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Biomedical subjects

D C Levin

Publications and source records attributed to D C Levin.

At least 19 recordsLinked to original sources
PubMed1992

Disparities in reimbursement to radiologists and nonradiologists for 65 common outpatient imaging studies.

The authors examined global charges (incorporating both technical and professional components) and global reimbursement allowances for all radiographic and ultrasound (US) examinations performed on Pennsylvania Blue Shield subscribers in the Lehigh Valley area of Pennsylvania during 1990. Data for radiologists and nonradiologists were compared with respect to all procedure codes for which at least 25 claims were submitted, yielding a sample of 40,619 radiographic examinations (54 procedure codes) and 9,761 US examinations (11 procedure codes). Radiologists' mean charges were higher than those of nonradiologists for 38 of the 54 radiographic codes. However, nonradiologists received higher mean reimbursement allowances for 39 of the 54 codes. Among the 11 US codes, nonradiologists' mean charges were higher for 10 and they received higher mean reimbursement allowances for seven. The averages of the mean reimbursement allowances for individual codes were higher for nonradiologists in both the radiographic and US categories. Pennsylvania Blue Shield has begun steps to eliminate disparities in reimbursements to providers who submit claims for imaging examinations.

Ambulatory Care↗
PubMed1991

Successful percutaneous closure of a complex coronary-to-pulmonary artery fistula using a detachable balloon: benefits of intra-procedural physiologic and angiographic assessment.

A 48-yr-old woman presented with a loud continuous precordial murmur and symptoms of fatigue. Color-flow doppler imaging and nuclear magnetic resonance imaging failed to show the cause of the murmur. Diagnostic catheterization showed a large left anterior descending coronary artery to pulmonary artery fistula with impaired left ventricular wall motion. Two detachable balloons were deployed in the fistula with complete abolition of flow in the main fistula channel. A small parallel channel of the fistula, previously not appreciated due to vessel overlap, remained patent but had trivial flow as assessed by green-dye and oximetric techniques. The patient had immediate resolution of her symptoms and return of normal ventricular wall motion.

Angiography↗
PubMed1991

Radiation exposure to angiographers under different fluoroscopic imaging conditions.

Radiation levels near an imaging chain commonly used in angiography were measured with both a 100- and a 200-mm-thick scatter phantom. The scatter was measured in lines parallel in space to the central ray of the x-ray beam, at lateral distances of 300, 500, and 800 mm. The effects of fluoroscopic kilovoltage and image intensifier magnification mode were also measured. The results indicate that the highest scattered radiation levels occur near the surface of the patient where the x-ray beam enters. Exposure rates were measured in both anteroposterior (AP) and posteroanterior (PA) geometries on a U-arm system. In PA geometry, the highest radiation levels occur below the angiographer's waist, an area well protected by the lead apron. The AP geometry increases the exposure rate to the neck, head, and upper extremities, areas where apron shielding is less effective.

Angiography↗
PubMed1991

Evidence for reduced fibrinolytic activity in unstable angina at rest. Clinical, biochemical, and angiographic correlates.

BACKGROUND: The goal of this study was to evaluate the role of the fibrinolytic system in patients with unstable angina at rest associated with transient electrocardiographic changes. METHODS AND RESULTS: Tissue plasminogen activator activity in plasma was comparable among patients with unstable angina (n = 17), patients with stable exertional angina (n = 10), and control patients with normal coronary arteriograms (n = 8). In contrast, plasminogen activator inhibitor-1 (PAI-1) activity in plasma was elevated in the unstable angina group (21.67 +/- 9.52 AU/ml) as compared with either the stable angina group (12.01 +/- 7.06 AU/ml, p less than 0.02) or the controls (12.49 +/- 8.54 AU/ml, p less than 0.02). Coronary angiography performed within 24 hours after the last anginal episode showed a similar extent of coronary artery disease in the unstable and stable angina groups. However, intracoronary thrombi were observed in eight patients in the unstable angina group while no thrombus was noted in the stable angina group (chi 2 = 7.22, p less than 0.01). CONCLUSIONS: We conclude that patients with unstable angina at rest have a reduced fibrinolytic activity and an increased incidence of intracoronary thrombi. It is postulated that elevated PAI-1 activity in the presence of coronary arterial wall injury may be an important factor leading to the development of acute coronary syndromes.

Angina Pectoris↗
PubMed1991

Home care for respiratory problems.

This article reviews current recommendations for the home care of geriatric patients with chronic pulmonary disease. Special attention is given to new bronchodilators, indications for home oxygen and ventilator use, as well as the use of nasal CPAP in elderly sleep apnea patients. The necessity of do not resuscitate (DNR) orders is also discussed.

Aged↗
PubMed1991

Efficacy of thrombolysis in infrainguinal bypass grafts.

The initial outcome of a consecutive series of 43 intra-arterial urokinase infusions for thrombosed infrainguinal grafts in 37 patients was analyzed. There was an 88% (38/43) technical success rate (complete clot lysis) and a 74% (32/43) clinical success rate. Complications occurred in 10 patients (23%) and were related to bleeding in four patients (9%). Patient age, graft age, location, material, and the duration of occlusion did not significantly influence the initial outcome, although there was a trend toward a higher bleeding complication rate among grafts less than or equal to 1 month of age at the time of thrombolysis. A second group of 43 infrainguinal grafts successfully recanalized using regional infusions of thrombolytic agents were followed for long-term patency. This group included 32 grafts successfully treated with urokinase and 11 grafts recanalized with streptokinase. By life-table analysis there was a 55.6% 1-year patency, which fell to 42.4% at 4 years. Vein grafts had significantly (p = 0.01) better long-term patency than prosthetic grafts (69.3% versus 28.6% at 30 months). Grafts with flow-limiting lesions identified and corrected by angioplasty or surgery also had significantly (p = 0.01) better long-term patency than those without such lesions (79.0% versus 9.8% at 2 years). Based on the results of our study compared with a survey of long-term results following secondary surgical procedures for thrombosed infrainguinal grafts, thrombolysis can be recommended in several circumstances. Thrombolysis is indicated for thrombosed vein grafts or when thrombus is present in distal runoff vessels. Thrombosed prosthetic grafts should be replaced by autogenous vein grafts whenever possible.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1979

Left heart catheterization and angiography via the percutaneous femoral approach using an arterial sheath.

An arterial sheath with a proximal hemostasis valve and a side-arm extension tube was used in 562 consecutive patients undergoing cardiac catheterization and angiography via the femoral approach. Serious complications were rare. There was one death, one peripheral embolism, and one episode of delayed groin hemorrhage. The incidence of minor complications, including hematoma formation, in this series compares favorably with our own and the reported experience of others using the conventional percutaneous femoral approach. The sheath technique facilitated catheter exchanges and reduced patient discomfort. In addition, femoral artery pressure could be monitored via the side arm of the sheath during the catheterization. This proved helpful during retrograde catheterization of patients with aortic stenosis, as well as in detection of damping of coronary artery catheter tip pressure during coronary arteriography and hypotension following left ventriculography. Based upon this experience, use of an arterial sheath has become our standard practice when left heart catheterization is performed via the femoral approach, and the use of several different catheters is anticipated.

Aged↗
PubMed1979

Cinefluoroscopy in evaluating left ventricular contractility and aneurysms.

Cardiac cinefluoroscopy was performed immediately prior to biplane left ventriculography in 113 patients and the findings of two independent observers compared to the angiographically documented state of the left ventricle. The observers' interpretations were correct in 44% and 46% of studies, respectively; there were 41% and 24% false negatives and 24% and 29% false positives. The observers agreed in only 59% of cases. The results show that cinefluoroscopy for evaluation of left ventricular contractility is grossly inaccurate and should not be performed.

Cineradiography↗
PubMed1979

Suprarenal aortic occlusion.

Proximal propagation of an occlusive distal aortic thrombus to the suprarenal level is rare, probably resulting from diminished renal blood flow, and is invariably accompanied by renal failure. Three similar cases of total suprarenal aortic occlusion with renal failure are presented. In each, one kidney was significantly smaller than the other, probably caused by long-standing disease. The combination of bilaterally absent or markedly decreased femoral pulses with diminished renal function or a unilateral small kidney should therefore be considered dangerous. To prevent proximal propagation of thrombosis and death from renal failure, such patients should undergo arteriography and surgical repair promptly even though their clinical symptoms might be relatively mild and stable.

Acute Kidney Injury↗
PubMed1978

Augmented arterial flow and pressure resulting from selective injections through catheters: clinical implications.

Injection of fluid through catheters positioned selectively in arteries results in substantial increases in flow and pressure in those arteries for the duration of the injection. This produces certain artifacts which may lead to misinterpretation of the arteriograms. Apparent direction of flow in major vessels, extent of collateral circulation, distribution of contrast medium throughout various branches of the arterial tree, and density of accumulation of contrast material in organs or tumors can be altered significantly by the injection technique.

Angiography↗
PubMed1978

Experimental myocardial infarction in dogs with normal coronary arteries. Angiographic resolution of coronary arterial emboli.

Percutaneous transcatheter embolization of the coronary arteries with autologous clot was performed in six dogs. The occlusions resolved completely within 14 days in the four surviving dogs. Postmortem examination revealed transmural myocardial infarction in two dogs and subendocardial infarcts in the other two. Histological sections showed no residual emboli in three dogs and a recanalized thrombus in an epicardial vessel in the fourth. These findings indicate that myocardial infarction can be produced by multiple occlusions of the distal coronary arterial branches, provided that common or contiguous myocardium is affected. The recanalized thrombus in one dog suggests that the thrombolytic process need not be complete for return to a normal angiographic appearance.

Angiography↗