Acetylcysteine protects against acute renal damage in patients with abnormal renal function undergoing a coronary procedure.
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OBJECTIVES: We sought to evaluate the efficacy of the antioxidant acetylcysteine in limiting the nephrotoxicity after coronary procedures. BACKGROUND: The increasingly frequent use of contrast-enhanced imaging for diagnosis or intervention in patients with coronary artery disease has generated concern about the avoidance of contrast-induced nephrotoxicity (CIN). Reactive oxygen species have been shown to cause CIN. METHODS: We prospectively studied 121 patients with chronic renal insufficiency (mean [+/-SD] serum creatinine concentration 2.8 +/- 0.8 mg/dl) who underwent a coronary procedure. Patients were randomly assigned to receive either acetylcysteine (400 mg orally twice daily) and 0.45% saline intravenously, before and after injection of the contrast agent, or placebo and 0.45% saline. Serum creatinine and blood urea nitrogen were measured before, 48 h and 7 days after the coronary procedure. RESULTS: Seventeen (14%) of the 121 patients had an increase in their serum creatinine concentration of at least 0.5 mg/dl at 48 h after administration of the contrast agent: 2 (3.3%) of the 60 patients in the acetylcysteine group and 15 (24.6%) of the 61 patients in the control group (p < 0.001). In the acetylcysteine group, the mean serum creatinine concentration decreased significantly from 2.8 +/- 0.8 to 2.5 +/- 1.0 mg/dl (p < 0.01) at 48 h after injection of the contrast medium, whereas in the control group, the mean serum creatinine concentration increased significantly from 2.8 +/- 0.8 to 3.1 +/- 1.0 mg/dl (p < 0.01). CONCLUSIONS: Prophylactic oral administration of the antioxidant acetylcysteine, along with hydration, reduces the acute renal damage induced by a contrast agent in patients with chronic renal insufficiency undergoing a coronary procedure. (+info)
Intrathecal injection of contrast medium to prevent polymethylmethacrylate leakage during percutaneous vertebroplasty.
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The major technical drawback of percutaneous vertebroplasty is the potential for neural compromise from leakage of polymethylmethaorylate into epidural or perivertebral veins. We have combined the procedure of intrathecal injection of contrast medium with vertebroplasty to better delineate spinal canal encroachment during injection when the posterior vertebral wall is compromised by myeloma. (+info)
Myocardial washout of sonicated iopamidol reflects coronary blood flow in the absence of autoregulation.
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OBJECTIVES: The aim of the study was to evaluate the relation between measurements derived from myocardial contrast echocardiography and coronary blood flow. BACKGROUND: Contrast echocardiography has the potential for measuring blood flow. METHODS: In six open chest anesthetized dogs, the left circumflex coronary artery was cannulated and perfused with blood drawn from the left femoral artery. While adenosine was infused into the circuit, circumflex flow was generated by a calibrated roller pump to the point of abolishing coronary autoregulation. At each of 25 levels of coronary blood flow, paired bolus injections of sonicated iopamidol were performed proximal to a mixing chamber. The perfused area of the left circumflex coronary artery was labeled by radioactive microspheres injected into the perfusion line. Two-dimensional echocardiographic images of the left ventricular short axis were digitized off-line, and myocardial videodensity was measured in the area perfused by the left circumflex coronary artery to generate time-intensity curves. RESULTS: The washout slope of curves showed a good correlation with coronary blood flow, ranging from 0.5 to 12.5 ml/min per g of tissue. This correlation was good both in individual dogs (correlation coefficient [r] ranging from 0.78 to 0.96) and in the group of animals as a whole (r = 0.85). Washout slope also showed a good correlation with coronary diastolic pressure (r = 0.80), which ranged from 23 to 114 mm Hg, suggesting a possible primary effect of pressure on contrast washout. However, coronary blood flow appeared to be a stronger predictor of washout slope (partial F = 26.5, p < 0.001) than did perfusion pressure (partial F = 5.9, p < 0.05 by multiple regression). The injection to injection variability in myocardial washout slope appeared to be high (24%). The gamma variate fitting of curves did not improve the correlation with coronary flow (r = 0.78). CONCLUSIONS: Myocardial washout of sonicated iopamidol reflects coronary blood flow in a model in which coronary autoregulation is abolished. (+info)
The effect of fibrin structure on fibrinolysis.
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Fibrin structure contributes to the regulation of the fibrinolytic rate. As the fibrin fiber size is decreased, the fibrinolytic rate also decreases. Fibrin structure was altered by either changing the ratio of thrombin to fibrinogen, i.e. altering the assembly rate or by adding a fibrin assembly inhibitor, iopamidol. Changes in the fibrinolytic rate were followed by measuring the time dependence of the decrease in the fiber mass/length ratio during fibrinolysis. A measure of the overall fibrinolytic rate was determined from the decrease in the mass/length ratio versus time. An 8-fold reduction in the fibrinolytic rate was seen on decreasing the mass/length ratio from 2.7 x 10(12) daltons/cm to 0.5 x 10(12) daltons/cm. It is shown that thin fibrin fibers have a decreased rate of conversion of plasminogen to plasmin by tissue plasminogen activator and that thin fibrin fibers are lysed more slowly than thick fibrin fibers. (+info)
Status epilepticus and seizures induced by iopamidol myelography.
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PURPOSE: To report that iopamidol myelography can induce status epilepticus (SE) in patients carrying the diagnosis of symptomatic epilepsy and to estimate the incidence of seizures in patients undergoing iopamidol myelography. METHODS: We retrospectively identified all patients with seizures/SE associated with 1350 iopamidol myelographies during the last 5 years at our institution. The impact of cervical versus lumbar myelography was analysed. RESULTS: Induced by iopamidol myelography two non-epileptic patients suffered from first generalised tonic-clonic seizures and a 67-year-old women with symptomatic epilepsy after a remote ischemic stroke developed a generalised tonic-clonic seizure evolving into a dialeptic and right nystagmus SE (i.e. complex focal status) of 5-hour duration. The incidence of seizures in non-epileptic patients was 0.15%. The incidence of seizure induction for lumbar myelography was lower than for myelographies that included the cervical subarachnoid space. CONCLUSIONS: Iopamidol myelography (especially if cervical) is associated with a risk of seizures in non-epileptic individuals and can induce SE in patients with epilepsy. Patients should be informed about the risk of seizure induction. (+info)
Role of vasa vasorum in transendothelial solute transport in the coronary vessel wall: a study with cryostatic micro-CT.
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Using cryostatic microscopic computed tomography (micro-CT), we sought to determine the role of coronary vasa vasorum (VV) in transendothelial solute transport in arteries with normal and increased permeability due to high plasma cholesterol levels. In 6-mo-old pigs on a normal (n=23) and 2% high cholesterol (HC) diet (n=8), 2-cm segments of the proximal left anterior descending coronary arteries were removed in vivo after a selective injection of X-ray contrast solution. Harvesting of the specimens occurred at 0, 15, 25, 35, or 45 s after completion of the contrast injection. Specimens were snap frozen and scanned in our cryostatic micro-CT. The spatial distribution of contrast in the coronary artery wall was quantified using the CT images. Right coronary arteries were infused with Microfil to determine VV density (VV/mm2) and the cumulative lumen surface area (mm2/mm3). Transendothelial diffusion of contrast into the coronary vessel wall is a dynamic process starting at both the subintima and the adventitia. The subintimal opacification moves as a wave toward the adventitia, whereas the adventitial wave resolves. The coronary vessel wall in animals on a HC diet shows higher opacification than in normal coronary arteries without an increase of VV total luminal surface area. The loss of endothelial integrity in hypercholesterolemia significantly alters VV solute washin to, and washout from, the coronary artery wall. (+info)
Interaction between iopamidol and gadopentetate dimeglumine: an in-vitro experimental study of direct mixing.
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OBJECTIVE: To determine whether or not there is any interaction between iopamidol and gadopentetate dimeglumine (Gd-DTPA) in test tubes using the direct mixing manner. MATERIALS AND METHODS: The test solution was prepared by mixing iopamidol (Iopamiron 300) and Gd-DTPA (Magnevist) at a ratio of 1:1. The color, viscosity, and pH of the mixed solutions were assessed immediately after mixing and 1,3,6, and 24 hours after mixing. The concentration of aromatic primary amines, content of iopamidol, concentration of free iodine ion, and content of Gd-DTPA in the mixed solution were determined, and the presence or absence of spots, other than those resulting from iopamidol and Gd-DTPA, was determined using thin layer chromatography. These tests were carried out immediately, and 24 hours after mixing. Using iopamidol alone and Gd-DTPA alone as controls, the same items were examined. RESULTS: There was no significant change in the appearance or pH of the mixed iopamidol and Gd-DTPA solution immediately and 1, 3, 6, and 24 hours after direct mixing. The study of iopamidol alone or Gd-DTPA alone showed no apparently abnormal values or findings. CONCLUSION: The direct mixing of iopamidol and Gd-DTPA in a test tube results in no significant interaction. (+info)
Gadopentetate dimeglumine as a potential alternative contrast medium during percutaneous coronary intervention: a case report.
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BACKGROUND: There have not been previous reports of patients undergoing percutaneous coronary intervention (PCI) using a gadolinium chelate. METHODS AND RESULTS: A 74-year-old woman, who had a history of anaphylactic shock 4 times in response to iodinated contrast media despite preprocedural intravenous administration of hydrocortisone, was hospitalized because of unstable angina refractory to intensive medical treatment. Fully considering the risks of iodinated agents, digital subtraction coronary angiography and PCI were performed using gadopentetate dimeglumine without any side effects or complications. CONCLUSIONS: Gadolinium chelates can be an alternative contrast media during PCI in particular patients with contraindications to iodinated media. (+info)