Analysis of perioperative risk factors for deep vein thrombosis in patients with femoral and pelvic fractures

Exploration on the effect of anserine on the alleviation of DVT and its molecular mechanism

Background

This study aimed to explore the regulatory effect of anserine on HUVEC cell injury and thrombosis in deep venous thrombosis (DVT) rats, and to elucidate the underlying molecular mechanisms.

Methods

Non-targeted metabolomics data analyses were conducted using an ultra-performance liquid chromatography system Vanquish UHPLC and mass spectrometer to detect plasma metabolism profiles. The transcriptome sequencing and gene intervention experiments were performed to verify the regulatory effect. Further in vivo and in vitro experiments were performed. Enzyme-linked immunosorbent assay was used to detect the levels of P-selectin, E-selectin, and vWF, hematoxylin-eosin (HE) staining was performed to observe thrombotic and inflammatory cell infiltration, flow cytometry and TUNEL assays were performed to detect apoptosis, and qPCR and WB assays were conducted to determine the gene and protein expression.

Results

Anserine alleviated HUVECs injury, reduced adhesion molecule expression, and inflammation. It decreased P-selectin, E-selectin, vWF, THBD, TFPI levels, and apoptosis while promoting NOS3, ET-1, and NO release in HUVECs. In DVT rats, anserine reduced P-selectin, E-selectin, vWF, thrombosis, cell infiltration, apoptosis, and promoted NO release. Transcriptome sequencing and gene intervention confirmed anserine's regulation of the PI3K-Akt pathway and coagulation via MYB. CARNMT1, a regulatory enzyme for anserine metabolism, increased anserine content, inhibiting coagulation, thrombosis, cell infiltration, and promoting NO release in rats.

Conclusion

This study confirmed anserine could alleviate DVT by improving the inflammatory response, inhibiting blood agglutination, and promoting vasodilation, providing new potential therapeutic targets, important scientific evidence for the development of DVT management, and new clues for an in-depth understanding of its molecular mechanisms.

Prevalence and risk factors for proximal deep vein thrombosis at admission in patients with traumatic fractures: a multicenter retrospective study

Objective

This study aimed to determine the associated risk factors for proximal deep vein thrombosis (DVT) in patients with lower extremity and pelvic-acetabular fractures.

Methods

The medical records of 4,056 patients with lower extremity and pelvic-acetabular fractures were retrospectively reviewed. The patients were classified into proximal or non-proximal DVT groups. Logistic regression models were used to determine the independent risk variables for proximal DVT. The predictive value of the related risk factors was further analyzed using receiver operating characteristic curves.

Results

The prevalence of proximal DVT was 3.16%. Sex, body mass index (BMI), fracture site, injury mechanism, diabetes, coronary heart disease (CHD), injury-to-admission interval, hematocrit, platelet counts, and D-dimer levels differed significantly between the two groups. BMI ≥ 24.0 kg/m2, femoral shaft fractures, high-energy injury, diabetes, injury-to-admission interval >24 h were independent risk factors for proximal DVT. CHD decreased the risk of proximal DVT. The platelet and D-dimer had high negative predictive value for predicting proximal DVT formation, with cut-off values of 174 × 109/L and 2.18 mg/L, respectively.

Conclusion

BMI ≥ 24.0 kg/m2, femoral shaft fractures, high-energy injury, diabetes, injury-to-admission interval >24 h were independent risk factors for proximal DVT in patients with lower extremity and pelvic-acetabular fractures. Platelet count and D-dimer level were effective indicators for excluding proximal DVT occurrence. CHD decreased the risk of proximal DVT.

Coagulation parameters correlate to venous thromboembolism occurrence during the perioperative period in patients with spinal fractures

BACKGROUND

Venous thromboembolism (VTE) is one of the leading causes of mortality in hospitalized patients. However, whether the coagulation-related parameters of the hospitalized patients could be used to predict the occurrence of VTE in patients with spinal injury surgery remained unclear.

METHOD

The patients with spinal fractures who met the inclusion and exclusion criteria were enrolled to be analyzed using a retrospective analysis approach. The association of risk factors of enrolled patients and operations to VTE occurrence were analyzed. The activated partial thromboplastin time, prothrombin time, thrombin time, D-dimer (D-D), fibrinogen (FIB) and fibrinogen degradation products (FDP) were detected. ROC and HR analysis were applied to evaluate the correlation of coagulation-related parameters and other parameters to VTE occurrence.

RESULT

The indicators of D-D, FIB and FDP were significantly elevated in VTE patients compared to non-VTE patients. The multivariate analysis of OR showed that six risk factors, including age ≥ 60, spinal cord injury, postoperative bedtime over 5 days, plasma D-dimer ≥ 0.54 mg/L, plasma fibrinogen ≥ 3.75 g/L and plasma FDP ≥ 5.19 mg/L, were positively correlated to VTE.

CONCLUSION

The six risk factors, including D-D, FIB, FDP, age ≥ 60, spinal cord injury, and postoperative bedtime over 5 days, could be used to predict the occurrence of VTE.

A nomogram model for predicting lower extremity deep vein thrombosis after gynecologic laparoscopic surgery: a retrospective cohort study

Objective

To investigate the risk factors associated with lower extremity deep vein thrombosis (LEDVT) and to establish a predictive model for patients who undergo gynecologic laparoscopic surgery.

Methods

A review of clinical data was conducted on patients who underwent gynecologic laparoscopic surgery between November 1, 2020, and January 31, 2022. Patients who developed LEDVT after surgery were included as the observation group, while the control group comprised patients who did not experience complications. Multivariate forward stepwise logistic regression models were used to identify independent risk factors associated with LEDVT. A nomogram model was then developed based on these risk factors.

Results

A total of 659 patients underwent gynecologic laparoscopic surgery during the study period, and 52 (7.89%) of these patients developed postoperative LEDVT. Multivariate logistic regression analysis showed that older age (adjusted OR, 1.085; 95% CI [1.034-1.138]; P < 0.05), longer operation duration (adjusted OR, 1.014; 95% CI [1.009-1.020]; P < 0.05), shorter activated partial thromboplastin time (APTT) (adjusted OR, 0.749; 95% CI [0.635-0.884]; P < 0.05), higher D-dimer (adjusted OR, 4.929; 95% CI [2.369-10.255]; P < 0.05), higher Human Epididymis Protein 4 (HE4) (adjusted OR, 1.007; 95% CI [1.001-1.012]; P < 0.05), and history of hypertension (adjusted OR, 3.732; 95% CI [1.405-9.915]; P < 0.05) were all independent risk factors for LEDVT in patients who underwent gynecologic laparoscopic surgery. A nomogram model was then created, which had an area under the curve of 0.927 (95% CI [0.893-0.961]; P < 0.05), a sensitivity of 96.1%, and a specificity of 79.5%.

Conclusions

A nomogram model that incorporates information on age, operation duration, APTT, D-dimer, history of hypertension, and HE4 could effectively predict the risk of LEDVT in patients undergoing gynecologic laparoscopic surgery, potentially helping to prevent the development of this complication.

Venous thromboembolism in orthopedic surgery: Global guidelines

Venous thromboembolism (VTE) is a severe complication that can occur after major orthopedic procedures. As VTE-related morbidity and mortality are a significant concern for both medical professionals and patients, and preventative measures are typically employed. Multiple organizations, including the American College of Chest Physicians (ACCP) and the American Academy of Orthopedic Surgeons (AAOS), have developed guidelines for VTE prophylaxis specifically in patients undergoing joint replacement procedures. However, recently, the International Consensus Meeting (ICM) was convened, which brought together over 600 experts from 68 countries and 135 international societies. These experts, spanning a range of medical disciplines including orthopedic surgery, anesthesia, cardiology, hematology, vascular, and internal medicine, conducted a comprehensive review of the literature using a strict Delphi process to generate practical recommendations for VTE prophylaxis across all types of orthopedic procedures. This review article summarizes some of the recommendations of the ICM.

Association between carotid ultrasonographic parameters and microvascular and macrovascular complications in diabetes: A systematic review and meta-analysis

OBJECTIVE

The present meta-analysis aimed to assess the association between carotid ultrasonographic parameters and diabetic microvascular and macrovascular complications.

METHODS

All published articles were searched in electronic databases including PubMed, Embase, Cochrane Library, and Web of Science databases from the inception to May 27, 2023. Common carotid artery intima-media thickness (CCA-IMT), carotid bifurcation intima-media thickness (CB-IMT), internal carotid artery intima-media thickness (ICA-IMT), carotid plaque, carotid plaque score, plaque number, plaque thickness, carotid atherosclerosis, and resistivity indices (RIs) of ultrasonographic parameters were assessed. The odds ratio (OR), weighted mean difference (WMD), with the 95 % confidence interval (CI) were pooled to estimate the effect. Subgroup analyses were performed in terms of the type of diabetes and study design. Sensitivity analysis was used to evaluate the robustness of the results.

RESULTS

A total of 25 studies involving 12,102 diabetic patients were included in this systematic review and meta-analysis. Our findings suggested the associations between increased CCA-IMT and the risk of diabetic microvascular (WMD: 0.059, 95%CI: 0.026 to 0.091, P < 0.001) and macrovascular complications (WMD: 0.124, 95%CI: 0.061 to 0.187, P < 0.001) including cardiovascular events (OR: 2.362, 95%CI: 1.913 to 2.916, P < 0.001). Subgroup analyses also elaborated an association between CCA-IMT and diabetic microvascular and macrovascular complications. The results of sensitivity analysis show that the association is relatively stable.

CONCLUSION

Our findings revealed associations between carotid ultrasonographic parameters and microvascular and macrovascular complications of diabetes. Application of the carotid ultrasonographic parameters could be a non-invasive method for the early detection of long-term complications of diabetes.

Risk factors for deep vein thrombosis in patients with pelvic or lower-extremity fractures in the emergency intensive care unit

Introduction

This study aimed to investigate the incidence of deep vein thrombosis (DVT) in patients with pelvic or lower-extremity fractures in the emergency intensive care unit (EICU), explore the independent risk factors for DVT, and investigate the predictive value of the Autar scale for DVT in these patients.

Methods

The clinical data of patients with single fractures of the pelvis, femur, or tibia in the EICU from August 2016 to August 2019 were retrospectively examined. The incidence of DVT was statistically analyzed. Logistic regression was used to analyze the independent risk factors for DVT in these patients. The receiver-operating characteristic (ROC) curve was used to evaluate the predictive value of the Autar scale for the risk of DVT.

Results

A total of 817 patients were enrolled in this study; of these, 142 (17.38%) had DVT. Significant differences were found in the incidence of DVT among the pelvic fractures, femoral fractures, and tibial fractures (P < 0.001). The multivariate logistic regression analysis showed multiple injuries (OR = 2.210, 95% CI: 1.166-4.187, P = 0.015), fracture site (compared with tibia fracture group, femur fracture group OR = 4.839, 95% CI: 2.688-8.711, P < 0.001; pelvic fracture group OR = 2.210, 95% CI: 1.225-3.988, P = 0.008), and Autar score (OR = 1.198, 95% CI: 1.016-1.353, P = 0.004) were independent risk factors for DVT in patients with pelvic or lower-extremity fractures in the EICU. The area under the ROC curve (AUROC) of the Autar score for predicting DVT was 0.606. When the Autar score was set as the cutoff value of 15.5, the sensitivity and specificity for predicting DVT in patients with pelvic or lower-extremity fractures were 45.1% and 70.7%, respectively.

Discussion

Fracture is a high-risk factor for DVT. Patients with a femoral fracture or multiple injuries have a higher risk of DVT. In the case of no contraindications, DVT prevention measures should be taken for patients with pelvic or lower-extremity fractures. Autar scale has a certain predictive value for the occurrence of DVT in patients with pelvic or lower-extremity fractures, but it is not ideal.

The Use of Machine Learning Techniques to Predict Deep Vein Thrombosis in Rehabilitation Inpatients

BACKGROUND

Rehabilitation is crucial to recovering patients' dysfunction, improving their life quality, and promoting an early return to their family and society. In China, most patients in rehabilitation units are patients transferred from neurology, neurosurgery, and orthopedics, and most of these patients face problems such as continuously bedridden or varying degrees of limb dysfunction, all of which are risk factors for deep venous thrombosis. The formation of deep venous thrombosis can delay the recovery process and result in significant morbidity, mortality, and higher healthcare costs, so early detection and individualized treatment are needed. Machine learning algorithms can help develop more precise prognostic models, which can be of great significance in the development of rehabilitation training programs. In this study, we aimed to develop a model of deep venous thrombosis for inpatients in the Department of Rehabilitation Medicine at the Affiliated Hospital of Nantong University using machine learning methods.

METHODS

We analyzed and compared 801 patients in the Department of Rehabilitation Medicine using machine learning. Support vector machine, logistic regression, decision tree, random forest classifier, and artificial neural network were used to build models.

RESULTS

Artificial neural network was the better predictor than other traditional machine learnings. D-dimer levels, bedridden time, Barthel Index, and fibrinogen degradation products were common predictors of adverse outcomes in these models.

CONCLUSIONS

Risk stratification can help healthcare practitioners to achieve improvements in clinical efficiency and specify appropriate rehabilitation training programs.

Quality evaluation of clinical practice guidelines for thromboprophylaxis in orthopaedic trauma based on AGREE II and AGREE-REX: a systematic review protocol

INTRODUCTION

Orthopaedic trauma patients are at high risk of venous thromboembolism (VTE). As VTE prophylaxis has gradually raised public concerns, guidelines related to this topic have increased over time. However, the existing recommendations of thromboprophylaxis guidelines in orthopaedic trauma patients are still inconsistent, and the quality of the guidelines and recommendations for the topic still lacks comprehensive assessments. This review aims to critically appraise clinical practice guidelines for thromboprophylaxis in orthopaedic trauma patients.

METHODS AND ANALYSIS

We will conduct a comprehensive literature search up to 31 October 2022 in databases (PubMed, EMBASE, CINAHL, Web of Science, the Cochrane Library, etc), academic websites and guideline repositories. The quality of the guidelines and recommendations will be assessed by five reviewers independently using the Appraisal of Guidelines Research and Evaluation II instrument (AGREE-II) and the AGREE - Recommendation EXcellence (AGREE-REX). We will summarise the characteristics of the guidelines and compare the differences between these recommendations.

ETHICS AND DISSEMINATION

This study will follow the Declaration of Helsinki and has received approval from the Ethics Committee on Biomedical Research, West China Hospital, Sichuan University (ethics approval no. 2021-989). The results will be summarised as a paper, disseminated through peer-reviewed journals, and will help guide further research in the future.

PROTOCOL REGISTRATION NUMBER

CRD42021273405.

Preoperative anemia and deep vein thrombosis in patients with perioperative bone trauma: a cohort study

Background

In current active prevention (including physical and drug prevention), the incidence of perioperative deep vein thrombosis (DVT) of the lower extremities remains high in patients with bone trauma. Risk factors need to be further optimized, and high-risk patients must be identified early. Preoperative comorbidities, especially preoperative anemia, and DVT in patients with perioperative bone trauma are not clear. The purpose of this study was to explore the causal relationship between preoperative anemia and DVT in patients with perioperative bone trauma, and further reduce the incidence of DVT in patients with bone trauma.

Objectives

To analyze the relationship between preoperative anemia and perioperative DVT in patients with femoral and pelvic fractures and provide a reference for the optimization of risk factors for DVT.

Methods

The clinical data of 1049 patients with femoral and pelvic fractures who received surgical treatment from May 2018 to June 2021 were retrospectively analyzed. Propensity score matching (PSM) was performed for the covariates of DVT. Modified Poisson regression was used to analyze the relationship between preoperative anemia and DVT.

Results

After matching 1:1 propensity scores in 1049 patients included in this study, there were 258 patients in the anemic and non-anemic groups. Preoperative anemia was statistically significant for the formation of DVT in patients with perioperative bone trauma (P = 0.000, RR = 1.567 [95% CI 1.217–2.017]). This conclusion remained true after PSM (P = 0.009, RR = 1.500 [95% CI 1.105–2.036]). Preoperative anemia has some predictive value for perioperative DVT, with DVT-associated preoperative anemia thresholds of 125 g/L and area under the receiver operating characteristic curve of 0.5877 (95% CI 0.5345 to 0.6408). On this basis, sensitivity and specificity were 89.2 and 30.3%, respectively, with a Youden index of 0.195. In addition, we conducted an E-value determination of the propensity score; the E-value analysis showed robustness to unmeasured confounding.

Conclusions

Preoperative anemia is highly correlated with perioperative DVT in patients with bone trauma, which is the cause of perioperative DVT in these patients.

Characteristics of Deep Venous Thrombosis in Isolated Lower Extremity Fractures and Unsolved Problems in Guidelines: A Review of Recent Literature

Deep venous thrombosis (DVT) has been characterized by a disorder of venous return caused by abnormal blood clotting in deep veins. It often occurs in the lower limbs and is a common complication in orthopaedics. Therefore, relevant professional organizations domestic and overseas had formulated and constantly updated relevant guidelines to prevent the occurrence of DVT. According to the management strategy of the guidelines, the incidence of DVT can be significantly reduced. However, due to the variety of fractures types, the guidelines cannot expound precautions and characteristics of DVT for all fracture types at present, and there are other related unresolved problems. For example, there is still a lack of consistent optimal strategies for the management of DVT following isolated lower extremity fractures with a higher incidence. The best anticoagulant strategies for patients with upper limb fractures, pediatric fractures, and those combined with other injuries are rarely described in orthopaedic guidelines, but such fractures are common in clinical orthopaedics. The long‐term complications after DVT, such as post‐thrombotic syndrome, are not well‐understood. In the absence of clear guidance, orthopaedic surgeons often resort to empiric anticoagulation or conservative treatment, so the prevention effects of DVT are inconsistent. The purpose of this review is to summarize the characteristics of DVT events after isolated lower extremity fractures and to discuss the unsolved issues in the guidelines by reviewing the previous literature and tracing the history of DVT discovery, to provide more scientific and comprehensive recommendations for the prediction and prevention of DVT.

Development and validation of a predictive nomogram for preoperative deep vein thrombosis (DVT) in isolated calcaneal fracture

The fact that most of the patients with preoperative DVTs after calcaneal fractures are asymptomatic brought challenges to the early intervention, and periodic imaging examinations aggravated the financial burden of the patients in preoperative detumescence period. This study aimed to use routine clinical data, obtained from the database of Surgical Site Infection in Orthopaedic Surgery (SSIOS), to construct and validate a nomogram for predicting preoperative DVT risk in patients with isolated calcaneal fracture. The nomogram was established base on 7 predictors independently related to preoperative DVT. The performance of the model was tested by concordance index (C-index), receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA), and the results were furtherly verified internally and externally. 952 patients were enrolled in this study, of which 711 were used as the training set. The AUC of the nomogram was 0.870 in the training set and 0.905 in the validation set. After internal verification, the modified C-index was 0.846. Calibration curve and decision curve analysis both performed well in the training set and validation set. In short, we constructed a nomogram for predicting preoperative DVT risk in patients with isolated calcaneal fracture and verified its accuracy and clinical practicability.

The Best Evidence for the Prevention and Management of Lower Extremity Deep Venous Thrombosis After Gynecological Malignant Tumor Surgery: A Systematic Review and Network Meta-Analysis

Background:

To search and obtain the relevant evidence of prevention and management of lower extremity deep venous thrombosis (DVT) after gynecological malignant tumor operation and to summarize the relevant evidence.

Methods

We searched the JBI evidence summary, up to date, the national comprehensive cancer network of the United States, the guide library of the National Institute of clinical medicine of the United Kingdom, PubMed, the Chinese biomedical literature database, CNKI, Wanfang, and other relevant evidence on the prevention and management of DVT in patients with gynecological malignant tumors. It includes clinical practice guidelines, best practice information book, expert consensus, evidence summary, original research, etc. The retrieval time limit is from database establishment till August 20, 2021. Two researchers independently evaluated the literature quality, combined with professional judgment, and extracted the literature that met the standards.

Results

Finally, 18 literatures were included, including eight guidelines, three evidence summaries, four systematic evaluations, two expert consensuses, and one best practice information volume. A total of 26 pieces of the best evidence on the prevention and management of postoperative venous thrombosis in gynecological malignant tumors were summarized. It includes risk assessment, drug prevention, mechanical prevention, management strategy, and health education.

Conclusion

This study summarized the best evidence of risk, prevention, and health management of DVT in postoperative patients with gynecological malignant tumors to provide evidence-based basis for clinical nurses and to improve the nursing level.

Incidence and risk factors of preoperative deep venous thrombosis following pelvic and acetabular fractures: a retrospective case–control study

The objective of this study was to investigate the prevalence of preoperative deep venous thrombosis (DVT) in the pelvic cavity and lower extremities following pelvic and acetabular fractures and to identify the risk factors of the occurrence of DVT. Duplex ultrasound (DUS) screening and blood tests were conducted in patients admitted from June 2012 to December 2020 for surgical treatment of pelvic and acetabular fractures. Univariate analyses were performed on data of demographics, comorbidities, time from injury to surgery, injury mechanism, accompanied injury, and laboratory results. The optimal cutoff values of continuous variables with statistical significance were obtained by using the receiver operating characteristic (ROC) curve. A multivariate logistic regression analysis was then employed to examine the independent values in terms of predicting preoperative DVT. A total of 607 patients with pelvic and acetabular fractures were included, among whom 82 (13.5%) patients sustained preoperative DVTs. Specifically, 31.7% (26/82) were diagnosed with proximal DVTs. Fifty-two (63.4%) patients had DVT within 7 days after injury, and 67 (81.7%) patients within 10 days. The multivariate logistic regression analysis identified 6 factors independently associated with the presence of preoperative DVT, including age > 46 years (odds ratio [OR] = 2.94), BMI > 26.73 kg/m2 (OR = 3.91), time from injury to surgery > 9 days (OR = 5.39), associated injury (OR = 7.85), ALB < 32.8 g/L (OR = 2.71) and FIB > 3.095 g/L (OR = 3.34). Despite the modern prophylactic regimen, the preoperative DVT in patients with pelvic and acetabular fractures still draws the attention of orthopaedic surgeons. Better understanding these risk factors can help surgeons refine the risk stratification profile and perform early interdisciplinary management for patients at high risk of DVT.

Coagulation and Aging: Implications for the Anesthesiologist

Purpose of Review

This narrative review focuses on aging-related modifications in coagulation resulting in increased thromboembolic and hemorrhagic risk of the elderly. We further discuss the current evidence and emerging data relating the perioperative treatment of elderly patients with antithrombotic therapy.

Recent Findings

Relevant changes in all elements of the Virchow’s triad can be found with aging. Increased blood stasis due to immobility, progressive endothelial dysfunction with altered microcirculation, elevated concentrations of several coagulation factors, and increased platelet reactivity all lead to a procoagulant state. Elderly people are, therefore, commonly treated with oral anticoagulation and antiplatelet drugs. This antithrombotic therapy might be essentially causative for their increased bleeding risk.

Summary

Elderly patients are at increased risk for thromboembolism due to changes in the hemostatic system in combination with frailty and multimorbidity. Both the thromboembolic due to aging and bleeding risk due to antithrombotic therapy need special attention in the elderly surgical patients.

The Perioperative Deep Vein Thrombosis in Lower Extremities in Patients With Pelvic Fracture: A Case-Control Study

This study was to investigate the incidences of DVT in lower extremities after pelvic fracture before and after operation, and explore the risk factors. The records of patients with pelvic fractures receiving operation were collected. The patients were examined by preoperative and postoperative ultrasonography, and divided into thrombosis group and non-thrombosis group according to the preoperative and postoperative ultrasonographic results. Totally, 128 patients with pelvic fractures were included in this study. The incidence of DVT was 21.09% preoperatively, and increased to 35.16% postoperatively. Peripheral DVT constituted 92.60% and 86.67% of preoperative and postoperative DVTs, respectively. The results showed that age (odds ratio [OR] = 1.07; 95% CI: 1.01-1.12; P = 0.013), fracture classification (OR = 3.80; 95% CI: 1.31-11.00; P = 0.014) and D-dimer at admission (OR = 1.04; 95% CI: 1.00-1.08; P = 0.029) were independent risk factors of preoperative DVT, and female (OR = 0.21; 95% CI: 0.06-0.81; P = 0.023) was independent protective factor. In addition, age (OR, 1.06; 95% CI, 1.00-1.11; P = 0.026), operative blood transfusion (OR, 1.34; 95% CI, 1.05-1.72; P = 0.020) were independent risk factors of postoperative DVT. In conclusion, the DVT prevention strategy has not changed the high incidence of DVT in pelvic fractures, and orthopedic surgeons should pay more attention to perioperative DVT. When a male or patient with Tile-C type pelvic fracture is at admission, it is should be reminded that the screening the DVT in lower extremities. In addition, the surgeon should stanch bleeding completely, to reduce the blood transfusion and formation of DVT.