Deep Vein Thrombosis In Symptomatic Patients Research Articles

C0454: Accuracy of Nurse-Performed Compression Ultrasonography in the Diagnosis of Proximal Symptomatic Deep Vein Thrombosis: A Prospective Cohort Study

Summary. Background: Compression ultrasonography(CUS) has been recognized as the diagnostic procedure ofchoice for the investigation of patients with suspecteddeep vein thrombosis (DVT); the aim of this study was toassess the diagnostic accuracy of nurse-performed CUSfor symptomatic proximal DVT of the lower limb. Mate-rial and Methods: We prospectively evaluated all consecu-tive outpatients referred for suspected DVT from January2011 to December 2012. All patients underwent bilateralproximal lower limb CUS, first by trained nurses andthen by physicians expert in vascular ultrasonography,with every group blinded with respect to each other. Thistest was repeated after 5–7 days in all negative or unclearexaminations. Interobserver agreement and accuracy ofnurse-performed CUS were calculated, considering thephysician’s final diagnosis as the reference test. Results:Six hundred ninety-seven patients were included in thestudy. DVT was diagnosed in 122 patients by expertultrasound physicians with an overall prevalence of17.5% (95% confidence interval [CI] 15.8%–20.6%).Nurse agreement with the physician in DVT diagnosiswas excellent (Cohen’s j 0.82, 95% CI 0.79–0.85). Nurse-performed CUS had a sensitivity of 84.4% (95% CI81.7%–87.1%) and a specificity of 97.0% (95% CI95.8%–98.3%) with a diagnostic accuracy of 94.8% (95%CI 93.2%–96.5%). Conclusion: Our results suggest thatnurse-performed CUS may be a potential useful alterna-tive to physician performed CUS with a good accuracy.However, sensibility of nurse-performed CUS appearedsuboptimal and future studies should incorporate in theevaluation of this technique other pretest tools that mayincrease its accuracy.Keywords: diagnostic tests; Doppler ultrasonography;nurses; vascular diseases; venous thrombosis.IntroductionPrompt diagnosis of deep vein thrombosis (DVT) isessential to decrease the risk of potentially fatal pulmo-nary embolism and postthrombotic syndrome inuntreated patients [1,2]. Diagnostic strategies in DVTshould be accurate, simple to apply, and cost effective.Currently, compression ultrasonography (CUS) is consid-ered the method of choice for the diagnosis of DVT insymptomatic patients, and its use has been validated inseveral prospective studies [2–4]. The potential advantagesof this technique are the ease of performance by manyoperators and the availability in many hospitals with vir-tually all ultrasound scanners, regardless of generation,model, and even probe frequency [5].Although CUS has shown good accuracy for the diag-nosis of symptomatic proximal DVT, its specificity andsensitivity for calf vein thrombi are much lower [2,4]. Forthis reason, CUS may be limited to the proximal veinsand repeated within 1 week when negative (serial proxi-mal CUS) or extended to both proximal and distal veinsand performed on a single occasion with color-Dopplersupport (whole-leg ultrasonography) [2,5]; both strategiesare reliable diagnostic options for the management ofthese patients [2,5].

Risk factors for symptomatic deep-vein thrombosis in patients after total ankle replacement who received routine chemical thromboprophylaxis

The aim of this study was to identify the incidence of post-operative symptomatic deep-vein thrombosis (DVT), as well as the risk factors for and location of DVT, in 665 patients (701 ankles) who underwent primary total ankle replacement. All patients received low-molecular-weight heparin prophylaxis. A total of 26 patients (3.9%, 26 ankles) had a symptomatic DVT, diagnosed by experienced radiologists using colour Doppler ultrasound. Most thrombi (22 patients, 84.6%) were localised distally in the operated limb. Using a logistic multiple regression model we identified obesity, a previous venous thromboembolic event and the absence of full post-operative weight-bearing as independent risk factors for developing a symptomatic DVT. The incidence of symptomatic DVT after total ankle replacement and use of low-molecular-weight heparin is comparable with that in patients undergoing total knee or hip replacement.

Metabolic Syndrome and the Incidence of Symptomatic Deep Vein Thrombosis Following Total Knee Arthroplasty

We asked if patients with metabolic syndrome undergoing total knee replacement (TKR) have an increased risk for symptomatic deep vein thrombosis (DVT) at 3 months followup. We reviewed 1460 patients from our joint registry undergoing primary, unilateral TKR between 1998-2006. Demographic variables of age, sex, comorbidity, and education were retrieved. Metabolic syndrome was defined as body mass index above 30 kg/m(2), diabetes, hypertension, and hypercholesterolemia. Logistic regression was used to examine the relationship of metabolic syndrome on the incidence of DVT. The overall incidence of symptomatic DVT was 4.4% (65/1460). Patients with metabolic syndrome had an increased incidence of DVT compared to those without metabolic syndrome (15.5% vs 3.4%). Adjusted analysis showed that the risk of symptomatic DVT in patients with metabolic syndrome was 3.2 times [odds ratio 3.2, 95% CI (1.0,15.4), p = 0.04] the risk in those without metabolic syndrome. Hospital protocols developed for prophylactic anticoagulation following TKR should give special consideration to patients with metabolic syndrome.

Exclusion of first-episode deep-vein thrombosis after-hours using D-dimer

The objective of this study was to test the safety of withholding anticoagulant treatment and additional call-back diagnostic testing with ultrasound in patients who have a negative D-dimer at presentation. Patients with signs and symptoms of deep-vein thrombosis who presented to the emergency department after regular hours and on weekends underwent D-dimer testing using the STA-Liatest D-di. In patients with negative D-dimer results, heparin therapy was withheld, and no further diagnostic testing for deep-vein thrombosis was done as part of the initial evaluation. Patients with positive D-dimer results underwent compression ultrasonography. The primary outcome measure was a diagnosis of new symptomatic venous thromboembolism confirmed by diagnostic testing during the 3-month follow-up period. Of the 260 eligible patients, 81 (31%) had a negative D-dimer and 179 (69%) had a positive D-dimer. No patient with a negative D-dimer at presentation had confirmed venous thromboembolism at 3-month follow-up. Three patients died: one by intracranial hemorrhage secondary to cerebrovascular accident; and two deaths of indeterminate cause almost 3 months after entry. The automated assay for D-dimer, the STA-Liatest D-di, seems to provide a simple method with high clinical utility for excluding acute first-episode deep-vein thrombosis in symptomatic patients who present to the emergency room after regular hours.

Low-dose warfarin does not decrease the rate of thrombosis in patients with cervix and vulvo-vaginal cancer treated with chemotherapy, radiation, and erythropoeitin

Objectives. We had previously reported an association between the use of recombinant human erythropoietin (rHuEPO) and thrombosis in patients with cervix and vulvo-vaginal cancer treated with chemotherapy and radiation. We hypothesized that low-dose warfarin would be effective prevention for thromboembolic events in this setting. Methods. A retrospective analysis of patients with cervical or vulvo-vaginal carcinoma receiving chemoradiation and rHuEpo was performed. Thirty-two patients received rHuEpo alone, and 24 received warfarin (1–2 mg) and rHuEpo. The primary endpoint was objectively proven symptomatic venous thrombosis. Results. There was no difference in the baseline characteristics (e.g. age, stage, body mass index, mean and peak hemoglobin, WBC and platelet counts, and number of transfusions) between these two groups. The rate of thrombosis also was not statistically different ( P = 0.62). Nine of 24 patients had a symptomatic deep vein thrombosis (DVT) while receiving warfarin compared to 10 of 32 patients not on warfarin. There was no difference between the two groups in the percentage of patients with upper extremity DVT ( P = 0.83) or lower extremity DVT ( P = 0.64). Conclusion. Daily low-dose warfarin did not alter the incidence of symptomatic DVT in patients with cervical or vulvo-vaginal cancer who received rHuEpo in conjunction with chemoradiation.

Incidence of symptomatic venous thrombosis in cervical and vulvo-vaginal carcinoma treated with concurrent chemoradiation, erythropoietin, and coumadin

8101 Background: We had previously reported an increase in the incidence of symptomatic deep vein thrombosis (DVT) in 144 cervical and vulvo-vaginal cancer patients receiving recombinant human erythropoietin (rHuEpo) compared to patients not receiving rHuEpo in conjunction with chemoradiation therapy (Cancer 2003; 98: 1514-20). From April 2002, we instituted a policy of prophylactic low dose coumadin in an attempt to prevent DVT in this cohort receiving rHuEpo. Methods: A retrospective analysis of 56 consecutive patients with cervical or vulvo-vaginal carcinoma (FIGO Stage IB-IVA) who received chemoradiation and rHuEpo from 2001 to 2003 were performed. Subjects were divided into two groups: 32 subjects received rHuEpo alone, 24 subjects received daily coumadin (1–2 mg) in addition to rHuEpo. Primary endpoint was symptomatic DVT proven by duplex ultrasound. Results: There was no difference in baseline characteristics (e.g. age, stage, body mass index, mean and peak hemoglobin, WBC and platelet counts recorded at the time of peak hemoglobin, and number of transfusions) between these two cohorts (p ≥ 0.06, Wilcoxon rank sum test). 9 out of 24 patients (37.5%) had a symptomatic DVT while receiving coumadin compared to 10 out of 32 patients (31.3%) not on any anticoagulation. The incidence of thrombosis was not different between the two groups studied (p=0.62, Chi-square test; OR=1.32, 95% CI=(0.43,4.02)). Out of the 9 patients who had a DVT while receiving coumadin, 7 developed upper extremity (UE) DVT while 3 had lower extremity (LE) DVT (1 patient had both UE and LE thromboses). For the 10 patients who were not on coumadin and developed thromboses, 9 were UE DVT and 2 were LE DVT (1 patient had both UE and LE DVT). There was no difference between the two groups in the percentage of patients with UE DVT (p=0.83, Chi-square test; OR=1.14, 95% CI=(0.35,3.74)) or LE DVT (p=0.64, Fisher's test; OR=2.2, 95% CI=(0.33,14.79)). Conclusions: Daily low dose coumadin did not alter the incidence of symptomatic DVT in patients with cervical or vulvo-vaginal cancer who received rHuEpo in conjunction with chemoradiation therapy. No significant financial relationships to disclose.

Sonography and venography of the lower extremities for diagnosing deep vein thrombosis in symptomatic patients

The purpose of this study was to investigate the efficacy of sonography and the frequency of indeterminate sonographic examinations in the evaluation of patients with suspected lower extremity deep vein thrombosis (DVT). We prospectively evaluated 136 symptomatic patients (157 extremities) with suspected DVT using sonography and contrast-enhanced venography ( n=106 patients, 115 extremities). Using venography as the reference standard for diagnosing DVT, the sensitivity and specificity of sonography was 92.8% and 98%, respectively, yielding an accuracy of 96.8%. The frequency of indeterminate examinations for calf DVT was 32.4%. One (0.7%) fatal pulmonary embolus occurred in our patients. The pulmonary embolism (PE) rate was 1.6% after lower extremity sonography with negative results. Sonography is highly accurate in detecting lower extremity DVT in symptomatic patients. Because of the high frequency of indeterminate studies in the calf and the associated possible risk of pulmonary emboli, we urge radiologists exercise additional caution when evaluating symptomatic patients with clinically suspected lower extremity DVT.

Diagnosing Upper-Extremity DVT

Like lower-extremity deep-vein thrombosis (DVT), upper-extremity DVT can cause edema and pulmonary embolism. In clinical practice, ultrasonography often is used to diagnose upper-extremity DVT in symptomatic patients, but the accuracy of this test is unknown. Researchers performed duplex color ultrasonography on 123 inpatients and outpatients referred for evaluation of suspected upper-extremity …

Emergency Department compression ultrasound to diagnose proximal deep vein thrombosis

Emergency Department (ED) patients with suspected deep vein thrombosis (DVT) require an objective vascular study such as ultrasound (US) to confirm the diagnosis prior to treatment or disposition. A simple compression US test of the common femoral vein and popliteal vein reliably detects proximal DVT in symptomatic patients. Application of compression US in the ED by Emergency Physicians (EPs) has been tested in a single previous study. We evaluated the ability of ED compression US, performed by EPs, to diagnose proximal DVT as compared to duplex US performed in a vascular laboratory. A prospective, observational study was conducted on a convenience sample of patients presenting to an ED with lower extremity symptoms and signs suggestive of DVT. Patients with a history of DVT in the symptomatic extremity were excluded. Final diagnosis of DVT was made by color-flow duplex US performed in a vascular laboratory. ED compression US was performed by one of six EP sonographers. In compression US, DVT was diagnosed by the inability to compress the common femoral vein or popliteal vein. The examination was considered indeterminate if the veins could not be clearly identified or compressibility was equivocal. For statistical analysis, an indeterminate examination was considered positive. In those cases where ED compression US was discordant with duplex US, and not indeterminate, we retrospectively reviewed the US findings. There were 76 patients who completed the study, and 18 patients (24%) were diagnosed with DVT by duplex US, among whom ED compression US was positive in 14, negative in 2, and indeterminate in 2. Among 58 patients diagnosed without DVT by duplex US, there were 4 false-positive ED compression US examinations and 10 indeterminate examinations. In all, ED compression US was indeterminate in 12 patients (15.8%). Compared to duplex US, ED compression US had a sensitivity of 88.9% (95% C.I. 65.3–98.6%) and specificity of 75.9% (62.8–86.1). Negative predictive value was 95.7% (85.2–99.5). Among ED patients with the clinical diagnosis of possible DVT, negative ED compression US greatly reduces the likelihood of DVT, such that discharge and outpatient follow-up can be considered. Because of limited specificity, positive results require confirmation, but may justify immediate treatment pending follow-up testing. Indeterminate results can be expected in a significant number of patients and mandate further testing prior to disposition.

Combination of a clinical risk assessment score and rapid whole blood D-dimer testing in the diagnosis of deep vein thrombosis in symptomatic patients

Purpose: The clinical diagnosis of deep vein thrombosis (DVT) is unreliable in more than 50% of cases, and, in recent years, plasma D-dimer assays have been used to predict the presence of DVT with high sensitivity and negative predictive values. This study investigated the use of a rapid whole blood test that could be performed and interpreted by the bedside in addition to a clinically derived risk assessment score (RAS) to determine whether a practical and cost-effective clinical model could be developed for the diagnosis and exclusion of DVT in symptomatic patients. Methods: Two hundred consecutive patients who were referred to the vascular laboratory with clinically suspected DVT underwent the following procedures: (1) clinical assessment and stratification into low, moderate, or high risk for DVT on the basis of an RAS related to history, symptoms, and physical examination findings; (2) rapid (5-minute) whole blood D-dimer testing with a semi-qualitative agglutination technique on a fingerprick blood sample; and (3) color flow duplex ultrasound scanning with standard criteria for the diagnosis of proximal and calf DVT. Results: Forty-six patients (23%) had acute DVT on duplex ultrasound scanning. Of these cases, 28 (61%) had proximal DVT and 18 (39%) were confined to the calf. A total of 88 patients were classified as low risk, 67 were classified as moderate, and 45 were classified as high risk on the basis of the RAS method. Of the patients who were classified at low risk, 4.5% (4/88) had DVT, as compared with 17.9% (12/67) in the moderate clinical risk group and 66.7% (30/45) in the high risk group. Isolated calf DVT was found in 30% (9/30), 50% (6/12), and 75% (3/4) of the high, moderate, and low risk groups, respectively. The sensitivity (8.7%, 26.1%, 65.2%), specificity (45.5%, 64.3%, 90.3%), positive predictive value (4.5%, 17.9%, 66.7%), and overall accuracy rate (37%, 55.5%, 84.5%) of the low, moderate, and high risk groups, respectively, in the diagnosis of DVT increased significantly with increasing risk score stratification. The sensitivity, specificity, positive and negative predictive value, and overall accuracy of the rapid D-dimer test for all DVT were 91.3%, 81.9%, 60%, 96.9%, and 84%, respectively, with a 100% sensitivity and negative predictive value for proximal DVT. A combination of the RAS and D-dimer identified a low risk group with a negative D-dimer as having less than a 1% likelihood of DVT and a high risk group with positive D-dimer as having a likelihood of more than 90%. Conclusion: A combination of clinical assessment and rapid D-dimer testing provides an effective means of excluding proximal DVT in symptomatic patients. The application of a clinical diagnostic model on the basis of these parameters has the potential for saving a large proportion of unnecessary duplex scans with the associated time and costs. (J Vasc Surg 1999;30:794-804.)

Failure of soluble fibrin polymers in the diagnosis of clinically suspected deep venous thrombosis.

A new diagnostic test has recently become available which is highly specific for plasma soluble fibrin polymers, the thrombus precursor protein (TpP) enzyme immunoassay. In order to evaluate the diagnostic accuracy of this test and that of a new rapid and automated test for the determination of D-dimers, the BC D-dimer test, in patients with clinically suspected deep vein thrombosis (DVT), 70 consecutive symptomatic patients underwent laboratory analysis with both tests and with the classic enzyme-linked immunosorbent assay (ELISA) D-dimer test, followed by the execution of a compression ultrasound (CUS) test of the affected limb. Patients with a positive CUS test were considered to have DVT (20 of 70), whereas those with a serially negative test and an uneventful 3-month follow-up test were regarded as not having DVT (50 of 70). The sensitivity of the TpP test (45.0%) was significantly lower than that of both the BC D-dimer test (80.0%; P = 0.02) and the classic ELISA test (90.0%; P = 0.002). The specificity of the TpP test (66.0%) did not differ from that of either D-dimer test (60.0 and 64.0%, respectively). The negative predictive value of the TpP test (75.0%) was significantly lower than that of the classic ELISA D-dimer test (94.1%; P = 0.02), which in turn did not differ from that of the BC D-dimer test (88.2%). The positive predictive value was similarly low for each investigated test (34.6, 44.4, and 50.0%, respectively). In conclusion, the TpP test can neither be used to detect a DVT nor to exclude its development in patients with the clinical suspicion of this disease. By contrast, the BC D-dimer might safely replace the classic ELISA test for excluding DVT in symptomatic patients.

Antiphospholipid Antibodies Do Not Seem to Be Associated With Deep Vein Thrombosis: A Case Control Study

Antiphospholipid antibodies (APAs) are associated with venous thromboembolism in patients with systemic lupus erythematosus (SLE). In patients without SLE, but with deep vein thrombosis (DVT) this association is established only for patients with lupus anticoagulant (LA). In a case-controlled study APAs were determined in 171 consecutive outpatients who underwent phlebography at the first episode of clinically suspected DVT of lower limbs. Phlebography confirmed the presence of DVT in 54 (32%) patients and excluded it in 117. Antiphospholipid antibodies (exluding LA) were detected in 5 (9.2%) of the 54 patients with DVT and in 7 (5.9%) of the 117 subjects without DVT, The prevalence of APAs tended to be higher in patients with DVT than in patients without DVT, but the difference was not statistically significant (p = 0.3%). Antiphospholipid antibodies in the absence of LA are not associated with DVT in symptomatic patients. Therefore future studies should be performed before changing our clinical approach in APA-A positive but LA-negative patients. Key Words: Antiphospholipid antibodies-Deep vein thrombosis.

Hyperhomocysteinemia and Deep-Vein Thrombosis A Case-Control Study

In a case-control study, fasting total homocysteinemia was determined in 208 consecutive outpatients who underwent phlebography because of the first episode of clinically suspected deep-vein thrombosis (DVT) of lower limbs. Contrast venography confirmed the clinical suspicion in 60 patients (28.8%). Hyperhomocysteinemia was detected in 15 of the 60 patients with DVT (25.0%), and in 17 of the 148 subjects without thrombosis (11.5%; p = 0.025). The OR for having an acute DVT in patients with hyperhomocysteinemia was 2.6 (95% CI: 1.1-5.9). It is concluded that high plasma homocysteine levels are significantly associated with DVT in symptomatic patients. Further studies are needed to clarify the clinical implications of this association.

Deep Venous Thrombosis and Lupus Anticoagulant

A definite evidence in favour of an association of deep-vein thrombosis (DVT) with lupus anticoagulant (LA) in patients free from systemic lupus erythematosus is still lacking. In a case-control study, LA was determined in 176 consecutive outpatients who underwent phlebography because of the first episode of clinically suspected DVT of lower limbs. The association between DVT and LA was described using odds ratios (OR). Contrast venography confirmed the clinical suspicion in 59 patients (33.5%). LA was detected in 5 of the 59 patients with DVT (8.5%), and in none of the 117 subjects with normal venogram (P = 0.007). The OR for having an acute DVT in patients with LA was 10.7 (95% CI: 1.2-94.2). LA is significantly associated with DVT in symptomatic patients. Further studies are needed to establish the clinical implications of this association.

Combined use of strain-gauge plethysmography and latex D-dimer test in clinically suspected deep venous thrombosis

The diagnostic value of a latex D-dimer test combined with strain-gauge plethysmography (SGP) was assessed in 425 patients referred to our vascular laboratory because of clinically suspected deep-vein thrombosis (DVT) of lower limbs, using venography as the reference standard. The inpatient/outpatient ratio was 236 189 . Adequate venograms were obtained in 401 patients and a DVT was diagnosed in 195 (49%). SGP results were borderline in 38 patients. In the 363 unequivocal cases, sensitivity of SGP was 88% and specificity 90%. The sensitivity of D-dimer latex test was 78% and the specificity 88%. Out of the 363 unequivocal cases, D-dimer test results were discordant with SGP in 88 cases, of whom 60% had DVT and 40% had not, and concordant in 275. The sensitivity of concordant results was 98% ( 124 127 ) and specificity 97% ( 143 148 ). Compared with strain-gauge plethysmography (plus venography in case of borderline results), the combined approach reduced the diagnostic errors (false positive plus false negative results) from 10% ( 40 401 ; 95% confidence interval, 7–13%) to 2% ( 8 401 ; 95% CI, 0.6–3.4%) albeit requiring a greater number of venographies, from 9% ( 38 401 ; 95% CI, 7–12%) to 31% ( 126 401 ; 95% CI, 27–36%). Most calf DVT (94%) were identified. We conclude that this test combination is valuable in the diagnosis of DVT in symptomatic patients, because of the high accuracy of concordant test results. Venography is required in case of borderline or discordant results.