraindications are carefully considered and a 12-hour time interval before and after surgery was guaranteed. This retrospective analysis should encourage a prospective trial of early LMWH prophylaxis.     

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.     

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.     

Thromboprophylaxis in adult and paediatric burn patients: A survey of practice in the United Kingdom

IntroductionPatients with burn injuries are at an increased risk of venous thromboembolism (VTE). This predisposition is secondary to the endothelial injury, hyper-coagulable state and stasis (Virchow’s triad) associated with burn injury. Although the true incidence of VTE in burn patients has not been adequately quantified, symptomatic VTE occurs in 0.2–7% of this population.VTE prophylaxis has proven clinical effectiveness and affords a reduction in the morbidity associated with such events, but the benefits and risk of complications need to be balanced in order to provide the best quality of care.Owing to the lack of prospective data on VTE in burns, practice varies greatly, not only internationally, but also between local burns services. Our aim was to better understand current VTE practice within United Kingdom (UK) burn care services by performing a comprehensive survey.MethodsWe contacted all the inpatient burn care services in the UK and collected data on current VTE practice via a standardised questionnaire. Services were given the choice to complete the survey by telephone or email and a follow-up plan was formulated.ResultsTwenty-five burn care services were contacted and 23 agreed to participate (92% response rate). Responding services treated adults, children or both and lead burn nurses or senior medical staff familiar with current VTE practice were interviewed.Routine VTE prophylaxis was provided in 84% of burn services and the majority utilised a combination of chemoprophylaxis and thromboembolic deterrent stockings (TEDS). All used low molecular weight heparin (LMWH) as their choice of chemoprophylaxis. Of those treating adults, all used a VTE prophylaxis protocol, but none of these applied to children. Only 56% of services treating children had such a protocol. The majority discontinued prophylaxis once patients were mobile.Discussion and conclusionAlthough the true burden of VTE in burn patients is unknown, we recognise that they are a population at risk. In addition to changes in the inflammatory and clotting pathways associated with thermal injury, prolonged hospital stay, ventilatory support, multiple surgeries, numerous central venous cannulations and reduced mobility all multiply this risk.The risk associated with the administration of heparin (bleeding complications and heparin-induced thrombocytopaenia) is low and can be reduced even further to 0.1% by the use of LMWH. The risk of symptomatic VTE is far greater, therefore the benefits of VTE prophylaxis would seem to outweigh the risks of not undertaking prophylactic measures. A higher LMWH dose and routine monitoring of anti-factor Xa levels are useful for acute burn patients.Two previous surveys, performed in Canada and the United States of America (USA), found routine administration of VTE prophylaxis to be 50% and 76% respectively. Of the 71 centres in the USA participating in the survey, 30% used a combination of sequential compression devices (SCD) and heparin and 24% did not provide VTE prophylaxis at all.A lack of prospective data on VTE in burn patients appears to be associated with diverse practice, and consensus on this topic could ensure that the potential morbidity caused by VTE is reduced. A clinical tool for identifying patients at risk and guidelines for management will standardise practice, which in turn should allow us to improve and maintain high quality care for burn patients.     

Aspirin Administered for Venous Thromboembolism Prophylaxis May Protect Against Stiffness Following Total Knee Arthroplasty

BackgroundAspirin has become the main agent for venous thromboembolism (VTE) prophylaxis following total knee arthroplasty (TKA). This study assessed whether aspirin is associated with less knee stiffness compared to warfarin and other chemoprophylaxis agents.MethodsThis is a retrospective review of all primary and revision TKAs performed between January 2009 and October 2020 at a high volume institution. Demographics, comorbidity data, and operative variables were extracted from medical records. VTE prophylaxis administered during this time period included aspirin, warfarin, and “others” (factor Xa, unfractionated heparin, low-molecular-weight heparin, fondaparinux, adenosine diphosphate receptor inhibitor, and direct thrombin inhibitor). The primary outcome assessed was manipulation under anesthesia (MUA) performed within 6 months of index surgery. Secondary outcome included major bleeding events. Univariate followed by multivariate regression analyses were performed.ResultsA total of 15,903 cases were included in the study, of which 531 (3.3%) patients developed stiffness that required MUA. The rates of MUA were 2.7% (251/9223) for patients receiving aspirin, 4.2% (238/5709) for patients receiving warfarin, and 4.3% (42/971) for all others (P’s < .001). Multivariate regression analysis confirmed that aspirin is associated with lower rates of VTE compared to warfarin (adjusted odds ratio 1.423, 95% confidence interval 1.158-1.747, P < .001) and compared to other anticoagulation medications (adjusted odds ratio 1.742, 95% confidence interval 1.122-2.704, P = .013). Major bleeding events were also significantly lower in patients who received aspirin compared to the other 2 groups (P’s = .001).ConclusionAspirin prophylaxis is associated with lower rates of MUA following TKA compared to warfarin and other VTE chemoprophylactic agents when grouped together.     

Status of venous thromboembolism prophylaxis among bariatric surgeons: have we changed our practice during the past decade?

BackgroundVenous thromboembolism (VTE) is considered one of the principal causes of morbidity and mortality in patients requiring bariatric surgery. A survey to all members of the American Society for Metabolic and Bariatric Surgery was conducted in 1998 and published in 2000 in the journal “Obesity Surgery.”MethodsA survey was repeated to all physician members of the American Society for Metabolic and Bariatric Surgery to determine the current practices for VTE prophylaxis. The results were compared with those of the previous study.ResultsOf the members, 35% completed the survey for a total of 332 responses. The number of cases annually per surgeon almost doubled since 1998 (145 versus 85). Laparoscopic gastric bypass has replaced open gastric bypass as the most common procedure performed, followed by laparoscopic gastric banding as the second most common procedure. Most surgeons (95%) use chemical prophylaxis to prevent VTE, but almost 60% preferred low-molecular-weight heparin compared with 13% in 1998. More than 60% of bariatric surgeons discharged their patients with chemical prophylaxis compared with 12% in 1998. Inferior vena cava filters for prophylaxis are considered by 55% compared with only 7% in 1998. The incidence of reported deep vein thrombosis was significantly lower in 2007 (2.635 versus .93), as was the incidence of pulmonary embolism (.95% versus .75%). Almost 50% of surgeons still reported ≥1 fatality because of VTE complications.ConclusionChemical prophylaxis for VTE with some type of heparin is the standard of care for patients undergoing bariatric surgery. Low-molecular-weight heparin is now used by two thirds of the respondents to this survey. Most surgeons who responded to the survey discharged their patients home with heparin, and many consider the use of inferior vena cava filters for VTE prophylaxis. Our findings support the American Society for Metabolic Bariatric Surgery position statement regarding VTE prophylaxis in this patient population. Research is necessary to establish the role of inferior vena cava filters, discharging patients with chemoprophylaxis and to determine the adequate dosage and duration of prophylaxis.