Four years of an aggressive prophylaxis and screening protocol for venous thromboembolism in a large trauma population

Retrospective analysis of tranexamic acid administration in French war-wounded between October 2016 and September 2020

INTRODUCTION

Since 2013, the French Army Health Service, in agreement with international experts, has recommended the administration of 1 g of tranexamic acid (TXA) in trauma patients in haemorrhagic shock or at risk of bleeding within 3 hours of the trauma.

METHODS

The aim of this analysis was to describe the administration of TXA in French military personnel wounded during military operations in the Sahelo-Sahelian band between October 2016 and September 2020. Data were collected from forward health records and hospital data from the French hospital where the casualty was finally evacuated. Underuse of TXA was defined as the lack of administration in casualties who had received a blood transfusion with one or more of red blood cells, low-titre whole blood or French lyophilised plasma within the first 24 hours of injury and overuse as its administration in the non-transfused casualty.

RESULTS

Of the 76 patients included, 75 were men with an average age of 28 years. Five patients died during their management. 19 patients received TXA (25%) and 16 patients were transfused (21%). Underuse of TXA occurred in 3 of the 16 patients (18.8%) transfused. Overuse occurred in 6 of 60 (10%) non-transfused patients.

CONCLUSION

The analysis found an important underuse of TXA (almost 20%) and highlighted the need for optimising the prehospital clinical practice guidelines to aid prehospital medical practitioners more accurately in administering TXA to casualties that will require blood products.

Perioperative Management of Incidental Pulmonary Embolisms on Trauma CT Scans: A Narrative Review

Unsuspected pulmonary embolism (PE) may be identified on an initial trauma computed tomography (CT) scan. The clinical importance of these incidental PEs remains to be elucidated. In patients who require surgery, careful management is needed. We sought to investigate the optimal perioperative management of such patients, including the use of pharmacological and mechanical thromboprophylaxis, possible thrombolytic therapy, and inferior vena cava (IVC) filters. A literature search was conducted, and all relevant articles were identified, investigated, and included. Medical guidelines were also consulted where appropriate. Pharmacological thromboprophylaxis is the mainstay of preoperative treatment, and low-molecular-weight heparins, fondaparinux, and unfractionated heparin may all be used. It has been suggested that prophylaxis should be administered as soon as possible after trauma. Such agents may be contraindicated in patients with significant bleeding, and mechanical prophylaxis and inferior vena cava filters may be favoured in these patients. Therapeutic anticoagulation and thrombolytic therapies may be considered but are associated with an increased risk of haemorrhage. Delaying surgery might help to minimise the risk of recurrent venous thromboembolism, and any interruption of prophylaxis must be strategically planned. Recommendations for postoperative care include a continuation of prophylaxis and therapeutic anticoagulation, with follow-up clinical evaluation within six months. Incidental PE is a common finding on trauma CT scans. Although the clinical significance is unknown, careful management of the balance between anticoagulation and bleeding is needed, especially in trauma patients and even more so in trauma patients requiring surgery.

Relationship Between the Incidence of Deep Vein Thrombosis During Hospitalization and the Energy of Injury in Tibial Plateau Fractures

This study aimed to investigate the relationship between the incidence of deep vein thrombosis (DVT) during hospitalization and the energy of injury in tibial plateau fractures (TPFs). One hundred and forty patients were enrolled between September 1, 2014, and October 1, 2017. According to Schatzker's classification, they were classified into the low-energy (type I-III) and high-energy (type IV-VI) groups. For DVT evaluation, duplex ultrasonography was performed in the lower extremities preoperatively and postoperatively. The location and changes of DVT were recorded. All patients underwent mechanical and chemical thromboprophylaxis. The incidence of DVT in TPFs was 36.43% and 46.43% preoperatively and postoperatively, respectively. The DVT incidence was 31.75% (20/63) in the low-energy group and 40.26% (31/77) in the high-energy group preoperatively, and 44.44% (28/63) in the low-energy group and 48.05% (37/77) in the high-energy group postoperatively. There was no significant difference between the 2 groups preoperatively (P = .298) and postoperatively (P = .785). The days between operation and discharge (P = .016), blood loss during surgery (P = .016), and preoperative d-dimer level (P = .02) showed differences between the 2 groups. Additionally, 29 new thrombi (14 [48.28%] in the high-energy group and 15 [51.72%] in the low-energy group) appeared and 16 preoperative thrombi disappeared postoperatively. Despite mechanical and chemical thromboprophylaxis, the DVT risk in patients with TPFs remains high. Although the DVT incidence is not significantly different between high-energy and low-energy injuries, the occurrence of DVT should be carefully monitored.

Incidence and locations of preoperative deep venous thrombosis (DVT) of lower extremity following tibial plateau fractures: a prospective cohort study

Background

There is still lack of data on deep vein thrombosis (DVT) following bone trauma. This study aimed to determine the epidemiologic characteristics of deep venous thrombosis (DVT) of lower extremities following tibial plateau fractures.

Methods

Retrospective analysis of prospectively collected data on patients presenting with tibial plateau fractures between October 2014 and December 2018 was conducted. Duplex ultrasonography (DUS) was routinely used to screen for preoperative DVT of bilateral lower extremities. Data on demographics, comorbidities, injury-related data, and laboratory biomarkers at admission were collected. Univariate analyses and multivariate logistic regression analyses were used to identify the independent risk factors associated with DVT.

Results

A total of 1179 patients were included, among whom 192 (16.3%) had a preoperative DVT, with incidence rate of 1.0% for proximal and 15.3% for distal DVT. The average interval between fracture occurrence and diagnosis of DVT was 3.5 days (median, 2 days), ranging from 0 to 19 days. DVT involved the injured extremity in 166 (86.4%) patients, both the injured and uninjured extremities in 14 patients (7.3%) and only the uninjured extremity in 12 patients (6.3%). Six risk factors were identified to be associated with DVT, including gender (male vs female), hypertension, open fracture, alkaline phosphatase > 100 u/L, sodium concentration < 135 mmol/L, and D-dimer > 0.5 mg/L.

Conclusion

These epidemiologic data are conducive to the individualized assessment, risk stratification, and development of targeted prevention programs.

Incidence and locations of deep venous thrombosis of the lower extremity following surgeries of tibial plateau fractures: a prospective cohort study

OBJECTIVE

To investigate the incidence of deep venous thrombosis (DVT) of the lower extremities following surgeries of tibial plateau fractures.

METHODS

Retrospective analysis of the prospectively collected data on patients undergoing surgeries of tibial plateau fractures between October 2014 and December 2018 was conducted. Duplex ultrasonography (DUS) was used to screen for postoperative DVT of the bilateral lower extremities. Data on demographics, comorbidities, injury, surgery, and laboratory biomarkers at admission were collected. Univariate analyses and multivariate logistic regression analyses were used to identify the independent risk factors associated with DVT.

RESULTS

Among 987 patients included, 46 (4.7%) had postoperative DVT, with incidence rate of 1.0% for proximal and 3.7% for distal DVT. The average interval between operation and DVT was 8.3 days (median, 5.8 days), ranging from 2 to 42 days. DVT involved the injured extremity in 39 (84.8%) patients, both the injured and uninjured extremity in 2 patients (4.3%) and only the uninjured extremity in 5 patients (10.9%). Five risk factors were identified to be associated with postoperative DVT, including age (≥ 41 vs < 41 years) (OR 3.08; 95% CI 1.43-6.61; p = 0.004), anesthesia (general vs regional) (OR 2.08; 95% CI 1.12-3.85; p = 0.021), hyponatremia (OR 2.21; 95% CI 1.21-4.06; p = 0.010), prolonged surgical time (OR 1.04; 95% CI 1.01-1.07; p = 0.017) and elevated D-dimer level (OR 2.79; 95% CI 1.34-4.83; p = 0.004).

CONCLUSION

These epidemiologic data may be helpful in individualized assessment, risk stratification, and development of targeted prevention programs.

A preliminary study of intensivist-performed DVT ultrasound screening in trauma ICU patients (APSIT Study)

Background

Multiple screening Duplex ultrasound scans (DUS) are performed in trauma patients at high risk of deep vein thrombosis (DVT) in the intensive care unit (ICU). Intensive care physician performed compression ultrasound (IP-CUS) has shown promise as a diagnostic test for DVT in a non-trauma setting. Whether IP-CUS can be used as a screening test in trauma patients is unknown. Our study aimed to assess the agreement between IP-CUS and vascular sonographer performed DUS for proximal lower extremity deep vein thrombosis (PLEDVT) screening in high-risk trauma patients in ICU.

Methods

A prospective observational study was conducted at the ICU of Alfred Hospital, a major trauma center in Melbourne, Australia, between Feb and Nov 2015. All adult major trauma patients admitted with high risk for DVT were eligible for inclusion. IP-CUS was performed immediately before or after DUS for PLEDVT screening. The paired studies were repeated twice weekly until the DVT diagnosis, death or ICU discharge. Written informed consent from the patient, or person responsible, or procedural authorisation, was obtained. The individuals performing the scans were blinded to the others’ results. The agreement analysis was performed using Cohen’s Kappa statistics and intraclass correlation coefficient for repeated binary measurements.

Results

During the study period, 117 patients had 193 pairs of scans, and 45 (39%) patients had more than one pair of scans. The median age (IQR) was 47 (28–68) years with 77% males, mean (SD) injury severity score 27.5 (9.53), and a median (IQR) ICU length of stay 7 (3.2–11.6) days. There were 16 cases (13.6%) of PLEDVT with an incidence rate of 2.6 (1.6–4.2) cases per 100 patient-days in ICU. The overall agreement was 96.7% (95% CI 94.15–99.33). The Cohen’s Kappa between the IP-CUS and DUS was 0.77 (95% CI 0.59–0.95), and the intraclass correlation coefficient for repeated binary measures was 0.75 (95% CI 0.67–0.81).

Conclusions

There is a substantial agreement between IP-CUS and DUS for PLEDVT screening in trauma patients in ICU with high risk for DVT. Large multicentre studies are needed to confirm this finding.

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.

Surveillance or no surveillance ultrasonography for deep vein thrombosis and outcomes of critically ill patients: a pre-planned sub-study of the PREVENT trial

PURPOSE

We examined the association between surveillance for deep vein thrombosis (DVT) among medical-surgical critically ill patients by twice-weekly ultrasonography and 90-day all-cause mortality.

METHODS

This was a pre-planned sub-study of the Pneumatic Compression for Preventing Venous Thromboembolism (PREVENT) trial (Clinicaltrials.gov: NCT02040103) that compared addition of intermittent pneumatic compression (IPC) to pharmacologic prophylaxis versus pharmacologic prophylaxis alone. The surveillance group included enrolled patients in the trial, while the non-surveillance group included eligible non-enrolled patients. Using logistic regression and Cox proportional hazards models, we examined the association of surveillance with the primary outcome of 90-day mortality. Secondary outcomes were DVT and pulmonary embolism (PE).

RESULTS

The surveillance group consisted of 1682 patients and the non-surveillance group included 383 patients. Using Cox proportional hazards model with bootstrapping, surveillance was associated with a decrease in 90-day mortality (adjusted HR 0.75; 95% CI 0.57, 0.98). Surveillance was associated with earlier diagnosis of DVT [(median 4 days (IQR 2, 10) vs. 20 days (IQR 16, 22)] and PE [median 4 days (IQR 2.5, 5) vs. 7.5 days (IQR 6.1, 28.9)]. There was an increase in diagnosis of DVT (adjusted HR 5.49; 95% CI 2.92, 13.02) with no change in frequency in diagnosis of PE (adjusted HR 0.56; 95% CI 0.19, 1.91).

CONCLUSIONS

Twice-weekly surveillance ultrasonography was associated with an increase in DVT detection, reduction in diagnostic testing for non-lower limb DVT and PE, earlier diagnosis of DVT and PE, and lower 90-day mortality.

TRIAL REGISTRATION

The PREVENT trial is registered at ClinicalTrials.gov, ID: NCT02040103. Registered on 3 November 2013; Current controlled trials, ID: ISRCTN44653506. Registered on 30 October 2013.

Analysis of venous thromboembolism in neurosurgical patients undergoing standard versus routine ultrasonography

Routine screening of high-risk asymptomatic trauma or surgical patients for venous thromboembolism (VTE) is controversial. Studies suggest against screening while others recognize that some patients at high risk may benefit. The purpose of this pilot study is to evaluate the benefit of routine screening using doppler ultrasonography for the early detection of deep venous thrombosis (DVT) in post-operative neurosurgical patients. This was a quasi-experimental study at a major academic tertiary care medical center. A total of 157 adults underwent cranial or spinal surgical interventions from March through August 2017 and received either standard screening (n = 104) versus routine ultrasonography screening (n = 53). There was no significant difference in incidence of DVT between the two groups: 11 (11%) in the standard screening group versus 5 (9%) in the routine screening group, p = 0.823. Upper and lower extremity ultrasonography was performed in 43 (41%) of the standard screening group versus 53 (100%) in the routine screening group, p < 0.001. DVT was identified in nearly one of every 6 ultrasonography screenings in the standard screening group versus 27 ultrasonography screenings required to identify one DVT in the routine screening group. There were the same number of screenings for upper extremity ultrasonography, but they did not yield or detect DVT; instead only superficial, untreatable, DVTs were reported. Total cost to diagnose one DVT, including screening and labor, averaged $13,664 in the standard group versus $56,525 in the routine group. Routine screening in neurosurgical patients who received VTE prophylaxis was not associated with lower incidence of VTE and mortality attributed to PE. Thus, routine screening may not be cost effective to prevent complications from DVT incidence.

Optimizing Lower Extremity Duplex Ultrasound Screening After Traumatic Injury

BACKGROUND

The risk assessment profile (RAP) score has been used to determine patients who would most benefit from lower extremity duplex ultrasound screening (LEDUS). We hypothesized that revising our LEDUS protocol to perform screening ultrasound examinations in patients with an RAP ≥8 within 48 h of admission would reduce the number of LEDUS performed without changing outcomes.

METHODS

A retrospective review was conducted on trauma patients admitted from July 1, 2014, to June 30, 2015, and July 1, 2016, to June 30, 2017. In 2014-2015, patients with an RAP score ≥5 underwent weekly LEDUS examinations starting on hospital day 4. In 2016-2017, the protocol was changed to start screening patients with an RAP score ≥8 by hospital day 2. Both protocols screened with weekly ultrasounds after the first examination. Demographic data, injury characteristics, LEDUS examination findings, chemoprophylaxis type, and venous thromboembolism incidence were collected.

RESULTS

A total of 602 patients underwent LEDUS examination in 2014-2015, whereas only 412 underwent LEDUS in 2016-2017. No significant difference was seen in the number of patients diagnosed with deep vein thrombosis (DVT) or pulmonary embolism. DVTs were most often identified on the first LEDUS examination in both cohorts. Of patients diagnosed with a DVT on an LEDUS examination, a significantly higher RAP score (12 versus 10), and a shorter time to first duplex (1 versus 3 d), and DVT diagnosis (2 versus 4 d) were observed in the 2016-2017 cohort. In patients diagnosed with a pulmonary embolism, no significant differences were demonstrated between cohorts.

CONCLUSIONS

Refinement of LEDUS protocols can decrease overutilization of hospital resources without compromising trauma patient outcomes.

Perioperative incidence and locations of deep vein thrombosis following specific isolated lower extremity fractures

PURPOSE

To determine perioperative incidence and locations of deep vein thrombosis (DVT) in injured and uninjured lower extremities following isolated lower extremity fractures (ILEFs).

METHODS

Retrospective analysis of a prospectively collected data of a consecutive patient series with ILEFs who underwent surgical treatment between September 2014 and September 2017 was performed. Patients' bilateral lower extremities were screened for DVT with duplex ultrasonography (DUS) before and after surgery. DVT occurrence was analyzed by location of DVT and fracture site. All patients received pharmacologic thromboprophylaxis while hospitalized. Data on demographics, time to surgery, time of DUS examinations, length of hospital stay and symptomatic pulmonary embolism (PE) was collected.

RESULTS

1825 patients were included in the study. The incidence of symptomatic PE was 1.6%. All patients were screened with DUS of the bilateral lower extremities in a mean of 3.5 days (range: 0-18 days) after injury, and a mean of 3.6 days (range: 1-11 days) after surgery. Preoperative DUS detected DVT in 547 patients (30.0%), including 3.7% of patients with proximal DVT. 792 patients (43.4%) were found to have a DVT postoperatively, but only 6.2% of patients with proximal DVT. Proximal DVT was detected postoperatively of the represented fractures: 6.5% of the hip, 14.5% of the femoral shaft, 4.5% of the tibial plateau, 4.6% of the tibial shaft, 1.7% of the patellar, and 2.0% of the peri-ankle. Interestingly, the rate of DVT in an uninjured lower limb was significantly higher postoperatively compared to preoperatively (16.4% vs. 4.9%), however, only 0.2% of patients had proximal DVT.

CONCLUSIONS

While the perioperative incidence of overall DVT is high following ILEFs, the majority were distal DVT, and the rate of symptomatic PE was low. Femoral shaft fractures were associated with the highest incidence for proximal DVT. The incidence was lower in more distal fractures. The majority of patients diagnosed with DVT postoperatively had already shown symptoms of DVT prior to surgery. DVT can occur in both the injured and uninjured leg, with an obviously higher incidence in the injured leg. The incidence of proximal DVT in an uninjured leg is rare.

Weight-based enoxaparin dosing and deep vein thrombosis in hospitalized trauma patients: A double-blind, randomized, pilot study

BACKGROUND

Venous thromboembolism is a cause of morbidity and mortality in trauma patients. Chemoprophylaxis with low-molecular-weight heparin at a standardized dose is recommended. Conventional chemoprophylaxis may be inadequate. We hypothesized that a weight-adjusted enoxaparin prophylaxis regimen would reduce the frequency of venous thromboembolism in hospitalized trauma patients and at 90-day follow-up.

METHODS

This prospective, randomized pilot study enrolled adult patients admitted to a level 1 trauma center between July 2013 and January 2015. Subjects were randomized to receive either standard (30 mg subcutaneously every 12 hours) or weight-based (0.5mg/kg subcutaneously every 12 hours) enoxaparin. Surveillance duplex ultrasound for lower extremity deep vein thrombosis was performed on hospital days 1, 3, and 7, and weekly thereafter. The primary outcome was deep vein thrombosis during hospitalization. Secondary outcomes included venous thromboembolism at 90 days and significant bleeding events.

RESULTS

Two hundred thirty-four (124 standard, 110 weight-based) subjects were enrolled. There was no difference between standard and weight-based regarding age, body mass index, percentage female gender, injury severity score, or percentage that had surgery. There was a trend toward less in-hospital deep vein thrombosis in weight-based (12 [9.7%] standard vs 4 [3.6%] weight-based, P = .075). At 90 days, there was no difference in venous thromboembolism (12 [9.7%] standard vs 6 [5.5%] weight-based, P =.34). There was 1 bleeding event, which occurred in a standard subject.

CONCLUSION

Weight-based enoxaparin dosing for venous thromboembolism chemoprophylaxis in trauma patients may provide better protection against venous thromboembolism than standard. A definitive study is necessary to determine whether weight-based dosing is superior to standard.

The rate of deep vein thrombosis doubles in trauma patients with hypercoagulable thromboelastography

BACKGROUND

Venous thromboembolism (VTE) in trauma can occur in patients at low risk. Conventional coagulation tests do not predict VTE. Studies investigating thromboelastography (TEG) for VTE risk are conflicting and have not included routine surveillance to detect deep vein thrombosis (DVT). We undertook a prospective study of TEG to evaluate its utility in predicting VTE.

METHODS

We conducted a prospective cohort study on all adult trauma patients admitted to our Level I trauma center from 2013 to 2015. TEG was performed immediately on arrival to the trauma bay. Hypercoagulable TEG was defined as reaction time (R) below, angle (α) above, or maximum amplitude (MA) above reference ranges. All patients received mechanical and/or pharmacologic prophylaxis and were followed up for DVT with our ultrasound surveillance protocol. The primary outcome was lower-extremity DVT. After bivariate analysis of variables related to DVT, those with p values of 0.100 or less were included for multivariate logistic regression.

RESULTS

A total of 983 patients were evaluated with TEG on admission; of these, 684 (69.6%) received at least one surveillance ultrasound during the index admission. Lower-extremity DVT was diagnosed in 99 (14.5%) patients. Hypercoagulability based on admission TEG occurred in 582 (85.1%) patients. The lower-extremity DVT rate was higher in patients with hypercoagulable TEG than in those without hypercoagulable TEG (15.6% vs. 8%; p = 0.039). Multivariate analysis showed hypercoagulable TEG remained associated with DVT after adjustment for relevant covariates available at admission, with an odds ratio of 2.41 (95% confidence interval, 1.11-5.24; p = 0.026).

CONCLUSION

Most trauma patients were hypercoagulable at admission and remained at risk of developing DVT. The rate of DVT doubled in patients with hypercoagulable TEG indices despite prophylaxis. Beyond its current clinical roles, TEG is useful for assessing DVT risk, particularly in patients otherwise perceived to be at low risk.

LEVEL OF EVIDENCE

Prognostic study, level II.

Venous thromboembolism in major trauma patients: a single-center retrospective cohort study of the epidemiology and utility of D-dimer for screening

Aim

Venous thromboembolism (VTE) can be a life‐threatening complication after major trauma. The aim of this study was to investigate the epidemiology of VTE and to assess the usefulness of D‐dimer for screening for VTE in major trauma cases among the Japanese population.

Methods

We examined a single‐center retrospective cohort of severely injured trauma patients who had been admitted to the emergency intensive care unit at Okayama University Hospital (Okayama, Japan) from April 2013 through to March 2016. Venous thromboembolism was confirmed by computed tomography angiography and computed tomography venography, which was determined based on the attending physician monitoring daily D‐dimer levels. Independent risk factors for VTE were determined by multiple logistic regression analysis. D‐dimer levels were evaluated using area under the receiver operating characteristic curve (AUROC) to predict VTE.

Results

The study cohort consisted of 204 trauma patients (median Injury Severity Score, 20). Of the 204 patients, 65 (32%) developed VTE. The median time from admission to VTE diagnosis was 10 days. In multiple logistic regression analysis, higher Injury Severity Score and the presence of lower extremity fractures were revealed to be a risk factor for VTE. D‐dimer levels at day 10 showed moderate accuracy, of which the AUROC was 0.785 (95% confidence interval, 0.704–0.866; P < 0.001). The cut‐off that maximized the Youden index was 12.45 μg/mL.

Conclusions

At least one of every three major trauma patients had potential development of VTE at a median of 10 days following admission to the intensive care unit. D‐dimer levels on day 10 can be a useful predictor of VTE.

Incidence and risk factors for preoperative deep venous thrombosis in 314 consecutive patients undergoing surgery for spinal metastasis

OBJECTIVE The authors of this study aimed to identify the incidence of and risk factors for preoperative deep venous thrombosis (DVT) in patients undergoing surgical treatment for spinal metastases. METHODS Univariate analysis of patient age, sex, ethnicity, laboratory values, comorbidities, preoperative ambulatory status, histopathological classification, spinal level, and surgical details was performed. Factors significantly associated with DVT univariately were entered into a multivariate logistic regression model. RESULTS The authors identified 314 patients, of whom 232 (73.9%) were screened preoperatively for a DVT. Of those screened, 22 (9.48%) were diagnosed with a DVT. The screened patients were older (median 62 vs 55 years, p = 0.0008), but otherwise similar in baseline characteristics. Nonambulatory status, previous history of DVT, lower partial thromboplastin time, and lower hemoglobin level were statistically significant and independent factors associated with positive results of screening for a DVT. Results of screening were positive in only 6.4% of ambulatory patients in contrast to 24.4% of nonambulatory patients, yielding an odds ratio of 4.73 (95% CI 1.88-11.90). All of the patients who had positive screening results underwent preoperative placement of an inferior vena cava filter. CONCLUSIONS Patients requiring surgery for spinal metastases represent a population with unique risks for venous thromboembolism. This study showed a 9.48% incidence of DVT in patients screened preoperatively. The highest rates of preoperative DVT were identified in nonambulatory patients, who were found to have a 4-fold increase in the likelihood of harboring a DVT. Understanding the preoperative thrombotic status may provide an opportunity for early intervention and risk stratification in this critically ill population.

Trauma patients warrant upper and lower extremity venous duplex ultrasound surveillance

Background:

Due to the high incidence of thromboembolic events (deep venous thrombosis [DVT] and pulmonary embolus [PE]) after injury, many trauma centers perform lower extremity surveillance duplex ultrasounds. We hypothesize that trauma patients are at a higher risk of upper extremity DVTs (UEDVTs) than lower extremity DVTs (LEDVTs), and therefore, all extremities should be evaluated.

Materials and Methods:

A retrospective chart and trauma registry review of Intensive Care Unit trauma patients with upper and LEDVTs detected on surveillance duplex ultrasound from January 2010 to December 2014 was carried out. Variables reviewed were age, gender, injury severity score, injury mechanism, clot location, day of clot detection, presence of central venous pressure catheter, presence of inferior vena cava filter, mechanical ventilation, and fracture.

Results:

A total of 136 patients had a DVT in a 5-year period: upper - 71 (52.2%), lower - 61 (44.9%), both upper and lower - 4 (2.9%). Overall, 75 (55.2%) patients had a UEDVT. Upper DVT vein: Brachial (62), axillary (26), subclavian (11), and internal jugular (10). Lower DVT vein: femoral (58), popliteal (14), below knee (4), and iliac (2). 10.3% had a PE: UEDVT - 5 (6.7%) and LEDVT - 9 (14.8%) P = 0.159.

Conclusions:

The majority of the DVTs in the study were in the upper extremities. For trauma centers that aggressively screen the lower extremities with venous duplex ultrasound, surveillance to include the upper extremities is warranted.

Surgical wound assessment by sonography in the prediction of surgical wound infections

BACKGROUND

Surgical site infections (SSIs) are important sources of morbidity, prolonged hospital stays, and readmissions, so they have become a major economic burden. We hypothesized that surgical wound assessment by sonography (SWATS) used at the bedside would detect wound fluid collections and that the presence of such collections would predict SSI better than standard clinical examination. If so, SWATS might be used to indicate early intervention that could prevent SSI morbidity.

METHODS

A prospective, single-institution observational study was conducted on adult inpatients following open abdominal surgery for trauma, gastrointestinal pathology, or biliary pathology at high risk (>5%) for SSI using traditional wound classifications. After informed consent was obtained, SWATS was performed using a smartphone-based ultrasound system on postoperative Day 2 to 4 and again before discharge or at postoperative Day 30, whichever came first. Primary treating physicians delivered standard wound care and were blinded to SWATS. SSI was diagnosed if treatment was implemented for suspected or documented wound infection by the treating physician. Results were analyzed by χ test and two-sample pooled variance t test where appropriate, with significance set at p < 0.05.

RESULTS

Forty-nine patients were studied. Nineteen patients had peri-incisional fluid collections found by SWATS. Eight of these patients went on to develop an SSI. SSI was significantly associated with the presence of fluid collections on SWATS (p = 0.009). SWATS had a sensitivity of 72.7% (0.43-0.92), a specificity of 71.1% (0.62-0.77), a positive predictive value of 42.1% (0.25-0.53), and a negative predictive value of 90.0% (0.79-0.97).

CONCLUSION

SWATS has a high negative predictive value that may allow it be an effective screening tool for developing SSI in high-risk surgical wounds. SWATS has the potential to be a useful and cost-effective adjunct to the clinician by objectively suggesting need for early therapy. Further study with larger sample sizes and randomized, SWATS-based interventions are required to validate this small study and determine its place in clinical care.

LEVEL OF EVIDENCE

Diagnostic study, level IV.

Thromboembolic Complications and Prophylaxis Patterns in Colorectal Surgery

IMPORTANCE

Venous thromboembolism (VTE) is an important complication of colorectal surgery, but its incidence is unclear in the era of VTE prophylaxis.

OBJECTIVE

To describe the incidence of and risk factors associated with thromboembolic complications and contemporary VTE prophylaxis patterns following colorectal surgery.

DESIGN, SETTING, AND PARTICIPANTS

Prospective data from the Washington State Surgical Care and Outcomes Assessment Program (SCOAP) linked to a statewide hospital discharge database. At 52 Washington State SCOAP hospitals, participants included consecutive patients undergoing colorectal surgery between January 1, 2006, and December 31, 2011.

MAIN OUTCOMES AND MEASURES

Venous thromboembolism complications in-hospital and up to 90 days after surgery.

RESULTS

Among 16,120 patients (mean age, 61.4 years; 54.5% female), the use of perioperative and in-hospital VTE chemoprophylaxis increased significantly from 31.6% to 86.4% and from 59.6% to 91.4%, respectively, by 2011 (P < .001 for trend for both). Overall, 10.6% (1399 of 13,230) were discharged on a chemoprophylaxis regimen. The incidence of VTE was 2.2% (360 of 16,120). Patients undergoing abdominal operations had higher rates of 90-day VTE compared with patients having pelvic operations (2.5% [246 of 9702] vs 1.8% [114 of 6413], P = .001). Those having an operation for cancer had a similar incidence of 90-day VTE compared with those having an operation for nonmalignant processes (2.1% [128 of 6213] vs 2.3% [232 of 9902], P = .24). On adjusted analysis, older age, nonelective surgery, history of VTE, and operations for inflammatory disease were associated with increased risk of 90-day VTE (P < .05 for all). There was no significant decrease in VTE over time.

CONCLUSIONS AND RELEVANCE

Venous thromboembolism rates are low and largely unchanged despite increases in perioperative and postoperative prophylaxis. These data should be considered in developing future guidelines.

Tranexamic acid as part of remote damage-control resuscitation in the prehospital setting: A critical appraisal of the medical literature and available alternatives

BACKGROUND

Hemorrhage remains the leading cause of preventable trauma-associated mortality. Interventions that improve prehospital hemorrhage control and resuscitation are needed. Tranexamic acid (TXA) has recently been shown to reduce mortality in trauma patients when administered upon hospital admission, and available data suggest that early dosing confers maximum benefit. Data regarding TXA implementation in prehospital trauma care and analyses of alternatives are lacking. This review examines the available evidence that would inform selection of hemostatic interventions to improve outcomes in prehospital trauma management as part of a broader strategy of "remote damage-control resuscitation" (RDCR).

METHODS

The medical literature available concerning both the safety and the efficacy of TXA and other hemostatic agents was reviewed.

RESULTS

TXA use in surgery was studied in 129 randomized controlled trials, and a meta-analysis was identified. More than 800,000 patients were followed up in large cohort study. In trauma, a large randomized controlled trial, the CRASH-2 study, recruited more than 20,000 patients, and two cohort studies studied more than 1,000 war casualties. In the prehospital setting, the US, French, British, and Israeli militaries as well as the British, Norwegian, and Israeli civilian ambulance services have implemented TXA use as part of RDCR policies.

CONCLUSION

Available data support the efficacy and the safety of TXA. High-level evidence supports its use in trauma and strongly suggests that its implementation in the prehospital setting offers a survival advantage to many patients, particularly when evacuation to surgical care may be delayed. TXA plays a central role in the development of RDCR strategies.

DVT surveillance program in the ICU: analysis of cost-effectiveness

BACKGROUND

Venous Thrombo-embolism (VTE--Deep venous thrombosis (DVT) and/or pulmonary embolism (PE)--in traumatized patients causes significant morbidity and mortality. The current study evaluates the effectiveness of DVT surveillance in reducing PE, and performs a cost-effectiveness analysis.

METHODS

All traumatized patients admitted to the adult ICU underwent twice weekly DVT surveillance by bilateral lower extremity venous Duplex examination (48-month surveillance period--SP). The rates of DVT and PE were recorded and compared to the rates observed in the 36-month pre-surveillance period (PSP). All patients in both periods received mechanical and pharmacologic prophylaxis unless contraindicated. Total costs--diagnostic, therapeutic and surveillance--for both periods were recorded and the incremental cost for each Quality Adjusted Life Year (QALY) gained was calculated.

RESULTS

4234 patients were eligible (PSP--1422 and SP--2812). Rate of DVT in SP (2.8%) was significantly higher than in PSP (1.3%) - p<0.05, and rate of PE in SP (0.7%) was significantly lower than that in PSP (1.5%) - p<0.05. Logistic regression demonstrated that surveillance was an independent predictor of increased DVT detection (OR: 2.53 - CI: 1.462-4.378) and decreased PE incidence (OR: 0.487 - CI: 0.262-0.904). The incremental cost was $509,091/life saved in the base case, translating to $29,102/QALY gained. A sensitivity analysis over four of the parameters used in the model indicated that the incremental cost ranged from $18,661 to $48,821/QALY gained.

CONCLUSIONS

Surveillance of traumatized ICU patients increases DVT detection and reduces PE incidence. Costs in terms of QALY gained compares favorably with other interventions accepted by society.

The effects of location and low-molecular-weight heparin administration on deep vein thrombosis outcomes in trauma patients

BACKGROUND

Deep vein thrombosis (DVT) is common after trauma. Pulmonary embolism (PE) is a feared complication of DVT. Standard doses of low-molecular-weight heparin (LMWH) are commonly used to prevent and treat DVT and PE. There is variable bioavailability of LMWH with standard therapy. The traditional concept that below-knee DVT is associated with a lower risk of subsequent PE may result in less aggressive therapy. The purposes of this study were to assess the rates of PE in above-knee versus below-knee DVT and longitudinally evaluate outcomes of DVT treated with LMWH therapy.

METHODS

This was a retrospective review of patients at a university Level I trauma center during the years 2005 through 2010. Patients diagnosed with lower-extremity DVT were included in this study. Patients were classified by location of lower-extremity DVT and type of LMWH therapy received. All high-risk trauma patients were evaluated with weekly duplex Doppler ultrasonography. All duplex studies were reviewed for DVT resolution or improvement. Symptomatic patients were evaluated with computed tomographic angiography to rule out PE. Demographics, total length of hospital stay, length of intensive care unit stay, and Injury Severity Score (ISS) were collected.

RESULTS

Three-hundred eight trauma patients with lower-extremity DVT were included. More patients developed below-knee DVT (65.6%) compared with above-knee DVT (34.4%). Increased length of hospital stay, intensive care unit stay, and higher ISS were noted in patients with above-knee DVT. More patients had below-knee DVT in the prophylactic dosing group. With LMWH therapy, three PEs occurred in patients in the prophylactic dosing group with below-knee DVT, and no PEs occurred in the therapeutic treatment group. The incidence of PE between patients with below-knee DVT compared with above-knee DVT overall was not different (3.3% and 4.7%, p = 0.59). To assess DVT outcomes, 157 of the 308 patients had serial duplex studies following diagnosis of lower-extremity DVT. The number of patients receiving either therapeutic or prophylactic LMWH was similar (51% and 49%). There was no difference in rates of resolution or improvement between LMWH dosing groups or location of DVT.

CONCLUSION

In screened trauma patients, below-knee DVT is more common than above-knee DVT. There was no difference in the incidence of PE between groups. Standard prophylactic and therapeutic dosing of LMWH does not affect the rates of resolution or improvement of lower-extremity DVT. Rates of resolution and improvement of DVT is not dependent of location of lower-extremity DVT.

LEVEL OF EVIDENCE

Therapeutic study, level IV; epidemiologic study, level III.

Venous thromboembolism after trauma: a never event?*

OBJECTIVE

Rates of venous thromboembolism as high as 58% have been reported after trauma, but there is no widely accepted screening protocol. If Medicare adds venous thromboembolism to the list of "preventable complications," they will no longer reimburse for treatment, which could have devastating effects on many urban centers. We hypothesized that prescreening with a risk assessment profile followed by routine surveillance with venous duplex ultrasound that could identify asymptomatic venous thromboembolism in trauma patients.

DESIGN

Prospective, observational trial with waiver of consent.

SETTING

Level I trauma center intensive care unit.

PATIENTS

At admission, 534 patients were prescreened with a risk assessment profile.

INTERVENTIONS

Patients (n = 106) with risk assessment profile scores >10 were considered high risk and received routine screening venous duplex ultrasound within 24 hrs and weekly thereafter.

RESULTS

In prescreened high-risk patients, 20 asymptomatic deep vein thrombosis were detected with venous duplex ultrasound (19%). An additional ten venous thromboembolisms occurred, including six symptomatic deep vein thrombosis and four pulmonary emboli, resulting in an overall venous thromboembolism rate of 28%. The most common risk factors discriminating venous thromboembolism vs. no venous thromboembolism were femoral central venous catheter (23% vs. 8%), operative intervention >2 hrs (77% vs. 46%), complex lower extremity fracture (53% vs. 32%), and pelvic fracture (70% vs. 47%), respectively (all p < .05). Risk assessment profile scores were higher in patients with venous thromboembolism (19 ± 6 vs. 14 ± 4, p = .001). Risk assessment profile score (odds ratio 1.14) and the combination of pelvic fracture requiring operative intervention >2 hrs (odds ratio 5.75) were independent predictors for development of venous thromboembolism. The rates of venous thromboembolism for no chemical prophylaxis (33%), unfractionated heparin (29%), dalteparin (40%), or inferior vena cava filters (20%) were not statistically different (p = .764).

CONCLUSIONS

Medicare's inclusion of venous thromboembolism after trauma as a "never event" should be questioned. In trauma patients, high-risk assessment profile score and pelvic fracture with prolonged operative intervention are independent predictors for venous thromboembolism development, despite thromboprophylaxis. Although routine venous duplex ultrasound screening may not be cost-effective for all trauma patients, prescreening using risk assessment profile yielded a cohort of patients with a high prevalence of venous thromboembolism. In such high-risk patients, routine venous duplex ultrasound and/or more aggressive prophylactic regimens may be beneficial.

Pulmonary emboli after blunt trauma: timing, clinical characteristics and natural history

BACKGROUND

Venous thromboembolism (VTE) frequently complicates the recovery of trauma patients, and contributes to morbidity and mortality. Recent studies showed an increase in diagnosis of pulmonary embolism (PE) mainly in the early or immediate period after trauma. The clinical significance of those incidental PEs is unclear.

METHODS

The study cohort included all blunt trauma patients who had a contrast-enhanced CT of the chest performed as part of their initial trauma assessment from January 1, 2005 to January 31, 2007 in a large academic Canadian trauma centre. Patients diagnosed with PE at any point during admission were identified using our institutional trauma registry. All chest CT scans and electronic charts were reviewed. Patients were classified according to time of PE detection (immediate, early or late) and symptoms (asymptomatic or symptomatic). The clinical characteristics and hospital course of the patients who were diagnosed with immediate PE were described.

RESULTS

1259 blunt trauma patients were reviewed. Six patients presented with immediate PE (0.5%); nine patients were found to have early PE (0.7%) and 13 had late PE (1.0%). All six of the patients with immediate PE were classified as asymptomatic. Five of the nine patients with early PE were symptomatic and all 13 patients who developed late PE were symptomatic. Amongst the six patients with immediate PE, five survived 24h hospitalisation. Four of them were managed with prophylactic low molecular weight heparin and no other thromboembolic events were observed during admission or after discharge.

CONCLUSIONS

The increased use of advanced CT technology in trauma patients has resulted in an increased diagnosis of incidental PEs that are asymptomatic. The clinical significance and management of these small, incidental PE are uncertain and further studies are needed to clarify the natural history of this controversial finding.

Diagnostic approach to deep venous thrombosis and pulmonary embolism in the critical care setting

Considerable progress has been made during the last 30 years in the prevention, diagnosis, and therapy of venous thromboembolism. This article discusses the epidemiology, pathophysiology, and clinical presentation of the disease as well as the diagnostic uncertainty that exists in the critical care setting. Diagnostic approaches for deep venous thrombosis and pulmonary embolism are considered, including clinical prediction rules, D-dimer, contrast venography, duplex ultrasonography, computed tomographic angiography and venography, magnetic resonance imaging, ventilation–perfusion scanning, chest radiograph, arterial blood gases, electrocardiography, and echocardiography.

Optional inferior vena cava filters in the trauma patient

Trauma patients are at exceedingly high risk of development of venous thromboembolism (VTE) including deep venous thrombosis and pulmonary embolism (PE). The epidemiology of VTE in trauma patients is reviewed. PE is thought to be the third major cause of death after trauma in those patients who survive longer than 24 hours after onset of injury. In fact, patients recovering from trauma have the highest rate of VTE among all subgroups of hospitalized patients. Various prophylactic and surveillance methods have been evaluated and found helpful in certain situations, but VTE complications can occur despite such measures. Therapeutic and prophylactic uses of inferior vena cava (IVC) filters in trauma patients are reviewed. Prophylactic IVC filter use is revealed to be a controversial subject with valid arguments on both sides of the issue. With the lack of prospective randomized trials of IVC filter use in trauma, it is impossible to make evidence-based recommendations. Unfortunately, two sets of guidelines are available for insertion of filters in trauma patients, with conflicting recommendations. The introduction of retrievable IVC filters seems to offer a unique solution for VTE protection in the trauma patient population, which often consists of younger members of our population. Lastly, current generations of FDA-approved retrieval filters are discussed.

Assessing the Use of Venous Thromboembolism Risk Assessment Profiles in the Trauma Population: Is It Necessary?

Deep venous thrombosis (DVT) and the subsequent development of venous thromboembolism (VTE) are a significant cause of mortality, morbidity, and cost of care in trauma patients. This study aims to: 1) validate 5 as a critical threshold for high risk; 2) validate risk factors associated with DVT/VTE development; 3) evaluate exogenous estrogen and smoking as risk factors; and 4) analyze daily risk assessment profile (RAP) score changes. We performed a retrospective chart review of trauma patients admitted from January 2001 through December 2005. Univariate odds ratios were performed to assess potential risk factors for VTE. Of the 110 charts reviewed, 31 patients had confirmed DVT/VTE. Three of 26 patients with an RAP score < 5 suffered a VTE; one resulted in death. Significant risk factors included femoral venous line insertion, operation longer than 2 hours, head abbreviated injury score > 2, and Glasgow Coma Scale score < 8. RAP fluctuations were due to a changing Glasgow Coma Scale score, and whether the patient received more than four transfusions, was in surgery for more than 2 hours, or required a femoral venous catheter or major venous repair. The RAP critical value (5) was not validated. We recommend all trauma patients be treated with prophylactic anticoagulants throughout the hospital stay unless clear contraindications exist.

Duplex ultrasound screening detects high rates of deep vein thromboses in critically ill trauma patients

OBJECTIVE

American College of Chest Physician (ACCP) guidelines stratify deep venous thrombosis (DVT) risk in trauma patients based on injury pattern and pharmacologic prophylaxis. Screening is only recommended for patients with high-risk injuries who are unable to receive pharmacologic prophylaxis. However, the prevalence of lower extremity DVT (LEDVT) in trauma patients may be higher than reported in previous studies as many studies on DVT screening have not investigated calf vein DVTs (CVDVT) and have not exclusively targeted critically ill patients. Given that current ACCP guidelines recommend treatment of CVDVTs, we investigated the efficacy of duplex ultrasound (DUS) screening in critically ill trauma patients for all LEDVTs, including CVDVT, regardless of injury pattern, risk factors, or pharmacologic prophylaxis.

METHODS

Medical records of 264 intensive care unit trauma patients who received DUS screening for LEDVT were retrospectively examined for the presence of injuries conferring high risk for LEDVT, patient specific DVT risk factors, and low molecular weight heparin (LMWH) prophylaxis.

RESULTS

Forty (15.2%) patients had LEDVTs found on DUS screening, 24 (60%) were CVDVT, and 30% of all DVTs were diagnosed within 1 week of admission. Patients without high-risk injuries receiving LMWH had a 13.5% DVT rate, which did not differ significantly from the 19.7% DVT rate in high-risk injury patients not receiving LMWH (P = .667).

CONCLUSIONS

Lower extremity DVT is common in critically ill trauma patients, particularly in the first week following injury, regardless of injury pattern, DVT risk factors, or pharmacologic prophylaxis. Previous studies have underestimated DVT rates by not investigating CVDVTs and not exclusively targeting critically ill patients. We recommend early and continued DUS DVT screening of all critically ill trauma patients.

Venous thromboembolic disease in trauma and surveillance ultrasonography

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Acquired thrombotic risk factors in the critical care setting

Acquired thrombotic risk factors include a variety of noninherited clinical conditions that can predispose an individual to an increased risk for venous thromboembolism. For patients in a critical care setting, certain acquired risk factors represent chronic conditions that the patients may have had before the current acute illness (e.g., malignancy, various cardiovascular risk factors, certain medications), whereas others may be directly related to the reason the patient is in an intensive care unit or the patient's management there (e.g., postoperative state, trauma, indwelling vascular access, certain medications). Optimal thromboprophylactic strategies depend on individual patient risk profiles including an assessment of the specific clinical setting. Treatment for patients with acquired thrombotic risk factors includes anticoagulant therapy and, if possible, resolution of the acquired risk factor(s). Heparin-induced thrombocytopenia represents a unique clinical situation in which all sources of heparin must be discontinued and the patient started on an alternative anticoagulant (e.g., a direct thrombin inhibitor) in the acute setting. The duration of anticoagulant therapy would vary depending on the specific clinical setting.

Venous thromboembolism as a marker of quality of care in trauma

BACKGROUND

Venous thromboembolism (VTE) is reported to occur among 7% to 58% of trauma patients. Variability in VTE rates might reflect differences in case mix and quality of care, but also screening practices or data capture. We explored the variation in VTE rates across trauma centers to determine its use as a measure of the quality of patient care.

STUDY DESIGN

The National Trauma Data Bank (version 7.1, admission year 2006) was used to capture a cohort at risk for VTE. Crude and adjusted rates of VTE were determined, and the observed and expected rates were compared across centers. Outlier hospitals were defined as those with considerably more (or fewer) patients than expected. We then assessed the level of concordance between outlier status for deep vein thrombosis (DVT) and pulmonary embolism (PE). Intraclass correlation coefficients (ICC) were calculated to evaluate for the presence of a "center" effect using multilevel modeling.

RESULTS

The 22,421 patients met inclusion criteria from 30 trauma centers. There was marked variability in the rate of VTE across centers, ranging from 0.2% to 13.3%, which was more pronounced for DVT (0.2% to 13.1%) than for PE (0% to 1.7%). There was poor concordance for DVT and PE outlier status. Intraclass correlation coefficient was four times greater for DVT (0.23) than for PE (0.06).

CONCLUSIONS

There was substantial variation in rates of VTE across trauma centers. There was no relationship between DVT and PE outlier status, which is counter to the understanding of the biologic relationship between the two. Lastly, the very low Intraclass correlation coefficient for PE compared with DVT suggests that to a large extent, practice variation has very little impact on PE rates. In light of these findings and concerns about patient ascertainment of DVT, VTE rates might not be a useful measure of quality of care.