Deep Vein Thrombosis Formation Research Articles

Sleep Apnea and Risk of Deep Vein Thrombosis: A Non-randomized, Pair-matched Cohort Study: Chou KT, Huang CC, Chen YM, et al. Am J Med 2012;125:374–80.

Sleep apnea is defined as apneic episodes during the sleeping hours, which may be due to either obstruction or temporary loss of central neurologic drive. The majority of patients with sleep apnea (90%) have obstructive sleep apnea (OSA). A growing body of research supports the association between OSA and a hypercoaguable state. This study from Taiwan sought to evaluate the association between OSA and deep vein thrombosis (DVT). The study was a nonrandomized pair-matched cohort model using the National Health Insurance Research Database in Taiwan to identify 5680 new diagnoses of DVT and their pair-matched controls between 2000 and 2007. Mean follow-up was 3.56 ± 2.12 years. The primary outcome was new diagnosis of DVT. The secondary outcome was use of continuous positive airway pressure (CPAP) devices as a proxy measure of OSA severity and its association with increased risk of DVT. The authors found a significantly higher incidence of DVT development in patients with sleep apnea when compared to controls (hazard ratio [HR] 3.113, p < 0.002). The only other demographic factors of significance were female sex (HR 2.145, p < 0.017) and hypertension (HR 2.510, p < 0.034). In the subset of patients with OSA who used CPAP, there was significantly higher risk of DVT (HR 9.575, p < 0.001 vs. HR 2.751, p < 0.007; respectively). The authors’ final conclusion was that sleep apnea is an independent risk factor for future development of DVT. They also posited that, if use of CPAP can be used as a proxy for worse disease, increasing severity of OSA increases risk of DVT formation.

Hardware Design and Research of Intermittent Pressure Thrombotic Treatment Controller Based on Cortex M3

Based on the master chip microcontroller ARM CortexM3, intermittent pressure thrombosis treatment instrument controller controls air pulse through the pump, thecushion is so quickly inflated.After each effective inflatable pressure, the controller makes automatically inflatable cushion air discharge, so the use of physical methods is to prevent and treat human venous thromboembolism, reduce venous stasis, and effectively prevent deep vein thrombosis formation.

Abstract 18175: Interaction of Platelets, Leukocytes and Released Neutrophil Extracellular Traps (NETs) Promote Deep Vein Thrombosis in vivo

Objective: Venous thromboembolism has a major medical impact and is the third leading cause of cardiovascular associated death. While the critical contribution of platelets to arterial thrombosis has been recognized, the mechanisms that trigger the development of deep vein thrombosis (DVT) are not yet fully understood and are believed to be mainly dependent on coagulation. Current in vivo models associated with endothelial disruption or complete stasis only incompletely reflect the pathophysiology of DVT in humans and hinder further understanding of this process. Here, we established a novel mouse model of DVT formation and assessed the dynamics of leukocyte (lc) and platelet (pt) recruitment in vivo. Methods: In our new model DVT was induced by reduction of blood flow in the inferior vena cava (IVC) (to 23.8% of baseline) in the absence of endothelial injury. Layered thrombi develop slowly over a prolonged period of time (&gt;6-12hrs) and occlude the entire IVC 24-48hrs later mimicking human venous thrombi. We observed the dynamics of pt (GPIb-/-, GPIIb-/-), lc (CX3CR1-EGFP, LysM-EGFP), and microparticle recruitment in the IVC in vivo by intravital microscopy. Results: Using corresponding transgenic mice we show here that lc accumulation required endothelial P-selectin, and, besides monocytes, consisted mainly of neutrophils which contribute to DVT development by NET release. In addition to innate immune cells, pts are indispensable for the initiation of venous thrombosis. Further, using low-TF and hTF mice we demonstrate that blood derived tissue factor (TF), exposed on NETs and microparticles, creates a procoagulatory environment that is supported by pt adhesion and activation. The intrinsic pathway of coagulation is also involved in DVT formation, since a factor XIIa inhibitor markedly impaired DVT development. Conclusion: Together, venous thrombosis in our model is driven by a concerted interaction of pts, lcs, and the coagulation cascade. Pts bind to endothelial cells mediated by GPIbα and GPIIb-IIIa, recruited lcs, and triggered NET release thereby initiating DVT. A modulation can be attained in three different ways: by aiming on the coagulation cascade (heparins, factor inhibitors), by impairing pt function and/or by inhibiting lc activation.

Incidence of deep vein thrombosis in patients diagnosed with superficial thrombophlebitis after presenting to an emergency department outpatient deep vein thrombosis service

ObjectiveTo determine the incidence of deep vein thrombosis (DVT) in patients diagnosed with superficial thrombophlebitis (STP) after presenting to an outpatient DVT service.MethodSix month prospective follow-up by telephone of patients...

Clinical investigation on the compliance and the validity of ventilator bundle

To investigate the compliance of ventilator bundle implementation and its preventive effect on ventilator associated pneumonia (VAP). A before and after design was used in this single center study. Patients aged from 18 to 80 years, with mechanical ventilation (MV) duration over 48 hours were recruited during 1 year before (control group) and 2 years after bundle implementation (intervention group). Measurements included the rate of successful ventilator bundle implementation in intervention group, incidence of VAP, duration of MV and mortality within 28 days in both groups. A total number of 237 patients, including 71 patients in control arm and 166 patients in intervention arm, were recruited in this study. There was no statistical significance in ratio of sex, mean age, category of diseases or mean acute physiology and chronic health evaluation II (APACHE II) score between two groups (all P>0.05). Significant changes were not found in MV duration [(5.9+/-5.6) days vs. (5.2+/-6.1) days], incidence of VAP (21.1% vs. 20.5%) and mortality within 28 days (16.9% vs. 19.8%) between control and intervention group as well. In intervention group, 57 of 166 (34.3%) patients were successfully implemented all of four ventilator bundle items. The successful rate of ventilator bundle implementation were 62.5% (35/56), 22.1% (21/95) and 6.7% (1/15) in patients received MV duration < or =3 days, 4-7 days and >7 days respectively. Among the four items of the bundle, head of bed elevation > or =30 degree angle had the lowest successful rate [43.4% (72/166)]. But it was much better in the implementation of daily wake-up plus weaning, prevention of peptic ulcer and prevention of deep vein thrombosis formation [92.2% (153/166), 88.0% (146/166) and 83.1% (138/166) respectively]. The poor compliance of ventilator bundle is an important factor in impacting the efficacy of ventilator bundle.

Epidural anaesthesia for caesarian section in a parturient with a single ventricle

Epidural anaesthesia for caesarian section in a parturient with a single ventricle

Analysis in related factors of deep vein thrombosis formation in diabetic patients and the nursing strategy

Objective To study the related factors in diabetic patients with lOwer extremital deep vein thrombosis(DVT) and the nursing strategy. Methods 58 diabetic cases underwent lower limbs 99mTc-MAA veins imaging and/or ultrasunography. The related laboratory data such as fasting plasma glucose(FPG),blood cholesterol, blood triglycerides and clinic informations such as age, disease courses, lower limbs symptoms (swelling, erooted veins and diabetic foot) and acute complication (diabetic ketoacidosis and hyperosmolar non ketotic diabetic coma) were collected simultaneously. The relationship of each factors with DVT incidence were analyzed. Results 28 patients (48.3%) complicated with lower limbs DVT. The DVT incidence was signifi-cantly different among patients with different age, disease courses, FPG, blood cholesterol, blood triglycerides, lower limbs symptoms and acute complication, respectively. No significant difference was seen in patients with different blood pressure, body weight index, diabetes type. Conclusions Various dangerous factors accumu-lating in DM such as old age, long disease courses, high FPG, high blood cholesterol and high blood triglyc-erides contribute to the high incidence of lower limbs DVT. Early intervention, comprehensive treatment and in-tensive nursing should be applied to reduce the incidence of DVT. Key words: Diabetes mellitns; Deep vein thrombosis; Related factors; Nursing strategy

Establishment of rat model of venous thromboembolism

To establish a rat model of venous thromboembolism (VTE). One hundred and forty-four SD rats were randomly divided into 2 equal groups: VTE-A group, undergoing local blocking of left femoral artery with micro vessel clip to cause deep vein thrombosis (DVT), and VTE-B group undergoing local blocking of left femoral artery with micro vessel clip in addition of administration of thrombin slowly injected from the distal end of the femoral vein blocked by micro clip. The rate of swelling limbs was observed. One, 4, and 7 days later 6 rats from each group were killed with their femoral veins taken out to observe the thrombosis rate by light microscopy. Other 18 rats in each group underwent injection of the thrombi from left femoral vein solution in normal saline into the right femoral vein 1, 4, and 7 days after DVT formation to establish model of DVT-pulmonary thromboembolism (PTE). The 6 rats of each group [VTE-A-D(n)P(n) and VTE-B-D(n)P(n) groups] were killed 1, 4, and 7 days after DVT-PTE formation respectively with their lungs taken out to observe the rate of PTE by light microscopy. (1) On day 1 after DVT, the successful rate of DVT was 100% in both VTE-A and VTE-B groups, and the swelling limb rate of the VTE-B group was 37.5% (27/72), significantly higher than that of the VTE-A group [16.7% (12/72), P = 0.005]. On day 7 after DVT, the positive thrombus rate of the VTE-B group was 83.3% (20/24), significantly higher than that of the VTE-A group [41.7% (10/24), P = 0.003]. One, 4, and 7 days after DVT, there were reddish, mixed, and organized thrombi in both VTE-A and VTE-B groups. (2) Tachypnea and tachycardia occurred immediately and disappeared spontaneously within 30 - 60 minutes when solution of thrombi was injected into pulmonary arteries via the right femoral veins. One rat died in the VTE-B-D(1)P(1) group 12 h after the embolization and was anatomically confirmed to suffer from fresh massive emboli lodged in pulmonary arteries. The successful rates of DVT-PTE model were 100% (18/18), 83.3% (15/18), and 44.4% (8/18) in the VTE-A-D(1)P(n), VTE-A-D(4)P(n), and VTE-A-D(7)P(n) groups respectively, and were 94.4% (17/18), 100% (18/18), and 83.3% (15/18) in the VTE-B-D(1)P(n), VTE-B-D(4)P(n), and VTE-B-D(7)P(n) groups respectively. The successful rate of DVT-PTE model in the VTE-B-D(7)P(n) group was higher than that in the VTE-A-D(7)P(n) group (P = 0.015). The thrombi in pulmonary arteries caused by the 4 or 7 days thrombi of DVT showed lower dissolubility in both VTE-A and VTE-B groups. A new rat model of VTE (DVT-PTE) has been successfully established. The successful rate of VTE can be increased when thrombin is slowly injected from the distal end of femoral vein blocked by micro clip in addition.

The Ultrasound of Intravenous Drug Abuse in the Groin - Vascular and Non-vascular Complications: A Pictorial Review

Intravenous drug abuse is a common social and medical problem. Incidence is estimated at 9·9 per 100 000 for England. In the ultrasound department, a common referral is for ‘IVDA QDVT’ (intravenous drug abuser, query deep vein thrombosis). Deep vein thrombosis (DVT) is a common complication of intravenous injection of drugs via the groin, but ultrasonically can present with a variety of different acute and chronic features, including complications. The groin should also be examined for other vascular and non-vascular complications. Non-vascular complications include cellulitis, sinus track formation, abscess and lymphadenitis. Vascular complications include arterial occlusion, arteriovenous fistula, pseudo-aneurysm, acute and chronic DVT, venous stenosis and complex collateral formation. The sonographer should also be aware of distant complications including endocarditis, septic pulmonary emboli and retroperitoneal extension of groin abscess. This is an increasing diagnostic problem. The sonographer should be aware of the range of pathologies both locally and systemically and be prepared to examine the veins, arteries and soft tissues, extending the examination above the groin and using imaging modalities if findings are atypical. If necessary, the radiologist should be involved at an early stage.

Preoperative Screening Using Venous Duplex Scanning Does Not Alter the Outcome in Patients at High Risk of Postoperative Venous Thromboembolism

Purpose: To assess whether preoperative screening using venous duplex scanning (VDS) of the bilateral lower extremities is useful for identifying patients at risk of developing postoperative venous thromboembolism (VTE). Materials and Methods: Three hundred fifty-two consecutive referral patients at high or highest risk for postoperative VTE according to the guidelines of the American College of Chest Physicians were studied. After VDS, all patients re- ceived low-dose unfractionated heparin for postoperative thromboprophylaxis. Patients were then followed for 3 months after surgery for investigation of clinically significant VTE. Results: Three hundred thirty patients were finally enrolled. Of these, orthopedic surgery patients were most common (140 patients, 42.4%), followed by general surgery (104 patients, 31.5%) and gynecologic (42 patients, 12.7%) surgery patients. Preoperative VDS identified 66 (20.0%) patients with deep vein thrombosis (DVT). Twenty-three (7.0%) pa- tients had proximal DVT and the remaining 43 (13.0%) had distal DVT. Postoperative symptomatic VTE was found in 26 (7.9%) patients who had no evidence of preoperative DVT. Twenty-two patients developed calf DVT, two developed proximal DVT and two developed pulmonary embolism. In contrast, no propagation of DVT or new thrombus formation was found after surgery in patients who had preoperative DVT. Multivariate analysis showed that an age of >75 years (OR 2.57, 95% CI 1.14-5.82, p = 0.023) was the only significant predictor of postoperative VTE.

DVT Prevention for the Obese Patient: Evidence-Based Nursing Interventions

Obesity is a risk factor for deep vein thrombosis (DVT), and as obesity increases, DVT rates will also elevate. The purpose of this article is to assist nurses in correctly selecting evidence-based interventions found effective in preventing DVT formation. To promote full understanding of this disease process, pathophysiologic changes associated with obesity will be linked with current research-based therapies of anticoagulation, compression therapy, and mobilization. A call for future research is proffered in multiple areas, to include assessment, determination of interventional effectiveness, and establishment of outcome measurements for both surgical and medical obese populations.

A Study on the Molecular Mechanism for Hereditary Type II Antithrombin Deficiency in a Chinese Pedigree.

Objective: To identify the phenotype and study for the genetic mechanism underlying the recurrence of deep vein thrombosis formation in members of a Chinese pedigree caused by antithrombin (AT) deficiency.Methods: AT antigen level (AT:Ag) and AT activity (AT:A) were detected with respectively immuno-nephelometry and chromogenic assay. All the seven exons and the flank regions of AT gene form the propositus were amplified by PCR. The purified PCR products were sequenced directly. After mutation was found, the corresponding gene fragments covering the mutated point from the other members of the pedigree were amplified and sequenced.Results: The plasma level of AT:Ag of the propositus was 29.80mg/dl and those of other 3 members of the kindred ranged from 30.90 to 34.00mg/dl, all were among normal range. The AT:A of the propositus was 56%, and those of the other members were 62% to 68%, all were lower than normal. A heterozygous G13830A missense mutation in exon 6 was identified, which has led to the substitution of histamine (CAT) 393 for arginine (CGT). The sequencing results from the pedigree suggested that all the three other members of the kindred also had the same heterozygous mutation.Conclusion: The R393H mutation in AT which is similar to the AT Glasgow and AT Avranches can cause reactive site injury in AT so that it is not able to inhibit thrombin anymore. The gene mutation found in this pedigree which was unreported in China is the molecular mechanism for recurrent thrombosis events in two members of the kindred.

Clinical risk factors for deep vein thrombosis after total hip and knee arthroplasty

To analyze the clinical risk factors for deep vein thrombosis (DVT) after total hip and knee arthroplasty in Chinese patients who received prophylactic treatment for DVT. We evaluated 128 total hip arthroplasty (THA) and total knee arthroplasty (TKA) in 95 patients performed at our center from April 2004 to August 2004, which included 48 THAs in 43 patients and 80 TKAs in 52 patients. There were 27 men and 68 women with a mean age of 59.77 years (range, 23-78 years). All patients had been given low-molecular-weight heparin before operation and for 7-10 days post-operation to prevent DVT. Color Doppler ultrasonography was used to detect DVT of bilateral lower extremities in all patients before operation and at 7-10 days after operation. Nineteen clinical factors were examined preoperation and 7-10 days post-operation in order to analyze their influences on DVT formation after surgery. There were 45 patients who developed DVT after operation. The incidence of DVT in all patients was 47.4% (45/95) and the incidence of proximal DVT was 3.2%. There were more asymptomatic DVT (57.8%, 26/45) than symptomatic ones, and some patients without DVT (14%, 7/50) presented some of the DVT symptoms. Logistic regression analysis demonstrated a definite association of female, obesity (representative by BMI), cement usage and diagnosed RA with DVT with odds ratio of 10.008, 3.094, 8.887, and 0.194 respectively. Other clinical factors had no statistically significant association with DVT. Female, obesity, and cement usage were the risk factors for DVT after THA and TKA, and diagnosed RA was the protecting factors for DVT after THA and TKA. Other clinical factors such as age, OA, type of implant, monolateral or bilateral operation, duration of anesthesia, surgery and bandage usage for blood control, time for immobilization et al were not the risk factors for DVT.

Incidence of DVT following surgery of the foot and ankle.

A prospective study was undertaken to establish the incidence of deep vein thrombosis (DVT) in patients who had undergone surgery of the foot and ankle. All consecutive patients who underwent foot and ankle surgery in the senior author's practice had duplex ultrasound performed of the bilateral calves at the first postoperative visit. Of 201 patients, deep calf clots were found in seven patients (3.5%), but none of these showed progression on follow-up ultrasound or extension proximal to the calf. By the authors' criteria, none of the studied patients required treatment. The authors feel that the rate and progression of DVT after foot and ankle surgery is low and does not require routine prophylaxis. Factors associated with risk of DVT formation were postoperative immobilization, hindfoot surgery, tourniquet time and advancing age.

Graduated compression and the prevention of deep vein thrombosis (Part 3).

The third of this three-part literature review discusses the effects of external compression on deep vein thrombosis formation and suggests design criteria for antiembolism stockings

Cement as a risk factor for deep-vein thrombosis

A total of 110 total knee replacements (TKRs) was randomised to receive either a cemented or an uncemented prosthesis. Postoperative venography at five to seven days was used to compare the prevalence, site and size of deep-vein thrombosis (DVT). We also compared the findings with those of postoperative venography in a group of patients with cemented total hip replacements (THRs). The total prevalence of DVT was significantly greater after uncemented (81%) than after cemented TKR (55%). Both knee groups had a significantly higher prevalence of DVT than in cemented hip replacements (32%). We found no difference in the proportion with proximal DVT in the three groups (14%, 15% and 16%). The median length of the thrombi was significantly greater after cemented (26.5 cm) than after uncemented TKR (11 cm) or after cemented THR (7 cm). This difference was mainly due to greater lengths of distal rather than proximal thrombi. We conclude that the use of cement may affect the formation of DVT after joint replacement, but does not appear to lead to an increased incidence.

Increased activation of coagulation and formation of late deep venous thrombosis following discontinuation of thromboprophylaxis after hip replacement surgery

Hip replacement surgery (HRS) is associated with a high frequency of deep vein thrombosis (DVT). At the same time there is a substantial systemic and local activation of coagulation. This study indicates that discontinuation of thromboprophylaxis one week after surgery may allow a second wave of coagulation and fibrinolysis activation to occur. An almost parallel increase in plasma TAT and D-dimer levels between the 6th and the 35th postoperative day may indicate late DVT formation. Repeated bilateral ascending venography is thought to be necessary to evaluate the suitability of using selected activation markers of the coagulation and fibrinolytic systems as indices of DVT formation.

DEEP VEIN THROMBOSIS

SUMMARY Deep vein thrombosis (DVT) is a common condition. Most cases arise as complications during the perioperative period. This can largely be prevented by adequate prophylaxis, principally using low‐dose subcutaneous heparin. Only a minority of DVTs produce serious complications, but it is not currently possible to predict the clinical behaviour of any DVT, once formed. For this reason, any identified DVT should be vigorously treated. The mainstay of treatment remains systemic anticoagulation with heparin and then warfarin. Warfarin should be continued for 1 month in postoperative cases and 3 months in spontaneous cases, provided there is no ongoing predisposing factor. Recurrent spontaneous DVT formation is an indication for lifelong anticoagulation. Recent evidence suggests that the subcutaneous route of administration of heparin has advantage over traditional intravenous infusion. Some large DVTs require thrombolysis, and it is now possible to treat the underlying anatomical defects with angioplasty and endovascular stenting, although the long‐term outcome of these procedures has not yet been established. For patients with contraindications to the use of anticoagulants, a variety of (temporary and permanent) percutaneously inserted vena caval filters are now available. The principal complications of DVT are pulmonary embolism, which may be fatal, and the development of a postphlebitic leg. The avoidance of these depends on adequate prophylaxis and vigorous treatment of the primary DVT.

Influence of prophylaxis on proximal venous thrombus formation after total hip arthroplasty

Deep vein thrombosis (DVT) is the most frequent complication after total hip arthroplasty, and proximal DVT is more likely to produce clinical pulmonary emboli than distal DVT. The authors have assessed the incidence and anatomic location of phlebographically proven fresh DVT following total hip arthroplasty in 855 patients over 39 years of age. Eight different regimens (2 warfarin, 3 aspirin, 1 dextran, 1 external pneumatic compression, and 1 dextran combined with external pneumatic compression) were evaluated and compared with an historical placebo control group from the same institution. No significant difference ( P<.05) existed in proximal DVT incidence between the placebo group and any of the three aspirin groups, the dextran group, the external pneumatic compression group, or the dextran combined with external pneumatic compression group. In contrast, warfarin, given both in traditional and low-dose regimens, provided a significant reduction in proximal DVT compared with the placebo group ( P<.001; statistical power, 0.84 and 0.99, respectively). The low-dose regimen had 10 times fewer bleeding complications than the traditional regimen. All prophylaxis regimens should be evaluated for both proximal and distal DVT formation, as well as for overall incidence. Low-dose warfarin offers the best protection against proximal thrombi of the agents studied, and it is also safer than traditional dosages of warfarin.

Response of Femoral Venous Oxygen Tension to Graduated Pressure Stockings - Possible Relationship to Deep Vein Thrombosis

Venous oxygen tension (pO2) was measured in discrete samples of blood obtained through the femoral vein of cardiac catheterisation patients before, during and after application of sustained external graduated pressure in the form of compression stockings (T. E. D. Kendall). There was a significant reduction (p less than 0.05) of pO2 from the baseline value both 30 sec and one minute after the application of the pressure stockings. Thereafter, the pO2 rose to baseline values. Two minutes after the stockings were removed there was again a significant reduction (p less than 0.05) of pO2 from the baseline value. We suggest that the decrease in venous pO2 on application of external pressure may be a reflection of washing out of stagnant hypoxic blood from the venous valve pockets, which may be related to the formation of deep vein thrombosis (DVT).