Updated guidelines to reduce venous thromboembolism in trauma patients: A Western Trauma Association critical decisions algorithm

Abstract

This is a recommended evaluation and management algorithm from the Western Trauma Association (WTA) Algorithms Committee focused on the management of pharmacologic prophylaxis for venous thromboembolism (VTE) prevention in trauma patients. Because there are few related published prospective, randomized clinical trials that have generated class I data on this topic in the trauma population, these recommendations are based primarily on published prospective and retrospective cohort studies, and expert opinion of the WTA members. The final algorithm is the result of an iterative process including an initial internal review and revision by the WTA Algorithm Committee members, and then final revisions based on input during and after presentation of the algorithm to the full WTA membership. Goals The algorithm (Fig. 1) and accompanying comments represent a safe and sensible approach to reducing VTE in trauma patients. The aim for this approach was to provide updated guidelines that apply to most patients, most of the time. We recognize that there will be multiple factors that may warrant or require deviation from any single recommended algorithm and that no algorithm can completely replace expert bedside clinical judgment. We encourage institutions and clinicians to use this algorithm as a general framework in the approach to trauma patients and to customize and adapt it to better suit the specifics of that program or location.Figure 1: The WTA algorithm for VTE prophylaxis after trauma. Circled letters correspond to sections in the associated article. Algorithm circle-bubbles represent patient criteria; algorithm square-bubbles represent expert recommendations. CrCl, creatinine clearance; Hb, hemoglobin; LMWH, enoxaparin; q8h, every 8 hours; q12h, every 12 hours; UFH, unfractionated heparin.Burden of Disease Venous thromboembolism, including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a potentially preventable complication after trauma. The focus of this algorithm is on optimizing the delivery of pharmacologic prophylaxis to prevent VTE and minimize any associated complications. For those trauma patients diagnosed with a DVT or PE, including distal upper extremity or calf thrombosis, specific treatments are addressed in other guidelines and will not be covered in this algorithm.1,2 Without pharmacologic prophylaxis, a 1994 study determined that the DVT rate was 58% in severely injured trauma patients who undergo serial impedance plethysmography with lower extremity contrast venography.3 In a landmark, 1996 New England Journal of Medicine publication 30 mg of subcutaneous enoxaparin twice daily performed better than 5,000 U of subcutaneous heparin twice daily at reducing DVT in moderate to severely injured trauma patients (31% vs. 44%, p = 0.04).4 The risk of major bleeding was low regardless of therapy, and importantly, the first dose of pharmacologic prophylaxis was initiated within 36 hours of the injury and continued through all surgical procedures except spinal fixation when a single preoperative dose was held.4 This study established that early, uninterrupted enoxaparin was superior to heparin at reducing VTE after trauma. In the last decade, a number of reviews and societal recommendations focused on improving the guidelines to reduce the rate of VTE and related complications after trauma.1,2,5–11 Despite this progress, debate persists regarding optimal dosing and timing of enoxaparin, including when to initiate, hold, and resume it before and after surgery or epidural placement. Trauma patients frequently receive a delayed, suboptimal dose of enoxaparin, which is then held for any potential surgical procedure despite substantial evidence that encourages early, uninterrupted pharmacologic prophylaxis. An updated algorithm on the appropriate management of VTE prophylaxis is therefore indicated. ALGORITHM The following lettered sections correspond to the letters identifying specific sections of the algorithm shown in Figure 1. In each section, we provide a brief summary of the important aspects and options that should be considered at that point in the evaluation and management process. A This algorithm is designed for adult trauma patients 18 years and older. Importantly, although younger children have a significantly lower VTE risk, older children and adolescents have a VTE risk that approaches their adult counterparts.12 Guidance for VTE prophylaxis in children can be found in the joint practice management guideline from the Pediatric Trauma Society and the Eastern Association for the Surgery of Trauma, which recommends, “pharmacologic prophylaxis be considered for children older than 15 years old and in younger postpubertal children with Injury Severity Score (ISS) greater than 25.”11 B Assessment of VTE risk will assist in determining which patients require pharmacologic prophylaxis. In general, an ISS of 10 or more suggests that pharmacologic prophylaxis should be initiated as soon as possible, whereas patients with an ISS of less than 10 are at lower VTE risk and may not require pharmacologic prophylaxis.13–15 Because ISS is not calculated in real time, the Greenfield Risk Assessment Profile or the Trauma Embolic Scoring System can assist with calculating VTE risk.13–15 Patients with spine or pelvic fractures, repair of venous injury, a history of VTE, or inherited clotting disorders have increased VTE risk and should be considered for pharmacologic prophylaxis.2,13,14 Among trauma patients with minor injuries, independent predictors of increased VTE risk are increased age, obesity, and lower extremity fractures; any combination of these three characteristics should encourage initiation of pharmacologic prophylaxis.13 C Patients with minor trauma may not require pharmacologic prophylaxis. Given the related pain with injection, potential for hematoma at the injection site, cost for the medication, and nursing costs for administration, avoiding pharmacologic prophylaxis may be indicated for select low-risk patients after minor trauma. The Trauma Embolic Scoring System can be used to assess VTE risk, as patients with a low score require no pharmacologic prophylaxis because of their low VTE rate.13 Ambulatory patients with minor injuries and short hospital stays may not require pharmacologic prophylaxis. Trauma patients capable of ambulation but confined to bed because of intoxication, restraints, or other reasons should receive pharmacologic prophylaxis. In general, trauma patients who require hospital admission for more than 24 hours require pharmacologic prophylaxis, whereas those hospitalized for less than 24 hours do not. For the patients who do not receive pharmacologic prophylaxis, mechanical prophylaxis and/or aspirin are low cost and low morbidity options, although their benefit is uncertain given the low VTE rate.13–16 D Appropriate delays in pharmacologic prophylaxis may occur for those patients with an active bleed, coagulopathy, hemodynamic instability, solid organ injury, traumatic brain injury (TBI), or spinal trauma. Quantifying the risk and benefit of initiating pharmacologic prophylaxis for each patient is a challenge that is best determined by the trauma team at bedside. Detailing every indication where a delay may be indicated is outside the scope of these guidelines; several are described below. However, it is important to note that the guidance in both the literature and clinical practice supports very short delays to the initiation of pharmacologic prophylaxis, even among these cohorts. Active Bleeding, Coagulopathy, or Hemodynamic Instability Control of active bleeding is necessary before starting pharmacologic prophylaxis. In the presence of hemodynamic instability, a hemoglobin drop of greater than 2 g/dL in under 12 hours or ongoing blood transfusion is an appropriate indication to delay the initiation of pharmacologic prophylaxis.2,4 Systemic coagulopathy was previously proposed as a reason to delay pharmacologic prophylaxis with one study holding pharmacologic prophylaxis for an elevated prothrombin time of more than 3 seconds above control or a platelet count of less than 50,000 per cubic millimeter.4 More recent studies indicate that prothrombin time and platelet count are not as reliable at predicting systemic coagulopathy as viscoelastic hemostatic assays, which may demonstrate hypocoagulability and hypercoagulability after trauma.2,17–19 The hypocoagulability due to trauma largely resolves within 24 hours, after which hypercoagulability becomes prevalent. In this setting, pharmacologic prophylaxis may be considered after the initial resuscitation is complete.17,20 Deferring the initiation of pharmacologic prophylaxis during trauma-induced coagulopathy is associated with an increased VTE rate such that the initiation of pharmacologic prophylaxis is encouraged if the hypocoagulable state is expected to resolve and there are no signs of ongoing bleeding.17 Solid Organ Injury Delays occur in the initiation of pharmacologic prophylaxis for patients with solid organ injury. Several studies indicate that patients with solid organ injury who received early pharmacologic prophylaxis had lower DVT and PE rates without increased risk of failure of nonoperative management, bleeding complications, or mortality; these risks did not increase when pharmacologic prophylaxis was started within 24 hours compared with within 48 hours.20–23 Early pharmacologic prophylaxis within 12 to 24 hours appeared to be safe across moderate American Association for the Surgery of Trauma injury grade and type of solid organ injury (liver, spleen, and/or kidney), without an increased risk of bleeding that necessitated intervention or blood transfusion.21 Although those with grade IV and V injuries should be approached with caution, pharmacologic prophylaxis may be initiated within 24 hours for most patients with solid organ injury.21–23 Traumatic Brain Injury Concern for progression of TBI is a common reason for the delay in initiation of pharmacologic prophylaxis. This delay is dependent on the type of TBI; those with “cerebral contusion, localized petechial hemorrhages, or diffuse axonal damage” may safely receive pharmacologic prophylaxis without delay.4 When pharmacologic prophylaxis is appropriately delayed, the follow-up computed tomography (CT) after TBI diagnosis is an important indicator for when to initiate pharmacologic prophylaxis.24 For patients with TBI progression on the follow-up CT, exposure to pharmacologic prophylaxis is a predictor for further progression, and it should be held until a follow-up CT demonstrates no progression.24 In contrast, if the follow-up CT demonstrates no TBI progression, then pharmacologic prophylaxis should be initiated.24 Importantly, progression of TBI occurs in about 10% of patients with a stable follow-up CT, regardless of whether pharmacologic prophylaxis is provided or not.24 Those trauma centers that provide pharmacologic prophylaxis within 24 hours after TBI have significantly lower rates of VTE with no difference in rates of late neurosurgical intervention.23,25–30 Even in the setting of combat related penetrating TBI, initiating pharmacologic prophylaxis 24 hours after injury for those patients with a stable CT was safe, with similar progression rates regardless of pharmacologic prophylaxis.29 The majority of TBI patients with a stable CT may be initiated on enoxaparin within 24 hours, and nearly all TBI patients should receive pharmacologic prophylaxis within 72 hours of the time of injury.23,28,31 Spinal Trauma In the absence of pharmacologic prophylaxis, patients who undergo spine surgery or those with spine trauma, fracture, or cord injury have a high of and delays than 72 hours to a substantial increase in the VTE prophylaxis be initiated as soon as after spine surgery or any spine that provide pharmacologic prophylaxis or after fixation are considered When a was that pharmacologic prophylaxis or the of spine the VTE rate and the rate of spinal hematoma was pharmacologic prophylaxis initiated within 48 hours of fixation of traumatic spine did not increase the risk of progression of injury, or complications including spinal prophylaxis for moderate to high VTE risk patients is encouraged regardless of pharmacologic prophylaxis. For patients who are not started on pharmacologic prophylaxis, mechanical prophylaxis with and when possible, should be the DVT if no pharmacologic prophylaxis is initiated and therefore is recommended for patients with a to pharmacologic In contrast, the of in patients who received pharmacologic prophylaxis did not to a in the DVT although the study had a low DVT rate and of the trauma mechanical prophylaxis with pharmacologic prophylaxis is therefore encouraged for moderate to high VTE risk patients in because those who received the combination had a lower of do not to reduce the VTE rate in the presence of pharmacologic but high may provide a benefit to those trauma patients who be started on pharmacologic is an important for VTE as early to a in A is safe in trauma patients and may reduce patient the rate of of spinal is associated with an increased DVT rate and should be to early venous should be considered in patients at high VTE risk who be started or on pharmacologic prophylaxis. Although debate with venous is not indicated or for all trauma after trauma not the risk of PE or PE, and to In trauma patients at low VTE risk, the high cost and low of that the practice may be institutions for in low-risk trauma patients to both and which may and the related complications such as venous venous or pain with For trauma patients at high VTE risk, is associated with a PE The Greenfield Risk Assessment Profile can which trauma patients may benefit from may be in high VTE risk patients who be started or on pharmacologic prophylaxis. the of DVT should not be a that all trauma patients have rates of and those centers with that do not will have DVT rates because of a lower for a venous prophylaxis be initiated as soon as and for most trauma patients may be initiated within 24 When high VTE risk trauma patients who receive enoxaparin within 24 hours of admission are compared with those who receive mechanical prophylaxis, minor and major bleeding do not in appropriate delays may occur in the initiation of pharmacologic prophylaxis because of active coagulopathy, hemodynamic instability, solid organ injury, TBI, or spinal trauma. In most pharmacologic prophylaxis may be started in less than 24 hours, and in every pharmacologic prophylaxis may be started in less than 72 prophylaxis is held because of surgery despite the evidence that it may be initiated before most surgical Trauma patients who require an are in that their first may occur within of or the pharmacologic prophylaxis is or for which to an increased VTE dosing of pharmacologic prophylaxis is not to trauma. In other patient at high risk for VTE, the use of preoperative pharmacologic prophylaxis the DVT rate without the complication for in should be initiated and continued Patients who surgery who received low heparin hours before surgery had a lower rate of DVT without or bleeding This benefit was not when low heparin was provided 12 hours or more We that the common and process of pharmacologic prophylaxis for 12 to 24 hours before surgical procedures is and will result in an increased VTE risk without an accompanying in the risk of bleeding to pharmacologic prophylaxis, the specific and initial dose should be determined for each is the recommended for most trauma patients with considered the of The for pharmacologic prophylaxis is the low heparin enoxaparin because of increased and more and compared with unfractionated less with which may reduce bleeding complications compared with unfractionated a lower of and not have the associated with heparin When the initial mg of enoxaparin twice daily should be considered the for most trauma patients, as 30 mg twice daily frequently in pharmacologic patients 18 to years with of more than and a creatinine of more than should be started on mg of enoxaparin twice as this dose is safe and the VTE Patients who are older than less than or who have a creatinine of 30 to should to receive initial dosing at 30 mg of enoxaparin twice The initial enoxaparin dose for trauma patients with a may be based on twice twice or 30 mg for to patients, mg for to patients, and mg for patients greater than Patients who are initiated on of enoxaparin based should be by because of the in creatinine after trauma that to in the enoxaparin Although enoxaparin is to heparin for pharmacologic prophylaxis, institutions to dose unfractionated heparin at 5,000 U three daily based in on a randomized that that this be and compared with 30 mg of enoxaparin twice This practice should be as the was because of an DVT rate of for unfractionated heparin for enoxaparin, and a 10% for the The difference in the VTE rate was which enoxaparin without vs. enoxaparin, p = In the study was not to a difference in the rate of PE or both of which the complication rate and More 30 mg of enoxaparin twice daily was established as superior to U of unfractionated heparin three daily at the prevention of VTE and for Quantifying the risk and benefit of the type and initial dose of pharmacologic prophylaxis for each patient is a challenge best determined by the trauma team at bedside. mg of enoxaparin twice daily is the recommended initial pharmacologic prophylaxis for most trauma patients. Detailing every indication where an or dose may be indicated is outside the scope of these guidelines; several are described below. In the presence of or a creatinine of subcutaneous unfractionated heparin at U every 8 hours may be Because enoxaparin is by the to patients with failure may to increased bleeding complications and should be not and for use in patients. lower enoxaparin in the setting of a creatinine of may be in the but is necessary before this can be In most other enoxaparin is to unfractionated as enoxaparin to lower VTE rates without increased bleeding Brain and Trauma For TBI patients, enoxaparin is associated with less VTE and than unfractionated heparin with no difference in the progression of brain regardless if the dose was in less than 24 hours after 24 to 48 hours, or after 48 those patients with spine trauma should receive early Patients with brain and spine trauma should be initiated on 30 mg of enoxaparin twice daily and considered for dose by Patients patients require specific dose recommendations for pharmacologic prophylaxis after trauma because of the as as the increase in and that occur the of require enoxaparin with more unfractionated heparin enoxaparin the and both are considered safe to use in during an admission for trauma, patients should receive 30 mg of enoxaparin twice daily by a of to or a of to For patients who more than initiating mg of enoxaparin twice daily is recommended with similar and prophylaxis with or aspirin should not be a for pharmacologic prophylaxis for most trauma patients because of the of related clinical The use of or aspirin may be considered in the setting of injuries, but if the patient injection with enoxaparin or unfractionated are for pharmacologic prophylaxis after 10 mg of and mg of twice both which are trials that or to enoxaparin demonstrate that have to better VTE rates with similar to bleeding In contrast, other that enoxaparin a lower VTE and a lower bleeding Because retrospective have the use of for pharmacologic prophylaxis after trauma, randomized trials are necessary before a for trauma The use of low dose aspirin may be considered for pharmacologic prophylaxis in trauma patients with injuries who For those trauma patients started on a for pharmacologic prophylaxis, aspirin may replace the after with similar prevention of I trauma patients require dose after initiating Because of the in and enoxaparin by is In one of trauma patients of mg or and of mg or enoxaparin by or to lower the VTE rate without bleeding complications in moderate to severely injured patients, trauma patients who require injuries, and surgical Although debate on the appropriate for suggests to for or to for should be considered for those patients who receive Although not for pharmacologic prophylaxis, with platelet may assist with platelet A randomized that used as an to enoxaparin did not lower rates of VTE with the enoxaparin In contrast, with platelet may if a hypercoagulability is due to platelet which encourages the of aspirin to the pharmacologic prophylaxis aspirin is the initial recommended dose is mg daily with the of the dose to mg daily on with platelet The uninterrupted dosing of pharmacologic prophylaxis should be the for most trauma patients their hospital Although the and benefit of uninterrupted pharmacologic prophylaxis established more than of trauma patients A is the number of and DVT risk such that patients who to have DVT risk compared with those with no For TBI patients who are started on pharmacologic prophylaxis, dosing an increase in the VTE The following are common reasons for pharmacologic procedure patient was from the for bleeding epidural and When holding pharmacologic prophylaxis, the rate of bleeding with pharmacologic prophylaxis is no than without VTE are compared with bleeding complications, the pharmacologic should focus on pharmacologic prophylaxis without The appropriate for holding or pharmacologic prophylaxis spinal epidural or and these are below. Although VTE is not indicated for all trauma may be in those at high VTE venous should be performed for evidence of DVT such as or For those trauma patients with injuries and in pharmacologic prophylaxis, venous may be a DVT or PE is then is necessary per and if it is then an should be considered as in Surgery in holding pharmacologic prophylaxis because of surgery is with few for brain or spine Given the delays and of that may occur during trauma patient holding pharmacologic prophylaxis can of pharmacologic prophylaxis. pharmacologic prophylaxis is safe for trauma and to a lower VTE The preoperative of pharmacologic prophylaxis is encouraged for surgical patients in other who have a high VTE risk and to a lower DVT rate without the complication The lower VTE rate is if pharmacologic prophylaxis is provided more than 12 hours reduce morbidity and in trauma patients injuries and are a of pain Patients who require an epidural have in pharmacologic such that epidural is associated with an increased VTE whereas previously this was not the a enoxaparin dose and epidural by a to before enoxaparin is at 10 and 10 the dose may be held for 10 epidural to for the necessary without prophylaxis. 10 the enoxaparin dosing may one dose is of enoxaparin are for pharmacologic prophylaxis, a for enoxaparin before epidural by a to before at of enoxaparin should be for any enoxaparin enoxaparin are encouraged with to the VTE rate associated with epidural For unfractionated a to is recommended before epidural by a before unfractionated heparin is which for uninterrupted platelet should be considered for those trauma patients who receive pharmacologic prophylaxis because of the risk of is recommended for patients who are considered high risk for every 3 from to or until pharmacologic prophylaxis is Trauma patients who are to enoxaparin may be considered low risk for and may not require platelet as the rate of clinical was with heparin compared with with The clinical diagnosis of may be by that thrombosis, and the heparin be with such as the which can for trauma patients for because of the of these and the with dosing and their may be considered in the setting of DVT or PE when there is a to appropriate The use of is among trauma centers although their is without a in PE is not In a randomized of high VTE risk trauma patients who to receive pharmacologic prophylaxis during the first 72 hours of a did not lower the of PE or which established the of of early of an in this The of an not regardless of whether a DVT is or guidelines provide recommendations and most studies have among patients diagnosed with an DVT or PE who receive an should be considered to reduce the rate of PE without the Trauma patients with TBI, or spine injuries, and those who undergo major surgery are at VTE risk and should be considered for pharmacologic prophylaxis. prophylaxis after for high VTE risk trauma patients is by evidence that demonstrates the practice is safe, and and may be considered for patients with TBI, or spine injuries, and those who undergo major The VTE risk occurs during the first 3 after injury with until the VTE rate to that of the general Venous for of trauma at a cost of pharmacologic prophylaxis with enoxaparin is associated with a low rate of bleeding complications, and is in patients at high VTE The of pharmacologic prophylaxis following or pelvic surgery for or was associated with a in VTE Because the optimal dose and of enoxaparin after trauma are not more than 30 mg twice daily should be and the of pharmacologic prophylaxis may be considered for to after the of For those who undergo major pharmacologic prophylaxis may be to from the of may be initiated for pharmacologic prophylaxis for high VTE risk trauma patients, as it shown to be as as enoxaparin with less bleeding complications and better and is not by the of may be considered for pharmacologic prophylaxis after This algorithm was designed to provide and guidance at reducing the VTE rate after trauma. Although there are multiple factors that will to from the most trauma patients should be initiated on early and of enoxaparin that should be by For most trauma patients, pharmacologic prophylaxis should uninterrupted the hospital and at after preventable and delays to the initiation and of pharmacologic prophylaxis should be a focus of all trauma and it associated with rates of VTE