Randomized clinical trial of intermittent pneumatic compression and low molecular weight heparin in trauma

Employing Deep Reinforcement Learning to Maximize Lower Limb Blood Flow Using Intermittent Pneumatic Compression

Intermittent pneumatic compression (IPC) systems apply external pressure to the lower limbs and enhance peripheral blood flow. We previously introduced a cardiac-gated compression system that enhanced arterial blood velocity (BV) in the lower limb compared to fixed compression timing (CT) for seated and standing subjects. However, these pilot studies found that the CT that maximized BV was not constant across individuals and could change over time. Current CT modelling methods for IPC are limited to predictions for a single day and one heartbeat ahead. However, IPC therapy for may span weeks or longer, the BV response to compression can vary with physiological state, and the best CT for eliciting the desired physiological outcome may change, even for the same individual. We propose that a deep reinforcement learning (DRL) algorithm can learn and adaptively modify CT to achieve a selected outcome using IPC. Herein, we target maximizing lower limb arterial BV as the desired outcome and build participant-specific simulated lower limb environments for 6 participants. We show that DRL can adaptively learn the CT for IPC that maximized arterial BV. Compared to previous work, the DRL agent achieves 98% ± 2 of the resultant blood flow and is faster at maximizing BV; the DRL agent can learn an "optimal" policy in 15 minutes ± 2 on average and can adapt on the fly. Given a desired objective, we posit that the proposed DRL agent can be implemented in IPC systems to rapidly learn the (potentially time-varying) "optimal" CT with a human-in-the-loop.

Combination of graduated compression stockings and intermittent pneumatic compression is better in preventing deep venous thrombosis than graduated compression stockings alone for patients following gynecological surgery: a meta-analysis

BACKGROUND

Deep vein thrombosis (DVT) is common in patients undergoing gynecological surgery. We aimed to investigate the preventive efficacy in DVT of graduated compression stockings (GCS) alone and in combination with intermittent pneumatic compression (GCS + IPC) after gynecological surgery.

METHODS

In November 2022, studies on the use of GCS and GCS + IPC for the prevention of DVT after gynecological surgery were searched in seven databases. After literature screening and data extraction based on specific inclusion and exclusion criteria, preventive efficacies, including the risk of DVT and anticoagulation function, of GCS and GCS + IPC were compared. Finally, sensitivity analysis and Egger's test were performed to evaluate the stability of the meta-analysis.

RESULTS

Six publications with moderate quality were included in this meta-analysis. The results showed that GCS + IPC significantly reduced DVT risk (P = 0.0002) and D-dimer levels (P = 0.0005) compared with GCS alone. Sensitivity analysis and Egger's test showed that the combined results of this study were stable and reliable.

CONCLUSIONS

Compared with GCS alone, GCS + IPS showed a higher preventive efficacy against DVT in patients following gynecological surgery.

Comparison of different intervention methods to reduce the incidence of venous thromboembolism: study protocol for a cluster-randomized, crossover trial

BACKGROUND

Venous thromboembolism (VTE) remains a priority challenge among orthopedic trauma patients. It is crucial to further improve the prophylaxis against VTE in routine orthopedic treatment. This study aims to compare the efficacy of two low molecular weight heparin (LMWH) regimens and additional intermittent pneumatic compression in preventing VTE among orthopedic trauma patients.

METHODS AND ANALYSIS

This is a cluster-randomized crossover clinical study conducted in four hospitals in Shanghai from December 2019 to December 2023. The unit of randomization is orthopedic wards, and each ward will define a cluster. All clusters will implement four diverse intervention measures and one control measure in a given random sequence. Perioperative orthopedic trauma patients aged ≥ 18 years with stable vital signs, Caprini score > 2, and no contraindication of anticoagulation or intermittent pneumatic compression (IPC) devices will be eligible. The sample size will be determined to be 2590, considering cluster effect, period effect, and interactions. We will generally use the intention-to-treat (ITT) at the subject level for each outcome. For the primary outcome of the study, the incidence of VTE will be presented as risk ratio and 95% CIs. Generalized estimating equation (GEE) will be deployed to compare differences and adjust cluster effect, period effect, and interaction among interventions and periods if applicable.

DISCUSSION

VTE is a complication that cannot be underestimated after major orthopedic surgery. Early identification, early assessment, and early prevention can significantly reduce the incidence of VTE. Most guidelines recommend both medical and physical prevention, and we hope to demonstrate how they would affect the incidence among perioperative orthopedic patients. We want to explore if there is a difference between the two types of LWMH with or without an IPC device to provide more evidence for future guidelines and prevent more patients from the threat of VTE.

ETHICS AND DISSEMINATION

The study received approval from the IRB of the coordinating center and all participating hospitals. Findings will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION

ChiCTR1900027659. Registered on 17 November 2019.

The effectiveness of venous thromboembolism prophylaxis interventions in trauma patients: A systematic review and network meta-analysis

BACKGROUND

Venous thromboembolism (VTE) is a major complication of trauma. Currently, there are few studies summarising the evidence for prophylaxis in trauma settings. This review provides evidence for the use of VTE prophylactic interventions in trauma patients to produce evidence-based guidelines.

METHODS

A PRISMA-compliant review was conducted from Sep 2021 to June 2023, using Embase, Medline and Google Scholar. The inclusion criteria were: randomized-controlled trials (RCTs) in English published after 2000 of adult trauma patients comparing VTE prophylaxis interventions, with a sample size higher than 20. The network analysis was conducted using RStudio. The results of the pairwise comparisons were presented in the form of a league table. The quality of evidence and heterogeneity sensitivity were assessed. The primary outcome focused on venous thromboembolism (VTE), and examined deep vein thrombosis (DVT) and pulmonary embolism (PE) as separate entities. The secondary outcomes included assessments of bleeding and mortality. PROSPERO registration: CRD42021266393.

RESULTS

Of the 7,948 search results, 23 studies with a total of 21,312 participants fulfilled screening criteria, which included orthopaedic, spine, solid organ, brain, spinal cord, and multi-region trauma. Of the eight papers comparing chemical prophylaxis medications in patients with hip or lower limb injuries, fondaparinux and enoxaparin were found to be significantly superior to placebo in respect of prevention of DVT, with no increased risk of bleeding. Regarding mechanical prophylaxis, meta-analysis of two studies of inferior vena cava filters failed to provide significant benefits to major trauma patients.

CONCLUSION

Enoxaparin and fondaparinux are safe and effective options for VTE prevention in trauma patients, with fondaparinux being a cheaper and easier administration option between the two. Inconclusive results were found in mechanical prophylaxis, requiring more larger-scale RCTs.

Randomized Trial of Sequential Compression Versus Ankle-Calf Movement to Increase Femoral Venous Velocity

Objective In postoperative patients with a high risk of bleeding, sequential compression devices (SCD) and ambulation are effective methods to reduce venous thromboembolic (VTE) risks. High leg venous flow decreases VTE risk. We postulated that ankle flexion and extension (AFE) while in bed increased leg venous flow velocity as well. We wished to compare the effectiveness of SCD versus AFE in increasing leg venous velocity. Methods Thirty-two healthy volunteers were recruited into the study. Each subject had two legs that were randomized into SCD or AFE. After 15 minutes of rest, SCD or AFE was applied, followed by 15 minutes of rest, and then an alternate treatment was given to the second leg. The sequence of leg and methodology was then reversed so the second treatment was applied to the first leg, and the first treatment to the second leg, and measurements were obtained. All treatments were separated by a rest period of 15 minutes. The venous velocity on each leg was measured by Doppler ultrasound at the superficial femoral vein. Venous velocity was measured initially (first cycle peak venous velocity) and during subsequent cycles. The alternate treatments on both legs with both treatments allowed for analysis in a manner where each subject could act as its control. Results Relative to baseline bed rest, SCD increased peak venous flow velocity by 112%, while AFE increased peak venous flow velocity by 161%. AFE resulted in 43% higher venous velocity on average than did SCDs (p<0.05). Conclusions AFE leads to significantly higher venous flow in the femoral veins of healthy subjects.

Clinical effectiveness of a pneumatic compression device combined with low-molecular-weight heparin for the prevention of deep vein thrombosis in trauma patients: A single-center retrospective cohort study

BACKGROUND

To investigate the clinical effectiveness of a pneumatic compression device (PCD) combined with low-molecular-weight heparin (LMWH) for the prevention and treatment of deep vein thrombosis (DVT) in trauma patients.

METHODS

This study retrospectively analyzed 286 patients with mild craniocerebral injury and clavicular fractures admitted to our department from January 2016 to February 2020. Patients treated with only LMWH served as the control group, and patients treated with a PCD combined with LMWH as the observation group. The incidence of DVT, postoperative changes in the visual analogue scale (VAS) score, and coagulation function were observed and compared between the two groups. Excluding the influence of other single factors, binary logistic regression analysis was used to evaluate the use of a PCD in the patient's postoperative coagulation function.

RESULTS

After excluding 34 patients who did not meet the inclusion criteria, 252 patients were were included. The incidence of DVT in the observation group was significantly lower than that in the control group (5.6% vs. 15.1%, χ2=4.605, P<0.05). The postoperative VAS scores of the two groups were lower than those before surgery (P<0.05). The coagulation function of the observation group was significantly higher than that of the control group, with a better combined anticoagulant effect (P<0.05). There were no significant differences between the two groups in preoperative or postoperative Glasgow Coma Scale scores, intraoperative blood loss, postoperative infection rate, or length of hospital stay (P>0.05). According to logistic regression analysis, the postoperative risk of DVT in patients who received LMWH alone was 1.764 times that of patients who received LMWH+PCD (P<0.05). The area under the receiver operating characteristic (AUROC) curve of partial thromboplastin time (APTT) and platelet (PLT) were greater than 0.5, indicating that they were the influence indicators of adding PCD to prevent DVT. Excluding the influence of other variables, LMWH+PCD effectively improved the coagulation function of patients.

CONCLUSIONS

Compared with LMWH alone, LMWH+PCD could improve blood rheology and coagulation function in patients with traumatic brain injury and clavicular fracture, reduce the incidence of DVT, shorten the length of hospital stay, and improve the clinical effectiveness of treatment.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members.As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

Venous Thromboembolism Prophylaxis in Critically Ill Adults: A Systematic Review and Network Meta-analysis

BACKGROUND

Critically ill adults are at increased risk of VTE, including DVT, and pulmonary embolism. Various agents exist for venous thromboprophylaxis in this population.

RESEARCH QUESTION

What is the comparative efficacy and safety of prophylaxis agents for prevention of VTE in critically ill adults?

STUDY DESIGN AND METHODS

Systematic review and network meta-analysis of randomized clinical trials (RCTs) evaluating efficacy of thromboprophylaxis agents among critically ill patients. We searched six databases (including PubMed, EMBASE, and Medline) from inception through January 2021 for RCTs of patients in the ICU receiving pharmacologic, mechanical, or combination therapy (pharmacologic agents and mechanical devices) for thromboprophylaxis. Two reviewers performed screening, full-text review, and extraction. We used the Grading of Recommendations Assessment, Development, and Evaluation to rate certainty of effect estimates.

RESULTS

We included 13 RCTs (9,619 patients). Compared with control treatment (a composite of no prophylaxis, placebo, or compression stockings only), low-molecular-weight heparin (LMWH) reduced the incidence of DVT (OR, 0.59 [95% credible interval [CrI], 0.33-0.90]; high certainty) and unfractionated heparin (UFH) may reduce the incidence of DVT (OR, 0.82 [95% CrI, 0.47-1.37]; low certainty). LMWH probably reduces DVT compared with UFH (OR, 0.72 [95% CrI, 0.46-0.98]; moderate certainty). Compressive devices may reduce risk of DVT compared with control treatments; however, this is based on low-certainty evidence (OR, 0.85 [95% CrI, 0.50-1.50]). Combination therapy showed unclear effect on DVT compared with either therapy alone (very low certainty).

INTERPRETATION

Among critically ill adults, compared with control treatment, LMWH reduces incidence of DVT, whereas UFH and mechanical compressive devices may reduce the risk of DVT. LMWH is probably more effective than UFH in reducing incidence of DVT and should be considered the primary pharmacologic agent for thromboprophylaxis. The efficacy and safety of combination pharmacologic therapy and mechanical compressive devices were unclear.

TRIAL REGISTRY

Open Science Framework; URL: https://osf.io/694aj.

Viscoelastic monitoring in trauma resuscitation

BACKGROUND

Traumatic injury results in both physical and physiologic insult. Successful care of the trauma patient depends upon timely correction of both physical and biochemical injury. Trauma-induced coagulopathy is a derangement of hemostasis and thrombosis that develops rapidly and can be fatal if not corrected. Viscoelastic monitoring (VEM) assays have been developed to provide rapid, accurate, and relatively comprehensive depictions of an individual's coagulation profile. VEM are increasingly being integrated into trauma resuscitation guidelines to provide dynamic and individualized guidance to correct coagulopathy.

STUDY DESIGN AND METHODS

We performed a narrative review of the search terms viscoelastic, thromboelastography, thromboelastometry, TEG, ROTEM, trauma, injury, resuscitation, and coagulopathy using PubMed. Particular focus was directed to articles describing algorithms for management of traumatic coagulopathy based on VEM assay parameters.

RESULTS

Our search identified 16 papers with VEM-guided resuscitation strategies in adult patients based on TEG, 12 such protocols in adults based on ROTEM, 1 protocol for children based on TEG, and 2 protocols for children based on ROTEM.

CONCLUSIONS

This review presents evidence to support VEM use to detect traumatic coagulopathy, discusses the role of VEM in trauma resuscitation, provides a summary of proposed treatment algorithms, and discusses pending questions in the field.

Thromboprophylaxis in critically ill patients: balancing on a tightrope

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a common and potentially fatal complication in the intensive care unit (ICU). Critically ill patients have some special characteristics that increase the risk for VTE and complicate risk stratification and diagnosis. Given the positive effect of thromboprophylaxis on main outcomes, its use is mandatory in these patients, which is documented by various studies and recommended by all published guidelines. However, anticoagulation management is not an easy issue in clinical practice, as the critical patient may be at high risk for thrombosis or, conversely, at increased risk of bleeding or may balance between thrombotic and bleeding risk. Thrombotic and bleeding risk scoring should be evaluated daily in order to select the appropriate form of thromboprophylaxis. The selection depends on the degree of bleeding risk and the subgroup of ICU patients involved, such as patients with sepsis, acute brain injury, major trauma or coronavirus disease-2019. If there is no bleeding risk or other contraindication, the patient should receive pharmacologic thromboprophylaxis with unfractionated heparin or low molecular weight heparins, weighing the advantages of each agent. If the patient is at high risk of bleeding or there is a contraindication to pharmacologic prophylaxis, he should receive mechanical thromboprophylaxis mainly with intermittent pneumatic compression or graduated compression stockings. Thromboprophylaxis compliance with the guidelines is a prerequisite for moving from theory to practice. Direct oral anticoagulants have been studied in ICU patients and have no place at present in VTE prophylaxis requiring further research.

Can Intermittent Pneumatic Compression Reduce the Incidence of Venous Thrombosis in Critically Ill Patients: A Systematic Review and Meta-Analysis

Venous thromboembolism (VTE) is a common complication for critically ill patients. Intermittent pneumatic compression (IPC) is recommended for patients with high risk of bleeding. We aim to evaluate the effectiveness of IPC for thromboprophylaxis in critically ill patients. We searched PubMed, Embase, and ClinicalTrials for randomized controlled trials (RCTs) and observational studies that evaluated IPC in critically ill patients. RevMan 5.3 software was used for the meta-analysis. A total of 10 studies were included. The IPC group significantly reduced the VTE incidence compared with no thromboprophylaxis group (risk ratio [RR]: 0.35, confidence interval [CI]: 0.18-0.68, P = .002) and the IPC group also showed lower VTE incidence than the graduated compression stockings (GCS) group (RR: 0.47, CI: 0.24-0.91, P = .03). There were no significant differences between using IPC and low-molecular-weight heparin (LMWH) for VTE incidence (RR: 1.26, CI: 0.72-2.22, P = .41), but LMWH showed significantly more bleeding events. Intermittent pneumatic compression as an adjunctive treatment did not further reduce VTE incidence (RR: 0.55, CI: 0.24-1.27, P = .16). Intermittent pneumatic compression can reduce the incidence of VTE for critically ill patients, which is better than GCS and similar to LMWH, but it has no significant advantage as an adjunct therapy for thromboprophylaxis.

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.

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020)

The Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock 2020 (J-SSCG 2020), a Japanese-specific set of clinical practice guidelines for sepsis and septic shock created as revised from J-SSCG 2016 jointly by the Japanese Society of Intensive Care Medicine and the Japanese Association for Acute Medicine, was first released in September 2020 and published in February 2021. An English-language version of these guidelines was created based on the contents of the original Japanese-language version. The purpose of this guideline is to assist medical staff in making appropriate decisions to improve the prognosis of patients undergoing treatment for sepsis and septic shock. We aimed to provide high-quality guidelines that are easy to use and understand for specialists, general clinicians, and multidisciplinary medical professionals. J-SSCG 2016 took up new subjects that were not present in SSCG 2016 (e.g., ICU-acquired weakness [ICU-AW], post-intensive care syndrome [PICS], and body temperature management). The J-SSCG 2020 covered a total of 22 areas with four additional new areas (patient- and family-centered care, sepsis treatment system, neuro-intensive treatment, and stress ulcers). A total of 118 important clinical issues (clinical questions, CQs) were extracted regardless of the presence or absence of evidence. These CQs also include those that have been given particular focus within Japan. This is a large-scale guideline covering multiple fields; thus, in addition to the 25 committee members, we had the participation and support of a total of 226 members who are professionals (physicians, nurses, physiotherapists, clinical engineers, and pharmacists) and medical workers with a history of sepsis or critical illness. The GRADE method was adopted for making recommendations, and the modified Delphi method was used to determine recommendations by voting from all committee members. As a result, 79 GRADE-based recommendations, 5 Good Practice Statements (GPS), 18 expert consensuses, 27 answers to background questions (BQs), and summaries of definitions and diagnosis of sepsis were created as responses to 118 CQs. We also incorporated visual information for each CQ according to the time course of treatment, and we will also distribute this as an app. The J-SSCG 2020 is expected to be widely used as a useful bedside guideline in the field of sepsis treatment both in Japan and overseas involving multiple disciplines.

Early Detection of Deep Venous Thrombosis in Trauma Patients

Background

This study was performed to determine whether trauma patients are at an increased risk of developing deep venous thrombosis (DVT) within the first 48 hours of hospitalization.

Materials and methods

A retrospective review was performed using a prospectively maintained database of patients admitted to a trauma center during a five-year time period. Patients hospitalized for greater than 48 hours who received a screening venous duplex for DVT were included in the study.

Results

There were 1067 venous duplex scans obtained, 689 (64.5%) within the first 48 hours of admission (early DVT group), 378 (35.4%) after the first 48 hours (late DVT group). Only 142 (13.2%) patients had a positive duplex scan for DVT, 55 (early group), 87 (late group). Comorbid conditions of congestive heart failure (P = 0.02), pelvic fractures (P = 0.04), and a lower initial systolic blood pressure on presentation (p = 0.04) were associated with early DVT. Head trauma (P < 0.01), mechanical ventilation (P < 0.001), and transfusion of blood products (P < 0.001), were predictors of DVT in the late group.

Conclusions

Trauma patients are at an increased risk of developing venous thrombosis early in the hospital course due to comorbidities associated with trauma. Whereas, venous thrombosis in trauma patients diagnosed after the first 48 hours of hospitalization appears to be associated with prolonged patient immobility.

Meta-Analysis of the Role of Intermittent Pneumatic Compression of the Lower Limbs to Prevent Venous Thromboembolism in Critically Ill Patients

Critically ill patients (patients treated in a medical or surgical intensive care unit) are at high risk of venous thromboembolism (VTE) development (deep vein thrombosis [DVT] and/or pulmonary embolism). Multiple thromboprophylaxis strategies have been used for the prevention of VTE in this population with various outcomes. Therefore, we aimed to evaluate the efficacy of intermittent pneumatic compression (IPC) prophylaxis in the lower limb compared with no treatment, anticoagulant use, or their combinations in reducing risk. A comprehensive electronic database search was conducted for all randomized clinical trials (RCTs) comparing the clinical outcomes of IPC versus anticoagulants or no treatment or their combinations for the prevention of VTE for critically ill patients. The primary outcome was VTE. The secondary outcome was DVT. We performed a Bayesian network meta-analysis to calculate odds ratios (ORs) and 95% credible intervals (CrIs). We included 5 RCTs with 3133 total patients, represented by a mean age of 49.61 ± 18 years, while 60.28% were male. There was a significant reduction of the primary outcome (incidence of VTE events) when no treatment was compared with IPC (OR = 0.36; 95% CrI = 0.18-0.71), anticoagulation alone (OR = 0.30; 95% CrI = 0.12-0.68), or anticoagulation with IPC (OR = 0.34; 95% CrI = 0.13-0.81). In addition, there was a significant reduction in DVT when no treatment was compared with IPC (OR = 0.45; 95% CrI = 0.21-0.9), anticoagulation alone (OR = 0.16; 95% CrI = 0.03-0.66), or anticoagulation with IPC (OR = 0.18; 95% CrI = 0.03-0.84). However, there were no significant differences between other comparisons (IPC vs anticoagulation alone, anticoagulation alone vs anticoagulation with IPC, or anticoagulation with IPC vs IPC alone) regarding VTE or DVT incidence. Among critically ill patients, IPC alone, anticoagulation alone, and IPC with anticoagulation were associated with a significant reduction of VTE and DVT incidence compared with no treatment. However, there was no significant difference between these modalities when compared together. Therefore, further larger studies comparing those different thromboprophylaxis modalities and their combinations are needed to provide more robust results for future clinical recommendations.

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.

Research quality in the study of mechanical methods of deep vein thrombosis prophylaxis

There is a lack of good-quality recent clinical data to support the use of mechanical methods to prevent deep vein thrombosis. Recommendations and meta-analyses have to rely on old data from evaluations of devices that are no longer available, with diagnostic methods that are obsolete. The aim of this narrative review is to examine the reasons why better recent evidence is not available, and how this will affect innovation in mechanical deep vein thrombosis prophylaxis. Analysis of recent published trials shows great variability in techniques and technologies, which complicates evaluation of the effectiveness of properties of intermittent pneumatic compression, graduated compression stockings, and electrical stimulation devices. Negative controlled trials have become difficult to conduct, and low rates of deep vein thrombosis have left many comparative trials of devices underpowered. There is a risk that if new approaches to enable clinical research are not developed that technological advancement of mechanical prophylaxis will be inhibited.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: prophylaxis for hospitalized and nonhospitalized medical patients

BACKGROUND

Venous thromboembolism (VTE) is the third most common vascular disease. Medical inpatients, long-term care residents, persons with minor injuries, and long-distance travelers are at increased risk.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) intend to support patients, clinicians, and others in decisions about preventing VTE in these groups.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and adult patients. The Grading of Recommendations Assessment, Development and Evaluation approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 19 recommendations for acutely ill and critically ill medical inpatients, people in long-term care facilities, outpatients with minor injuries, and long-distance travelers.

CONCLUSIONS

Strong recommendations included provision of pharmacological VTE prophylaxis in acutely or critically ill inpatients at acceptable bleeding risk, use of mechanical prophylaxis when bleeding risk is unacceptable, against the use of direct oral anticoagulants during hospitalization, and against extending pharmacological prophylaxis after hospital discharge. Conditional recommendations included not to use VTE prophylaxis routinely in long-term care patients or outpatients with minor VTE risk factors. The panel conditionally recommended use of graduated compression stockings or low-molecular-weight heparin in long-distance travelers only if they are at high risk for VTE.

Chemoprophylaxis for Venous Thromboembolism in Operative Treatment of Fractures of the Tibia and Distal Bones: A Systematic Review and Meta-analysis

OBJECTIVES

Clinical practice has shifted from therapeutic anticoagulation of any lower extremity venous thromboembolism (VTE) to only thromboses with risk of proximal extension or embolization-clinically important VTE (CIVTE). Isolated operative fractures of the tibia or distal bone of the lower extremity are associated with low-to-intermediate VTE risk, and there is wide variability in the choice to anticoagulate as well as anticoagulant. We sought to evaluate the role for chemoprophylaxis of VTE and CIVTE in these injuries by meta-analysis of Level I evidence.

DATA SOURCES

Articles in English, Chinese, French, and German in MEDLINE, Biosis, and EMBASE from 1988 to 2016.

STUDY SELECTION

Randomized controlled trials describing chemoprophylaxis of VTE after operative management of fractures of the tibia and distal bones. Independent review of 1502 citations yielded 5 studies (1181 patients) meeting inclusion criteria.

DATA EXTRACTION

Chemoprophylaxis regimen, VTE, CIVTE, and major bleeding events were recorded. Study quality was assessed with regard to randomization, outcome assessment allocation and treatment concealment, and commercial funding.

DATA SYNTHESIS

A random-effects model meta-analysis determined that chemoprophylaxis with a low-molecular-weight heparin (LMWH) compared with placebo or no intervention significantly reduced the risk of any VTE [pooled relative risk (RR) = 0.696, 95% confidence interval (0.490-0.989), P = 0.043; homogeneity P = 0.818, I = 0%]. However, chemoprophylaxis with a LMWH compared with placebo did not significantly reduce the risk of CIVTE [RR = 0.865, 95% confidence interval (pooled RR = 0.112-3.863), P = 0.790; homogeneity P = 0.718, I = 0%]. No major bleeding events occurred. Funnel plots did not suggest publication bias. The number needed to treat was 31 patients treated with chemoprophylaxis using a LMWH to prevent 1 VTE and 584 patients to prevent 1 CIVTE.

CONCLUSIONS

Meta-analysis of Level I evidence suggests that routine postoperative anticoagulation after surgical management of an isolated fracture of the tibia or distal bone in patients without risk factors for VTE is unlikely to provide a clinical benefit, based on the absence of a treatment effect for preventing VTE warranting therapeutic anticoagulation.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Anti-Xa-guided enoxaparin thromboprophylaxis reduces rate of deep venous thromboembolism in high-risk trauma patients

BACKGROUND

Appropriate prophylaxis against venous thromboembolism (VTE) remains undefined. This study evaluated an anti-Xa-guided enoxaparin thromboprophylaxis (TPX) protocol on the incidence of VTE in high-risk trauma patients based on Greenfield's Risk Assessment Profile (RAP) score.

METHODS

This is a retrospective observational study of patients admitted to a trauma intensive care unit over a 12-month period. Patients were included if they received anti-Xa-guided enoxaparin TPX. Dosage was adjusted to a prophylactic peak anti-Xa level of 0.2 to 0.4 IU/mL. Subgroup analysis was performed on high-risk patients (RAP score ≥10) who received lower-extremity duplex ultrasound surveillance for deep vein thrombosis (DVT). Data are expressed as mean ± SD. Significance was assessed at p < 0.05.

RESULTS

One hundred thirty-one patients received anti-Xa-guided enoxaparin TPX. Four patients were excluded for age or acute VTE on admission. Fifty-six patients with RAP score of ≥10 and surveillance duplex evaluations were included in the subgroup analysis with mean age 43 ± 20 years, Injury Severity Score of 25 ± 10, and RAP score of 16 ± 4. Prophylactic anti-Xa levels were initially achieved in 34.6% of patients. An additional 25.2% required 40 to 60 mg twice daily to reach prophylactic levels; 39.4% never reached prophylactic levels. Weight, body mass index, ISS, and RAP score were significantly higher with subprophylactic anti-Xa levels. One patient developed bleeding complications (0.8%). No patient developed intracerebral bleeding or heparin-induced thrombocytopenia.Nine VTE events occurred in the high-risk subgroup, including four DVT (7.1%), all asymptomatic, and five pulmonary emboli (8.9%). The historical rate of DVT in similar patients (ISS 31 ± 12 and RAP score 16 ± 5) was 20.5%, a significant decrease (p = 0.031). Mean chest Abbreviated Injury Scale scores were significantly higher for patients developing pulmonary emboli than DVT, 3.0 ± 1.1 vs. 0.0 (p < 0.001).

CONCLUSIONS

Mean chest Abbreviated Injury Scale score was higher in patients developing pulmonary embolism. Increased weight, body mass index, ISS, and RAP score are associated with subprophylactic anti-Xa levels. Anti-Xa-guided enoxaparin dosing reduced the rate of DVT from 20.5% to 7.1% in high-risk trauma patients.

LEVEL OF EVIDENCE

Therapeutic study, level IV.

Prevention of venous thromboembolism in gynecologic oncology surgery

Gynecologic oncology patients are at a high-risk of postoperative venous thromboembolism and these events are a source of major morbidity and mortality. Given the availability of prophylaxis regimens, a structured comprehensive plan for prophylaxis is necessary to care for this population. There are many prophylaxis strategies and pharmacologic agents available to the practicing gynecologic oncologist. Current venous thromboembolism prophylaxis strategies include mechanical prophylaxis, preoperative pharmacologic prophylaxis, postoperative pharmacologic prophylaxis and extended duration pharmacologic prophylaxis that the patient continues at home after hospital discharge. In this review, we will summarize the available pharmacologic prophylaxis agents and discuss currently used prophylaxis strategies. When available, evidence from the gynecologic oncology patient population will be highlighted.

Pharmacological and Mechanical Thromboprophylaxis in Critically Ill Patients: a Network Meta-Analysis of 12 Trials

Thromboprophylaxis for venous thromboembolism is widely used in critically ill patients. However, only limited evidence exists regarding the efficacy and safety of the various thromboprophylaxis techniques, especially mechanical thromboprophylaxis. Therefore, we performed meta-analysis of randomized controlled trials (RCTs) that compared the overall incidence of deep vein thrombosis (DVT) for between unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), and intermittent pneumatic compression (IPC) in critically ill patients. A Bayesian random effects model for multiple treatment comparisons was constructed. The primary outcome measure was the overall incidence of DVT at the longest follow-up. The secondary outcome measure was the incidence of major bleeding, as defined by the original trials. Our analysis included 8,622 patients from 12 RCTs. The incidence of DVT was significantly lower in patients treated with UFH (OR, 0.45; 95% CrI, 0.22-0.83) or LMWH (OR, 0.38; 95% CrI, 0.18-0.72) than in patients in the control group. IPC was associated with a reduced incidence of DVT compared to the control group, but the effect was not statistically significant (OR, 0.50; 95% CrI, 0.20-1.23). The risk of DVT was similar for patients treated with UFH and LMWH (OR, 1.16; 95% CrI, 0.68-2.11). The risk of major bleeding was similar between the treatment groups in medical critically ill patients and also in critically ill patients with a high risk of bleeding. In critically ill patients, the efficacy of mechanical thromboprophylaxis in reducing the risk of DVT is not as robust as those of pharmacological thromboprophylaxis.

Thromboprophylaxis using combined intermittent pneumatic compression and pharmacologic prophylaxis versus pharmacologic prophylaxis alone in critically ill patients: study protocol for a randomized controlled trial

BACKGROUND

Venous thromboembolism (VTE) remains a common problem in critically ill patients. Pharmacologic prophylaxis is currently the standard of care based on high-level evidence from randomized controlled trials. However, limited evidence exists regarding the effectiveness of intermittent pneumatic compression (IPC) devices. The Pneumatic compREssion for preventing VENous Thromboembolism (PREVENT trial) aims to determine whether the adjunct use of IPC with pharmacologic prophylaxis compared to pharmacologic prophylaxis alone in critically ill patients reduces the risk of VTE.

METHODS/DESIGN

The PREVENT trial is a multicenter randomized controlled trial, which will recruit 2000 critically ill patients from over 20 hospitals in three countries. The primary outcome is the incidence of proximal lower extremity deep vein thrombosis (DVT) within 28 days after randomization. Radiologists interpreting the scans are blinded to intervention allocation, whereas the patients and caregivers are unblinded. The trial has 80 % power to detect a 3 % absolute risk reduction in proximal DVT from 7 to 4 %.

DISCUSSION

The first patient was enrolled in July 2014. As of May 2015, a total of 650 patients have been enrolled from 13 centers in Saudi Arabia, Canada and Australia. The first interim analysis is anticipated in July 2016. We expect to complete recruitment by 2018.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02040103 (registered on 3 November 2013). Current controlled trials: ISRCTN44653506 (registered on 30 October 2013).

Inferior vena cava (IVC) filters in children: A 10-year single center experience

BACKGROUND

Venous thromboembolism (VTE) is an increasingly recognized problem among children and adolescents. Although inferior vena cava (IVC) filter placement for pulmonary embolism prevention is well reported in adults, data regarding safety and efficacy in the pediatric age group are lacking.

PROCEDURE

At a large university hospital with a level I trauma center, medical records of children and adolescents who underwent IVC filter insertion were reviewed. Appropriateness of referral for retrieval was assessed in each case.

RESULTS

Fifty-nine children and adolescents (mean age 16 years) successfully underwent IVC filter insertion. All filters placed were retrievable. In 47 patients (79.7%), prophylactic filters were placed in the absence of acute VTE in the setting of trauma. In eight patients (13.5%), filters were placed due to contraindication to anticoagulation therapy with concomitant lower extremity deep vein thrombosis or pulmonary embolism. Filters were successfully retrieved in only 12 patients (20.3%), although an attempt at removal was appropriate and feasible in over 90% of cases. Mean duration of follow-up was 2.1 (range 0.4-7.3) years. A significantly higher retrieval rate was found in patients followed at our thrombosis clinic (P < 0.01). Ten patients (17%) experienced at least one filter-related complication.

CONCLUSIONS

Although in most cases, IVC filters were placed for prophylactic indications, the evidence to support their role in this setting is limited. Their low retrieval rate and high filter-related complication rate question their extensive utilization in children. Dedicated follow-up is necessary to detect complications and to ensure that an attempt at retrieval is made when feasible.

Venous Thromboembolism Prophylaxis in Orthopaedic Trauma Patients: A Survey of OTA Member Practice Patterns and OTA Expert Panel Recommendations

OBJECTIVES

First, to provide the readership with a summation of the current practice patterns of North American orthopaedic surgeons for venous thromboembolism prophylaxis after musculoskeletal trauma. Second, to establish a set of guidelines and recommendations based on the most current and best available evidence for venous thromboembolism (VTE) prophylaxis after musculoskeletal trauma.

METHODS

A 24 item questionnaire titled "OTA VTE Prophylaxis Survey" was sent to active members of the Orthopaedic Trauma Association. PubMed and OVID/MEDLINE were used to search the current published literature regarding VTE prophylaxis in trauma patients using the following search terms: deep venous thrombosis, DVT, pulmonary embolism, PE, venous thromboembolism, VTE, prophylaxis, trauma, fracture, pneumatic compression device, PCD, sequential compression device, SCD, screening, ultrasound, duplex, ultrasonography, DUS, venography, magnetic resonance venography, MRV, inferior vena cava, IVC, filter, and IVCF. Each recommendation was graded using articles that were considered by the subcommittee as "the best available evidence" using the grading system adopted and endorsed by the American Academy of Orthopedic Surgeons' Evidenced Based Quality and Value committee.

RESULTS

Overall, 185 of 1545 members completed the online survey. The range and variety of prophylaxis and screening methods used among orthopaedic trauma surgeons in North America is large, with a number of agents or methods for which no literature exists to support their use in musculoskeletal trauma. A set of recommendations and guidelines were constructed based on the results of the literature analysis and graded according to guidelines mentioned above.

CONCLUSIONS

Due to the wide variability in practice patterns, poor scientific support for various therapeutic regimens and important medical-legal implications highlighted by the survey, a standardized set of guidelines and recommendations for VTE prophylaxis after musculoskeletal trauma will be critical in helping to improve patient care and minimize surgeons' exposure to potentially litigious activity.

LEVEL OF EVIDENCE

Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.

Venous thromboembolism in the ICU: main characteristics, diagnosis and thromboprophylaxis

Venous thromboembolism (VTE), including pulmonary embolism (PE) and deep venous thrombosis (DVT), is a common and severe complication of critical illness. Although well documented in the general population, the prevalence of PE is less known in the ICU, where it is more difficult to diagnose and to treat. Critically ill patients are at high risk of VTE because they combine both general risk factors together with specific ICU risk factors of VTE, like sedation, immobilization, vasopressors or central venous catheter. Compression ultrasonography and computed tomography (CT) scan are the primary tools to diagnose DVT and PE, respectively, in the ICU. CT scan, as well as transesophageal echography, are good for evaluating the severity of PE. Thromboprophylaxis is needed in all ICU patients, mainly with low molecular weight heparin, such as fragmine, which can be used even in cases of non-severe renal failure. Mechanical thromboprophylaxis has to be used if anticoagulation is not possible. Nevertheless, VTE can occur despite well-conducted thromboprophylaxis.

Methods and Guidelines for Venous Thromboembolism Prevention in Polytrauma Patients with Pelvic and Acetabular Fractures

Sequential compression devices and chemical prophylaxis are the standard venous thromboembolism (VTE) prevention for trauma patients with acetabular and pelvic fractures. Current chemical pharmacological contemplates the use of heparins or fondaparinux. Other anticoagulants include coumarins and aspirin, however these oral agents can be challenging to administer and may need monitoring. When contraindications to anticoagulation in high-risk patients are present, prophylactic inferior vena cava filters can be an option to prevent pulmonary emboli. Unfortunately strong evidence about the most effective method, and the timing of their commencement, in patients with pelvic and acetabular fractures remains controversial.

Prospective Evaluation of Weight-Based Prophylactic Enoxaparin Dosing in Critically Ill Trauma Patients: Adequacy of AntiXa Levels is Improved

Venous thromboembolism (VTE) is a leading cause of death in multisystem trauma patients; the importance of VTE prevention is well recognized. Presently, standard dose enoxaparin (30 mg BID) is used as chemical prophylaxis, regardless of weight or physiologic status. However, evidence suggests decreased bioavailability of enoxaparin in critically ill patients. Therefore, we hypothesized that a weight-based enoxaparin dosing regimen would provide more adequate prophylaxis (as indicated by antifactor Xa levels) for patients in our trauma intensive care unit (TICU).These data were prospectively collected in TICU patients admitted over a 5-month period given twice daily 0.6 mg/kg enoxaparin (actual body weight). Patients were compared with a historical cohort receiving standard dosing. Anti-Xa levels were collected at 11.5 hours (trough, goal ≥0.1 IU/mL) after each evening administration. Patient demographics, admission weight, dose, and daily anti-Xa levels were recorded. Patients with renal insufficiency or brain, spine, or spinal cord injury were excluded. Data were collected from 26 patients in the standard-dose group and 37 in the weight-based group. Sixty-four trough anti-Xa measurements were taken in the standard dose group and 74 collected in the weight-based group. Evaluating only levels measured after the third dose, the change in dosing of enoxaparin from 30 to 0.6 mg/kg resulted in an increased percentage of patients with goal antifactor Xa levels from 8 per cent to 61 per cent ( P < 0.0001). Examining all troughs, the change in dose resulted in an increase in patients with a goal anti-Xa level from 19 to 59 per cent ( P < 0.0001). Weight-based dosing of enoxaparin in trauma ICU patients yields superior results with respect to adequate anti-Xa levels when compared with standard dosing. These findings suggest that weight-based dosing may provide superior VTE prophylaxis in TICU patients. Evaluation of the effects of this dosing paradigm on actual VTE rate is ongoing at our institution.

Does traumatic brain injury increase the risk for venous thromboembolism in polytrauma patients?

BACKGROUND

Trauma is a major risk factor for venous thromboembolism (VTE). Traumatic brain injury (TBI) is generally considered to further increase the VTE risk, which should prompt routine thromboprophylaxis. However, the associated risk for intracranial hemorrhage often delays anticoagulants. We test the hypothesis that TBI associated with polytrauma results in a higher rate of VTE than polytrauma without TBI.

METHODS

From August 2011 to June 2013, a prospective observational trial with informed consent was performed in 148 intensive care unit (ICU) patients with a Greenfield Risk Assessment Profile score of 10 or greater.

RESULTS

Demographics, Greenfield Risk Assessment Profile scores, the incidence of polytrauma, and mortality were similar, but TBI patients had worse Injury Severity Scores (ISS) (32 vs. 22), longer ICU lengths of stay (21 days vs. 12 days), more hypercoagulable thromboelastogram values on admission (94% vs. 79%), more received unfractionated heparin prophylaxis (65% vs. 36%), and the prophylaxis start date was more than a day later (all p < 0.05). Nevertheless, the VTE rate with TBI was similar to that without TBI (25% vs. 26%, p = 0.507). Furthermore, VTE occurred at similar time points after ICU admission with and without TBI. In both groups, about 30% of the VTEs were detected within 2 days of ICU admission and 50% of the VTEs occurred within 10 days of admission despite chemical and mechanical thromboprophylaxis.

CONCLUSION

In complex polytrauma patients who survived to ICU admission and who were prescreened for high VTE risk, TBI did not further increase the risk for VTE. The most likely explanation is that no single risk factor is necessary or sufficient for VTE development, especially in those who routinely receive chemical and mechanical thromboprophylaxis.

LEVEL OF EVIDENCE

Epidemiologic study, level III.

Thromboprophylaxis and VTE rates in soldiers wounded in Operation Enduring Freedom and Operation Iraqi Freedom

OBJECTIVES

US soldiers suffer catastrophic injuries during combat. We sought to define risk factors and rates for VTE in this population.

METHODS

We gathered data each hospital day on all patients injured in Afghanistan or Iraq who were admitted to the Walter Reed Army Medical Center (WRAMC). We analyzed prophylaxis rates and efficacy and identified risk factors for VTE.

RESULTS

We recorded data on 506 combat casualties directly admitted to WRAMC after medical air evacuation. The average injury severity score for the group was 18.4 ± 11.7, and the most common reason for air evacuation was injury by improvised explosive device (65%). As part of the initial resuscitation, patients received 4.7 ± 9.0 and 4.00 ± 7.8 units of packed RBCs and fresh frozen plasma, respectively, and 42 patients received factor VIIa. Forty-six patients (9.1%) were given a diagnosis of VTE prior to discharge, 18 (3.6%) during air evacuation, and 28 (5.5%) during the hospital stay. In Cox regression analysis, administration of 1 unit of packed RBCs was associated with a hazard ratio (HR) of 1.04 (95% CI, 1.02-1.07; P = .002), and enoxaparin, 30 mg bid, administered subcutaneously for the majority of hospital days was associated with a HR of 0.31 (95% CI, 0.11-0.86; P = .02) for VTE during the hospitalization.

CONCLUSIONS

Patients who suffer traumatic injuries in combat overseas are at high risk for VTE during evacuation and recovery. Those with large resuscitations are at particularly high risk, and low-molecular-weight heparin is associated with a decrease in VTE.

Dalteparin versus Enoxaparin for the prevention of venous thromboembolic events in trauma patients

BACKGROUND

The use of low-molecular-weight heparin (LMWH) for the chemoprophylaxis of venous thromboembolism (VTE) in trauma patients is supported by Level-1 evidence. Because Enoxaparin was the agent used in the majority of studies for establishing the efficacy of LMWH in VTE, it remains unclear if Dalteparin provides an equivalent effect.

OBJECTIVE

To compare Dalteparin to Enoxaparin and investigate their equivalence as VTE prophylaxis in trauma.

PATIENTS/SETTING

Trauma patients receiving VTE chemoprophylaxis in the Surgical Intensive Care Unit of a Level-1 Trauma Center from 2009 (Enoxaparin) to 2010 (Dalteparin) were included.

MEASUREMENTS

The primary outcome was the incidence of clinically significant VTE. Secondary outcomes included heparin-induced thrombocytopenia (HIT), major bleeding, and drug acquisition cost savings. Equivalence margins were set between -5 and 5 %.

MAIN RESULTS

A total of 610 patient records (277 Enoxaparin, 333 Dalteparin) were reviewed. The two study groups did not differ significantly: blunt trauma 67 vs. 62 %, p = 0.27; mean Injury Severity Score (ISS) 17 ± 10 vs. 16 ± 10, p = 0.34; Acute Physiology and Chronic Health Evaluation (APACHE) II score 17 ± 9 vs. 17 ± 10, p = 0.76; time to first dose of LMWH 69 ± 98 vs. 65 ± 67 h, p = 0.57). The rates of deep venous thrombosis (DVT) (3.2 vs. 3.3 %, p = 1.00), pulmonary emboli (PE) (1.8 vs. 1.2 %, p = 0.74), and overall VTE (5.1 vs. 4.5 %, p = 0.85) did not differ. The absolute difference in the incidence of overall VTE was 0.5 % [95 % confidence interval (CI): -2.9, 4.0 %, p = 0.85]. The 95 % CI was within the predefined equivalence margins. There were no significant differences in the frequency of HIT or major bleeding. The total year-on-year cost savings, achieved with 277 patients during the switch to Dalteparin, was estimated to be $107,778.

CONCLUSIONS

Dalteparin is equivalent to Enoxaparin in terms of VTE in trauma patients and can be safely used in this population, with no increase in complications and significant cost savings.

Stratified meta-analysis of intermittent pneumatic compression of the lower limbs to prevent venous thromboembolism in hospitalized patients

BACKGROUND

Optimal thromboprophylaxis for patients at risk of bleeding remains uncertain. This meta-analysis assessed whether intermittent pneumatic compression (IPC) of the lower limbs was effective in reducing venous thromboembolism and whether combining pharmacological thromboprophylaxis with IPC would enhance its effectiveness.

METHODS AND RESULTS

Two reviewers searched MEDLINE, EMBASE, and the Cochrane controlled trial register (1966-February 2013) for randomized, controlled trials and assessed the outcomes and quality of the trials independently. Trials comparing IPC with pharmacological thromboprophylaxis, thromboembolic deterrent stockings, no prophylaxis, and a combination of IPC and pharmacological thromboprophylaxis were considered. Trials that used IPC <24 hours or compared different types of IPC were excluded. A total of 16 164 hospitalized patients from 70 trials met the inclusion criteria and were subjected to meta-analysis. IPC was more effective than no IPC prophylaxis in reducing deep vein thrombosis (7.3% versus 16.7%; absolute risk reduction, 9.4%; 95% confidence interval [CI], 7.9-10.9; relative risk, 0.43; 95% CI, 0.36-0.52; P<0.01; I(2)=34%) and pulmonary embolism (1.2% versus 2.8%; absolute risk reduction, 1.6%; 95% CI, 0.9-2.3; relative risk, 0.48; 95% CI, 0.33-0.69; P<0.01; I(2)=0%). IPC was also more effective than thromboembolic deterrent stockings in reducing deep vein thrombosis and appeared to be as effective as pharmacological thromboprophylaxis but with a reduced risk of bleeding (relative risk, 0.41; 95% CI, 0.25-0.65; P<0.01; I(2)=0%). Adding pharmacological thromboprophylaxis to IPC further reduced the risk of deep vein thrombosis (relative risk, 0.54; 95% CI, 0.32-0.91; P=0.02; I(2)=0%) compared with IPC alone.

CONCLUSIONS

IPC was effective in reducing venous thromboembolism, and combining pharmacological thromboprophylaxis with IPC was more effective than using IPC alone.

Thromboprophylaxis for trauma patients

BACKGROUND

Trauma is a leading causes of death and disability in young people. Venous thromboembolism (VTE) is a principal cause of death. Trauma patients are at high risk of deep vein thrombosis (DVT). The incidence varies according to the method used to measure the DVT and the location of the thrombosis. Due to prolonged rest and coagulation abnormalities, trauma patients are at increased risk of thrombus formation. Thromboprohylaxis, either mechanical or pharmacological, may decrease mortality and morbidity in trauma patients who survive beyond the first day in hospital, by decreasing the risk of VTE in this population.A previous systematic review did not find evidence of effectiveness for either pharmacological or mechanical interventions. However, this systematic review was conducted 10 years ago and most of the included studies were of poor quality. Since then new trials have been conducted. Although current guidelines recommend the use of thromboprophylaxis in trauma patients, there has not been a comprehensive and updated systematic review since the one published.

OBJECTIVES

To assess the effects of thromboprophylaxis in trauma patients on mortality and incidence of deep vein thrombosis and pulmonary embolism. To compare the effects of different thromboprophylaxis interventions and their effects according to the type of trauma.

SEARCH METHODS

We searched The Cochrane Injuries Group Specialised Register (searched April 30 2009), Cochrane Central Register of Controlled Trials 2009, issue 2 (The Cochrane Library), MEDLINE (Ovid) 1950 to April (week 3) 2009, EMBASE (Ovid) 1980 to (week 17) April 2009, PubMed (searched 29 April 2009), ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED) (1970 to April 2009), ISI Web of Science: Conference Proceedings Citation Index-Science (CPCI-S) (1990 to April 2009).

SELECTION CRITERIA

Randomized controlled clinical trials involving people of any age with major trauma defined by one or more of the following criteria: physiological: penetrating or blunt trauma with more than two organs and unstable vital signs, anatomical: people with an Injury Severity Score (ISS) higher than 9, mechanism: people who are involved in a 'high energy' event with a risk for severe injury despite stable or normal vital signs. We excluded trials that only recruited outpatients, trials that recruited people with hip fractures only, or people with acute spinal injuries.

DATA COLLECTION AND ANALYSIS

Four authors, in pairs (LB and CM, EF and RC), independently examined the titles and the abstracts, extracted data, assessed the risk of bias of the trials and analysed the data. PP resolved any disagreement between the authors.

MAIN RESULTS

Sixteen studies were included (n=3005). Four trials compared the effect of any type (mechanical and/or pharmacological) of prophylaxis versus no prophylaxis. Prophylaxis reduced the risk of DVT in people with trauma (RR 0.52; 95% CI 0.32 to 0.84). Mechanical prophylaxis reduced the risk of DVT (RR = 0.43; 95% CI 0.25 to 0.73). Pharmacological prophylaxis was more effective than mechanical methods at reducing the risk of DVT (RR 0.48; 95% CI 0.25 to 0.95). LMWH appeared to reduce the risk of DVT compared to UH (RR 0.68; 95% CI 0.50 to 0.94). People who received both mechanical and pharmacological prophylaxis had a lower risk of DVT (RR 0.34; 95% CI 0.19 to 0.60)

AUTHORS' CONCLUSIONS

We did not find evidence that thromboprophylaxis reduces mortality or PE in any of the comparisons assessed. However, we found some evidence that thromboprophylaxis prevents DVT. Although the strength of the evidence was not high, taking into account existing information from other related conditions such as surgery, we recommend the use of any DVT prophylactic method for people with severe trauma.

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.

Thromboprophylaxis following major skeletal trauma: a systematic review

PURPOSE

Venous thromboembolic disease following skeletal polytrauma is a major issue for trauma surgeons, but there is no consensus of opinion regarding the optimal form of prophylaxis. The purpose of this paper was to compare the incidence of venous thromboembolic events (VTE) after major skeletal trauma managed with different prophylactic methods and their combinations.

METHODS

A search of AMED, CINAHL, Cochrane Library, EMBASE and MEDLINE databases was performed from their inception to July 2010. A search of unpublished literature databases was undertaken. All randomised controlled trials assessing the incidence of VTE events between two or more forms of thromboprophylaxis for patient following major skeletal trauma were included. Two reviewers independently identified all eligible articles, extracted the data, and critically appraised all included publications using the Critical Appraisal Skills Programme tool.

RESULTS

A total of 11 papers were identified. The findings of this study suggest that low molecular weight heparin (LMWH) may be superior to low dose heparin (LDH), and that LMWH should be used in addition to mechanical prophylaxis measures in patients following major skeletal trauma. There is limited evidence for the use of electrostimulation. There appeared to be no significant difference between the use of LDH compared to calf compression devices. However, the evidence-base was insufficient in both size and methodological quality.

CONCLUSIONS

There is currently insufficient research to be able to inform trauma surgeons as to the optimal method of thromboprophylaxis for patients following major skeletal trauma.

Adverse drug events associated with disorders of coagulation

Disorders of coagulation are common adverse drug events encountered in critically ill patients and present a serious concern for intensive care unit (ICU) clinicians. Dosing strategies for medications used in the ICU are typically developed for use in noncritically ill patients and, therefore, do not account for the altered pharmacokinetic and pharmacodynamic properties encountered in the critically ill as well as the increased potential for drug-drug interactions, given the far greater number of medications ordered. This substantially increases the risk for coagulation-related adverse reactions, such as a bleeding or prothrombotic events. Although many medications used in the ICU have the potential to cause coagulation disorders, the exact incidence will vary based on the specific medication, dose, concomitant drug therapy, ICU setting, and patient-specific comorbidities. Clinicians must strongly consider these factors when evaluating the risk/benefit ratio for a particular therapy. This review surveys recent literature documenting the risk for adverse drug reactions specific to bleeding and/or clotting with commonly used medications in the ICU.