Mechanical compression versus subcutaneous heparin therapy in postoperative and posttrauma patients: a systematic review and meta-analysis

A systematic review of venous thromboembolism mechanical prophylaxis devices during surgery

PURPOSE

Hospitalisation and surgery are major risk factors for venous thromboembolism (VTE). Intermittent pneumatic compression (IPC) and graduated compression stockings (GCS) are common mechanical prophylaxis devices used to prevent VTE. This review compares the safety and efficacy of IPC and GCS used singularly and in combination for surgical patients.

METHODS

Ovid Medline and Pubmed were searched in a systematic review of the literature, and relevant articles were assessed against eligibility criteria for inclusion along PRISMA guidelines.

RESULTS

This review is a narrative description and critical analysis of available evidence. Fourteen articles were included in this review after meeting the criteria. Results of seven studies comparing the efficacy of IPC versus GCS had high heterogeneity but overall suggested IPC was superior to GCS. A further seven studies compared the combination of IPC and GCS versus GCS alone, the results of which suggest that combination mechanical prophylaxis may be superior to GCS alone in high-risk patients. No studies compared combination therapy to IPC alone. IPC appeared to have a superior safety profile, although it had a worse compliance rate and the quality of evidence was poor. The addition of pharmacological prophylaxis may make mechanical prophylaxis superfluous in the post-operative setting.

CONCLUSION

IPC may be superior to GCS when used as a single prophylactic device. A combination of IPC and GCS may be more efficacious than GCS alone for high-risk patients. Further high-quality research is needed focusing on clinical relevance, safety and comparing combination mechanical prophylaxis to IPC alone, particularly in high-risk surgical settings when pharmacological prophylaxis is contraindicated.

The association of timing of pharmacological prophylaxis and venous thromboembolism in patients with moderate-to-severe traumatic brain injury: A retrospective cohort study

OBJECTIVES:

Patients with traumatic brain injury (TBI) have an increased risk for venous thromboembolism (VTE). The current guidelines recommend pharmacologic prophylaxis, but its timing remains unclear.

METHODS:

In this retrospective cohort study, patients with moderate-to-severe TBI admitted to a tertiary care intensive care unit between 2016 and 2019 were categorized into two groups according to the timing of pharmacologic prophylaxis: early if prophylaxis was given within 72 h from hospital admission and late if after 72 h.

RESULTS:

Of the 322 patients in the cohort, 46 (14.3%) did not receive pharmacological prophylaxis, mainly due to early brain death; 152 (47.2%) received early pharmacologic prophylaxis and 124 (38.5%) received late prophylaxis. Predictors of late pharmacologic prophylaxis were lower body mass index, intracerebral hemorrhage (odds ratio [OR], 3.361; 95% confidence interval [CI], 1.269–8.904), hemorrhagic contusion (OR, 3.469; 95% CI, 1.039–11.576), and lower platelet count. VTE was diagnosed in 43 patients on a median of 10 days after trauma (Q1, Q3: 5, 15): 6.6% of the early prophylaxis group and 26.6% of the late group (P < 0.001). On multivariable logistic regression analysis, the predictors of VTE were Acute Physiology and Chronic Health Evaluation II score, subarachnoid hemorrhage, and late versus early pharmacologic prophylaxis (OR, 3.858; 95% CI, 1.687–8.825). The late prophylaxis group had higher rate of tracheostomy, longer duration of mechanical ventilation and stay in the hospital, lower discharge Glasgow coma scale, but similar survival, compared with the early group.

CONCLUSIONS:

Late prophylaxis (>72 h) was associated with higher VTE rate in patients with moderate-to-severe TBI, but not with higher mortality.

A Review of Current and Future Antithrombotic Strategies in Surgical Patients-Leaving the Graduated Compression Stockings Behind?

Venous thromboembolism (VTE) remains an important consideration within surgery, with recent evidence looking to refine clinical guidance. This review provides a contemporary update of existing clinical evidence for antithrombotic regimens for surgical patients, providing future directions for prophylaxis regimens and research. For moderate to high VTE risk patients, existing evidence supports the use of heparins for prophylaxis. Direct oral anticoagulants (DOACs) have been validated within orthopaedic surgery, although there remain few completed randomised controlled trials in other surgical specialties. Recent trials have also cast doubt on the efficacy of mechanical prophylaxis, especially when adjuvant to pharmacological prophylaxis. Despite the ongoing uncertainty in higher VTE risk patients, there remains a lack of evidence for mechanical prophylaxis in low VTE risk patients, with a recent systematic search failing to identify high-quality evidence. Future research on rigorously developed and validated risk assessment models will allow the better stratification of patients for clinical and academic use. Mechanical prophylaxis' role in modern practice remains uncertain, requiring high-quality trials to investigate select populations in which it may hold benefit and to explore whether intermittent pneumatic compression is more effective. The validation of DOACs and aspirin in wider specialties may permit pharmacological thromboprophylactic regimens that are easier to administer.

Anticoagulation in Patients with Platelet Disorders

Platelet disorders comprise heterogeneous diseases featured by reduced platelet counts and/or impaired platelet function causing variable bleeding symptoms. Despite their bleeding diathesis, patients with platelet disorders can develop transient or permanent prothrombotic conditions that necessitate prophylactic or therapeutic anticoagulation. Anticoagulation in patients with platelet disorders is a matter of concern because the bleeding risk could add to the hemorrhagic risk related to the platelet defect. This review provides an overview on the evidence on anticoagulation in patients with acquired and inherited thrombocytopenia and/or platelet dysfunction. We summarize tools to evaluate and balance bleeding- and thrombotic risks and describe a practical approach on how to manage these patients if they have an indication for prophylactic or therapeutic anticoagulation.

American Society of Hematology 2021 guidelines for management of venous thromboembolism: prevention and treatment in patients with cancer

BACKGROUND

Venous thromboembolism (VTE) is a common complication among patients with cancer. Patients with cancer and VTE are at a markedly increased risk for morbidity and mortality.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about the prevention and treatment of VTE in patients with cancer.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The guideline development process was supported by updated or new systematic evidence reviews. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

Recommendations address mechanical and pharmacological prophylaxis in hospitalized medical patients with cancer, those undergoing a surgical procedure, and ambulatory patients receiving cancer chemotherapy. The recommendations also address the use of anticoagulation for the initial, short-term, and long-term treatment of VTE in patients with cancer.

CONCLUSIONS

Strong recommendations include not using thromboprophylaxis in ambulatory patients receiving cancer chemotherapy at low risk of VTE and to use low-molecular-weight heparin (LMWH) for initial treatment of VTE in patients with cancer. Conditional recommendations include using thromboprophylaxis in hospitalized medical patients with cancer, LMWH or fondaparinux for surgical patients with cancer, LMWH or direct oral anticoagulants (DOAC) in ambulatory patients with cancer receiving systemic therapy at high risk of VTE and LMWH or DOAC for initial treatment of VTE, DOAC for the short-term treatment of VTE, and LMWH or DOAC for the long-term treatment of VTE in patients with cancer.

[Perioperative medical prophylaxis of venous thromboembolic events in head and neck surgery : A retrospective study and recommendations]

BACKGROUND

In the authors' department, a newly implemented clinical algorithm for application of perioperative thrombosis prophylaxis in head and neck surgery recommends restrictive handling of anticoagulants. This retrospective study aims to evaluate the algorithm by comparing incidences of venous thromboembolic events (VTE) and surgical revisions due to postoperative hemorrhage.

MATERIALS AND METHODS

Perioperative incidences of deep vein thrombosis and pulmonary embolism as well as surgical revisions due to postoperative hemorrhage after head and neck surgery were determined based on all patients operated in the department over a period of 36 months. The incidences before (group I) and after (group II) implementation of the restrictive algorithm were compared.

RESULTS

A total of 9276 patients were included. The incidences of VTE (0.12%) and surgical revisions due to postoperative hemorrhage (1.4%) were low. Incidences of VTE were non-significantly higher in group II (0.16%) than in group I (0.08%; p > 0.45, chi-square-test). Case analysis revealed that this difference was not due to implementation of the restrictive algorithm. The incidence of surgical revision due to postoperative hemorrhage was identical in the two groups (1.4%).

CONCLUSION

After restricting the indication for thrombosis prophylaxis, the incidence of VTE or surgical revision due to postoperative hemorrhage did not change significantly. The provided clinical algorithm represents a low-risk and low-cost strategy of perioperative risk stratification.

Prevention of thromboembolism in spinal cord injury -S1 guideline

Introduction

Traumatic and non-traumatic spinal cord injury bears a high risk for thromboembolism in the first few months after injury. So far, there is no consented guideline regarding diagnostic and prophylactic measures to prevent thromboembolic events in spinal cord injury. Based on a Pubmed research of related original papers and review articles, international guidelines and a survey conducted in German-speaking spinal cord injury centers about best practice prophylactic procedures at each site, a consensus process was initiated, which included spinal cord medicine experts and representatives from medical societies involved in the comprehensive care of spinal cord injury patients. The recommendations comply with the German S3 practice guidelines on prevention of venous thromboembolism.

Recommendations

Specific clinical or instrument-based screening methods are not recommended in asymptomatic SCI patients. Based on the severity of neurological dysfunction (motor completeness, ambulatory function) low dose low molecular weight heparins are recommended to be administered up to 24 weeks after injury. Besides, mechanical methods (compression stockings, intermittent pneumatic compression) can be applied. In chronic SCI patients admitted to the hospital, thromboembolism prophylactic measures need to be based on the reason for admission and the necessity for immobilization.

Conclusions

Recommendations for thromboembolism diagnostic and prophylactic measures follow best practice in most spinal cord injury centers. More research evidence needs to be generated to administer more individually tailored risk-adapted prophylactic strategies in the future, which may help to further prevent thromboembolic events without causing major side effects. The present article is a translation of the guideline recently published online (https://www.awmf.org/uploads/tx_szleitlinien/179-015l_S1_Thromboembolieprophylaxe-bei-Querschnittlaehmung_2020-09.pdf).

Venous Thromboembolism Prophylaxis in Aesthetic Surgery: A Survey of Plastic Surgeons' Practices

BACKGROUND

Deep venous thrombosis and pulmonary embolism, collectively known as venous thromboembolism (VTE), are among the most feared yet preventable surgical complications. Although many recommendations exist to reduce the risk of VTE, the actual VTE prophylaxis practices of aesthetic plastic surgeons remain unknown.

OBJECTIVES

The primary aim of this study was to elucidate plastic surgeons' experiences with VTE, preferred VTE prophylaxis practices, and areas in which VTE prevention may be improved.

METHODS

Members of The Aesthetic Society were queried via a 55-question electronic survey regarding their experience with VTE as well as their VTE prophylaxis practices. Anonymous responses were collected and analyzed by the Mayo Clinic Survey Research Center.

RESULTS

The survey was sent to 1729 of The Aesthetic Society members, of whom 286 responded. Fifty percent, 38%, and 6% of respondents reported having had a patient develop a deep venous thrombosis, pulmonary embolism, or death secondary to VTE, respectively. Procedures performed on the back or trunk were associated with the highest rate of VTE. Lower extremity procedures were associated with a significantly higher rate of VTE than expected. Over 90% of respondents reported utilizing a patient risk stratification assessment tool. Although at least one-half of respondents reported that the surgical facility in which they operate maintains some form of VTE prophylaxis protocol, 39% self-reported nonadherence with these protocols.

CONCLUSIONS

Considerable variability exists in VTE prophylaxis practices among The Aesthetic Society responders. Future efforts should simplify guidelines and tailor prophylaxis recommendations to the aesthetic surgery population. Furthermore, education of plastic surgeons performing aesthetic surgery and more diligent surgical venue supervision is needed to narrow the gap between current recommendations and actual practices.

Prophylaxis in nonorthopaedic surgery

Surgery increases the risk (by 20-fold) of venous thromboembolism (VTE), but there are prophylaxis methods (mechanical, pharmaceutical or combined) that safely reduce the incidence rate of VTE. The administration of prophylaxis requires a prior assessment of the risks associated with the patient and with the type of surgery. The Caprini and Rogers scales classify patients into four VTE risk categories (very low, low, moderate and high). In pharmacological prophylaxis, the risk of bleeding should also be assessed. At this time, the recommendation is to administer prophylaxis to all patients: mechanical prophylaxis for low, moderate or high risk with contraindications for the administration of heparin; combined with heparin for very high risk; and with drugs such as low-molecular-weight heparin, unfractionated heparin and fondaparinux for moderate to high risk. These measurements should be kept until full ambulation, discharge, or at least seven days (for major oncologic and bariatric surgery, maintain for four weeks).

Vascularized Free Tissue Transfer in a Patient with Hemophilia B: Case Report and Literature Review

Hemophilia is a blood disorder characterized by impairment of the coagulation cascade leading to an increased bleeding risk (Kauffman, 2014). As such, surgical management of these patients can become difficult and well-defined surgical guidelines are not yet in place (Assoumane et al., 2017). Close monitoring of perioperative factor levels may be even more crucial for those undergoing microvascular free tissue transfer. This is because either a hypercoagulable or hypocoagulable bleeding state has the potential to further increase the risk of vascular compromise to the flap. We report a successful case of mandibular reconstruction using a free fibular flap in a patient with severe hemophilia B and the protocols we used, as well as a review of the literature of similar cases. In the literature, we identified 6 cases of microvascular free tissue transfer in patients with hemophilia; two of these cases had complications which were both related to excess bleeding. It is crucial that these cases be managed in a multidisciplinary fashion in close consultation with a hematologist. The role of venothromboembolism (VTE) prophylaxis in the hemophilic patient undergoing free tissue transfer is discussed.

American Society of Hematology 2019 guidelines for management of venous thromboembolism: prevention of venous thromboembolism in surgical hospitalized patients

BACKGROUND

Venous thromboembolism (VTE) is a common source of perioperative morbidity and mortality.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about preventing VTE in patients undergoing surgery.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic reviews. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 30 recommendations, including for major surgery in general (n = 8), orthopedic surgery (n = 7), major general surgery (n = 3), major neurosurgical procedures (n = 2), urological surgery (n = 4), cardiac surgery and major vascular surgery (n = 2), major trauma (n = 2), and major gynecological surgery (n = 2).

CONCLUSIONS

For patients undergoing major surgery in general, the panel made conditional recommendations for mechanical prophylaxis over no prophylaxis, for pneumatic compression prophylaxis over graduated compression stockings, and against inferior vena cava filters. In patients undergoing total hip or total knee arthroplasty, conditional recommendations included using either aspirin or anticoagulants, as well as for a direct oral anticoagulant over low-molecular-weight heparin (LMWH). For major general surgery, the panel suggested pharmacological prophylaxis over no prophylaxis, using LMWH or unfractionated heparin. For major neurosurgery, transurethral resection of the prostate, or radical prostatectomy, the panel suggested against pharmacological prophylaxis. For major trauma surgery or major gynecological surgery, the panel suggested pharmacological prophylaxis over no prophylaxis.

Antithrombotic prophylaxis for surgery-associated venous thromboembolism risk in patients with inherited platelet disorders. The SPATA-DVT Study

Major surgery is associated with an increased risk of venous thromboembolism (VTE), thus the application of mechanical or pharmacologic prophylaxis is recommended. The incidence of VTE in patients with inherited platelet disorders (IPD) undergoing surgical procedures is unknown and no information on the current use and safety of thromboprophylaxis, particularly of low-molecular-weight-heparin in these patients is available. Here we explored the approach to thromboprophylaxis and thrombotic outcomes in IPD patients undergoing surgery at VTE-risk participating in the multicenter SPATA study. We evaluated 210 surgical procedures carried out in 155 patients with well-defined forms of IPD (VTE-risk: 31% high, 28.6% intermediate, 25.2% low, 15.2% very low). The use of thromboprophylaxis was low (23.3% of procedures), with higher prevalence in orthopedic and gynecological surgeries, and was related to VTE-risk. The most frequently employed thromboprophylaxis was mechanical and appeared to be effective, as no patients developed thrombosis, including patients belonging to the highest VTE-risk classes. Low-molecular-weight-heparin use was low (10.5%) and it did not influence the incidence of post-surgical bleeding or of antihemorrhagic prohemostatic interventions use. Two thromboembolic events were registered, both occurring after high VTE-risk procedures in patients who did not receive thromboprophylaxis (4.7%). Our findings suggest that VTE incidence is low in patients with IPD undergoing surgery at VTE-risk and that it is predicted by the Caprini score. Mechanical thromboprophylaxis may be of benefit in patients with IPD undergoing invasive procedures at VTE-risk and low-molecular-weight-heparin should be considered for major surgery.

Novel screening criteria for post-traumatic venous thromboembolism by using D-dimer

AIM

Because severe trauma patients frequently manifest coagulopathy, it is extremely important to detect venous thromboembolism (VTE) in the acute phase. However, no reference value for D-dimer in post-traumatic VTE has been reported given the substantial increase in its levels after injury. Therefore, this study evaluates the ability of our screening criteria using D-dimer to detect VTE in severe trauma patients.

METHODS

Trauma patients (n = 455) who were admitted to our emergency medical center during October 2011-June 2015 were included in this study. To prevent VTE, intermittent pneumatic compression was carried out in most patients. Our screening criteria included the following: (i) ≥5 days of hospital stay, (ii) increasing D-dimer levels across 3 measuring days, (iii) D-dimer levels ≥15 μg/mL. Patients who met these screening criteria underwent contrast-enhanced computed tomography (CE-CT) to detect VTE.

RESULTS

During the study period, 108 cases satisfied the screening criteria; 73 of these underwent CE-CT, 34 of whom were diagnosed with VTE (positive predictive value, 46.6%). The median hospital stay on satisfying the screening criteria and before undergoing CE-CT was 7 and 10 days, respectively. No patient had VTE symptoms at the time of diagnosis. Also, none of the remaining 347 patients who did not satisfy the screening criteria had VTE symptoms.

CONCLUSION

The screening criteria using D-dimer presented herein can be used as reference for efficiently detecting VTE in severe trauma patients.

Indications for medical compression stockings in venous and lymphatic disorders: An evidence-based consensus statement

Objective Medical compression stockings are a standard, non-invasive treatment option for all venous and lymphatic diseases. The aim of this consensus document is to provide up-to-date recommendations and evidence grading on the indications for treatment, based on evidence accumulated during the past decade, under the auspices of the International Compression Club. Methods A systematic literature review was conducted and, using PRISMA guidelines, 51 relevant publications were selected for an evidence-based analysis of an initial 2407 unrefined results. Key search terms included: 'acute', CEAP', 'chronic', 'compression stockings', 'compression therapy', 'lymph', 'lymphatic disease', 'vein' and 'venous disease'. Evidence extracted from the publications was graded initially by the panel members individually and then refined at the consensus meeting. Results Based on the current evidence, 25 recommendations for chronic and acute venous disorders were made. Of these, 24 recommendations were graded as: Grade 1A (n = 4), 1B (n = 13), 1C (n = 2), 2B (n = 4) and 2C (n = 1). The panel members found moderately robust evidence for medical compression stockings in patients with venous symptoms and prevention and treatment of venous oedema. Robust evidence was found for prevention and treatment of venous leg ulcers. Recommendations for stocking-use after great saphenous vein interventions were limited to the first post-interventional week. No randomised clinical trials are available that document a prophylactic effect of medical compression stockings on the progression of chronic venous disease (CVD). In acute deep vein thrombosis, immediate compression is recommended to reduce pain and swelling. Despite conflicting results from a recent study to prevent post-thrombotic syndrome, medical compression stockings are still recommended. In thromboprophylaxis, the role of stockings in addition to anticoagulation is limited. For the maintenance phase of lymphoedema management, compression stockings are the most important intervention. Conclusion The beneficial value of applying compression stockings in the treatment of venous and lymphatic disease is supported by this document, with 19/25 recommendations rated as Grade 1 evidence. For recommendations rated with Grade 2 level of evidence, further studies are needed.

Effect of low molecular weight heparin on venous thromboembolism disease in thoracotomy patients with cancer

Background

Much attention has been given to venous thromboembolism (VTE) disease, and many guidelines for prophylaxis have been published. However, there are few published data on patients who underwent thoracotomy. This study is to compare the effect of low molecular weight heparin (LMWH) combined mechanical approaches with mechanical approaches alone in prevention of VTE in the post thoracotomy cancer patients.

Methods

This study used a prospective, randomized-controlled design. Patients with cancer who were scheduled for thoracotomy were divided into two groups: group A and group B. In group A, patients were given intermittent pneumatic compression (IPC) and elastic stockings (ES) postoperatively. Additionally, at 24 hours post-operation, patients were subcutaneously injected with LMWH calcium (nadroparin calcium; GlaxoSmithKline, China) for 7 days. In group B, patients were only given postoperative IPC and ES. The primary end points were incidence of pulmonary embolism (PE), deep vein thrombosis (DVT), and the PE severity index (PESI) of PE patients. The secondary end points were hemoglobin (HGB), platelet (PLT), D-dimer, the PO2/FiO2 ratio (P/F) at postoperative day (POD) 7, the chest drainage time (CDT) and the length of stay (LOS) in hospital after operation.

Results

A total of 90 patients were included in the final data analysis (40 patients in group A and 50 patients in group B). At POD7, the incidence of PE, DVT and PESI was 17.50%, 5.00% and 102.14±9.87, respectively, in group A. And 8.00%, 8.00% and 97.00±4.24, respectively, in group B. There were no significant differences between two groups (all P values were >0.05). There were no significant differences of HGB, PLT, D-dimer and P/F between two groups at the 7th day post operation (all P value >0.05).

Conclusions

LMWH combined mechanical prophylaxis did not significant reduced the rate of VTE in thoracotomy cancer patients.

The Prophylaxis of Venous Thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is the third most common cardiovascular condition, after myocardial infarction and stroke. Prophylactic measures in accordance with current guidelines can significantly reduce the risk of VTE and the associated morbidity and mortality. Until now, the German interdisciplinary, evidence- and consensus-based (S3) clinical practice guideline on VTE prophylaxis was based on a complete review of all pertinent literature available in MEDLINE up to January 2008. More recent publications and drug approvals have made a thorough revision necessary.

METHODS

A systematic search was carried out in the MEDLINE and Embase databases for publications that appeared from 1 January 2008 to 7 August 2013. Updates of 5 national and international reference guidelines and 2 new Health Technology Assessment (HTA) reports were considered as well. A structured consensus-finding process was carried out with delegates from 27 scientific medical societies and from the Union of Medical Specialist Associations.

RESULTS

46 randomized controlled trials (RCTs) were included for critical appraisal. New findings led to re-evaluation of the value of compression stockings in combination with pharmacological prophylaxis (open recommendation), and suggest equal value of non-vitamin K antagonist oral anticoagulants (NOACs) and low molecular weight heparins (LMWH) or fondaparinux in elective hip and knee replacement (strong recommendation). For patients undergoing hip fracture surgery, we recommend LMWH or fondaparinux.

CONCLUSION

Further research is needed to assess the value of NOACs for pharmacological prophylaxis in orthopedic/trauma patients undergoing surgical procedures other than the ones mentioned above, and into the benefit and harm of new devices available for mechanical prophylaxis. The stringent implementation of basic measures such as early mobilization, movement exercises, and patient instruction is a key point to prevent venous thrombo - embolism.

Clinical evaluation of whole blood prothrombin time (PT) and international normalized ratio (INR) using a Laser Speckle Rheology sensor

Prothrombin time (PT) and the associated international normalized ratio (INR) are routinely tested to assess the risk of bleeding or thrombosis and to monitor response to anticoagulant therapy in patients. To measure PT/INR, conventional coagulation testing (CCT) is performed, which is time-consuming and requires the separation of cellular components from whole blood. Here, we report on a portable and battery-operated optical sensor that can rapidly quantify PT/INR within seconds by measuring alterations in the viscoelastic properties of a drop of whole blood following activation of coagulation with thromboplastin. In this study, PT/INR values were measured in 60 patients using the optical sensor and compared with the corresponding CCT values. Our results report a close correlation and high concordance between PT/INR measured using the two approaches. These findings confirm the accuracy of our optical sensing approach for rapid PT/INR testing in whole blood and highlight the potential for use at the point-of-care or for patient self-testing.

Venous thromboembolism prophylaxis in urology: A review

Venous thromboembolism is potentially a lethal problem, and is associated with chronic morbidity. Venous thromboembolism is frequently diagnosed after urological surgery, yet the role of perioperative venous thromboembolism prophylaxis is not clearly defined. Any current recommendations are largely based on evidence derived from other surgical specialties. Even within different guidelines, there remains significant variation, suggesting a consensus is required. The present review aims to define the problem of venous thromboembolism within the urological population, and identifies patients at risk. It evaluates the role of various types of mechanical and pharmacological prophylaxis, along with its timing and duration of administration in common urological operations. The current guidelines are summarized and compared in order to give the reader a better perspective of this vital condition.

[Prophylaxis of venous thromboembolic events in head and neck surgery]

BACKGROUND

Application of perioperative thrombosis prophylaxis in head and neck surgery lacks consistent standards in Germany. Due to sparse data, the latest German S3 guideline concerning prophylaxis of thromboembolic events recommends a restrictive handling of anticoagulants in head and neck surgery, with few specific recommendations.

OBJECTIVE

The aim of this paper is to provide concrete clinical recommendations based on a systematic literature review and the S3 guidelines.

MATERIALS AND METHODS

A keyword-based literature search was performed and the German S3 guideline "Prophylaxis of Venous Thromboembolic Events" was used to state the current level of evidence and provide a clinical algorithm.

RESULTS

Eight additional cohort studies dealing with the incidence of thromboembolic events in head and neck surgery were identified. There were no randomized controlled trials. In the proposed algorithm, a classification of dispositional (patient history) and expositional (operation time) risk into three groups enables preoperative risk evaluation indicating the individual demand for prophylaxis. In short operations without major tissue traumatization, routine drug-based thrombosis prophylaxis is not necessary, provided no third-grade risk factors (earlier thromboembolic event, coagulopathy, or malignant disease) are present. Low molecular weight heparins should be used as anticoagulants for drug-based prophylaxis.

CONCLUSION

Prophylaxis of thromboembolic events in head and neck surgery is of high clinical relevance but there is currently limited evidence regarding its implementation. This paper is based on a systematic literature review and provides a clinical algorithm for head and neck surgeons.

Detailed assessment of benefits and risks of retrievable inferior vena cava filters on patients with complicated injuries: the da Vinci multicentre randomised controlled trial study protocol

INTRODUCTION

Retrievable inferior vena cava (IVC) filters have been increasingly used in patients with major trauma who have contraindications to anticoagulant prophylaxis as a primary prophylactic measure against venous thromboembolism (VTE). The benefits, risks and cost-effectiveness of such strategy are uncertain.

METHODS AND ANALYSIS

Patients with major trauma, defined by an estimated Injury Severity Score >15, who have contraindications to anticoagulant VTE prophylaxis within 72 hours of hospitalisation to the study centre will be eligible for this randomised multicentre controlled trial. After obtaining consent from patients, or the persons responsible for the patients, study patients are randomly allocated to either control or IVC filter, within 72 hours of trauma admission, in a 1:1 ratio by permuted blocks stratified by study centre. The primary outcomes are (1) the composite endpoint of (A) pulmonary embolism (PE) as demonstrated by CT pulmonary angiography, high probability ventilation/perfusion scan, transoesophageal echocardiography (by showing clots within pulmonary arterial trunk), pulmonary angiography or postmortem examination during the same hospitalisation or 90-day after trauma whichever is earlier and (B) hospital mortality; and (2) the total cost of treatment including the costs of an IVC filter, total number of CT and ultrasound scans required, length of intensive care unit and hospital stay, procedures and drugs required to treat PE or complications related to the IVC filters. The study started in June 2015 and the final enrolment target is 240 patients. No interim analysis is planned; incidence of fatal PE is used as safety stopping rule for the trial.

ETHICS AND DISSEMINATION

Ethics approval was obtained in all four participating centres in Australia. Results of the main trial and each of the secondary endpoints will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ACTRN12614000963628; Pre-results.

The Efficacy of Dextran-40 as a Venous Thromboembolism Prophylaxis Strategy in Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

The incidence of venous thromboembolism (VTE) in peritoneal malignancies can approach 30 to 50 per cent without prophylaxis. Prophylaxis in cytoreductive surgeries (CRS) presents a challenge to preoperative heparin-based therapy because of an increased risk of coagulopathy and potential for bleeding. Herein, we report the large series of CRS and hyperthermic intraperitoneal chemotherapy receiving dextran-40 prophylaxis. Retrospective chart review of peritoneal malignancies patients undergoing CRS at University of Nebraska Medical Center identified 69 individuals who received dextran-40 between 2010 and 2013. The incidences of VTEs, perioperative bleeding, complications, morbidity, and mortality were determined in-hospital and at 90 days. Of the 69 patients treated, the 30-day VTE rate was 8.7 per cent, and no pulmonary embolisms, bleeding, anaphylactoid reaction, or mortality were observed with dextran usage. The specific VTE events included three upper extremity and three lower extremity VTEs. No additional VTE events were identified between 30 and 90 days. In conclusion, dextran-40 prophylaxis was not associated with any perioperative bleeding events, and the observed incidence of VTE was comparable to reported heparin-based prophylaxis in CRS/hyperthermic intraperitoneal chemotherapy patients. This data supports further exploration of dextran-40 as a VTE prophylactic agent in complex surgical oncology cases.

Hemodynamic effects of electrical muscle stimulation in the prophylaxis of deep vein thrombosis for intensive care unit patients: a randomized trial

Background

Deep vein thrombosis (DVT) is a major complication in critical care. There are various methods of prophylaxis, but none of them fully prevent DVT, and each method has adverse effects. Electrical muscle stimulation (EMS) could be a new effective approach to prevent DVT in intensive care unit (ICU) patients. We hypothesized that EMS increases the venous flow of the lower limbs and has a prophylactic effect against the formation of DVT.

Methods

This study included 26 patients admitted to a single ICU. We enrolled patients who could not move themselves due to spinal cord injury, head injury, central nervous system abnormalities, and sedation for mechanical ventilation. The patients were randomly allocated to either the EMS group or the control group. Patients in the EMS group received 30-min sessions of EMS applied to the bilateral lower extremities on arbitrary days within 14 days after admission. The control patients received no EMS. The peak flow velocity and diameter of the popliteal vein (Pop.V) and common femoral vein (CFV) were measured by ultrasound and then the volumes of venous flow were calculated using a formula.

Results

There were no statistically significant differences in patient characteristics between the two groups except for the mortality rate. In the EMS group, the median and interquartile range (IQR, 25th–75th percentile) of velocities of the Pop.V and CFV were higher during EMS compared with at rest: 10.6 (8.0–14.8) vs 24.5 (15.1–37.8) cm/s and 17.0 (12.3–23.8) vs 24.3 (17.0–33.0) cm/s, respectively (p < 0.05). The median (IQR) of volumes of venous flow of the Pop.V and CFV at rest and during EMS were 4.2 (2.7–7.2) vs 8.6 (5.4–16.1) cm³/s and 12.9 (9.7–21.4) vs 20.8 (12.3–34.1) cm³/s, respectively (p < 0.05). There were no major complications related to EMS.

Conclusions

EMS increased the venous flow of the lower limbs. EMS could be one potential method for venous thromboprophylaxis.

Trial registration

UMIN000013642

Assessment of anti-factor Xa activity of enoxaparin for venous thromboembolism prophylaxis in morbidly obese surgical patients

BACKGROUND:

Venous thromboembolism (VTE) can be encountered by 60% of hospitalized patients. Anticoagulants have been recommended to reduce the risk of VTE in patients with risk factors. However, no specific dosing recommendations for obese patients are provided in the current practice guidelines. The purpose of this study was to determine the efficacy and safety of weight-based dosing of enoxaparin for VTE prophylaxis among morbidly obese patients undergoing surgery.

METHODS:

Adult patients were enrolled if they have a body mass index (BMI) of ≥35 kg/m² and were scheduled for surgery. These patients were prescribed enoxaparin (0.5 mg/kg subcutaneously [SC] once daily). Peak anti-factor Xa levels were measured 4 h after the third dose of enoxaparin. The primary outcome measure was to determine whether a weight-based dosing of enoxaparin of 0.5 mg/kg produce the anticipated peak anti-Xa levels (0.2–0.6 IU/m) among obese patients undergoing surgery. Secondary outcomes include the incidence of VTE, the incidence of minor or major bleeding, and the incidence of heparin-induced thrombocytopenia (HIT).

RESULTS:

Fifty patients were enrolled in the study. The mean age was 53 ± 16 years, 74% of the patients were female. The mean BMI was 40.5 ± 5, and the average enoxaparin dose was 50 ± 9.8 SC daily. Nearly 88% of the patients reached the target anti-factor Xa (0.427 ± 0.17). None of the patients developed HIT or VTE. There was no incidence of major or minor bleeding.

CONCLUSIONS:

Weight-based enoxaparin dose led to the anticipated peak anti-Xa levels (0.2–0.6 IU/mL) in most of the morbidly obese study patients undergoing surgery without any evidence of major side effects. The weight-based dosing of enoxaparin was also effective in preventing VTE in all patients. Although these results are promising, further comparative trials are needed in the setting of morbidly obese surgical patients.

A critical balance: managing coagulation in patients with glioma

Cancer-associated thrombosis, including both arterial and venous thromboembolism (VTE), is a significant source of morbidity and mortality in patients with glioma. This risk is highest in the immediate postoperative period and is increased by chemotherapy, radiation, and corticosteroids. Systemic anticoagulation with low molecular weight heparin is the treatment of choice in both the therapeutic and prophylactic settings. However, these patients are also at risk of intracranial hemorrhage, a potentially catastrophic complication of anticoagulation, and this risk must be carefully balanced against the risk of VTE. In this review we outline the incidence, pathophysiology and management of thrombosis in patients with glioma, with a focus on clinical considerations including perioperative management, chemotherapy-induced thrombocytopenia, and end-of-life management.

Deep Venous Thrombosis and Tendon Healing

Tendon metabolism after acute Achilles tendon rupture (ATR) is associated with major complications related to immobilization, which results in reduced circulation, high risk of deep venous thrombosis (DVT), impaired healing and functional deficits.DVT has been demonstrated to occur in up to 50 % of the patients with ATR. Suffering from a DVT during tendon healing has been demonstrated as an independent predictive factor for impaired patient outcome at 1 year after ATR, suggesting that specific interventions are warranted to prevent DVT. Since pharmacological DVT prophylaxis has low or no effect during lower leg immobilization it is speculated whether adjuvant treatment with intermittent pneumatic compression (IPC) applied during lower limb immobilization can reduce the incidence of DVT.IPC, which acts through mechanical, chemical and molecular mechanisms, has been demonstrated to enhance neuro-vascular ingrowth in a tendon repair model and stimulate collagen production leading to improved maximum force during healing.Recently, a prospective randomized trial compared adjuvant IPC applied under an orthosis versus plaster cast only in ATR patients. The study found at 2 weeks post-operatively 21 % DVTs in the IPC-group compared to 37 % in the control group. Patients that received no IPC treatment exhibited an almost threefold increased odds for DVT, independently of age. Furthermore, using microdialysis technique, adjuvant IPC treatment was shown to increase the metabolic healing activity at 2 weeks post-ATR.Tendon healing is impaired by reduced circulation and DVT. The demonstration that adjuvant IPC effectively reduced DVT incidence, and also is capable of enhancing the metabolic response suggests that IPC treatment may not only be a viable means of prophylaxis against DVT, but possibly also a method of promoting healing.

Serotonin reuptake inhibitors and post-gastrostomy bleeding: reevaluating the link

Introduction

Serotonin reuptake inhibitors (SRIs) are one of the most commonly prescribed classes of medications with a relatively safe side-effect profile. However, SRIs are being increasingly reported to be associated with bleeding complications in patients undergoing invasive procedures resulting from inhibition of serotonin reuptake by platelets and impaired platelet aggregation. The aim of our study was to determine whether there is an increased risk of post-percutaneous endoscopic gastrostomy (PEG) bleeding in patients exposed to SRIs after controlling for other mediations known to increase the risk of bleeding and major comorbidities.

Methods

This was a single-center cohort study that included who underwent PEG tube placement by standard pull-guidewire technique from July 2006 to June 2014. Patients were categorized into groups based on the medications (SRIs, aspirin, non-steroidal anti-inflammatory drugs, and anticoagulants) administered during the index hospitalization. The incidence of post-PEG bleeding was noted in two distinct post-procedure periods: within 48 hours, and between 48 hours and 14 days.

Results

A total of 637 PEG tube placements were done on 570 patients during the study period. There were 107 patients (18.8%) with major bleeding within 48 hours of PEG and 79 patients (13.9%) with major bleeding between 48 hours and 14 days. There was no significant increase in the post-PEG bleeding in patients taking a combination of an SRI along with aspirin or non-steroidal anti-inflammatory drugs. Patients on subcutaneous heparin for prophylaxis against thromboembolic events were more likely to have oozing at the PEG site requiring blood transfusion.

Conclusion

We did not notice an increase in post-PEG bleeding in patients on SRIs. However, in view of the limitation that our study is retrospective and that there are no known significant side effects of withdrawal of SRIs for a short duration, withholding SRIs could be a safe clinical option in patients undergoing PEG tube placement.

Thrombosis prophylaxis and mortality risk among critically ill adults

BACKGROUND

The optimal approach for managing increased risk of VTE among critically ill adults is unknown.

METHODS

An observational study of 294,896 episodes of critical illness among adults was conducted in 271 geographically dispersed US adult ICUs. The primary outcomes were all-cause ICU and in-hospital mortality after adjustment for acuity and other factors among groups of patients assigned, based on clinical judgment, to prophylactic anticoagulation, mechanical devices, both, or neither. Outcomes of those managed with prophylactic anticoagulation or mechanical devices were compared in a separate paired, propensity-matched cohort.

RESULTS

After adjustment for propensity to receive VTE prophylaxis, APACHE (Acute Physiology and Chronic Health Evaluation) IV scores, and management with mechanical ventilation, the group treated with prophylactic anticoagulation was the only one with significantly lower risk of dying than those not provided VTE prophylaxis (ICU, 0.81 [95% CI, 0.79-0.84]; hospital, 0.84 [95% CI, 0.82-0.86; P < .0001). The mortality risk of those receiving mechanical device prophylaxis was not lower than that of patients without VTE prophylaxis. A study of 87,107 pairs of patients matched for propensity to receive VTE prophylaxis found that those managed with prophylactic anticoagulation therapy had significantly lower risk of death (ICU subhazard ratio, 0.82 [95% CI, 0.78-0.85]; hospital subhazard ratio, 0.82 [95% CI, 0.79-0.85]; P < .001) than those receiving only mechanical device prophylaxis.

CONCLUSIONS

These findings support a recommendation for prophylactic anticoagulation therapy in preference to mechanical device prophylaxis for critically ill adult patients who do not have a contraindication to anticoagulation.

Meta-analysis of randomized trials comparing combined compression and anticoagulation with either modality alone for prevention of venous thromboembolism after surgery

Background

Although venous thromboembolism (VTE) is an important cause of postoperative morbidity and mortality, there is still no consensus on the optimal strategy for VTE prevention after major surgery. The objective of this review was to determine the benefits and risks of thromboprophylaxis with both compression and anticoagulation, compared with either modality alone.

Methods

A systematic review of MEDLINE, CENTRAL and Embase databases was performed to identify eligible randomized trials. The literature search and data extraction were carried out independently by two reviewers. Outcomes of interest were deep vein thrombosis (DVT), pulmonary embolism, bleeding, limb injury and mortality.

Results

Twenty-five studies were eligible for inclusion. Adding compression to anticoagulation decreased the risk of DVT by 49 per cent (risk ratio (RR) 0·51, 95 per cent confidence interval 0·36 to 0·73). The corresponding funnel plot suggested publication bias and, overall, the evidence for this comparison was judged to be of low quality. Adding anticoagulation to compression decreased the risk of DVT by 44 per cent (RR 0·56, 0·45 to 0·69) while increasing the risk of bleeding (RR 1·74, 1·29 to 2·34). There was no suggestion of publication bias and the evidence for this comparison was judged to be of moderate quality.

Conclusion

Combined compression and anticoagulation is more effective at preventing postoperative DVT than either modality alone. However, adding anticoagulation to compression increases the risk of bleeding, and the evidence that adding compression to anticoagulation reduces VTE risk is of low quality.

Approach to outcome measurement in the prevention of thrombosis in surgical and medical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

This article provides the rationale for the approach to making recommendations primarily used in four articles of the Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines: orthopedic surgery, nonorthopedic surgery, nonsurgical patients, and stroke. Some of the early clinical trials of antithrombotic prophylaxis with a placebo or no treatment group used symptomatic VTE and fatal PE to measure efficacy of the treatment. These trials suggest a benefit of thromboprophylaxis in reducing fatal PE. In contrast, most of the recent clinical trials comparing the efficacy of alternative anticoagulants used a surrogate outcome, asymptomatic DVT detected at mandatory venography. This outcome is fundamentally unsatisfactory because it does not allow a trade-off with serious bleeding; that trade-off requires knowledge of the number of symptomatic events that thromboprophylaxis prevents. In this article, we review the merits and limitations of four approaches to estimating reduction in symptomatic thrombosis: (1) direct measurement of symptomatic thrombosis, (2) use of asymptomatic events for relative risks and symptomatic events from randomized controlled trials for baseline risk, (3) use of baseline risk estimates from studies that did not perform surveillance and relative effect from asymptomatic events in randomized controlled trials, and (4) use of available data to estimate the proportion of asymptomatic events that will become symptomatic. All approaches have their limitations. The optimal choice of approach depends on the nature of the evidence available.

An audit of pressure sores caused by intermittent compression devices used to prevent venous thromboembolism

When intermittent compression devices (ICDs) are used to prevent venous thromboembolism (VTE) they can cause pressure sores in a selected group of women, undergoing long operations. A prospective audit pre and post intervention showed a reduced risk with an alternative device, without increasing the risk of VTE.

Prevention of VTE in nonsurgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

This guideline addressed VTE prevention in hospitalized medical patients, outpatients with cancer, the chronically immobilized, long-distance travelers, and those with asymptomatic thrombophilia.

METHODS

This guideline follows methods described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

For acutely ill hospitalized medical patients at increased risk of thrombosis, we recommend anticoagulant thromboprophylaxis with low-molecular-weight heparin (LMWH), low-dose unfractionated heparin (LDUH) bid, LDUH tid, or fondaparinux (Grade 1B) and suggest against extending the duration of thromboprophylaxis beyond the period of patient immobilization or acute hospital stay (Grade 2B). For acutely ill hospitalized medical patients at low risk of thrombosis, we recommend against the use of pharmacologic prophylaxis or mechanical prophylaxis (Grade 1B). For acutely ill hospitalized medical patients at increased risk of thrombosis who are bleeding or are at high risk for major bleeding, we suggest mechanical thromboprophylaxis with graduated compression stockings (GCS) (Grade 2C) or intermittent pneumatic compression (IPC) (Grade 2C). For critically ill patients, we suggest using LMWH or LDUH thromboprophylaxis (Grade 2C). For critically ill patients who are bleeding or are at high risk for major bleeding, we suggest mechanical thromboprophylaxis with GCS and/or IPC at least until the bleeding risk decreases (Grade 2C). In outpatients with cancer who have no additional risk factors for VTE we suggest against routine prophylaxis with LMWH or LDUH (Grade 2B) and recommend against the prophylactic use of vitamin K antagonists (Grade 1B).

CONCLUSIONS

Decisions regarding prophylaxis in nonsurgical patients should be made after consideration of risk factors for both thrombosis and bleeding, clinical context, and patients' values and preferences.

Prevention of VTE in nonorthopedic surgical patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

VTE is a common cause of preventable death in surgical patients.

METHODS

We developed recommendations for thromboprophylaxis in nonorthopedic surgical patients by using systematic methods as described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines. Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

We describe several alternatives for stratifying the risk of VTE in general and abdominal-pelvic surgical patients. When the risk for VTE is very low (< 0.5%), we recommend that no specific pharmacologic (Grade 1B) or mechanical (Grade 2C) prophylaxis be used other than early ambulation. For patients at low risk for VTE (∼1.5%), we suggest mechanical prophylaxis, preferably with intermittent pneumatic compression (IPC), over no prophylaxis (Grade 2C). For patients at moderate risk for VTE (∼3%) who are not at high risk for major bleeding complications, we suggest low-molecular-weight heparin (LMWH) (Grade 2B), low-dose unfractionated heparin (Grade 2B), or mechanical prophylaxis with IPC (Grade 2C) over no prophylaxis. For patients at high risk for VTE (∼6%) who are not at high risk for major bleeding complications, we recommend pharmacologic prophylaxis with LMWH (Grade 1B) or low-dose unfractionated heparin (Grade 1B) over no prophylaxis. In these patients, we suggest adding mechanical prophylaxis with elastic stockings or IPC to pharmacologic prophylaxis (Grade 2C). For patients at high risk for VTE undergoing abdominal or pelvic surgery for cancer, we recommend extended-duration, postoperative, pharmacologic prophylaxis (4 weeks) with LMWH over limited-duration prophylaxis (Grade 1B). For patients at moderate to high risk for VTE who are at high risk for major bleeding complications or those in whom the consequences of bleeding are believed to be particularly severe, we suggest use of mechanical prophylaxis, preferably with IPC, over no prophylaxis until the risk of bleeding diminishes and pharmacologic prophylaxis may be initiated (Grade 2C). For patients in all risk groups, we suggest that an inferior vena cava filter not be used for primary VTE prevention (Grade 2C) and that surveillance with venous compression ultrasonography should not be performed (Grade 2C). We developed similar recommendations for other nonorthopedic surgical populations.

CONCLUSIONS

Optimal thromboprophylaxis in nonorthopedic surgical patients will consider the risks of VTE and bleeding complications as well as the values and preferences of individual patients.

Assessment of venous thromboembolism risk and adequacy of prophylaxis in selected acute care medical centres in Arabian Gulf States: results from the ENDORSE study

OBJECTIVES

To assess the prevalence of venous thromboembolism (VTE) risk in acutely ill surgical and medical patients in selected acute care centres in the Arabian Gulf States, and to determine the proportion of at-risk patients who received effective prophylaxis in accordance with 2004 American College of Chest Physicians (ACCP) guidelines.

MATERIALS AND METHODS

Eight hospitals from 3 countries (Kuwait, Kingdom of Saudi Arabia, and United Arab Emirates) contributed to the global ENDORSE (Epidemiological International Day for the Evaluation of Patients at Risk for Venous Thromboembolism in the Acute Hospital Care Setting) study. Medical records were reviewed for all the in-patients aged ≥40 years admitted to medical wards, and in patients aged ≥18 admitted to surgical wards. The VTE risk and recommended prophylaxis were assessed according to the 2004 ACCP guidelines.

RESULTS

Of 1,291 evaluable patients, 801 were considered at risk of VTE; 391 (48.8%) surgical patients and 410 (51.2%) medical patients. Of the 801 patients, 322 (40.2%) received ACCP-recommended VTE prophylaxis; 159 (40.7%) of surgical patients and 163 (39.8%) of medical patients.

CONCLUSIONS

The data showed that VTE prophylaxis was underutilized in high-risk hospitalized patients. We recommend that active measures should be implemented in acute care centres in these Arabian Gulf countries to ensure identification of patients at risk of VTE and institute the appropriate prophylaxis.

Deep vein thrombosis prophylaxis in trauma patients

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are known collectively as venous thromboembolism (VTE). Venous thromboembolic events are common and potentially life-threatening complications following trauma with an incidence of 5 to 63%. DVT prophylaxis is essential in the management of trauma patients. Currently, the optimal VTE prophylaxis strategy for trauma patients is unknown. Traditionally, pelvic and lower extremity fractures, head injury, and prolonged immobilization have been considered risk factors for VTE; however it is unclear which combination of risk factors defines a high-risk group. Modalities available for trauma patient thromboprophylaxis are classified into pharmacologic anticoagulation, mechanical prophylaxis, and inferior vena cava (IVC) filters. The available pharmacologic agents include low-dose heparin (LDH), low molecular weight heparin (LMWH), and factor Xa inhibitors. Mechanical prophylaxis methods include graduated compression stockings (GCSs), pneumatic compression devices (PCDs), and A-V foot pumps. IVCs are traditionally used in high risk patients in whom pharmacological prophylaxis is contraindicated. Both EAST and ACCP guidelines recommend primary use of LMWHs in trauma patients; however there are still controversies regarding the definitive VTE prophylaxis in trauma patients. Large randomized prospective clinical studies would be required to provide level I evidence to define the optimal VTE prophylaxis in trauma patients.

Prophylaxis for venous thromboembolism: guidelines translated for the clinician

Venous thromboembolism is a major cause of morbidity and mortality worldwide and most often affects hospitalized postoperative surgical and medical patients. Venous thromboembolism prophylaxis undoubtedly improves the care of these patients, as demonstrated by the current literature and guidelines. Failure to prescribe prophylaxis when indicated, however, remains a vital health care concern. The American College of Chest Physicians (ACCP) published their most recent guidelines regarding venous thromboembolism prophylaxis in 2008. In this review, we aim to summarize the most recent ACCP prophylaxis guidelines with practical application and interpretation for the practicing physician. Here we present the most practical information from these guidelines and summarize essential recommendations in key tables. We will briefly review the grading system used in the guidelines for the level of evidence and the strength of the recommendation. We will then discuss the recommendations for prophylaxis in the various patient populations described in these guidelines including general and orthopedic surgery, gynecologic surgery, urologic surgery, thoracic surgery, neurosurgery, trauma, medical conditions, cancer patients, and critical care. In addition, we will discuss recent clinical trials regarding novel anticoagulants for venous thromboembolism prophylaxis and share some conclusions.

Venous thromboembolic disease in trauma and surveillance ultrasonography

BACKGROUND

The literature reports a wide variation in the incidence of venous thromboembolic (VTE) disease in trauma patients. The performance of routine surveillance venous duplex ultrasound of bilateral lower extremities is controversial. Furthermore, recent examinations of the national trauma databank registry have suggested that routine duplex surveillance is associated with higher deep venous thrombosis (DVT) detection rates.

MATERIALS AND METHODS

We examined the incidence and risk factors for VTE disease in 2827 trauma patients admitted over a 2-y period to a state-verified level I trauma center. Detailed chart review was carried out for patients with VTE disease. We then evaluated the effects of a routine bilateral lower extremity duplex surveillance guideline on VTE detection in the subset of injury patients admitted to the trauma service.

RESULTS

We found an approximately 2% incidence of venous thromboembolic disease in a mostly blunt trauma population. Amongst patients with VTE disease, the most common risk factors were obesity and significant head injury. We then evaluated the 998 patients with injury who were admitted to the trauma service 1 y before and after surveillance guideline implementation. Despite a nearly 5-fold increase in the number of duplex scans, with a substantial increase in cost, we found no significant difference in the incidence of DVT.

CONCLUSIONS

Our preliminary data argue against the use of routine duplex surveillance of lower extremities for DVT in trauma patients. A larger, prospective analysis is necessary to confirm these findings.

Incidence and risk factors for fatal pulmonary embolism after major trauma: a nested cohort study

BACKGROUND

Venous thromboembolism is common after major trauma. Strategies to prevent fatal pulmonary embolism (PE) are widely utilized, but the incidence and risk factors for fatal PE are poorly understood.

METHODS

Using linked data from the intensive care unit, trauma registry, Western Australian Death Registry, and post-mortem reports, the incidence and risk factors for fatal PE in a consecutive cohort of major trauma patients, admitted between 1994 and 2002, were assessed. Non-linear relationships between continuous predictors and risk of fatal PE were modelled by logistic regression.

RESULTS

Of the 971 consecutive trauma patients considered in the study, 134 (13.8%) died after their injuries. Fatal PE accounted for 11.9% of all deaths despite unfractionated heparin prophylaxis being used in 44% of these patients. Fatal PE occurred in those who were older (mean age 51- vs 37-yr-old, P=0.01), with more co-morbidities (Charlson's co-morbidity index 1.1 vs 0.2, P=0.01), had a larger BMI (31.8 vs 24.5, P=0.01), and less severe head and systemic injuries when compared with those who died of other causes. Sites of injuries were not significantly related to the risk of fatal PE. Fatal PE occurred much later than deaths from other causes (median 18 vs 2 days, P=0.01), and the estimated attributable mortality of PE was 49% (95% confidence interval 36-62%).

CONCLUSIONS

Fatal PE appeared to be a potential preventable cause of late mortality after major trauma. Severity of injuries, co-morbidity, and BMI were important risk factors for fatal PE after major trauma.