Thermally injured patients are at significant risk for thromboembolic complications

BACKGROUND: The incidence of thromboembolic complications such as deep vein thrombosis (DVT) and pulmonary embolism (PE) in thermally injured patients is considered sufficiently uncommon that routine prophylactic measures are not warranted. Nevertheless, the incidence of DVT/PE may be increasing. METHODS: The records of 1,300 patients admitted to our unit from January 1990 to June 1995 were reviewed. RESULTS: Twenty-three patients developed a clinically significant DVT, eight patients developed a PE, and two patients developed both a DVT and a PE, for an overall DVT/PE incidence of 2.9%. Four of 10 PEs were felt to be fatal. The DVT/PE patients were older (mean age, 42.6 vs. 28.7; p < 0.001) and had larger burns (37% vs. 18%, p < 0.001) than patients without evidence of DVT/PE. Body weight appeared to also influence DVT/PE rates, with obese patients (>30% over ideal body weight) having a higher incidence than patients with low or normal body weight (7.2 vs. 2.7%, p < 0.015). Age and total body surface area (TBSA) burn had a synergistic effect on DVT/PE risk, with the sum of age and TBSA burn exerting the strongest independent effect when discriminant function analysis was performed (p < 0.001). CONCLUSION: One can identify a population at increased risk of DVT/PE on the basis of the sum of age and TBSA burn, but prospective screening trials that assess all risk factors for DVT/PE should be performed before routine prophylaxis is used in thermally injured patients.     

Pneumatic compression devices for prophylaxis of deep venous thrombosis (DVT)

A pneumatic compression device was applied to 155 patients with a normal Doppler venous examination who underwent a general surgical procedure of at least 1 hr in duration. One hundred fifty-three patients had neither PE nor DVT clinically or by Doppler studies, one patient had a venographically proven DVT, and one patient had a clinical pulmonary embolism verified by lung scanning. Using clinical and Doppler criteria, the device was effective in the prophylaxis of thromboembolic complications.     

Thromboembolic complications after spinal surgery in trauma patients

Background?Deep venous thrombosis (DVT) and pulmonary embolism (PE) may be significant complications following spinal surgery. The incidence rate ranges from 0.5% to 2.5% in patients with symptomatic thromboembolic disease and up to 15% in patients with non-symptomatic thrombotic complications. We determined the incidence of symptomatic thromboembolism after spinal surgery in patients with postoperative systemic prophylaxis and investigated general and specific risk factors for development of this disease.

Patients and methods?We analyzed the clinical records of 978 patients who had undergone surgery of the spine because of trauma and who had been admitted to our level-I trauma center between 1980 and 2004. Spinal procedures included anterior and/or posterior spinal fusion, video-assisted thoracoscopic fusion, and spinal decompression. Symptomatic thromboembolic disease was diagnosed when patients showed significant clinical signs or symptoms of DVT or PE. In cases of DVT, diagnosis was confirmed by duplex scan of the lower limbs; in cases of PE, diagnosis was confirmed by CT-scanning of the thorax or at post mortem.

Results?The incidence rate of symptomatic thromboembolic complications was 2.2% (n 22). 17 patients showed clinical signs of deep venous thrombosis, with 4 of them developing pulmonary embolism subsequently. The other 5 patients developed pulmonary embolism without prior clinical signs of deep venous thrombosis. 6 patients died because of thromboembolic disease. Thromboembolic complications were more frequent in older patients and among males, as well as in patients with regular tobacco consumption and obesity. Thromboembolic complications were also seen more frequently in patients with surgical procedures at the lumbar spine, in patients with anterior spinal fusion, and in those with motor deficits in the lower extremities.

Interpretation?We found a rather low rate of clinically significant thromboembolic complications after spinal surgery because of trauma, compared to the results reported in the literature. Level of spinal surgery, surgical approach, and motor deficits in the lower extremities were identified as specific risk factors for DVT or PE. Age, sex, obesity and regular smoking were identified as general risk factors.     

Thromboembolic complications after spinal surgery in trauma patients

Background Deep venous thrombosis (DVT) and pulmonary embolism (PE) may be significant complications following spinal surgery. The incidence rate ranges from 0.5% to 2.5% in patients with symptomatic thromboembolic disease and up to 15% in patients with non-symptomatic thrombotic complications. We determined the incidence of symptomatic thromboembolism after spinal surgery in patients with postoperative systemic prophylaxis and investigated general and specific risk factors for development of this disease.

Patients and methods We analyzed the clinical records of 978 patients who had undergone surgery of the spine because of trauma and who had been admitted to our level-I trauma center between 1980 and 2004. Spinal procedures included anterior and/or posterior spinal fusion, video-assisted thoracoscopic fusion, and spinal decompression. Symptomatic thromboembolic disease was diagnosed when patients showed significant clinical signs or symptoms of DVT or PE. In cases of DVT, diagnosis was confirmed by duplex scan of the lower limbs; in cases of PE, diagnosis was confirmed by CT-scanning of the thorax or at post mortem.

Results The incidence rate of symptomatic thromboembolic complications was 2.2% (n 22). 17 patients showed clinical signs of deep venous thrombosis, with 4 of them developing pulmonary embolism subsequently. The other 5 patients developed pulmonary embolism without prior clinical signs of deep venous thrombosis. 6 patients died because of thromboembolic disease. Thromboembolic complications were more frequent in older patients and among males, as well as in patients with regular tobacco consumption and obesity. Thromboembolic complications were also seen more frequently in patients with surgical procedures at the lumbar spine, in patients with anterior spinal fusion, and in those with motor deficits in the lower extremities.

Interpretation We found a rather low rate of clinically significant thromboembolic complications after spinal surgery because of trauma, compared to the results reported in the literature. Level of spinal surgery, surgical approach, and motor deficits in the lower extremities were identified as specific risk factors for DVT or PE. Age, sex, obesity and regular smoking were identified as general risk factors.     

Thromboembolic complications after arthroscopic knee surgery: Incidence and risk factors in 101 patients

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are less common after knee arthroscopy than after elective hip and knee arthroplasties. There is no consensus on the optimal prophylaxis. In this prospective cohort study, we used ultrasound, phlebography and lung scan pre-and postoperatively to assess the incidence of thromboembolic complications in 101 consecutive patients who underwent knee arthroscopy. Preoperatively, patients were screened for typical risk factors for DVT such as age, obesity, varicose veins, contraceptive pills and nicotine abuse. All patients received a once-daily injection of 5000 IU of low molecular weight heparin, at least 12 hours prior to surgery.

5 weeks after surgery, the same screening tests were repeated. In 12 of the 101 patients either DVT or PE was diagnosed. DVT occurred in 8 cases, 4 of which were silent and 4 symptomatic. The number of PEs was 9, 8 silent and 1 symptomatic. We found no correlation between DVT or PE and individual clinical risk factors, but there was a tendency towards the development of DVT and PE, with a higher number of risk factors. We found no correlation between DVT and intraoperative risk factors such as use of a tourniquet, type of anesthesia or duration of surgery. The relatively high rate of thromboembolic events after knee arthroscopy in our study suggests the need of all patients for routine use of thromboprophylaxis, probably in a higher dose than given.     

Operative venodilation: a previously unsuspected factor in the cause of postoperative deep vein thrombosis

Intraoperative venodilation in veins distant from the site of operation has been shown to occur in animals and has been directly correlated with focal venous endothelial damage. This exposure of subendothelial collagen could serve as initiation sites for thrombus formation. This study tests the hypothesis that human beings (1) significant operative venodilation occurs and that it correlates with postoperative deep venous thrombosis (DVT); (2) operative venodilation can be pharmacologically controlled; and (3) this control reduces the incidence of postoperative DVT. Twenty-one patients undergoing total hip replacement had their contralateral cephalic vein continuously monitored with modified ultrasonographic instrumentation, with a continuous on-line recorder graphing venous diameter. Patients were randomly assigned to receive 0.5 mg of dihydroergotamine and 5000 U of heparin (DHE/Hep) for prophylaxis or placebo, with investigators "blinded" Postoperatively, all patients underwent ascending phlebography. Patients in whom postoperative DVT developed (11) had a mean operative venodilation of 28.9% +/- 3.93%, and those in whom DVT did not develop (10) had a mean venodilation of 11.6% +/- 1.55% (p = 0.001). Only 17% (2/12) dilating less than 20% baseline diameter had DVT compared with 100% (9/9) dilating greater than 20% of baseline diameter (p = 0.002). Patients receiving venotonic agent DHE had significantly less venodilation and DVT (p less than 0.001) compared with patients receiving the placebo. Patients who had DVT and whose veins dilated greater than 20% were older than patients who did not have DVT and whose veins minimally dilated: p = 0.04 and p = 0.07, respectively. Although there was a trend toward increased venoconstriction in patients receiving DHE/Hep (p = 0.09), there was no correlation of venoconstriction with ultimate thrombotic outcome. Maximal venodilation occurs during handling of soft tissue (muscle), and this occurs significantly sooner than maximal venoconstriction, which occurs during bone manipulation. We conclude that excessive operative venodilation is a new and important etiologic factor that leads to postoperative DVT. Operative venodilation can be pharmacologically controlled with the venotonic agent DHE. The combination DHE/Hep reduces postoperative DVT by the reduction of operative venodilation in the presence of low doses of an anticoagulant. These findings offer a new approach for predicting postoperative DVT and an object rationale for developing effective prophylaxis.     

A potentially expanded role for enoxaparin in preventing venous thromboembolism in high risk blunt trauma patients

BACKGROUND: Venous thromboembolism (VTE) is a frequent and potentially life-threatening complication after trauma. The purpose of this study is to investigate the effectiveness of enoxaparin in preventing deep venous thrombosis (DVT) and pulmonary embolism (PE) after injury in patients who are at high risk for developing VTE. STUDY DESIGN: A prospective single-cohort observational study was initiated for seriously injured blunt trauma patients admitted to a Level I trauma center during a 7-month period. Patients were eligible for the study if time hospitalized was > or = 72 hours, Injury Severity Score (ISS) was > or = 9, enoxaparin was started within 24 hours after admission, and one or more of the following high risk criteria were met: age > 50 years, ISS > or = 16, presence of a femoral vein catheter, Abbreviated Injury Score (AIS) > or = 3 for any body region, Glasgow Coma Scale (GCS) Score < or = 8, presence of major pelvic, femur, or tibia fracture, and presence of direct blunt mechanism venous injury. Patients with closed head injuries and nonoperatively treated solid abdominal organ injuries were also potential participants. The primary outcomes measured were thromboembolic events--either a documented lower extremity DVT by duplex color-flow doppler ultrasonography or a PE documented by rapid infusion CT pulmonary angiography or conventional pulmonary angiography. RESULTS: There were 118 patients enrolled in the study. Two patients (2%) developed DVT, one of which was proximal to the calf (95% confidence interval, 0% to 6%). Two of 12 patients (17%) with splenic injuries who received enoxaparin failed initial nonoperative management. There were no other bleeding complications, and no clinical evidence or documented episodes of PE. One patient died from multiple system organ failure. CONCLUSIONS: Enoxaparin is a practical and effective method for reducing the incidence of VTE in high risk, seriously injured patients. This study supports further investigation into the safety of enoxaparin prophylaxis in patients with closed head injuries and nonoperatively treated solid abdominal organ injuries.     

Efficacy of pneumatic compression stocking prophylaxis in the prevention of deep venous thrombosis and pulmonary embolism following 139 lumbar laminectomies with instrumented fusions

OBJECTIVE: Low-dose heparin (LDH) regimens reduce the frequency of deep venous thrombosis (DVT) and pulmonary embolism (PE) in spinal surgery but pose a risk of postoperative hemorrhage threatening neurologic function. Pneumatic compression stocking (CS) could provide an alternative means of mechanical prophylaxis alone against DVT and PE and would possibly avoid its hemorrhagic complications. METHODS: The efficacy of CS alone in preventing DVT and PE was evaluated in 139 patients undergoing multilevel lumbar laminectomies (average 3.8 levels) with instrumented fusions (average 1.4 levels). All patients received CS stocking prophylaxis intraoperatively and throughout the average 5-day postoperative course including following ambulation. Doppler screening for DVT was routinely performed 2 days postoperatively. Subsequent Doppler studies or computed tomography angiograms were selectively performed in symptomatic patients with potential DVT/PE. RESULTS: Four (2.8%) patients developed DVT 2-6 days postoperatively and required inferior vena cava (IVC) filters. One of the four had a positive routine screening Doppler study performed the second postoperative day. Two developed DVT the fourth postoperative day. The fourth patient developed DVT 6 days postoperatively but 3 weeks later embolized around the IVC filter. This patient, the only one to develop a PE, tested positive for Factor V Leiden mutation (hypercoagulable syndrome) and remains on long-term warfarin. CONCLUSIONS: Pneumatic compression stocking prophylaxis effectively reduced the incidence of DVT (2.8%) and PE (0.7%) in 139 patients undergoing multilevel lumbar laminectomies with instrumented fusions. These rates compared favorably with those reported in spinal series employing LDH prophylaxis.     

Analysis of deep vein thrombosis in burn patients

OBJECTIVE: Deep vein thrombosis (DVT) represents a major cause of morbidity in surgical patients. Controversial reports exist on the incidence of DVT in burn patients. We report our experience over a 10-year period. METHODS: Patients admitted to our Burn Unit over the period 1991-2001 and diagnosed with DVT were identified. Their records were retrospectively reviewed for demographic factors, extent and severity of burn injury and outcome. RESULTS: A total of 4102 patients were admitted to the WPH Burn unit during the study period. All patients received routine subcutaneous heparin prophylaxis. Ten patients were diagnosed with DVT (0.25%). Compared to our total burn population, these patients were older (mean age 47 +/- 22.7 years versus 35 +/- 22 years P = 0.14) and had more extensive burns (mean total body surface area (TBSA) 34.7 +/- 25.3% versus 12 +/- 15.7% P = 0.02). Two patients developed non-fatal pulmonary embolism (PE). There were three deaths, none due to thromboembolic disease. There were no complications from the routine administration of subcutaneous heparin. CONCLUSION: The incidence of DVT in our study is much less than the incidence reported in other critically ill patients and less than that of most reports on burn patients. In our experience, routine heparin prophylaxis is effective for the prevention of DVT in burn patients.     

Normal D-dimer levels do not exclude thrombotic complications in trauma patients

BACKGROUND: Deep venous thrombosis (DVT) and pulmonary embolism (PE) are common complications in trauma patients. These diagnoses can be difficult and expensive to make. Recent studies report that a negative D-dimer test excludes thrombotic complications. We questioned the predictive value of a D-dimer test to exclude DVT and PE. METHODS: Adult trauma patients admitted March 1999 to March 2001, with an Injury Severity Score > or =9 and expected length of stay >3 days, were approached for enrollment. Bilateral lower extremity duplex ultrasounds and d-dimer levels were performed within 36 hours of admission, day 3-4, day 7, and weekly until discharge. RESULTS: Twenty-three patients were diagnosed with DVTs, with 18 DVTs detected within the first week of admission. Five DVT patients had normal D-dimer levels. One of three PE patients tested had a normal D-dimer level. The false negative rate for DVT by d-dimer assay was 24%, and the sensitivity was 76%. The negative predictive value for D-dimers was 92%. All false negative d-dimer tests occurred in patients diagnosed with DVT or PE within the 4 days after admission. CONCLUSION: In the early postinjury phase, a negative d-dimer test does not exclude DVT or PE. However, the negative predictive value of a D-dimer test after the first 4 days from admission rose to 100%. Patients with clinical signs and symptoms of DVT or PE in the immediate postinjury phase should undergo further screening to exclude thromboembolic complications.     

Inferior vena cava filter placement for pulmonary embolism risk reduction in super morbidly obese undergoing bariatric surgery

BACKGROUND: Pulmonary embolism (PE) is a leading cause of mortality after bariatric surgery. We evaluated inferior vena cava (IVC) filter use for PE risk reduction in high-risk super morbidly obese bariatric surgery patients. METHODS: IVC filters were inserted according to the patient's risk factors, including immobility, previous deep venous thrombosis (DVT)/PE, venous stasis, and pulmonary compromise. All filters were placed concomitant to bariatric surgery and were placed through a right internal jugular vein access site. We analyzed the prospectively collected data from this cohort and evaluated the incidence of PE and complications. RESULTS: Since April 2003, 41 patients (12 men and 29 women) with a mean age of 47.3 +/- 10.0 years and body mass index of 64.2 +/- 12 kg/m2 (range 47-105) underwent IVC filter placement. These and all other patients underwent standard DVT/PE risk reduction measures. All IVC filter patients had one or more significant risk factors for thromboembolic events. No instances of PE were documented, although 1 patient experienced DVT, and no immediate or late complications related to filter placement occurred. One patient, with a body mass index of 105 kg/m2, died secondary to rhabdomyolysis after an extended procedure. The average filter placement time was 34.3 +/- 9 minutes. CONCLUSION: IVC filter placement for PE risk reduction is safe and feasible in the super morbidly obese. Our data have shown that the filters can be placed expeditiously and with minimal morbidity concomitant with bariatric surgery. In this limited series, IVC filter placement was associated with no PE. Additional studies are needed to confirm the efficacy of IVC filter placement for PE risk reduction and related mortality in the super morbidly obese.     

Evaluation of a disease management plan for prevention and diagnosis of thromboembolic disease in major trauma patients

Evaluate the effectiveness of our program of thromboembolic disease (TED) prophylaxis.Multisystem trauma patients with closed head injury, spinal cord injury, and/or long bone/pelvic fractures severe enough to require inpatient rehabilitation are at high risk for TED: deep venous thrombosis (DVT) and pulmonary embolism (PE). A retrospective analysis of 262 such trauma patients, from September 1995 through July 1997, was performed to evaluate the effectiveness of our program of TED prophylaxis. Mechanical compression devices (CDs) and/or anticoagulation treatment were the primary methods of prophylaxis. If clinical suspicion of TED was present, duplex ultrasound (DU) was used. Otherwise, patients were screened once by DU before transfer to a rehabilitation facility.There was 99% compliance with prophylaxis use. One hundred one patients died of injuries less than 48 hours after admission. Forty-four patients died in the hospital more than 48 hours after admission; 4 (9%) had TED manifest as DVTs (3 patients; 66% at the level of the popliteal or above) and PE (1 patient; 2%). One hundred seventeen patients survived and were transferred to rehabilitation facilities. Fourteen of these (12%) had TED manifest as DVTs (13 patients; 71% at the level of the popliteal or above) before transfer and PE (1 patient; 1%). Three patients developed DVTs without PEs during 2-month follow-up in rehabilitation. Of the 14 patients who developed TED, 7 had prophylaxis with CDs alone and 5 had CDs plus heparin, aspirin, or caval filter (CD+), an incidence of 11%. Increased injury severity score and increased length of stay were associated with development of TED (p < 0.05). Forty-two percent of patients with TED were suspected on the basis of clinical examination and confirmed by DU; 9 of 105 (8.5%) were found exclusively by the single DU screening of clinically negative lower extremities.The compliance rate for TED prophylaxis in these severely injured trauma patients was high. An 11% incidence of TED was found in this population; 4 of 160 patients (2.5%) died with or from TED. Compression devices alone or CD+ offered equal prophylaxis. Single DU screening of clinically negative lower extremities demonstrated an 8.6% incidence of TED; clinical suspicion of TED as an indication for DU screening increased positive findings to 42%.     

Evaluation of the applicability, efficacy, and safety of a thromboembolic event prophylaxis guideline designed for quality improvement of the traumatically injured patient

BACKGROUND: Thromboembolic events (TE) such as deep venous thrombosis (DVT) and pulmonary embolism (PE) are common after trauma. Our Trauma Practice Management Committee developed an evidence-based DVT/PE prophylaxis guideline using a modified Delphi approach to standardize care and reduce TE rates. Our objective was to evaluate the applicability, efficacy, and safety of this guideline in the traumatized patient, especially those admitted first to the intensive care unit (ICU). METHODS: We developed a risk-stratified DVT/PE prophylaxis guideline incorporating specific injuries, pertinent history, and physiologic parameters, favoring aggressive therapy in those at highest risk of dying from a PE. We prospectively collected data using this guideline in all patients admitted to the trauma or orthopedic-trauma services that were expected to stay for more than 48 hours (March-December 2003). Comparison was made with historical controls. Data collected included DVT, PE, prophylaxis level chosen, inferior vena cava filters, admission service and location, TRISS scores, length of stay, outcomes, adverse events, and specific risk factors. RESULTS: TE rates after implementation of the guideline were lower than historical controls for all patients (1.9% vs. 1.0%, p = 0.059) and for patients admitted first to the ICU (6.3% vs. 2%, p = 0.018). Completed sheets were collected for 46% of the targeted population. No bleeding events caused by guideline anticoagulation were noted, and one death occurred after inferior vena cava filter placement. Nine of the 12 TEs in the treatment group were in patients with spine or closed-head injury, delaying chemical prophylaxis. CONCLUSION: Form-based, risk-adjusted prophylaxis against TE leads to lower TE rates in a general and orthopedic ICU trauma population. Protocol compliance should be enforced.     

A Comparison of Two Different Prophylactic Dose Regimens of Low Molecular Weight Heparin in Bariatric Surgery

Background: Deep venous thrombosis (DVT) is a significant risk in patients undergoing surgery for morbid obesity and may be associated with significant morbidity and mortality. In a consecutive group of patients in one bariatric surgery practice, the initial group of patients who received prophylaxis for DVT was given enoxaparin 30 mg q12h while the later group was given enoxaparin 40 mg q12h. Methods: 481 patients who underwent primary and revisional bariatric surgery over 38 months (October 1997 - December 2000) were evaluated. All patients received a multi-modality DVT prophylaxis protocol that included: early ambulation, graduated compression stockings, intermittent pneumatic compression, and enoxaparin (LMWH) in two dosage groups. The first 92 patients (19%) in the series (Group I) received LMWH 30 mg q12h while the subsequent 389 patients (81%) (Group II) received LMWH 40 mg q12h. Results: Group I patients were not different from Group II patients in body mass index (BMI) (51.7 vs 50.3 kg/m²), age (43.7 vs 44.3 yrs), sex (men 20.2% vs 15.8%) or history of previous DVT (3.2% vs 3.9%). Group I patients did have significantly longer procedure times (213 vs 175 min, p<0.05) and hospital stays (5.67 d vs 3.81 d, p<0.05) than Group II. There were a total of 7 (1.4%) postoperative DVT complications. 5 DVT complications occurred in Group I (5.4%) compared with 2 DVT complications in Group II (0.6%) (p < 0.01 by Fisher Exact Test two-tailed). One patient in each group required treatment for hemorrhage. Conclusion: A multi-modality prophylaxis treatment protocol in patients undergoing bariatric surgery is feasible and achieves a low incidence of postoperative DVT complications. The use of a higher dose of enoxaparin, 40 mg q12h, may reduce the incidence of DVT complications in patients following bariatric surgery without an increase in bleeding complications.     

Normal d-dimer levels do not exclude thrombotic complications in trauma patients

Background

Deep venous thrombosis (DVT) and pulmonary embolism (PE) are common complications in trauma patients. These diagnoses can be difficult and expensive to make. Recent studies report that a negative d-dimer test excludes thrombotic complications. We questioned the predictive value of a d-dimer test to exclude DVT and PE.

Methods

Adult trauma patients admitted March 1999 to March 2001, with an Injury Severity Score ≥9 and expected length of stay >3 days, were approached for enrollment. Bilateral lower extremity duplex ultrasounds and d-dimer levels were performed within 36 hours of admission, day 3-4, day 7, and weekly until discharge.

Results

Twenty-three patients were diagnosed with DVTs, with 18 DVTs detected within the first week of admission. Five DVT patients had normal d-dimer levels. One of three PE patients tested had a normal d-dimer level. The false negative rate for DVT by d-dimer assay was 24%, and the sensitivity was 76%. The negative predictive value for d-dimers was 92%. All false negative d-dimer tests occurred in patients diagnosed with DVT or PE within the 4 days after admission.

Conclusion

In the early postinjury phase, a negative d-dimer test does not exclude DVT or PE. However, the negative predictive value of a d-dimer test after the first 4 days from admission rose to 100%. Patients with clinical signs and symptoms of DVT or PE in the immediate postinjury phase should undergo further screening to exclude thromboembolic complications.     

Acute complications associated with greenfield filter insertion in high-risk trauma patients

BACKGROUND: Use of Greenfield filters (GFs) to prevent fatal pulmonary embolism (PE) in trauma patients is generally well accepted. Nonetheless, a surprisingly small number of trauma surgeons insert filters in their patients. Among the reasons cited is fear of complications. METHODS: We observed three femoral arteriovenous fistulae (AVF) in trauma patients who had inferior vena caval placement of filters for PE prophylaxis in one 12-month period (academic year 1999). In an effort to document the magnitude of this problem, we evaluated trauma patients who had a GF inserted in academic year 2000. RESULTS: During that year, 133 consecutive patients (8.6% of trauma admissions) received 133 GFs through a percutaneous approach. The most common isolated indications for GF insertion included closed head injuries (n = 28), multiple long bone fractures (n = 27), pelvic and acetabular fractures (n = 6), spinal cord injuries (n = 16), and vertebral fractures (n = 3). Five patients had documented deep venous thrombosis (DVT) diagnosed by duplex ultrasonography before GF placement, and 11 patients had other indications requiring a filter. There were 37 patients with more than one indication requiring filter placement. Most patients (57%) underwent preinsertion duplex scanning of their lower extremity veins; 77% of patients underwent postinsertion scanning. Filters were inserted an average of 6.8 +/- 0.6 (SE) days after trauma. No AVF were suspected clinically or detected ultrasonographically. No operative or postoperative complications occurred. DVT was observed in 30% of patients despite 92% prophylaxis; there was a 26% incidence of de novo thrombi detected. None of the patients evidenced DVT clinically. CONCLUSION: Our data indicate that complications of GF insertion for prophylaxis against PE from DVT complicating trauma patients continue to be negligible. In addition, the incidence of insertion-site thrombosis may be lower than expected. Moreover, femoral AVF is a rare complication of this procedure.     

Prophylaxis against venous thromboembolism in orthopedic surgery

Venous thromboembolism (VTE), which is manifested as deep vein thrombosis (DVT) and pulmonary embolism (PE), represents a significant cause of death, disability, and discomfort. They are frequent complications of various surgical procedures. The aging population and the survival of more severely injured patients may suggest an increasing risk of thromboembolism in the trauma patients. Expanded understanding of the population at risk challenges physicians to carefully examine risk factors for VTE to identify high-risk patients who can benefit from prophylaxis. An accurate knowledge of evidence-based risk factors is important in predicting and preventing postoperative DVT, and can be incorporated into a decision support system for appropriate thromboprophylaxis use. Standard use of DVT prophylaxis in a high-risk trauma population leads to a low incidence of DVT. The incidence of VTE is common in Asia. The evaluation includes laboratory tests, Doppler test and phlebography. Screening Doppler sonography should be performed for surveillance on all critically injured patients to identify DVT. D-Dimer is a useful marker to monitor prophylaxis in trauma surgery patients. The optimal time to start prophylaxis is between 2 hours before and 10 hours after surgery, but the risk of PE continues for several weeks. Thromboprophylaxis includes graduated compression stockings and anticoagulants for prophylaxis. Anticoagulants include Warfarin, which belongs to Vitamin K antagonists, unfractionated heparin, low molecular weight heparins, factor Xa indirect inhibitor Fondaparinux, and the oral IIa inhibitor Melagatran and ximelagatran. Recombinant human soluble thrombomodulin is a new and highly effective antithrombotic agent. Prophylactic placement of vena caval filters in selected trauma patients may decrease the incidence of PE. The indications for prophylactic inferior vena cava filter insertion include prolonged immobilization with multiple injuries, closed head injury, pelvic fracture, spine fracture, multiple long bone fracture, and attending discretion. Multiple-trauma patients are at increased risk for DVT but are also at increased risk of bleeding, and the use of heparin may be contraindicated. Serial compression devices (SCDs) are an alternative for DVT prophylaxis. Compression devices provide adequate DVT prophylaxis with a low failure rate and no device-related complications. Immobilization is one of important reasons of VTE. The ambulant patient is far less Ukely to develop complications of inactivity, not only venous thrombosis, but also contractures, decubitus ulcers, or osteoporosis ( with its associated fatigue fractures), as well as bowel or bladder complications.     

The incidence of venous thromboembolism after total hip arthroplasty: a specific hypotensive epidural anesthesia protocol.

We retrospectively reviewed all consecutive unilateral primary total hip arthroplasty (THA) procedures performed by 3 attending surgeons on the Arthroplasty Service at our institution from January 1, 1990, to December 31, 1993. All surgery was performed under a specific hypotensive epidural anesthesia protocol. Hypotensive epidural anesthesia at our institution provides a lower level of hypotension (mean arterial pressure of 50-60 mmHg) as compared to hypotensive anesthesia used more generally around the world (mean arterial pressure >70 mmHg). For each patient, hospital and postdischarge office records for a minimum of 3 months after surgery were reviewed for the type of postoperative screening test, the incidence of deep venous thrombosis (DVT), and the incidence of symptomatic pulmonary embolism (PE). Overall, 2,592 primary unilateral THAs were performed with 78.6% (2,037 of 2,592) of patients receiving a venogram. Our protocol for thromboembolic disease prophylaxis in these patients included aspirin postoperatively as well as antithromboembolic disease stockings and early ambulation (24-48 hours postoperatively). The 555 patients who did not receive venography were managed with a different protocol that included warfarin postoperatively as well as antithromboembolic disease stockings and early ambulation. This high-risk group consisted of patients who received warfarin preoperatively (ie, cardiac valve) or patients with a history of DVT who were to receive warfarin postoperatively, regardless of venography result. Overall, DVT was diagnosed in 10.3% (210 of 2,037) of patients who had a venogram. Of these patients who had venography, 2.3% (46 of 2,037) had an isolated proximal DVT; 6.0% (123 of 2,037), a distal DVT; and 2.0% (41 of 2,037), both a proximal and a distal DVT. Of the 87 cases of proximal DVT identified, 60.9% (53 of 87) were femoral DVT; 18.4% (16 of 87), popliteal DVT; and 20.7% (18 of 87), both femoral and popliteal DVT. Of the 164 distal DVT, 68.3% (112 of 164) were major calf DVT and 31.7% (52 of 164) were minor calf DVT. The overall incidence of major venous thrombosis (sum of proximal and major calf thrombi) was 9.8% (199 of 2,037) in patients who had venography. Ventilation-perfusion scanning was used selectively in patients symptomatic for PE. Overall, symptomatic PE was diagnosed by ventilation-perfusion scan in 1.0% (26 of 2,592) of patients, with 0.58% (15 of 2,592) of patients having an in-hospital PE. Of the 15 patients who had an in-hospital PE, 11 patients had a venogram, and only 3 of 11 were positive. Late symptomatic PE was defined from discharge (mean, 7 +/- 2 days) to 3 months after discharge from the hospital and occurred in 0.42% (11 of 2,592) of patients. One of the 11 late symptomatic PEs was fatal. In the overall study, this represents 0.04% (1 of 2,592) fatal PE. Of the 11 patients with a late symptomatic PE, 10 had venograms in the hospital, and all 10 were negative for DVT. Overall, in the patients with a positive venogram, the incidence of symptomatic PE was 1.4% (3 of 210), whereas in the patients with a negative venogram, the incidence of symptomatic PE was 0.44% (8 of 1,827). At our institution, patients who undergo primary THA performed with hypotensive epidural anesthesia, postoperative aspirin, antithromboembolic disease stockings, and early ambulation have a low risk for thromboembolic disease.     

The incidence of thromboembolism in the surgical intensive care unit

The clinical diagnosis of deep venous thrombosis (DVT) is unreliable. Studies have been performed examining the utility of frequent duplex scans. However, these studies included patients outside of the intensive care unit. The incidence of venous thromboembolism and the effect of a less intense surveillance protocol was prospectively examined at a level-1 urban trauma center for a 6 month period. During the study period there were 726 admission to the surgical intensive care unit. Sequential compression devices (SCDs) were used for DVT prophylaxis in 93 per cent of the admissions. A total of 114 duplex scans were ordered: 42 per cent for surveillance and the rest for evaluation of a clinical indication. Twelve DVTs were discovered (11% overall DVT rate). No patient on subcutaneous heparin or low-molecular-weight heparin developed a DVT or pulmonary embolism (PE). Four patients suffered a PE; however, none were found to have a lower extremity DVT on duplex ultrasound and all received SCD prophylaxis. Overall, proper use of DVT prophylaxis for intensive care unit days 1-14 was 77 per cent. The incidence of venous thromboembolism in a group of patients at overall high risk was low. A program of DVT surveillance with duplex ultrasound was not cost-effective.     

Routine prophylactic vena cava filtration is not indicated after acute spinal cord injury

BACKGROUND: Acute spinal cord injury (SCI) is a devastating problem, with over 10,000 new cases annually. Pulmonary embolism (PE) is a well-recognized risk in SCI patients, although no clear recommendations for prophylaxis exist. We therefore evaluated whether routine placement of prophylactic inferior vena cava filters is indicated in SCI patients. METHODS: The trauma registry of a regional trauma center was used to identify patients sustaining acute SCI resulting in tetraplegia or paraplegia after blunt or penetrating trauma for a 5-year period beginning in January 1995. Patients were analyzed for demographics, mechanism of injury, Injury Severity Score, associated long bone or pelvic fracture, severe closed-head injury, type of deep venous thrombosis (DVT) prophylaxis, level of SCI, and incidence of DVT and PE. DVT prophylaxis was performed in all patients with sequential compression devices (SCDs) when extremity fracture status permitted. Data are expressed as mean +/- SD and analyzed using Fisher's exact test. RESULTS: There were 8,269 admissions during the study period, with an overall incidence of DVT and PE of 11.8% and 0.9%, respectively. There were 111 (1.3%) patients who sustained SCI, with an incidence of DVT and PE of 9.0% and 1.8%, respectively, and no deaths. Of these 111 patients, 41.4% were paraplegics and 58.6% were tetraplegics, and 17.1% of patients had severe closed-head injury. Mean hospital length of stay was 23 +/- 20 days for SCI patients. Surveillance duplex ultrasound was performed an average of 2.3 +/- 2.1 times during each hospitalization. Mean Injury Severity Score was 30.0 +/- 12.2. The incidence of DVT and PE in those patients with SCDs alone was 7.1% and 2.3%; for SCDs plus subcutaneous heparin, the incidence was 11.1% and 2.8%; and for SCDs plus low-molecular-weight heparin, the incidence was 7.4% and 0%, respectively, with no statistical difference between groups. The incidence of DVT in SCI patients with long bone fractures was 37.5%, which was significantly greater than the total SCI population (p < 0.02). CONCLUSION: The incidence of DVT and PE in SCI patients was similar to that of the overall trauma population when appropriate DVT prophylaxis was used. Subgroup analysis demonstrated that SCI associated with long bone fracture significantly increases the incidence of DVT. On the basis of the low incidence of PE in the present study, routine placement of prophylactic caval filters does not appear warranted in all SCI patients. However, SCI patients with long bone fractures, patients with DVT formation despite prophylactic anticoagulation, or patients with contraindications to anticoagulation may be appropriate candidates for prophylactic caval filtration.