Addition of local anesthetics to contrast media. II. Increase of acute mortality in mice with intravenous contrast administration

The acute intravenous toxicity (i.v. LD50) of solutions of the ratio 1.5 contrast media metrizoate or diatrizoate and the ratio 3.0 contrast medium metrizamide was determined in mice with and without the addition of local anesthetics to the solutions. The two local anesthetics mepivacaine or lidocaine were added to final concentrations up to 2.0 mg/ml of the contrast medium solutions. This corresponds to clinically used concentrations. All additions of local anesthetics to the solutions increased the mortalities caused by the contrast medium solutions. Addition of local anesthetics to a final concentration of 2 mg/ml approximately doubled the acute intravenous toxicity of the contrast media. The ratio 3 contrast media produce less hypertonic solutions than the ratio 1.5 contrast media and should be preferred for angiography because they cause less pain and do not require the addition of local anesthetics which increase the acute toxicity of the solutions.     

Iopamidol and meglumine diatrizoate: comparison of effects on patient discomfort during aortofemoral arteriography

Iopamidol was compared with Renografin-60 (meglumine diatrizoate, Squibb) in a controlled, randomized double-blind study of 40 patients undergoing peripheral arteriography for arteriosclerotic occlusive disease to determine which agent caused less discomfort. Each patient was evaluated for objective signs of discomfort and subjective feelings of pain and heat. Monitoring was achieved by multiple physical examinations, chemical tests, electrocardiograms, and intra-arterial pressure recordings. It is concluded that iopamidol is safe and causes significantly less patient discomfort than Renografin-60.     

Sodium addition to nonionic contrast media. Effects on cardiac monophasic action potentials and hemodynamics in a dog model

In order to study the electrophysiologic and hemodynamic effects of sodium addition to low-osmolality contrast media during coronary arteriography, eight dogs with surgically opened thoraces were studied. Epicardial monophasic action potentials (MAP) were recorded from the contrast perfused area, using suction electrodes. Six milliliters of iohexol, iohexol with addition of 20 to 80 mmol/L Na+ and ioxaglate, were selectively administered into the left coronary artery. Only minor hemodynamic alterations occurred with the iohexol solutions, whereas ioxaglate decreased left ventricular (LV) inotropy and pressures initially. Iohexol and iohexol containing less than 40 mmol/L Na+ did not change MAP duration significantly. The addition of 80 mmol/L Na+ to iohexol lengthened MAP duration at 25%, 50%, and 90% repolarization by 14 +/- 2, 18 +/- 3, and 18 +/- 5 mseconds, respectively. Ioxaglate lengthened MAP duration by 14 +/- 3, 17 +/- 3, and 26 +/- 8 mseconds, respectively. Thus, during coronary arteriography in dogs, iohexol with sodium added, like ioxaglate, induced regional electrophysiologic changes in the contrast-perfused area of the myocardium, while sodium-free iohexol did not.     

Comparison of low-osmolar contrast media in cardiac angiography

Two hundred and twenty-five patients investigated by left ventricular, coronary artery and/or proximal aortic angiography were randomly assigned to one of three contrast medium groups (Hexabrix 320, Niopam 300 or Omnipaque 300). Subjective response to injection of contrast medium was noted at the time of investigation and during the next 24 h. No significant difference was found between the three currently available low-osmolar contrast media.     

Nephrotoxicity of ionic and non-ionic contrast media in aorto-femoral angiography

Nineteen patients examined with aorto-femoral angiography were randomized into two contrast medium groups (meglumine metrizoate and iohexol). Urine activity of beta-hexosaminidase, a specific renal enzyme, was determined before and on three occasions after angiography. No change of beta-hexosaminidase activity was found after angiography with iohexol, while there was a significant increase after examination with meglumine metrizoate. This indicates that meglumine metrizoate even following injection into the abdominal aorta damages renal cells which could not be shown with iohexol as contrast medium. We therefore recommend that at least patients with impaired renal function should be examined with the non-ionic contrast medium iohexol to minimize the danger of further damage to the kidneys and a possible renal failure.     

A survey of contrast media used in coronary angiography

In recent years, various contrast media have been developed for use in coronary angiography. These contrast media may be divided into ionic contrast media of high osmolality, those of low osmolality, and nonionic contrast materials. We conducted our own clinical studies with 40 patients. In random succession a standard contrast medium (ionic, of high osmolality) and a new-generation contrast medium (either nonionic or ionic with low osmolality) were injected into the right and left coronary arteries. After each injection we measured the systolic and diastolic blood pressure using a liquid-filled coronary catherter. In addition, the change in the length of the cardiac cycle was registered in terms of the R-R interval (in ms) and at the same time, leads I, II, and III of the ECG were recorded. We studied the influence of the various contrast media on the activity of ATPase in in vitro experiments, using Lasser and Lang's [30]. When ionic contrast media of low osmolality and nonionic contrast media were utilized the heart rate showed no change. Disturbances of rhythm such as ventricular tachycardia or fibrillation were not observed. All of the contrast media used produced the same ECG changes. These changes can be ascribed to the inhibition of ATPase. The arterial blood pressure was lowered significantly only by ionic contrast media of high osmolality only.     

Effects of contrast media on renal graft function and survival after cerebral angiography of cadaveric donors

The effects of intravascularly administered ionic contrast media on renal graft function and survival were retrospectively evaluated in 211 recipients of cadaveric renal transplants. The renal grafts were explanted from the donors within 24 hours (mean 16 hours) after cerebral angiography. There were no differences in renal function or graft survival between those exposed and those not exposed to contrast media before nephrectomy.     

Comparison of low-osmolar contrast media in paediatric cardiac angiography

Sixty-two children investigated by cardiac angiography for a wide spectrum of congenital heart disease were randomly assigned to one of two groups, one for iohexol, 350 mg I/ml (Omnipaque, Nycomed UK Ltd) and one for iopamidol, 370 mg I/ml (Niopam, E. Merck Ltd). Changes in systolic pressure, end-diastolic pressure when the injection was made into a ventricle, heart rate and rhythm and plasma osmolality were assessed at 1 min and 3 min after the injection of contrast medium. The angiograms were subjectively assessed for angiographic quality. No significant differences were detected between the two groups.     

High-concentration contrast media in MDCT angiography: principles and rationale

MD-CTA is a powerful and continuously evolving technology for noninvasive (minimally invasive) cardiovascular imaging. CM administration is an integral part of this evolution, and needs to be continuously adopted and optimized to take full advantage of this technology. A basic understanding of physiologic and pharmacokinetic principles, as well as an understanding of the effects of injection parameters on arterial enhancement—in terms of injection rate and injection duration—allow the development of optimized CM delivery protocols for current and future vascular MDCT.     

Early hemodynamic cardiovascular reactions to nonionic low-osmolar contrast media in coronary angiography

During the last 20 years there was an essential improvement in the tolerance of intravasal contrast media, leading to the nonionic low osmotic contrast media. In 26 consecutive patients with different stages of coronary heart disease the nonionic low osmolar contrast media iopamidol (Solutrast) and iopromide (Ultravist) were tested during coronary artery and left ventricular angiography. In both contrast media there were practically identically only slight early haemodynamic reactions with a decrease of heart rate, systolic pressure in the left ventricle, pressure in the aorta and an increase in pressure in the pulmonary artery and partly in cardiac output. These reactions are probably due to higher osmolality in comparison with blood. Therefore, further development of isotonic contrast media would be necessary.     

Gadolinium chelates in angiography and interventional radiology: a useful alternative to iodinated contrast media for angiography

Gadolinium has physical properties that are well suited for radiographic imaging. Digital subtraction angiography with a gadolinium chelate as contrast medium can provide images of suitable quality for diagnosis and intervention. The overall safety profile of gadolinium-based contrast media is excellent. In particular, these contrast media are well tolerated in patients with renal insufficiency when administered intraarterially in doses of less than 0.3-0.4 mmol per kilogram body weight, with a decreased incidence of contrast medium-induced nephropathy, as compared with similar volumes of iodinated contrast material. The currently available formulations of gadolinium chelates can be injected safely into every arterial and venous structure. However, substantial data are lacking on the intraarterial use of gadolinium in patients with renal insufficiency, particularly at doses that exceed those routinely used in magnetic resonance angiography. Gadolinium chelates in appropriate volumes are useful alternative contrast media in selected high-risk patients undergoing angiographic studies.     

The reaction of cerebral arteries to non-ionic contrast media during cerebral angiography

Summary The purpose of this study was to evaluate possible vasoconstrictive or vasocilatator effects of the low osmolar non-ionic contrast medium iohexol (Omnipaque) on the calibre of cerebral arteries. The diameters of respectively 5 and 6 different locations of the vertebral and carotid arteries were recorded from angiograms of 3 successive injections. The material consisted of 18 patients. It could not be shown that Omnipaque induced vasoconstriction or vasodilatation when normal doses and adequate technique was applied. The difference in diameters found were not statistically significant and are probably due to natural pulsations and to the difficulties in performing exact measurements.     

Study of isotonic contrast media in intravenous digital subtraction angiography

Arterial enhancement obtained with isotonic contrast media in intravenous digital subtraction angiography was studied. Ten dogs were injected with ioxaglate, iopamidol, and ioxitalamate at equal iodine concentration and at concentrations corresponding to plasma osmolality. Three variables were studied: osmolality, injection rate, and iodine dose. Provided their iodine concentration is sufficient, isotonic contrast media appear as efficient as the corresponding hypertonic formulation, at equal iodine dose. Moreover, the use of isotonic ioxaglate allows a lower dose of iodine to be administered without significant reduction in peak arterial value.