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Russell D Hull

Publications and source records attributed to Russell D Hull.

34 records · Page 2Linked to original sources
PubMed2004

D-dimer for the exclusion of acute venous thrombosis and pulmonary embolism: a systematic review.

BACKGROUND: Despite extensive literature, the diagnostic role of d-dimer for deep venous thrombosis (DVT) or pulmonary embolism (PE) remains unclear, reflecting multiple d-dimer assays and concerns about differing sensitivities and variability. PURPOSE: To systematically review trials that assessed sensitivity, specificity, likelihood ratios, and variability among d-dimer assays. DATA SOURCES: Studies in all languages were identified by searching PubMed from 1983 to January 2003 and EMBASE from 1988 to January 2003. STUDY SELECTION: The researchers selected prospective studies that compared d-dimer with a reference standard. Studies of high methodologic quality were included in the primary analyses; sensitivity analysis included additional weaker studies. DATA EXTRACTION: Two authors collected data on study-level factors: d-dimer assay used, cutoff value, and whether patients had suspected DVT or PE. DATA SYNTHESIS: For DVT, the enzyme-linked immunosorbent assay (ELISA) and quantitative rapid ELISA dominate the rank order for these values: sensitivity, 0.96 (95% confidence limit [CL], 0.91 to 1.00), and negative likelihood ratio, 0.12 (CL, 0.04 to 0.33); and sensitivity, 0.96 (CL, 0.90 to 1.00), and negative likelihood ratio, 0.09 (CL, 0.02 to 0.41), respectively. For PE, the ELISA and quantitative rapid ELISA also dominate the rank order for these values: sensitivity, 0.95 (CL, 0.85 to 1.00), and negative likelihood ratio, 0.13 (CL, 0.03 to 0.58); and sensitivity, 0.95 (CL, 0.83 to 1.00), and negative likelihood ratio, 0.13 (CL, 0.02 to 0.84), respectively. The ELISA and quantitative rapid ELISA have negative likelihood ratios that yield a high certainty for excluding DVT or PE. The positive likelihood values, which are in the general range of 1.5 to 2.5, do not greatly increase the certainty of diagnosis. Sensitivity analyses do not affect these findings. LIMITATIONS: Although many studies evaluated multiple d-dimer assays, findings are based largely on indirect comparisons of test performance characteristics across studies. CONCLUSION: The ELISAs in general dominate the comparative ranking among the d-dimer assays for sensitivity and negative likelihood ratio. For excluding PE or DVT, a negative result on quantitative rapid ELISA is as diagnostically useful as a normal lung scan or negative duplex ultrasonography finding.

Acute Disease↗
PubMed2004

Heparin and low-molecular-weight heparin therapy for venous thromboembolism: will unfractionated heparin survive?

Recent improvements in clinical trials methodology and the use of accurate objective tests to detect venous thromboembolism (VTE) have made it possible to carry out a series of randomized trials to evaluate various treatments for VTE. The results of these trials have resolved many of the uncertainties a clinician confronts in selecting the appropriate course of anticoagulant therapy. These trials have shown that the intensity of both initial heparin treatment and long-term anticoagulant therapy must be sufficient to prevent unacceptable rates of recurrence of VTE. Patients with proximal deep vein thrombosis who receive inadequate anticoagulant therapy have a risk of clinically evident, objectively documented recurrent VTE that approaches 20% to 25%. The need for adequate therapy with heparin and the importance of monitoring blood levels of the effect of heparin have been established. The importance of achieving adequate heparinization was suggested by a nonrandomized trial in 1972 and randomized trials in the 1980s have confirmed this finding. Furthermore, randomized trials have demonstrated the importance of achieving adequate heparinization early in the course of therapy. Unfractionated heparin by continuous intravenous infusion has provided an effective therapy for more than half a century, but the need to monitor therapy and establish therapeutic levels is a fundamental problem. It is evident that validated heparin protocols are more successful in establishing adequate heparinization than intuitive ordering by the clinician. However, even with the best of care using a heparin protocol, some patients treated with intravenous heparin will receive subtherapeutic treatment. In this context, subtherapeutic treatment reflects a practical limitation of the use of unfractionated heparin, rather than a poor standard of care. Furthermore, it is recognized that the practical difficulties associated with heparin administration are compounded by the substantive practical difficulties of standardizing activated partial thromboplastin time (aPTT) testing and the therapeutic range. Our findings have emphasized the confounding effect that initial heparin treatment has on long-term outcome. In all trials of long-term treatment, it is imperative that the initial therapy is of adequate intensity and duration; failure to administer adequate initial treatment may lead to a poor outcome that is falsely attributed to the long-term therapy under evaluation. Treatment with low-molecular-weight heparin (LMWH), which does not require monitoring or dose finding, has largely replaced unfractionated heparin for the initial management of VTE. Efficacy in terms of recurrent VTE or extension of thrombus has been at least as good with LMWH as unfractionated heparin and there is evidence that the incidence of major bleeding, heparin-induced thrombocytopenia, and osteoporosis are less with LMWH as compared with unfractionated heparin. Although unfractionated heparin may survive as a treatment option for acute VTE, its use has been largely supplanted by LMWH.

Drug Monitoring↗
PubMed2004

Uptake of new treatment strategies for deep vein thrombosis: an international audit.

OBJECTIVE: Study of the uptake of new medical technologies provides useful information on the transfer of published evidence into usual practice. We conducted an audit of selected hospitals in three countries (Canada, France, and Switzerland) to identify clinical predictors of low-molecular-weight (LMW) heparin use and outpatient treatment, and to compare the pace of uptake of these new therapeutic approaches across hospitals. DESIGN: Historical review of medical records. SETTING AND PARTICIPANTS: We reviewed the medical records of 3043 patients diagnosed with deep vein thrombosis (DVT) in five Canadian, two French, and two Swiss teaching hospitals from 1994 to 1998. Measures. We explored independent clinical variables associated with LMW heparin use and outpatient treatment, and determined crude and adjusted rates of LMW heparin use and outpatient treatment across hospitals. RESULTS: For the years studied, the overall rates of LMW heparin use and outpatient treatment in the study sample were 34.1 and 15.8%, respectively, with higher rates of use in later years. Many comorbidities were negatively associated with outpatient treatment, and risk-adjusted rates of use of these new approaches varied significantly across hospitals. CONCLUSION: There has been a relatively rapid uptake of LMW heparins and outpatient treatment for DVT in their early years of availability, but the pace of uptake has varied considerably across hospitals and countries.

Aged↗
PubMed2003

Venous thromboembolic disease: comparison of the diagnostic process in men and women.

BACKGROUND: There has been concern that women may be limited to fewer major diagnostic tests than men. Whether this applies to patients with pulmonary embolism (PE) or deep venous thrombosis (DVT) has not been determined. OBJECTIVE: To assess whether there is a sex disparity in the application of diagnostic tests for PE or DVT, in reaching a diagnosis, or in using medical facilities. DESIGN: A study of cross-sectional samples of hospitalizations from 21 separate years using data from the National Hospital Discharge Survey. SETTING: Noninstitutional hospitals in the 50 states and the District of Columbia from 1979 through 1999. PATIENTS: The National Hospital Discharge Survey abstracts demographic and medical information from the medical records of inpatients. For 1979 through 1999, the number of patients sampled ranged from 181000 to 307000.Measurements The number of sampled patients with DVT and with PE and the number of diagnostic tests performed were determined from the International Classification of Diseases, Ninth Revision, Clinical Modification codes at discharge. A multistage estimation procedure gave an estimation of values for the entire United States. RESULTS: Age-adjusted rates of the diagnosis of PE per 100000 population and of DVT per 100000 population were not lower in women. Rates of the use of ventilation-perfusion lung scans, venous ultrasonography of the lower extremities, and contrast venography were not lower in women. Durations of hospitalization for PE or DVT were comparable in men and women. CONCLUSION: Data from the National Hospital Discharge Survey do not support a sex bias in the diagnosis of PE or DVT, the use of diagnostic tests, or the duration of hospitalization for PE or DVT.

Cross-Sectional Studies↗
PubMed2003

Tracking the uptake of evidence: two decades of hospital practice trends for diagnosing deep vein thrombosis and pulmonary embolism.

BACKGROUND: Advances in clinical research methods have led to prospective randomized controlled (level 1) clinical studies evaluating diagnostic modalities resulting in a paradigm shift in the literature for diagnosing deep vein thrombosis (DVT) and pulmonary embolism (PE). To assess whether these advances correlate with clinical practice, we analyzed 21-year trends in diagnostic testing for patients with venous thromboembolism. METHODS: We used discharge data from the National Hospital Discharge Survey (1979-1999) to determine DVT and PE cases annually. Procedure fields were screened to determine patients who had DVT or PE or who underwent venography, arteriography of the pulmonary arteries, pulmonary scintigraphy, or DVT ultrasonic scanning. Searching EMBASE, MEDLINE, and the American Thoracic Society guidelines, a literature-based time line of level 1 studies was derived and juxtaposed against trends and procedure use. RESULTS: Improved diagnostic tests resulted in diagnostic changes in patients with suspected venous thromboembolism. These observed changes correlated over time in subsequent years with level 1 studies. Diagnostic DVT approaches showed an initial marked increased use of venography followed by a rapid decline that coincided with increased use of Doppler ultrasonography. Diagnostic approaches to PE were characterized by initial marked increases in lung scanning followed by a rapid decline as use of ultrasonography considerably increased and pulmonary angiography modestly increased. CONCLUSIONS: Diagnostic approaches to DVT and PE have changed markedly during the past 2 decades, in temporal harmony with the evolving literature. Change in clinical practice occurs over years, and long-term follow-up is required to capture this change.

Diagnostic Techniques and Procedures↗
PubMed2003

Gadolinium-enhanced magnetic resonance angiography for detection of acute pulmonary embolism: an in-depth review.

STUDY OBJECTIVE: To review the published experience with gadolinium-enhanced magnetic resonance angiography (MRA) for the detection of acute pulmonary embolism (PE) in order to test the hypothesis that gadolinium-enhanced MRA may be potentially sensitive and specific enough to include it among diagnostic alternatives in the evaluation of patients with suspected PE. METHODS: Studies were identified by searching MEDLINE for trials that used gadolinium-enhanced MRA to diagnose acute PE based on the visualization of an intraluminal filling defect or a cutoff vessel, using pulmonary angiography as a reference standard. RESULTS: Twenty-eight investigations were identified in which MRA was used to diagnose PE. Only three studies, however, met the criteria for inclusion in the analysis. In these three case series, the sensitivity of gadolinium-enhanced MRA ranged from 77 to 100%, and the specificity ranged from 95 to 98%. CONCLUSION: Gadolinium-enhanced MRA may be a useful diagnostic alternative in some patients with suspected acute PE, particularly if they have an elevated creatinine level, have an allergy to radiographic contrast material, or should, if possible, avoid exposure to ionizing radiation.

Acute Disease↗
PubMed2003

Coumarin therapy in thrombosis.

Oral anticoagulants are the most commonly used agents in the long-term prophylaxis and treatment of arterial and venous thrombotic disorders. As new and expanded indications for their use, such as the prevention of recurrent myocardial infarction or the treatment of systemic embolism in atrial fibrillation, are developed, the use of oral anticoagulants is rising. Also, in North America, oral anticoagulants are used commonly for preventing venous thromboembolism following orthopedic surgery. This article reviews the pharmacology of warfarin sodium, the most commonly used oral anticoagulant in North America, and discusses practical aspects of the use of this agent in thrombotic disorder management.

Anticoagulants↗
PubMed2003

Tinzaparin in the treatment of venous thromboembolism.

Low molecular weight heparin (LMWH) has been widely used for the initial treatment of patients presenting with venous thromboembolism. The LMWH, tinzaparin, has been shown in randomised clinical trials to be as effective and safe as unfractionated heparin for the initial treatment of venous thromboembolism and in clinical trials, it has been used in place of warfarin for the long-term treatment of deep vein thrombosis. Tinzaparin can safely be given to patients with significant renal impairment (creatinine clearance of > or = 20 ml/min) and the dose of tinzaparin does not need to be altered in patients with a body mass index of > 25.

Administration, Oral↗
PubMedDate not supplied

Venous thromboembolic disease: comparison of the diagnostic process in blacks and whites.

BACKGROUND: There has been concern that a disproportionate use of some health services exists among races. Whether this applies to patients with pulmonary embolism (PE) or deep venous thrombosis (DVT) has not been determined. OBJECTIVE: To assess if there is a racial disparity in the application of diagnostic tests for PE or DVT, or in reaching a diagnosis or using medical facilities. DESIGN: A study of cross-sectional samples of hospitalizations during 21 years using data from the National Hospital Discharge Survey. SETTING: Noninstitutional hospitals in 50 states and the District of Columbia from January 1, 1979, through December 31, 1999. PATIENTS: The National Hospital Discharge Survey abstracts demographic and medical information from the medical records of inpatients. For 1979 through 1999, the number of patients sampled ranged annually from 181 000 to 307 000. Measurements The number of sampled patients with DVT and with PE and the number of diagnostic tests performed were determined from the International Classification of Diseases, Ninth Revision, Clinical Modification codes at discharge. A multistage estimation procedure gave an estimate of values for the entire United States. RESULTS: The age-adjusted rates of diagnosis of PE and of DVT per 100 000 population were not lower in blacks than in whites. Rates of use of radioisotopic lung scans, venous ultrasonography of the lower extremities, and contrast venography were comparable between races. The durations of hospitalization for patients with a primary discharge diagnosis of PE and of DVT were also comparable. CONCLUSIONS: There is nothing to suggest that diagnostic tests are being withheld, and there is no evidence of a failure to reach a diagnosis in blacks with thromboembolic disease.

Adult↗