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J Ginsberg

Publications and source records attributed to J Ginsberg.

At least 19 recordsLinked to original sources
PubMed2001

Dose-response study of recombinant factor VIIa/tissue factor inhibitor recombinant nematode anticoagulant protein c2 in prevention of postoperative venous thromboembolism in patients undergoing total knee replacement.

BACKGROUND: With the best prophylactics now available, venous thromboembolism after total knee replacement remains substantial (25% to 27%). Recombinant nematode anticoagulant protein c2 (rNAPc2) is a potent inhibitor of factor VIIa/tissue factor complex that has the potential to reduce this risk. The present study was performed to determine an efficacious and safe dose of rNAPc2 for prevention of venous thromboembolism after elective, unilateral total knee replacement. METHODS AND RESULTS: This open-label, sequential dose-ranging study was conducted in 11 centers in Canada, Europe, and the United States. Five regimens were tested. Injections were administered subcutaneously on the day of surgery (day 1) and days 3, 5, and optionally, day 7. Primary efficacy outcome was a composite of overall deep vein thrombosis based on mandatory unilateral venography (day 7+/-2) and confirmed symptomatic venous thromboembolism recorded </=48 hours after the last dose of rNAPc2. Primary safety outcome was major bleeding </=72 hours after the last dose. An independent, blinded Central Adjudication Committee assessed all outcome events. Of 293 patients studied, 251 (86%) could be evaluated for primary efficacy analysis. A dosage of 3.0 microgram/kg administered within 1 hour after surgery provided the best observed results, with an overall deep vein thrombosis rate of 12.2%, a proximal deep vein thrombosis rate of 1.3%, and a major bleeding rate of 2.3%. CONCLUSIONS: A randomized, double-blind trial that compared rNAPc2 with current best prophylactics is warranted based on encouraging, first-reported clinical results for a factor VIIa/tissue factor inhibitor evaluated for thrombosis prophylaxis.

Aged↗
PubMed2001

Patterns of population subdivision, gene flow and genetic variability in the African wild dog (Lycaon pictus).

African wild dogs are large, highly mobile carnivores that are known to disperse over considerable distances and are rare throughout much of their geographical range. Consequently, genetic variation within and differentiation between geographically separated populations is predicted to be minimal. We determined the genetic diversity of mitochondrial DNA (mtDNA) control region sequences and microsatellite loci in seven populations of African wild dogs. Analysis of mtDNA nucleotide diversity suggests that, historically, wild dog populations have been small relative to other large carnivores. However, population declines due to recent habitat loss have not caused a dramatic reduction in genetic diversity. We found one historical and eight recent mtDNA genotypes in 280 individuals that defined two highly divergent clades. In contrast to a previous, more limited, mtDNA analysis, sequences from these clades are not geographically restricted to eastern or southern African populations. Rather, we found a large admixture zone spanning populations from Botswana, Zimbabwe and south-eastern Tanzania. Mitochondrial and microsatellite differentiation between populations was significant and unique mtDNA genotypes and alleles characterized the populations. However, gene flow estimates (Nm) based on microsatellite data were generally greater than one migrant per generation. In contrast, gene flow estimates based on the mtDNA control region were lower than expected given differences in the mode of inheritance of mitochondrial and nuclear markers which suggests a male bias in long-distance dispersal.

Africa↗
PubMed2001

A comparison of three rapid D-dimer methods for the diagnosis of venous thromboembolism.

We compared three rapid D-dimer methods for the diagnosis of venous thromboembolism. Patients presenting to four teaching hospitals with the possible diagnosis of deep vein thrombosis or pulmonary embolism were investigated with a combination of clinical likelihood, D-dimer (SimpliRED) and initial non-invasive testing. Patients were assigned as being positive or negative for deep vein thrombosis or pulmonary embolism based on their three-month outcome and initial test results. The three D-dimer methods compared were: (a) Accuclot D-dimer (b) IL-Test D-dimer (c) SimpliRED D-dimer. Of 993 patients, 141 had objectively confirmed deep vein thrombosis or pulmonary embolism. The sensitivity of SimpliRED, Accuclot and IL-Test were 79, 90 and 87% respectively. All three D-dimer tests gave similar negative predictive values. The SimpliRED D-dimer was found to be less sensitive than the Accuclot or IL-Test. When combined with pre-test probability all three methods are probably acceptable for use in the diagnosis of venous thromboembolism.

Fibrin Fibrinogen Degradation Products↗
PubMed2001

Hyperplacentosis: a novel cause of hyperthyroidism.

Human chorionic gonadotropin (hCG), which is capable of thyrotropic activity, is believed responsible for the hyperthyroidism of gestational trophoblastic disease and hyperemesis gravidarum. Hyperplacentosis is a condition of heightened trophoblastic activity characterized by increased placental weight and circulating hCG levels higher than those associated with normal pregnancy. We report the first case of hyperthyroidism associated with hyperplacentosis. Correction of the hyperthyroidism occurred after hysterotomy and correlated with declining hCG levels. Hyperplacentosis should be included among the causes of hCG-mediated hyperthyroidism.

Adult↗
PubMed2000

Treatment of warfarin-associated coagulopathy with oral vitamin K: a randomised controlled trial.

BACKGROUND: Warfarin-associated coagulopathy is a frequent clinical complication. We aimed to assess whether treatment with vitamin K is safe and more effective than placebo in rapidly lowering the international normalised ratio (INR) into the therapeutic range in over anticoagulated patients receiving warfarin. METHODS: We did a multicentre, double-blind, placebo-controlled, randomised trial in five tertiary care hospitals. In this study, patients receiving warfarin who had an INR value between 4.5 and 10.0, and who did not have an indication for the immediate normalisation of their INR, had their warfarin withheld, and were randomly allocated to receive either 1 mg of vitamin K or placebo orally. The primary outcome measure was the INR value on the day after treatment. Secondary outcome measures included INR values on subsequent days, and the risk of haemorrhage and recurrent thrombosis over a 3 month follow-up period. FINDINGS: Patients given vitamin K had a more rapid decrease in the INR than those given placebo (25 of 45 (56%] vs nine of 44 [20%] patients with INR values of 1.8-3.2 on the day after treatment, respectively, p=0.001; odds ratio [OR] 0.21, 95% CI 0.07-0.57). Fewer patients given vitamin K had bleeding episodes during the follow-up period than those given placebo (two [4%] vs eight [17%] patients, respectively, p=0.050; OR 0.87, 95% CI 0.019-0.999). INTERPRETATION: Low dose oral vitamin K is more effective than placebo for the rapid lowering of raised INR values in patients taking warfarin.

Administration, Oral↗
PubMed2000

The characterization of phospholipase D in FRTL-5 thyroid cells.

We previously demonstrated that TSH activates phospholipase D (PLD) in Fischer rat thyroid line (FRTL)-5 cells. To date, two types of mammalian phosphatidylcholine-specific PLD cDNAs, designated as PLD-1 and PLD-2, have been cloned. The present study determined the PLD isoform composition in FRTL-5 thyroid cells and which isoform is regulated by TSH. PLD-1 is activated by small molecular weight G-proteins, such as ADP-ribosylation factor (ARF) and RhoA family members, while PLD-2 is relatively independent of such stimuli. We established the presence of PLD-1 and PLD-2 by Western blot analysis and compared PLD activity in cytosol, membranes and combined fractions in the presence and absence of GTPgammaS. The membrane fraction showed very little activity in the absence of GTPgammaS, but this activity increased approximately 5-fold (P<0.05, ANOVA) in the presence of GTPgammaS. Maximal PLD activity was seen with the combination of membrane plus cytosolic fractions (which contained ARF and RhoA) where the addition of GTPgammaS increased PLD activity approximately 8-fold (P<0.05, ANOVA). To determine the relative activities of PLD-1 and PLD-2 in FRTL-5 thyroid cells, cell-free PLD assays were performed in the presence of GTPgammaS or GDPbetaS with varying concentrations of phosphatidylinositol 4,5-bisphosphate (PIP(2)). PLD-2 contributed only approximately 19% of the total amount of PLD activity in the membranes and PLD-1 was the predominant PLD isoform. TSH stimulated PLD-1 activity by up to 2. 3-fold over control values (P<0.01, ANOVA). To establish the dependence of PLD-1 on small molecular weight G-proteins, the translocations of ARF and RhoA to the membrane fractions was determined after stimulation by TSH. Both ARF and RhoA were maximally translocated to the membrane fraction after 10 min incubation with 100 microU/ml TSH by approximately 1.7- and 2.3-fold over control values, respectively (P<0.02 and P<0.03, ANOVA). It is concluded that TSH stimulates PLD-1 activity in FRTL-5 thyroid cells and this is accompanied by the translocation of ARF and RhoA to the membrane fraction.

Animals↗
PubMed2000

Pharmacokinetic profile of a low-molecular weight heparin (reviparin) in pregnant patients. A prospective cohort study.

Anticoagulant therapy during pregnancy is problematic. Patients are frequently treated with long-term low-molecular weight heparin despite a lack of evidence for its effectiveness, and in the absence of validated dosing recommendations. The objectives of this investigation were to characterize the safety and pharmacokinetic behavior of a low-molecular weight heparin (reviparin) administered throughout pregnancy. Forty-two patients followed in a tertiary-care rheumatology clinic who received prophylactic doses of reviparin (4900 anti-Xa units subcutaneously once daily) were enrolled in this investigation. Anti-Xa heparin levels, weights, and gestational ages of the patients were obtained on up to four occasions distributed throughout their pregnancy. The achieved anti-Xa heparin levels were highly correlated with the patient's weight, irrespective of the gestational age. No toxicity other than injection site hematomas was observed. The achieved intensity of anticoagulation with reviparin varies during pregnancy in direct proportion to the patient's weight. This variability may mandate dose adjustment in response to changes in a patient's weight during pregnancy, particularly if low-molecular weight heparin is administered at therapeutic doses.

Abortion, Habitual↗
PubMed2000

Assessment of deep vein thrombosis or pulmonary embolism by the combined use of clinical model and noninvasive diagnostic tests.

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are relatively common diseases and are amenable to therapy but with a potentially fatal outcome if untreated. The diagnosis can be made in most patients with use of the noninvasive imaging tests, but limitations exist. The standard first choice of investigation in patients with suspected DVT is compression ultrasonography (CUS). As with all tests, there is a potential for false-positive and false-negative results. The latter are especially an issue for calf vein thrombi, and this in part has led to the concept of serial CUS testing of the proximal venous system and not imaging of the calf. The premise of the repeat (serial) CUS test is that only thrombi that extend to the proximal system are clinically relevant, and these thrombi will be detected during subsequent testing. However, despite the safety of the serial CUS testing concept, it is inconvenient and expensive. The standard first choice of investigation in patients with suspected PE, the ventilation-perfusion (V/Q) lung scan is nondiagnostic in most cases. In the past few years, the diagnostic process has improved because of the validation of clinical models that accurately categorize patients as having low (5%), moderate (20% to 30%), or high probability (>60%) for venous thromboembolic disease. Among the improvements this provides is the elimination of serial CUS testing if the ultrasound results are normal and the clinical probability is low in patients with suspected DVT. In patients with suspected PE in whom further testing is necessary, determination of clinical probability allows selection of invasive (angiography) or noninvasive testing (serial ultrasound) in patients with non-high-probability V/Q scans. The fibrin degradation product D-dimer has had a high negative predictive value; negative results with enzyme-linked immunosorbent assay (ELISA) tests effectively rule out DVT or PE. In addition, a negative result with less-sentive D-dimer testing and a low clinical probability excludes DVT or PE.

Algorithms↗
PubMed2000

Incidence of recurrent thromboembolic and bleeding complications among patients with venous thromboembolism in relation to both malignancy and achieved international normalized ratio: a retrospective analysis.

PURPOSE: Initial heparinization followed by vitamin K antagonists is the treatment of choice for patients with venous thromboembolism. There is controversy whether known malignancy is a risk factor for recurrences and bleeding complications during this treatment. Furthermore, the incidence of such events in these patients is dependent on the achieved International Normalized Ratio (INR). The aim of this study was to assess the incidence of venous thromboembolic recurrence and major bleeding among patients with venous thromboembolism in relation to both malignancy and the achieved INR. PATIENTS AND METHODS: In a retrospective analysis, the INR-specific incidence of venous thromboembolic and major bleeding events during oral anticoagulant therapy was calculated separately for patients with and without malignancy. Eligible patients participated in two multicenter, randomized clinical trials on the initial treatment of venous thromboembolism. Patients were initially treated with heparin (standard or low-molecular weight). Treatment with vitamin K antagonists was started within 1 day and continued for 3 months, with a target INR of 2.0 to 3.0. RESULTS: In 1,303 eligible patients (264 with malignancy), 35 recurrences and 12 bleeds occurred. Patients with malignancy, compared with nonmalignant patients, had a clinically and statistically significantly increased overall incidence of recurrence (27.1 v 9.0, respectively, per 100 patient-years) as well as bleeding (13.3 v 2.1, respectively, per 100 patient-years). In both groups of patients, the incidence of recurrence was lower when the INR was above 2.0 compared with below 2.0. CONCLUSION: Although adequately dosed vitamin K antagonists are effective in patients with malignant disease, the incidence of thrombotic and bleeding complications remains higher than in patients without malignancy.

Aged↗
PubMed1999

The effects of lysophosphatidate on thyrotropin-mediated differentiated thyroid function in FRTL-5 thyroid cells.

Lysophosphatidate (LPA; 1-acyl-sn-glycero-3-phosphate) is a novel lipid mediator with diverse biological activity. The intracellular mechanisms that mediate the actions of LPA include activation of phospholipase C and protein kinase C (PKC), increases in intracellular Ca2+, inhibition of adenylyl cyclase, and activation of phospholipase D (PLD). We have shown that thyrotropin (TSH) mediated PLD activation involves both the cyclic adenosine monophosphate (cAMP) and PKC pathways. We determined the effects of LPA (10 or 50 microM; 30 minutes) on TSH- and forskolin-mediated cAMP production in FRTL-5 thyroid cells. Basal cAMP was unaffected by LPA. However, both 10 microM and 50 microM LPA inhibited TSH-mediated cAMP production by 66% and 64%, respectively (p < 0.01, ANOVA). A similar inhibition of forskolin-mediated cAMP production was observed following LPA (p < 0.01, ANOVA). After 30-minutes exposure to 50 microM LPA, TSH-mediated iodide uptake (IU) was unaffected. However, 50 microM LPA enhanced TSH-IU after 24-hour exposure by 23%+/-8% (p < 0.03, ANOVA) and inhibited TSH-IU following 72-hour exposure by 43%+/-10% (p < 0.02, ANOVA). There was no effect of LPA on basal IU. To determine whether PLD activation mediated the effects of LPA, PLD activity was examined in FRTL-5 thyroid cells 30 minutes after LPA exposure. While PLD was increased 3.5-fold compared to control values following 50 microM LPA (p < 0.05, ANOVA), no increase in PLD activation was seen following treatment with 10 microM LPA. Preliminary evidence revealed no effect of a protein kinase C inhibitor on LPA inhibition of cAMP generation. To examine the products of PLD activation, we measured the production of phosphatidate (PA) and diacylglycerol (DAG) in FRTL-5 thyroid cells following treatment with 50 microM LPA or 100 microU/mL TSH. Within 1 minute following LPA, a rapid spike of DAG production was observed (1.5- +/- 0.2-fold above basal, p < 0.05, ANOVA). No similar increases in PA or bisPA were demonstrated. However, TSH caused a steady increase in PA and DAG that reached a maximum after 30 minutes. In summary, the effects of LPA on differentiated thyroid function in FRTL-5 thyroid cells are complex. LPA inhibits TSH- and forskolin-mediated cAMP generation most likely via a direct inhibition of adenylyl cyclase, whereas its effects on TSH-IU involve other mechanisms, possibly including PLD activation.

Animals↗
PubMed1999

Discordant measures of androgen-binding kinetics in two mutant androgen receptors causing mild or partial androgen insensitivity, respectively.

We have characterized two different mutations of the human androgen receptor (hAR) found in two unrelated subjects with androgen insensitivity syndrome (AIS): in one, the external genitalia were ambiguous (partial, PAIS); in the other, they were male, but small (mild, MAIS). Single base substitutions have been found in both individuals: E772A in the PAIS subject, and R871G in the MAIS patient. In COS-1 cells transfected with the E772A and R871G hARs, the apparent equilibrium dissociation constants (Kd) for mibolerone (MB) and methyltrienolone are normal. Nonetheless, the mutant hAR from the PAIS subject (E772A) has elevated nonequilibrium dissociation rate constants (k(diss)) for both androgens. In contrast, the MAIS subject's hAR (R871G) has k(diss) values that are apparently normal for MB and methyltrienolone; in addition, the R871G hAR's ability to bind MB resists thermal stress better than the hAR from the PAIS subject. The E772A and R871G hARs, therefore, confer the same pattern of discordant androgen-binding parameters in transfected COS-1 cells as observed previously in the subjects' genital skin fibroblasts. This proves their pathogenicity and correlates with the relative severity of the clinical phenotype. In COS-1 cells transfected with an androgen-responsive reporter gene, trans-activation was 50% of normal in cells containing either mutant hAR. However, mutant hAR-MB binding is unstable during prolonged incubation with MB, whereas normal hAR-MB binding increases. Thus, normal equilibrium dissociation constants alone, as determined by Scatchard analysis, may not be indicative of normal hAR function. An increased k(diss) despite a normal Kd for a given androgen suggests that it not only has increased egress from a mutant ligand-binding pocket, but also increased access to it. This hypothesis has certain implications in terms of the three-dimensional model of the ligand-binding domain of the nuclear receptor superfamily.

Amino Acid Sequence↗
PubMed1998

Assessment of outpatient treatment of deep-vein thrombosis with low-molecular-weight heparin.

BACKGROUND: Low-molecular-weight (LMW) heparins are safe and effective for out-of-hospital treatment of acute deep-vein thrombosis (DVT) in a clinical trial setting. We examined the efficacy, safety, and feasibility of home treatment with LMW heparin of consecutive eligible patients with acute DVT in a routine care setting. In addition, we report our experience with patient compliance, acceptance, and satisfaction. METHODS: We performed a prospective cohort study of consecutive patients presenting to 2 thromboembolism clinics in a large Ontario city. Eligible patients were treated with LMW heparin for a minimum of 5 days and with long-term warfarin sodium. Outcomes included the incidences of bleeding and recurrence of DVT and pulmonary embolism and patient satisfaction as determined by a questionnaire. RESULTS: One hundred thirteen patients with objectively confirmed DVT underwent screening; 89 patients were treated at home with LMW heparin. During the study, 1 patient died of a combination of pulmonary embolism and major bleeding, another patient required admission to the hospital for bleeding, and 5 patients with active malignant disease had recurrent DVT. Of the patients who completed the satisfaction questionnaire, 75 (91%) of 82 were pleased with home treatment; 44 (70%) of 63 felt comfortable self-injecting the LMW heparin; and 71 (92%) of 77 were satisfied with the support and instruction they received during the outpatient treatment. CONCLUSIONS: Outpatient treatment of DVT with LMW heparin is safe, effective, and feasible for most patients and is associated with a high degree of patient satisfaction.

Adult↗
PubMed1998

EWS-FLI1 fusion transcript structure is an independent determinant of prognosis in Ewing's sarcoma.

PURPOSE: More than 90% of Ewing's sarcomas (ES) contain a fusion of the EWS and FLI1 genes, due to the t(11;22)(q24;q12) translocation. At the molecular level, the EWS-FLI1 rearrangements show great diversity. Specifically, many different combinations of exons from EWS and FLI1 encode in-frame fusion transcripts and result in differences in the length and composition of the chimeric protein, which functions as an oncogenic aberrant transcription factor. In the most common fusion type (type 1), EWS exon 7 is linked in frame with exon 6 of FLI1. As the fundamental pathogenetic lesion in ES, the molecular heterogeneity of these fusion transcripts may have functional and clinical significance. PATIENTS AND METHODS: We performed a clinical and pathologic analysis of 112 patients with ES in which EWS-FLI1 fusion transcripts were identified by reverse-transcriptase polymerase chain reaction (RT-PCR). Adequate treatment and follow-up data were available in 99 patients treated with curative intent. Median follow-up in these 99 patients was 26 months (range, 1 to 140 months). Univariate and multivariate survival analyses were performed that included other prognostic factors, such as age, tumor location, size, and stage. RESULTS: Among the 99 patients suitable for survival analysis, the tumors in 64 patients contained the type 1 fusion and in 35 patients contained less common fusion types. Stage at presentation was localized in 74 patients and metastatic in 25. Metastases (relative risk [RR] = 2.6; P = .008), and type 1 EWS-FLI1 fusion (RR = 0.37; P = .014) were, respectively, independent negative and positive prognostic factors for overall survival by multivariate analysis. Among 74 patients with localized tumors, the type 1 EWS-FLI1 fusion was also a significant positive predictor of overall survival (RR = 0.32; P = .034) by multivariate analysis. CONCLUSION: EWS-FLI1 fusion type appears to be prognostically relevant in ES, independent of tumor site, stage, and size. Further studies are needed to clarify the biologic basis of this phenomenon.

Adolescent↗
PubMed1998

Low-dose oral vitamin K reliably reverses over-anticoagulation due to warfarin.

BACKGROUND: Patients receiving long-term warfarin frequently develop asymptomatic excessive prolongation of their international normalized ratio (INR) results. The most appropriate management strategy in these patients is unknown. This prospective cohort study was designed to address whether 1 mg of oral vitamin K effectively reduces the INR value of such patients. METHODS: A prospective cohort study was performed in two tertiary care teaching hospitals, in which 62 patients receiving warfarin who had INR values between 4.5 and 10.0 received 1 mg of oral vitamin K. All patients had daily INR values and clinical assessments performed. RESULTS: The mean INR value at presentation was 5.79 (95% confidence interval (CI) 5.48 to 6.09, range 4.5 to 9.5). Sixteen hours after receiving the 1 mg of oral vitamin K, the mean INR was 2.86 (95% CI 2.50 to 3.23). On the second and third days after vitamin K, the mean INR values were 2.20 (1.93 to 2.47) and 2.14 (1.85 to 2.44), respectively. No adverse events or bleeding complications were observed. In three patients (6%) the INR value rose between the time of vitamin K administration and the next INR determination; two patients received a further 2 mg dose of subcutaneous vitamin K. CONCLUSIONS: In patients receiving warfarin who have asymptomatic excessive prolongations in their INR results, 1 mg of oral vitamin K reliably reduces the INR to the therapeutic range within 24 h. This therapy is more convenient, less expensive, and might be safer than parenteral vitamin K. Thus, it should be considered in all non-bleeding patients receiving warfarin, who present with INR results of 4.5 to 9.5.

Administration, Oral↗
PubMed1997

Low-molecular-weight heparin in the treatment of patients with venous thromboembolism.

BACKGROUND: Low-molecular-weight heparin is known to be safe and effective for the initial treatment of patients with proximal deep-vein thrombosis. However, its application to pulmonary embolism or previous episodes of thromboembolism has not been studied. METHODS: We randomly assigned 1021 patients with symptomatic venous thromboembolism to fixed-dose, subcutaneous low-molecular-weight heparin (reviparin sodium) or adjusted-dose, intravenous unfractionated heparin. Oral anticoagulant therapy with a coumarin derivative was started concomitantly and continued for 12 weeks. Approximately one third of the patients had associated pulmonary embolism. The outcome events studied over the 12 weeks were symptomatic recurrent venous thromboembolism, major bleeding, and death. We sought to determine whether low-molecular-weight heparin is at least equivalent to unfractionated heparin in patients with venous thromboembolism. RESULTS: Twenty-seven of the 510 patients assigned to low-molecular-weight heparin (5.3 percent) had recurrent thromboembolic events, as compared with 25 of the 511 patients assigned to unfractionated heparin (4.9 percent). The difference of 0.4 percentage point indicates that the two therapies have equivalent value according to our predetermined definition of equivalence. Sixteen patients assigned to low-molecular-weight heparin (3.1 percent) and 12 patients assigned to unfractionated heparin (2.3 percent) had episodes of major bleeding (P= 0.63), and the mortality rates in the two groups were 7.1 percent and 7.6 percent, respectively (P=0.89). CONCLUSIONS: Fixed-dose, subcutaneous low-molecular-weight heparin is as effective and safe as adjusted-dose, intravenous unfractionated heparin for the initial management of venous thromboembolism, regardless of whether the patient has pulmonary embolism or a history of venous thromboembolism.

Anticoagulants↗
PubMed1997

A comparison of compression ultrasound with color Doppler ultrasound for the diagnosis of symptomless postoperative deep vein thrombosis.

BACKGROUND: Despite advances in primary prophylaxis, venous thromboembolism still occurs in a considerable number of high-risk surgical patients. Screening with conventional ultrasound imaging to detect asymptomatic deep vein thrombosis (DVT) has been suggested as a strategy to improve management of such patients, but it is insufficiently sensitive. We evaluated the ability of color Doppler ultrasound to improve the sensitivity of compression ultrasound in the detection of asymptomatic DVT in high-risk orthopedic patients. METHODS: We prospectively evaluated bilateral compression and color Doppler ultrasound measurements of the entire leg in 204 consecutive patients who underwent elective hip or knee replacement surgery, using contrast venography as the reference test. The sensitivity, specificity, and positive predictive value of the ultrasonography tests were determined. RESULTS: The sensitivity, specificity, and positive predictive value (with 95% confidence intervals [CIs]) of compression ultrasound for the detection of proximal DVT were 60% (39%-81%), 96% (92%-99%), and 71% (48%-89%) respectively. The sensitivity, specificity, and positive predictive value (with 95% CIs) of compression ultrasound for the detection of calf vein thrombosis were 33% (18%-52%), 91% (83%-96%), and 58% (34%-80%), respectively. Color Doppler ultrasonography did not identify any additional proximal or calf vein thrombi to those detected by compression ultrasound alone. The sensitivity for all thrombi was 47% (95% CI, 34%-61%) with a positive predictive value of 65% (95% CI, 48%-79%). CONCLUSIONS: Color Doppler ultrasonography has a moderate to low accuracy for the detection of DVT in patients who have had hip and knee replacement surgery. Color Doppler ultrasonography does not increase the detection rate for asymptomatic DVT over compression ultrasound and thus cannot be recommended as a screening test in this setting.

Hip Prosthesis↗