Randomized,pilot study of intermittent pneumatic compression devices plus dalteparin versus intermittent pneumatic compression devices plus heparin for prevention of venous thromboembolism in patients undergoing craniotomy

BACKGROUND: Unfractionated heparin and the low molecular weight heparin, dalteparin, are used for prophylaxis against venous thromboembolism in patients undergoing craniotomy. These drugs were compared in a randomized, prospective pilot study comparing intermittent pneumatic compression devices plus dalteparin to intermittent pneumatic compression devices plus heparin. METHODS: One hundred patients undergoing craniotomy were randomly allocated to receive perioperative prophylaxis with subcutaneous (SC heparin, 5000 units every 12 hours, or dalteparin, 2,500 units once a day, begun at induction of anesthesia and continued for 7 days or until the patient was ambulating. Entry criteria were age over 18 years, no deep vein thrombosis (DVT) preoperatively as judged by lower limb duplex ultrasound and no clinical evidence of pulmonary embolism preoperatively. Patients with hypersensitivity to heparin, penetrating head injury or who refused informed consent were excluded. Patients underwent a duplex study 1 week after surgery and 1 month clinical follow-up. All patients were treated with lower limb intermittent pneumatic compression devices. RESULTS: There were no differences between groups in age, gender, and risk factors for venous thromboembolism. There were no differences between groups in intraoperative blood loss, transfusion requirements or postoperative platelet counts. Two patients receiving dalteparin developed DVT (one symptomatic and one asymptomatic). No patient treated with heparin developed DVT and no patient in either group developed pulmonary embolism. There were two hemorrhages that did not require repeat craniotomy in patients receiving dalteparin and one that did require surgical evacuation in a patient treated with heparin. Drug was stopped in two patients treated with dalteparin because of thrombocytopenia. None of these differences were statistically significant. CONCLUSION: There was no significant difference in postoperative hemorrhage, venous thromboembolism or thrombocytopenia between heparin and dalteparin. The results suggest that, given the small sample size of this trial, both drugs appear to be safe and the incidence of venous thromboembolism by postoperative screening duplex ultrasound appears to be low when these agents are used in combination with intermittent pneumatic compression devices.     

An overview of venous thromboembolism prophylaxis

This symposium reviewed the risk factors and problems associated with venous thromboembolism in surgical patients, especially those patients having total hip replacement. The importance of venous thromboembolism prophylaxis was emphasized by a theoretical analysis indicating that venous thromboembolism in patients having hip replacement not only saves lives but is also effective. A discussion of the pharmacology of low-molecular-weight heparin (LMWH) included a review of its role, clinically and experimentally, in venous thromboembolism prophylaxis. Three of the discussants presented their favorable experiences with LMWH in reducing the incidence of venous thromboembolism in patients having hip replacement. It can be concluded that LMWH does reduce the incidence of venous thromboembolism in patients having hip replacement without causing an increase in blood loss. If its effectiveness and safety remain substantiated, LMWH may soon become the preferred agent for venous thromboembolism prophylaxis.     

Factor V Leiden and Postoperative Deep Vein Thrombosis in Patients Undergoing Open Roux-en-Y Gastric Bypass Surgery

Background: Patients undergoing bariatric surgery are at risk for deep venous thrombosis (DVT) and fatal pulmonary embolus. In the presence of genetic hypercoagulable disorders, accepted methods of DVT prophylaxis utilizing sequential compression devices and subcutaneous unfractionated heparin may not be adequate to prevent DVT or fatal PE. Methods and Results: 3 morbidly obese patients are described who underwent open Roux-en-y gastric bypass and either had a previous diagnosis of Factor V Leiden or developed thrombosis in the presence of standard prophylaxis. Each was found to have the most common point mutation for Factor V Leiden, R506Q. All 3 patients had prophylactic inferior vena caval filters placed to prevent recurrent PE. Conclusion: The presence of venous thromboembolism either without known risk factors or in the presence of standard perioperative prophylaxis for DVT should warrant a hypercoagulable work-up. Inferior vena caval filter placement is indicated in the presence of a hypercoagulable disorder prior to surgical intervention in the morbidly obese population. The recent literature is reviewed.     

Heparin prophylaxis and the risk of venous thromboembolism after robotic-assisted laparoscopic prostatectomy

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? The incidence of deep venous thrombosis (DVT) in major urological surgery has decreased over time with the introduction of pharmacological prophylaxis, early mobilization, and the use of sequential mechanical compression devices. We examined the value of heparin prophylaxis in robotic assisted laparoscopic prostatectomy (RALP), where the risk of DVT is already low. The rate of thromboemolic events within 30 days was 0.6% in this series. Heparin did not influence estimated blood loss, haematrocrit change, or length of stay. The incidence of thromboembolism is low after RALP, which may obviate the use of heparin prophylaxis. However, its use appears to be safe and does not affect surgical outcomes.

OBJECTIVE

? The incidence of venous thromboembolism (VTE) after robotic‐assisted laparoscopic prostatectomy (RALP) in patients receiving perioperative heparin prophylaxis was compared with those who did not receive such prophylaxis.

MATERIALS AND METHODS

? Between July 2007 to February 2010, a total of 307 RALPs were performed at our institution by two surgeons. A total of 187 patients operated on by surgeon 1 received perioperative heparin prophylaxis, whereas 120 patients operated on by surgeon 2 did not receive any. ? All demographic, clinical and pathological data were prospectively recorded, whereas the incidence of venous thromboembolism within 30 days of the operation was retrospectively reviewed. Evaluation for potential VTE was based on clinical symptoms.

RESULTS

? Cohorts were comparable with respect to PSA, clinical stage, preoperative Gleason score, body mass index, smoking status, pathological stage, path Gleason score and margin status. A total of two thromboemoblic events occurred (0.6%) within 30 days of surgery (one in each arm of the study). ? Heparin prophylaxis did not influence estimated blood loss (P= 0.076) or haematocrit change from preoperative levels (P= 0.378). Length of stay was comparable between the two groups (1.4 vs 1.3 days; P= 0.159).

CONCLUSION

? The incidence of thromboembolism is low after RALP, which may obviate the need for heparin prophylaxis. However, its use is safe and does not impact surgical outcomes. Larger series are needed to confirm the results obtained in the present study.     

重视普通外科围手术期静脉血栓栓塞症规范化防治

普通外科围手术期病人是静脉血栓栓塞症(VTE)的高发人群,近年来国内外已经日益重视普通外科围手术期VTE的预防,但是在开展预防的前提下普通外科围手术期VTE仍时有发生,目前国内围手术期的风险评估和预防实施率仍不高,因此有必要重视普通外科围手术期VTE的规范化防治。规范化预防包括采用Caprini评分进行VTE风险评估以及在此基础上结合出血评估采用相应的机械预防和药物预防措施。规范化治疗主要是请血管外科和呼吸科专科医师协助根据指南对深静脉血栓形成(DVT)和肺动脉栓塞(PE)进行及时的诊断和治疗。治疗首选抗凝,其次根据病人病情和危险分层可进行溶栓、腔内治疗。同时植入滤器应严格按照指征。     

Heparin Thromboprophylaxis in Gastric Bypass Surgery

Background: Patients undergoing gastric bypass surgery are at risk for postoperative venous thromboembolism. Thromboprophylaxis often includes fixed doses of some type of heparin. However, it is unlikely that the same dose of subcutaneous heparin will be optimal for all patients, because heparin pharmacokinetics depend on a number of patient variables, including thickness of the adipose layer. Methods: An adjusted-dose, unfractionated heparin protocol was developed using pharmacokinetic data from 245 medical and surgical patients. Heparin doses were adjusted to achieve subtherapeutic peak anti-factor Xa heparin activity levels of 0.11-0.25 units/mL. This protocol was then applied to a prospective series of 700 patients undergoing laparoscopic Roux-en-Y gastric bypass who had no history of thromboembolism. Heparin prophylaxis was begun the evening of the day of surgery. Results: No patients were diagnosed with a deep venous thrombosis, but 3 (0.4%) were diagnosed with a non-fatal pulmonary embolism. Heparin therapy was halted because of bleeding in 2.3% of patients but only half of these required blood transfusions (1% of total). No patient required reoperation. Minor wound hematomas occurred in 0.6%. There were no deaths from any cause in this series. Conclusion: Use of a monitored, adjusted-dose unfractionated heparin prophylactic protocol in a laparoscopic gastric bypass patient population resulted in doses greater than those used in traditional fixed-dose protocols. However, bleeding and thromboembolism rates were very low and no patients died.     

Use of venous thromboembolism prophylaxis for surgical patients: a multicentre analysis of practice in Spain.

OBJECTIVE: To assess the use of venous thromboembolism prophylaxis in surgical patients. DESIGN: Retrospective multicentre study. SETTING: Eight acute-care teaching hospitals with more than 400 beds, Spain. PATIENTS: Medical records of all consecutive patients undergoing operations in the general surgical and trauma and orthopaedic services during the month of April, 1997, were randomly selected. INTERVENTION: The sample size for each type of operation (general, trauma-orthopaedic) was calculated from the number of operations done at each hospital (with an absolute precision of 5%, and an alpha error of 5%) and the prevalence of the use of venous thromboembolism prophylaxis obtained from a random sample of 50 records (25 from patients in general surgery and 25 from patients in orthopaedic surgery) from each centre. MAIN OUTCOME MEASURES: Appropriate and inappropriate pharmacological prophylaxis defined according to a combination of risk categories for venous thromboembolism, doses of antithrombotic agents given, time of starting prophylaxis, and its duration. RESULTS: A total of 1848 medical records (general surgery, n = 1025; trauma-orthopaedic surgery, n = 823) were included. Physical methods (elastic stockings, intermittent pneumatic compression) were used in only 0.3% of patients. Pharmacological prophylaxis consisted of low molecular weight heparin in 99% of cases. The percentage given heparin-based prophylaxis was 54%. Overall, appropriate prophylaxis was given in 1175 patients (64%). Use of thromboprophylaxis ranged from 27% to 70% among the participating hospitals. Prophylaxis was more likely to be appropriate in orthopaedic patients (577, 70%) than in general surgical patients (598, 58%) in both the high and moderate risk categories. CONCLUSIONS: Given the large variability between the participating hospitals, more specific protocols and recommendations about prophylaxis of thromboembolism in surgical patients are needed.     

Complications of subcutaneous low-dose heparin therapy in neurosurgical patients

BACKGROUND Venous thromboembolism is a major cause of postoperative morbidity and mortality in neurosurgery. The use of low-dose unfractionated heparin therapy perioperatively for prophylaxis against deep vein thromboses and pulmonary embolism has been well demonstrated in many other surgical specialties but is less commonly used in neurosurgery because of fears of devastating postoperative hematomas.

METHODS The safety of such therapy has been analyzed in 950 patients undergoing an inpatient neurosurgical procedure. 872 patients (152 cranial procedures) completed treatment with 5000 U sodium heparin subcutaneously twice a day, commencing before surgery and continuing till patients were ambulatory.

RESULTS There were three minor hemorrhagic complications—two superficial wound hematomas (one requiring treatment) and one gastrointestinal hemorrhage—identified. Three clinically significant major complications developed, two epidural hematomas after spinal surgery requiring evacuation and one intraventricular hemorrhage after brain biopsy.

CONCLUSION This report, along with an analysis of previously published reports of low-dose perioperative heparin therapy in neurosurgical patients, suggests that such therapy is unlikely to be associated with increased morbidity. Given the known efficacy of low-dose heparin in reducing venous thromboembolism in other surgical patients, such therapy may reduce mortality and morbidity from thromboembolic complications in neurosurgical patients with minimal risk.     

Current Practices in the Prophylaxis of Venous Thromboembolism in Bariatric Surgery

Background: Morbidly obese patients undergoing bariatric surgery have commonly been concluded to be at high risk for the development of perioperative venous thromboembolism. Due to its clinically silent nature, primary prevention is the key to reduce morbidity and mortality. There is no clear consensus in the literature regarding the optimum approach to minimize this preventable phenomenon. Methods: Members of the American Society for Bariatric Surgery were surveyed regarding their current practices in the prophylaxis of venous thromboembolism in their bariatric patients. Results: 31% of the members completed the survey. 62% were in private practice, and 38% practiced in an academic hospital. The number of bariatric surgeries done per year ranged from 5 to 325, with a mean of 85 procedures per member. The gastric bypass was the most commonly performed procedure at 61.7%, followed by vertical banded gastroplasty at 23.3%, biliary pancreatic diversion at 9.3%, laparoscopic gastroplasty at 4.0%, laparoscopic gastric bypass at 1.6%, and horizontal banded gastroplasty at 0.1%. 86% felt that their bariatric patients were at high risk for developing deep vein thrombosis (DVT) and pulmonary embolism (PE) with a self-reported incidence of 2.63% and 0.95%, respectively. 48% had at least one death due to PE. Routine prophylaxis is used by over 95% of members. 62% ranked the various methods of prophylaxis from most preferred to least preferred, while 38% used a combination of 2 or more prophylactic methods simultaneously. Low-dose heparin was the most preferred prophylaxis by 50% of members, followed by intermittent pneumatic compression stockings at 33%, low molecular weight heparins at 13%, and other methods at 4%. Over 83% indicated that safety with few complications, ease of administration, and effectiveness were the most important criteria for selecting their most preferred prophylactic method. Only 2% routinely performed testing to rule out venous thromboembolism before discharge, and 11% routinely discharged patients with prophylaxis. Conclusions: The prevailing opinion of members of the American Society for Bariatric Surgery is that morbidly obese patients are at high risk for developing perioperative venous thromboembolism. A vast majority routinely use prophylaxis. Despite these measures, fatal PE is still widespread. A lack of consensus in the method of prophylaxis was seen. A multicentric randomized controlled study comparing the efficacy of the various methods of prophylaxis will be the only manner to determine the best prophylaxis and its usefulness. This study will be costly and probably not warranted due to the low incidence of this condition in the morbidly obese patient.     

Heparin-induced thrombocytopenia after elective hip joint replacement with postoperative prevention of thromboembolism with low-molecular-weight heparin

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a severe side effect of the prophylaxis of venous thromboembolism with unfractionated heparin. The aim of the present study is to gain more information on the incidence of HIT during prophylaxis of venous thromboembolism with low-molecular-weight heparin in elective hip surgery. METHODS: 586 consecutive patients were included into the prospective study, who were admitted to hospital for elective hip replacement. The incidence of thrombocytopenia, clinically manifest venous thromboembolism and of the heparin-induced IgG antibodies were analysed during prophylaxis with low molecular-weight heparin. Patients received once daily subcutaneously low molecular-weight heparin for a mean of 28 days postoperatively. Platelet counts and clinical examinations for the presence of venous thromboembolism were done at days 0, 2, 7 (+/- 1) and 12 (+/- 2). Heparin-induced IgG antibodies were determined before and after a 12 (+/- 2) days prophylaxis with low molecular-weight heparin in 265 of 586 patients randomly. Patients were reexamined for thromboembolic complications after 3 and 6 months. The clinical suspicion of thromboembolic complication was documented objectively. RESULTS: None of the patients developed a decrease of platelets of < 50% of the initial value. Ten of 265 patients had elevated IgG antibodies against heparin/platelet factor 4 before prophylaxis (3.8%). After the 12 (+/- 2) days prophylaxis 13 of 265 patients had elevated IgG antibodies (4.9%). C14 serotonin assay was positive in 0 of 10 patients before treatment and in 3 of 19 patients at day 12 (+/- 2). Ten patients developed venous thromboembolism postoperatively (8 x deep venous thrombosis, 2 x pulmonary embolism, no fatal embolism). Only 1/19 patients with elevated antiheparin IgG titres developed venous thromboembolism. The C14 serotonin assay was negative in this patient. Two patients died in the postoperative phase due to underlying cardiovascular diseases. CONCLUSIONS: In patients with elective hip replacement prophylaxis of venous thromboembolism with low molecular-weight heparin was associated with a very low incidence of HIT, and hence screening for HIT antibodies is not required.     

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.     

Prevention of venous thromboembolism in patients with spinal cord injury: effects of sequential pneumatic compression and heparin

OBJECTIVE: To estimate the incidence of and risk factors for venous thromboembolism in patients with acute traumatic spinal cord injury (SCI) and evaluate the effectiveness of sequential pneumatic compression devices (SCD), gradient elastic stockings (GES), and heparin in preventing thromboembolism. DESIGN: Prentice's case-cohort design. SETTING: All patients admitted to our hospital between 1976 and 1995 with acute traumatic SCI. MAIN OUTCOME MEASURES: Demographic characteristics, venous thromboembolism risk factors, methods of surveillance and prophylaxis, and thromboembolic events during the first 6 weeks following injury. RESULTS: Venous thromboembolism occurred in 84 of 428 patients (19.6%). Venous thromboembolism increased from 21% between 1976 and 1979 to 31% between 1980 and 1984, then decreased to 16% between 1985 and 1989 and to 8% between 1990 and 1995. Routine surveillance for venous thromboembolism increased through 1983, and SCD/GES use increased after 1983, with a concurrent decline in incidence of thromboembolism. Multivariate analysis showed that SCD/GES reduced the risk of deep venous thrombosis (DVT) or pulmonary embolism (relative risk, 0.5; 95% CI, 0.28 to 0.90). Multivariate analysis suggested a reduced risk of DVT in patients receiving heparin therapy within the first 14 to 42 days after injury, but estimates of reduced risk were not statistically significant (p = .064 for first 14 days, p = .13 for heparin anytime). CONCLUSION: The SCD/GES combination and heparin are each effective in preventing venous thromboembolism in individuals' acute traumatic SCI. Effectiveness of heparin prophylaxis may be greatest during the first 14 days after injury, whereas benefit from SCD continues to 6 weeks after injury.     

Current status of pulmonary embolism and venous thrombosis prophylaxis

Prophylaxis for venous thromboembolism is an area that has received intense study in certain conditions, but less than adequate coverage in other areas. In considering who needs prophylaxis, patients are categorized into levels of risk. Clinical venous thromboembolism can be correlated to these levels of risk. Methods of prophylaxis include pharmacologic, mechanical, and combinations of these. Each category of surgical and medical patient requires specific types of prophylaxis. In certain orthopedic indications, the length of prophylaxis outlasts the inpatient hospital stay and may be as long as 1 month after discharge. Even with the best prophylaxis today, the incidence of deep venous thrombosis (DVT) and pulmonary embolism (PE) is decreased by only approximately 70% to 80%. Further developments should allow for greater declines in the rates of venous thromboembolism, with its subsequent short-term consequence of pulmonary embolism and lower extremity morbidity and long-term consequence of the disabling syndrome of chronic venous insufficiency (CVI).     

Perioperative thromboprophylaxis in children: development of a guideline for management

Background:  Venous thromboembolic (VTE) events can occur in children at the time of surgery where a patient has associated prothrombotic risk factors. There is currently little advice available to anesthetists on how to assess the risks and provide prophylaxis.
Aim/Objective:  To increase awareness of thrombosis in the perioperative pediatric patient, and to give some guidance when considering prophylaxis in this group.
Method/Results:  A guideline outlining risk factors for venous thromboembolism in patients presenting for surgery was written as a flowchart. Recommendations for low risk patients was early mobilization and good hydration; for moderate risk patients having major general surgery to include physical prophylaxis where size permits, i.e. elastic stockings and compression devices; for high-risk patients undergoing major orthopaedic or general surgery to also receive prophylactic low molecular weight heparin enoxaparin 0.5 mg·kg⁻¹ b.d.
Conclusion:  Children with multiple risk factors for VTE should be considered for prophylactic measures when presenting for prolonged major surgery.     

Venous thromboembolism prophylaxis in urology: A review

Venous thromboembolism is potentially a lethal problem, and is associated with chronic morbidity. Venous thromboembolism is frequently diagnosed after urological surgery, yet the role of perioperative venous thromboembolism prophylaxis is not clearly defined. Any current recommendations are largely based on evidence derived from other surgical specialties. Even within different guidelines, there remains significant variation, suggesting a consensus is required. The present review aims to define the problem of venous thromboembolism within the urological population, and identifies patients at risk. It evaluates the role of various types of mechanical and pharmacological prophylaxis, along with its timing and duration of administration in common urological operations. The current guidelines are summarized and compared in order to give the reader a better perspective of this vital condition.     

Current clinical concepts in perioperative anticoagulation

Management of patients with significant risks for thromboembolism in the perioperative period requires consideration of both risks of thromboembolism and risks of anticoagulant therapy. Patients who are receiving warfarin therapy because of recent venous thromboembolism, nonvalvular atrial fibrillation, and mechanical heart valves are at increased risk during the interval when the warfarin is discontinued and when the international normalized ratio is at a subtherapeutic level. In patients with an acute venous thromboembolic event within the past month, the use of intravenous heparin appears to be justified both preoperatively and postoperatively. If the venous thromboembolic event was within the past 2 to 3 months, use of intravenous heparin appears justified in the postoperative period. More than 3 months after an acute episode of venous thrombophlebitis, the relatively low risk of recurrence does not appear to justify the risks of complications from intravenous heparin. Patients with increased risks of arterial embolism, specifically those with nonvalvular atrial fibrillation and mechanical heart valves, are generally not at sufficient risk of arterial embolism to justify use of intravenous heparin during the perioperative subtherapeutic international normalized ratio interval when warfarin is withheld. A potential increased risk of recurrent arterial embolism when the preceding event was within a month suggests that elective surgery should be deferred beyond a month whenever possible in such patients. The use of fixed-dose, subcutaneous low molecular weight heparin has been observed to have advantages over use of unfractionated intravenous heparin both in terms of safety and efficiency. Further refinements in management of patients with significant risks of thromboembolism may occur with increased experience with low molecular weight heparin.     

Thromboseprophylaxe in der Chirurgie

Prevention of venous thromboembolism has become routine in all surgical disciplines and consists of physical and pharmacological measures. The indications and choice of prophylaxis modality depend on the individual patient risk profile which is determined by the combination of exposing and predisposing risk factors. The exposing risk factors are characterized by the type and extent of surgery or trauma, whereas the predisposing risk factors relate to patient-inherent risk factors. This is also taken into consideration for the compilation of guidelines. This review summarizes the recommendations of the German S3 guidelines related to surgery and also discusses the perioperative management of patients receiving long-term anticoagulation with new oral anticoagulants (rivaroxaban, apixaban, dabigatran).     

Standards and perspectives for thromboembolism prophylaxis

Thromboembolic complications are one of the most severe complications after orthopaedic or trauma surgery. More than 50% of patients undergoing total knee replacement are at risk of suffering deep-vein thrombosis if not provided sufficient prophylaxis. The former standard prophylaxis with unfractionated heparin has been changed over the few last years to low molecular weight heparin or heparinoids, due to the increased incidence of heparin-induced thrombocytopenia under therapy with unfractionated heparin. Risk management is based on different risk levels: highest risk, high risk, intermediate risk and low risk. The probabilities of suffering from deep-vein thrombosis have been determined dependent on the risk level. In patients with total knee replacement, which are at highest risk, a higher dose for the prevention of thromboembolism has been recommended. The synthetic, selective antithrombin-binding pentasaccharide fondaparinux has been successfully used in prophylaxis for the prevention of thrombosis in highest risk patients. However, because of a higher risk of bleeding, this pentasaccharide can be only given 6-8 h after surgery. Low molecular weight heparins and the pentasaccharide are the standard pharmacological prophylaxis for the prevention of venous thromboembolism. Physical therapy, pneumatic compression, A-V impulse systems, passive ankle motion systems and graduated compression stockings are an additional, effective prophylaxis without side effects.     

Prevention of Venous Thromboembolism in Patients with Spinal Cord Injury: Effects of Sequential Pneumatic Compression and Heparin

Abstract

Objective: To estimate the incidence of and risk factors for venous thromboembolism in patients with acute traumatic spinal cord injury (SCI) and evaluate the effectiveness of sequential pneumatic compression devices (SCD), gradient elastic stockings (GES), and heparin in preventing thromboembolism. Design: Prentice’s case-cohort design.

Setting: All patients admitted to our hospital between 1976 and 1995 with acute traumatic SCI. Main outcome measures: Demographic characteristics, venous thromboembolism risk factors, methods of surveillance and prophylaxis, and thromboembolic events during the first 6 weeks following injury. Results: Venous thromboembolism occurred in 84 of 428 patients (19.6%). Venous thromboembolism increased from 21% between 1976 and 1979 to 31% between 1980 and 1984, then decreased to 16% between 1985 and 1989 and to 8% between 1990 and 1995. Routine surveillance for venous thromboembolism increased through 1983, and SCD/GES use increased after 1983, with a concurrent decline in incidence of thromboembolism. Multivariate analysis showed that SCD/GES reduced the risk of deep venous thrombosis (DVT) or pulmonary embolism (relative risk, 0.5; 95% CI, 0.28 to 0.90). Multivariate analysis suggested a reduced risk of DVT in patients receiving heparin therapy within the first 14 to 42 days after injury, but estimates of reduced risk were not statistically significant (p = .064 for first 14 days, p = .13 for heparin anytime).

Conclusion: The SCD/GES combination and heparin are each effective in preventing venous thromboembolism in individuals’ acute traumatic SCI. Effectiveness of heparin prophylaxis may be greatest during the first 14 days after injury, whereas benefit from SCD continues to 6 weeks after injury.     

Prophylaxis of venous thromboembolism by aspirin, warfarin and heparin in patients with hip fracture. A prospective clinical study with cost-benefit analysis

Seven hundred and thirty-four patients were included in a prospective study for incidence of clinical venous thromboembolism under prophylaxis with either heparin, aspirin or warfarin and for the expenditure of hospital resources. Thromboembolic complications were more frequent (P less than 0.02) and hospital costs clearly higher in the low-dose heparin treated patient group compared with the aspirin and warfarin groups. There were no distinct differences between aspirin and warfarin treated patients neither in results nor in costs. However, carefully monitored treatment with warfarin with Thrombotest always less than 0.20, appeared to be the most effective prophylaxis in patients with hip fractures. In conclusion we now use aspirin as general prophylaxis in orthopaedic patients, and warfarin in patients with established risk of thromboembolic complications.