Screening for major deep vein thrombosis in seriously injured patients: a prospective study

Deep vein thrombosis in donor or recipient veins encountered during lower extremity reconstruction with a free anterolateral thigh perforator flap: How do we deal with it?

Background

The free anterolateral thigh perforator (ALTP) flap has been successfully adopted to reconstruct traumatic soft tissue defects in the lower extremities. However, the occurrence of deep vein thrombosis (DVT) in donor or recipient veins has been overlooked, and there has been no reliable guideline to manage it. Therefore, in this study, we review our cases where the ALTP flaps were transferred to traumatic lower limbs even though DVT was found in the pedicle or recipient veins. Furthermore, based on our experiences, we suggest an algorithmic approach for dealing with DVT.

Patients and methods

This study included 108 patients who underwent lower extremity reconstruction using a free ALTP flap between January 2014 and January 2021. All medical records were reviewed, including preoperative assessment data, intraoperative findings, and postoperative complications. Notably, when DVT was found in both the donor and recipient veins, we thoroughly assessed operative findings, surgical solutions, and final outcomes.

Results

Sixty-one of 108 (56.4%) patients underwent computed tomographic venography (CTV) preoperatively, revealing DVT in 11 of these 61 (18%) patients. Three of these 11 patients had iliofemoral DVT, and surgery was delayed more than two weeks after detection. The remaining eight patients had calf DVT and underwent free ALTP flap transfer as scheduled. Conversely, 47 of 108 (43.6%) patients did not undergo CTV, and an occult DVT was found in five of these 47 (10.6%) patients. In two of these five patients, free flap surgery was replaced with amputation and local flap coverage. In the remaining three patients and one patient with an occult DVT that was not found on CTV, the free ALTP flap transfer was carried out. In 15 patients with DVT, free ALTP flap transfer was performed using various alternative methods for venorrhaphy. Consequently, all flaps survived, with partial necrosis occurring in two patients.

Conclusion

If DVT-affected veins are appropriately managed, the free ALTP flap can be successfully transferred to the traumatic lower limb even when DVT occurs in donor or recipient veins. The author's algorithm can help surgeons overcome the insufficiency of veins for pedicle anastomosis due to DVT and avoid postoperative thromboembolic complications.

Routine Lower Extremity Screening Ultrasound Protocols in Trauma Patients Are Not Cost Effective

BACKGROUND

Despite prophylaxis, deep vein thrombosis (DVT) and pulmonary embolism remain dreaded complications following traumatic injury and are associated with significant morbidity and mortality. Screening ultrasound (US) protocols have been employed in trauma centers for early detection of lower extremity (LE) deep venous thrombosis. We hypothesized that screening lower extremity venous duplex US would not prove cost effective in our trauma population who receives early pharmacologic prophylaxis.

METHODS

Data was collected for one year on all adult trauma patients admitted to the trauma service from December 2019 to 2020. DVT screening US was obtained at 3 days after admission for patients with long bone or pelvic fracture, spinal cord injury, immobility, and/or spinal fracture requiring surgery. Screening US was obtained at 7 days for all others and repeated weekly until discharge. Data was retrospectively collected and analyzed.

RESULTS

Exactly 1365 patients met inclusion criteria with median ISS 12 (IQR, 9-17), median age 56 (IQR, 36-73 years), and with majority blunt injuries (90.7%). A total of 1369 screening US were performed finding 27 DVTs (2%). The total cost of screening for the year analyzed amounted to over $270,000 with 50.7 screening US needed to detect 1 DVT. This resulted in an average screening cost of over $10,000 for the detection of a single DVT.

DISCUSSION

In trauma patients receiving early pharmacologic prophylaxis, routine LE screening US protocols to detect LE DVT are not cost effective.

Duplex ultrasound surveillance for deep vein thrombosis after acute traumatic spinal cord injury at rehabilitation admission

Context/objective: To determine the prevalence of deep vein thrombosis (DVT) detected through routine duplex screening and factors associated with DVT in spinal cord injury (SCI) patients on admission to rehabilitation.Design: Retrospective chart review of medical records.Setting: Acute inpatient rehabilitation.Participants: One hundred and eighty-nine individuals admitted to rehabilitation within 2 weeks of initial traumatic SCI who underwent routine surveillance with duplex scan for DVT.Interventions: Duplex scan of lower extremities.Outcome measures: The dependent variable was positive duplex screening for either any DVT (distal and/or proximal) or proximal DVT.Results: Of the 189 patients, 31 patients (16.4%) had a positive scan for any (proximal and/or distal) DVT, with 9 (4.8%) positive for a proximal DVT and 22 (11.6%) positive for isolated distal DVT. Of those with isolated distal DVT, 31.8% later developed propagation with either proximal DVTs or pulmonary embolism (mean = 22 days). Factors significantly associated with positive duplex scans for any (proximal and/or distal) DVT include more severe neurological injury (AIS A, B or C versus AIS D: χ² = 7.1791, df = 1, P = 0.007) and older age (age ≥50 years old: χ² = 14.9410, df = 1, P = 0.000).Conclusion: In acute traumatic SCI, older age and more severe neurological impairment (AIS A, B, and C) are independent risk factors for positive duplex screening for any (proximal and/or distal) DVT detected on rehabilitation admission. Individuals with an acute distal DVT have a high likelihood for future thrombus progression. Routine surveillance for these patients may be warranted.

Lethal Trauma Pulmonary Embolism is a Black Swan Event in Patients at Risk for Deep Vein Thrombosis: An Evidence-Based Review

We delineated the incidence of trauma patient pulmonary embolism (PE) and risk conditions by performing a systematic literature review of those at risk for deep vein thrombosis (DVT). The PE proportion was 1.4 per cent (95% confidence interval = 1.2–1.6) in at-risk patients. Of 10 conditions, PE was only associated with increased age (P < 0.01) or leg injury (P < 0.01; risk ratio = 1.6). As lower extremity DVT (LEDVT) proportions increased, mortality proportions (P = 0.02) and hospital stay (P = 0.0002) increased, but PE proportions did not (P = 0.13). LEDVT was lower with chemoprophylaxis (CP) (4.9%) than without CP (19.1%; P < 0.01). PEwas lower withCP (1.0%) than without CP (2.2%; P = 0.0004). Mortality was lower with CP (6.6%) than without CP (11.6%; P = 0.002). PE was similar with (1.2%) and without (1.9%; P = 0.19) mechanical prophylaxis (MP). LEDVT was lower with MP (8.5%) than without MP (12.2%; P = 0.0005). PE proportions were similar with (1.3%) and without (1.5%; P = 0.24) LEDVTsurveillance. Mortality was higher with LEDVTsurveillance (7.9%) than without (4.8%; P < 0.01). A PE mortality of 19.7 per cent (95% confidence interval = 18–22) 3 a 1.4 per cent PE proportion yielded a 0.28 per cent lethal PE proportion. As PE proportions increased, mortality (P = 0.52) and hospital stay (P = 0.13) did not. Of 176 patients with PE, 76 per cent had no LEDVT. In trauma patients at risk for DVT, PE is infrequent, has a minimal impact on outcomes, and death is a black swan event. LEDVTsurveillance did not improve outcomes. Because PE was not associated with LEDVT and most patients with PE had no LEDVT, preventing, diagnosing, and treating LEDVT may be ineffective PE prophylaxis.

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.

Rate of lower-extremity ultrasonography in trauma patients is associated with rate of deep venous thrombosis but not pulmonary embolism

BACKGROUND

Disparate lower-extremity ultrasonography (LUS) screening practices among trauma institutions reflecta lack of consensus regarding screening indications and whether screening improves outcomes. We hypothesized that LUS screening for deep-vein thrombosis (DVT) is not associated with a reduced incidence of pulmonary embolism (PE).

METHODS

The 2012 ACS National Trauma Data Bank Research Data Set was queried to identify 442,108 patients treated at institutions reporting at least one LUS and at least one DVT. Institutions performing LUS on more than 2% of admitted patients were designated high-screening facilities and remaining institutions were designated low-screening facilities. Patient characteristics and risk factors were used to develop a logistic regression model to assess the independent associations between LUS and DVT and between LUS and PE.

RESULTS

Overall, DVT and PE were reported in 0.94% and 0.37% of the study population, respectively. DVT and PE were reported more commonly in designated high-screening than low-screening facilities (DVT: 1.12% vs 0.72%, P < .0001; PE: 0.40% vs 0.33%, P = .0004). Multivariable logistic regression demonstrated that LUS was associated independently with DVT (odds ratio 1.43, confidence interval 1.34-1.53) but not PE (odds ratio 1.01, confidence interval 0.92-1.12) (c-statistic 0.86 and 0.85, respectively). Sensitivity analyses performed at various rates for designating HS facilities did not alter the significance of these relationships.

CONCLUSION

LUS in trauma patients is not associated with a change in the incidence of PE. Aggressive LUS DVT screening protocols appear to detect many clinically insignificant DVTs for which subsequent therapeutic intervention may be unnecessary, and the use of these protocols should be questioned.

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.

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.

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.

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.

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.

Duplex ultrasound screening for deep vein thrombosis in asymptomatic trauma patients: a survey of individual trauma surgeon opinions and current trauma center practices

BACKGROUND

Many national agencies have suggested that deep vein thrombosis (DVT) rates measure quality of hospital care. However, none provide recommendations for standardized screening. If screening practices vary among clinicians or hospitals, DVT rates could be biased-centers which perform more duplex ultrasounds report more DVTs. We hypothesized that trauma surgeons have varying opinions regarding duplex ultrasound screening for DVT in asymptomatic trauma patients, which result in varying practice patterns.

METHODS

We conducted two web-based surveys regarding the use of duplex ultrasound screening for DVT in asymptomatic trauma patients. The first (individual provider level) surveyed members of two national trauma surgery organizations (American Association for the Surgery of Trauma and Eastern Association for the Surgery of Trauma). The second (trauma center level) surveyed practice patterns of National Trauma Data Bank hospitals.

RESULTS

Three hundred seventeen individual surgeons completed surveys. There was wide variation in individual opinions regarding DVT screening in asymptomatic trauma patients (53% agree, 36% disagree, and 11% neither agree nor disagree). Two hundred thirteen National Trauma Data Bank hospitals completed surveys of which 28% (n=60) have a written guideline regarding DVT screening in asymptomatic trauma patients. The proportion of centers with a written protocol varied significantly by trauma center level (p<0.001) but not by teaching status. Opinions and practice patterns suggest that screening should start early and be performed weekly. The main risk factors used to suggest DVT screening are spinal cord injury and pelvic fracture.

CONCLUSIONS

There are wide variations in trauma surgeons' opinions and trauma centers' practices regarding duplex ultrasound screening for DVT in asymptomatic trauma patients. This variability combined with the fact that performing more duplex ultrasounds finds more DVTs may influence reported DVT rates. DVT rates alone are biased and not reflective of true quality of trauma care.

Predictors of posttraumatic deep vein thrombosis (DVT): hospital practice versus patient factors-an analysis of the National Trauma Data Bank (NTDB)

OBJECTIVE

Trauma centers that perform more duplex ultrasounds report more deep vein thromboses (DVT). However, it is uncertain if this is due to variations in hospital practices or patient characteristics and case mix. We hypothesize that admission to trauma centers that use duplex ultrasound more frequently, independently predicts DVT reporting for individual patients, controlling for patient-level risk factors.

METHODS

We analyzed patients from trauma centers reporting at least one vascular ultrasound and one DVT to the National Trauma Data Bank (v6.2). Because National Trauma Data Bank contains no data on hospital duplex surveillance practice, we defined "screening" trauma centers as those performing ultrasound on more than 2% of patients. The primary outcome measure was DVT diagnosis. Multiple logistic regression was performed, using patient-level risk factor covariates as well as hospital duplex rate to compare patients at "screening" versus "non-screening" trauma centers. Sensitivity analysis was performed by varying duplex rate cutoff, outcome measure, and patient population.

RESULTS

Approximately half of 492,496 patients were admitted to "screening" trauma centers. Unadjusted DVT rate was threefold higher in "screening" trauma center patients (1.18% vs. 0.35%, p < 0.001). Age > or = 40 years, extremity injury, head injury, ventilator days > or = 3, venous injury and major surgery were independently associated with DVT diagnosis. "Screening" trauma center admission was independently associated with a higher likelihood of DVT reporting (odds ratio, 2.16; 95% confidence interval, 1.07-4.34). No qualitative differences were identified on sensitivity analyses.

CONCLUSIONS

Trauma center ultrasound practice is an independent predictor of DVT diagnosis for individual patients, controlling for patient-level risk factors. Elevated DVT rates at these centers are due to surveillance bias. In the absence of standardized surveillance, hospital DVT rate is an inappropriate quality of care measure after trauma.

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

BACKGROUND

This retrospective review of a prospectively collected database was conducted to analyze the efficacy of 4 years of aggressive prophylaxis and screening protocols for venous thromboembolism (VTE) in a large population of trauma patients.

METHODS

Trauma patients at a Level I Trauma Center found to be nonambulatory or otherwise high risk were placed on a protocol of lower-extremity (LE) compression devices and subcutaneous enoxaparin as soon as feasible after admission. Duplex scans of LEs were conducted weekly.

RESULTS

During 4 years, 2,939 patients were admitted to trauma with length of stay >2 days. There was a 3.2% incidence of VTE in the length of stay >2 days population, 2.5% rate of deep venous thrombosis (DVT), and 0.7% pulmonary embolism. All VTE patients had factors known to increase risk of VTE and were included in our prophylaxis and screening protocol. Twenty-one percent of these received pharmacologic prophylaxis within the first 2 days of admission; 62% received enoxaparin at some point before diagnosis of VTE. Duplex scans were conducted in 982 patients. Notably, 86% of LE DVTs were found on routine screening duplex.

CONCLUSION

To our knowledge, this is the largest population of trauma patients followed by screening duplexes. All patients with VTEs were identified as high risk, and screening revealed multiple patients with an asymptomatic DVT. We conclude our aggressive prophylaxis regimen lead to low rates of VTE and think screening duplex is a critical component for identifying unsuspected DVT.

Venous thromboembolism in trauma patients

Serial venous duplex scans (VDS) were done in 507 trauma patients with at least one risk factor (RF) for venous thromboembolism (VTE) during a 2-year study period. Deep vein thrombosis (DVT) was detected in 31 (6.1%) patients. This incidence was 3.1 per cent in low (1-2 RFs), 3.4 per cent in moderate (3-5 RFs), and 7.7 per cent in high (> or =6 RFs) VTE scores (P = 0.172). Incidence was statistically different (3% vs. 7.2%, P = 0.048) on reanalyzing patients in two risk categories, low-risk (1-4 RFs) and high-risk (> or =5 RFs). Only 4 of 16 RFs had statistically higher incidence of DVT in patients with or without RFs: previous VTE (27.3% vs. 5.6%, odds ratio (OR) 6.628, P = 0.024), spinal cord injury (22.6% vs. 5%, OR 5.493, P = 0.001), pelvic fractures (11.4% vs. 5.1%, OR 2.373, P = 0.042), and head injury with a greater than two Abbreviated Injury Score (10.5% vs. 4.2%, OR 2.639, P = 0.014). On reanalyzing patients with > or =5 RFs vs. <5RFs, obesity (14.3 vs. 6.1%, P = 0.007), malignancy (5.6% vs. 0.6%, P = 0.006), coagulopathy (10.8% vs. 1.8%, P = 0.000), and previous VTE (3.2% vs. 0%, P = 0.019) were significant on univariate analysis. Patients with DVT had 3.70 +/- 1.75 RFs and a 9.61 +/- 4.93 VTE score, whereas, patients without DVT had 2.66 +/- 1.50 RFs and a 6.83 +/- 3.91 VTE score (P = 0.000). DVTs had a direct positive relationship with higher VTE scores, length of stay, and number of VDS (>1 r, P < or = 0.001). Increasing age was a weak risk factor (0.03 r, P = 0.5). First two VDS diagnosed 77 per cent of DVTs. Patients with injury severity score of > or =15 and 25 had higher DVTs compared with the ones with lower injury severity score levels (P < or = 0.05). Pulmonary embolism was silent in 63 per cent and DVTs were asymptomatic in 68 per cent.

Can increased incidence of deep vein thrombosis (DVT) be used as a marker of quality of care in the absence of standardized screening? The potential effect of surveillance bias on reported DVT rates after trauma

BACKGROUND

Deep vein thrombosis (DVT) is a significant cause of morbidity and mortality in trauma patients, even with appropriate prophylaxis. Many national agencies (Agency for Healthcare Research and Quality, Joint Commission, National Quality Forum) have suggested DVT incidence as a measurement of health care quality, but none has recommended a standardized screening approach. Duplex ultrasound serves an important role as a noninvasive diagnostic tool for detection of DVT. However, screening of asymptomatic patients for DVT is somewhat controversial and these practices vary widely among trauma centers. We hypothesized that as the number of screening duplex examinations in trauma patients increases, the rate of DVT identification will also increase.

METHODS

Retrospective cohort study of 21,961 patients from an urban, university-based Level I trauma center for more than 11 years (1995-2005). We grouped patients according to admission at the trauma service either before or after implementation of a written practice management guideline for DVT prophylaxis and duplex ultrasound surveillance in 1998. We compared duplex, DVT, and pulmonary embolism rates per 1,000 trauma admissions using Fisher's exact test.

RESULTS

The proportion of trauma patients having a duplex ultrasound increased significantly (20.9-81.5 per 1,000 trauma admissions, p < 0.0001). The rate of DVT reported increased 10-fold (0.7-7.0 per 1,000 admissions, p = 0.0024), significantly, between the two periods. The pulmonary embolism rate increased almost fivefold (0.7-3.2 per 1,000 admissions, p = 0.15), although this difference was not statistically significant.

CONCLUSIONS

Increasing the number of duplex screening exams resulted in an increased rate of DVT identification. In the absence of standardized surveillance, DVT rates may be more influenced by how often caregivers look for these events rather than the quality of care provided.

A survey of thromboprophylaxis management in patients with major trauma

BACKGROUND

Venous thromboembolism (VTE) is a common life-threatening complication of major trauma. Although clinical guidelines clearly suggest routine VTE prevention with low-molecular-weight heparin (LMWH) in this specific group of patients, there is still a lack of strong recommendations regarding the timing and the modality of heparin administration and the role of mechanical prophylaxis. We tested the hypothesis that there is significant practice variation in thromboprophylaxis management of patients with major trauma among intensive care unit (ICU) specialists.

METHODS

Two hundred Italian ICU specialists, representing 200 ICU throughout the country, were contacted by telephone and were asked (1) whether they routinely prescribe pharmacological antithrombotic prophylaxis in patients with major trauma, whether prophylaxis is prescribed to all patients or to selected patients, and the type of prophylaxis and the timing of administration and (2) whether they recommend physical prevention, whether this is prescribed to all patients or to selected patients, and the type of physical prophylaxis.

RESULTS

In patients with major trauma, 85% of the interviewed ICU specialists answered that they prescribe pharmacological prophylaxis for VTE. 37.6% of them prescribe prophylaxis only to selected patients based on the level of risk, 87.7% prescribe low-molecular-weight heparin, and 42.4% start prophylaxis immediately after hospitalization. Only 61% of the interviewed specialists prescribe physical prophylaxis; 82.8% of them use elastic stockings, 9.8% intermittent pneumatic compression, and 7.4% other mechanical devices. Physical prophylaxis is prescribed to all patients by 41%, and by 59% only in case of contraindication to pharmacological prevention. Inferior vena cava (IVC) filter insertion is considered by 47% when anticoagulation is contraindicated; 91.4% of them recommend the IVC filter only if deep vein thrombosis (DVT) has been diagnosed.

CONCLUSIONS

Even when there are clinical guidelines, prescription of VTE prevention in patients with major trauma is underused and timing and modality of prophylaxis are rather heterogeneous. When anticoagulation is contraindicated, IVC filters are commonly recommended only in the presence of DVT.

Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy

This article discusses the prevention of venous thromboembolism (VTE) and is part of the Seventh American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following. We recommend against the use of aspirin alone as thromboprophylaxis for any patient group (Grade 1A). For moderate-risk general surgery patients, we recommend prophylaxis with low-dose unfractionated heparin (LDUH) (5,000 U bid) or low-molecular-weight heparin (LMWH) [< or = 3,400 U once daily] (both Grade 1A). For higher risk general surgery patients, we recommend thromboprophylaxis with LDUH (5,000 U tid) or LMWH (> 3,400 U daily) [both Grade 1A]. For high-risk general surgery patients with multiple risk factors, we recommend combining pharmacologic methods (LDUH three times daily or LMWH, > 3,400 U daily) with the use of graduated compression stockings and/or intermittent pneumatic compression devices (Grade 1C+). We recommend that thromboprophylaxis be used in all patients undergoing major gynecologic surgery (Grade 1A) or major, open urologic procedures, and we recommend prophylaxis with LDUH two times or three times daily (Grade 1A). For patients undergoing elective total hip or knee arthroplasty, we recommend one of the following three anticoagulant agents: LMWH, fondaparinux, or adjusted-dose vitamin K antagonist (VKA) [international normalized ratio (INR) target, 2.5; range, 2.0 to 3.0] (all Grade 1A). For patients undergoing hip fracture surgery (HFS), we recommend the routine use of fondaparinux (Grade 1A), LMWH (Grade 1C+), VKA (target INR, 2.5; range, 2.0 to 3.0) [Grade 2B], or LDUH (Grade 1B). We recommend that patients undergoing hip or knee arthroplasty, or HFS receive thromboprophylaxis for at least 10 days (Grade 1A). We recommend that all trauma patients with at least one risk factor for VTE receive thromboprophylaxis (Grade 1A). In acutely ill medical patients who have been admitted to the hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, we recommend prophylaxis with LDUH (Grade 1A) or LMWH (Grade 1A). We recommend, on admission to the intensive care unit, all patients be assessed for their risk of VTE. Accordingly, most patients should receive thromboprophylaxis (Grade 1A).

The Impact of Pelvic and Lower Extremity Fractures on the Incidence of Lower Extremity Deep Vein Thrombosis in High-Risk Trauma Patients

Lower extremity fractures (LEFx) and pelvic fractures (PFx) are believed to increase the risk of lower extremity deep vein thrombosis (LEDVT). We studied trauma patients at high risk for LEDVT to determine whether an increased incidence of LEDVT was associated with LEFx and/or PFx. From January 1995 through December 1997 4163 trauma patients were admitted to our Level I trauma center. One thousand ninety-three patients at high risk for LEDVT were screened with serial lower extremity venous duplex ultrasound. Their medical records were retrospectively reviewed for demographics, mechanism of injury, and fracture data. The occurrence of LEDVT, pulmonary embolus, and LEDVT prophylaxis and treatment were noted. The incidence of LEDVT in the fracture group (Fx) was compared with that in the nonfracture group (NFx) using chi-square analysis and logistic regression. Statistical significance was set at ≤0.05. Complete data were available for 1059 of 1093 patients. Five hundred sixty-nine (53.73%) patients had PFx and/or LEFx, 151 (14.26%) patients had PFx only, 317 (29.3%) patients had LEFx only, and 101 (9.54%) patients had both PFx and LEFx. Four hundred ninety (46.27%) patients had NFx. In 1059 patients LEDVT was detected in 125 (11.8%). Sixty-three patients in the Fx groups developed LEDVT (50.4%): 19 (15.2%) PFx patients, 15 (12.0%) PFx/LEFx patients, and 29 (23.2%) LEFx patients. Sixty-two (49.6%) NFx patients developed LEDVT. LEDVT incidence was not significantly different between the Fx and NFx groups or among the PFx, LEFx, and PFx/LEFx groups ( P = 0.317). Nine patients developed pulmonary embolism: four NFx patients, two LEFx patients, two PFx patients, and one PFx/LEFx patient. Significant predictors of LEDVT were age and hospital length of stay. Mean age in patients with LEDVT was 47.58 years and in patients without LEDVT it was 40.89 years ( P < 0.001). Mean hospital length of stay in patients with LEDVT was 29.81 days and in patients without LEDVT it was 16.84 days. The power of this study to detect differences representing medium effect sizes was greater than 90 per cent. We conclude that LEFx and/or PFx was not associated with an increased incidence of LEDVT in trauma patients at high risk for LEDVT. Lower extremity venous duplex ultrasound needs to be performed in both Fx and NFx groups to detect LEDVTs.

Thromboprophylaxis in non-surgical patients: who, when and how?

Because of the serious lack of useable, relevant information, most recommendations for prevention of thrombosis in non-surgical patients are extrapolations from much larger clinical trials experienced in surgery. Directly relevant evidence comes predominantly from very small randomized trials, many of them open label and carried out more than 20 years before the introduction of more recent and important changes in clinical care that may have substantially reduced the baseline thrombosis risk. In these early studies, low-dose heparin and low-molecular-weight heparins prevented subclinical deep vein thrombosis in ischaemic stroke, myocardial infarction and among elderly medical inpatients. Although it is likely that these drugs also prevent subclinical deep vein thrombosis after spinal cord injury or other major trauma, and when patients require intensive medical care, the supporting evidence in these circumstances comes mainly from cohort studies and poorly controlled comparisons. In contrast, the heparins have not reduced mortality or demonstrably prevented pulmonary embolism after ischaemic stroke or among elderly medical inpatients in large and well-conducted clinical endpoint trials, from which no clinically important benefit could be demonstrated. From analyses it is suggested that such benefit is probably more difficult to demonstrate for medical than for surgical patients. In the absence of sufficient information that is specific to medical patients, various forms of prophylaxis known to be effective in surgery will continue to be applied in high-risk individuals. After venous thromboembolism, it now appears that the best duration of oral anticoagulant therapy to prevent a recurrence is determined to a greater extent by whether the thrombotic episode was idiopathic or triggered by a clinically recognizable cause, whether it was transient or continuing, and whether the deep vein thrombosis was extensive, limited to the calf veins or was a first or recurrent event.

Thrombosis risk in the trauma patient. Prevention and treatment

Hypercoagulability is frequently seen in the trauma patients. Debate continues over the best method of prophylaxis, diagnosis, and treatment for the trauma patient. From experience with orthopedic and general surgery patients, much has been learned about prophylaxis and diagnosis, and as treatment protocols have been taken from internal medicine literature. Universal guidelines relating specifically to the trauma patient have not, however, been established. Overall, most of the literature suggests using LMWH for the prophylaxis of trauma patients. When LMWH is contraindicated, SCD should be used, with AVFP as a second choice. Surveillance screening for DVT remains controversial, but surveillance before transfer to extended care facilities has proven beneficial. Finally, when DVT is diagnosed, treatment should be initiated as soon as possible and should be continued until the DVT has resolved. Long-term anticoagulation therapy or use of caval filters may be necessary to prevent the morbidity of PE or thrombophlebitic syndrome.