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Biomedical subjects

H O Stolberg

Publications and source records attributed to H O Stolberg.

11 recordsLinked to original sources
PubMed1991

Intravascular contrast media. Ionic versus nonionic: current status.

The development of LOCM is one of the most important medical discoveries made at the end of this century. In developing nonionic compounds, Almén showed that it was possible to decrease the osmolality by a factor of 2 and also thereby reduce the chemotoxicity by as much as a factor of 20. Serious adverse side effects after the intravascular administration of contrast material are caused by a combination of osmotoxic and chemotoxic properties of an individual contrast media molecule as well as the ionic composition of the agent when in solution. Worldwide clinical experience with the use of LOCM, ionic and nonionic, consistently has shown the new material to be safer and more comfortable in clinical practice. Some form of limited use of LOCM is now part of virtually every radiologist's daily practice, and the focus is turning to the low-risk-no-risk group. There are gray areas between risk categories, with some evidence even suggesting that the 20- to 40-year-old age group may be at risk to the same or even a greater degree than other commonly accepted risk groups such as the elderly. The future promises even better and safer but, in all likelihood, expensive, contrast agents for intravascular use. The ultimate decision on choice of contrast or the fate of LOCM rests with public policy makers, organized medicine, and the individual physician and patient. Based on penetration of the marketplace (nearly 50%) in terms of LOCM sales in 1990, there is a growing awareness within our specialty as well as the public sector of the improvements offered by LOCM. It is unlikely that a major conversion back to the universal use of HOCM will ever occur. As long as cost remains the major focus of the debate over the choice, however, physicians need to be informed advocates, familiar with the science, yet sensitive to the economic implications of the decisions they make to best serve the interests of their patients.

Angiography↗
PubMed1989

Death following coronary angiography in a young woman with isolated left coronary ostial stenosis.

A 35-year-old woman with angina of five years duration underwent elective cardiac catheterization and coronary angiography which revealed left main stenosis. Immediately afterwards, the patient became distressed, hypotensive and bradycardic. She died despite emergency percutaneous transluminal coronary angioplasty and resuscitative efforts. Autopsy confirmed isolated left coronary ostial stenosis due to the combination of a congenital abnormality of the ostium and initial segment of left main coronary artery, together with a superimposed myointimal flap bridging the ostium. A unique association was an abnormal configuration of the ostia of the branches of the aortic arch.

Adult↗
PubMed1988

Protective effects of corticosteroids in contrast material anaphylaxis.

A prospective, randomized study of the potential protective effects of corticosteroids administered as pretreatment against contrast material (CM) reactions is reported. Patients (n = 6,763) from multiple institutions received either a single dose of steroids (32 mg of oral methylprednisolone, approximately 2 hours before CM challenge), a double dose (32 mg approximately 12 hours and 2 hours before CM challenge), or placebo. All contrast injections were with ionic media and were given intravenously. The two-dose (but not the one-dose) corticosteroid regimen provided significant protection. The effect on reaction incidences of a number of historical variables is also tabulated.

Anaphylaxis↗
PubMed1987

Pretreatment with corticosteroids to alleviate reactions to intravenous contrast material.

The x-ray contrast mediums used over the past three decades have been salts of iodinated acids administered in highly hypertonic concentrations. We conducted a multiinstitutional randomized study of the protective effects of pretreatment with corticosteroids against reactions to intravenous contrast material. We gave 6763 patients two doses of oral corticosteroids (methylprednisolone, 32 mg) approximately 12 hours and 2 hours before challenge with contrast material, one dose of oral prednisolone approximately 2 hours before challenge, or placebo in the same dosages. The two-dose corticosteroid regimen, but not the one-dose regimen, significantly reduced the incidence of reactions of all types (P less than 0.05) except a category of reactions dominated by hives, for which the reduction approached significance (P = 0.055). In recent years, several relatively expensive monomeric nonionic iodinated compounds having approximately half the osmolality of the corresponding ionic compounds and a lower reaction rate have become available. With our two-dose corticosteroid regimen, the incidence of reactions necessitating therapy in patients receiving the ionic medium approximated that reported in an unblinded nonrandomized study of patients receiving a newer intravenous nonionic medium without corticosteroid pretreatment. We conclude that the much less expensive ionic medium, if administered with corticosteroid pretreatment, may serve as a reasonable alternative to intravenous nonionic medium, without loss of safety.

Administration, Oral↗
PubMed1987

Intravenous digital subtraction angiography by peripheral injection.

We describe a technique for performing intravenous digital subtraction arteriography by peripheral injection and review our experience of 504 studies in 469 patients. The technique gave adequate opacification for anatomical definition of vessels in 93% of patients studied and was suitable for studies of the pulmonary arteries and left ventricle as well as the major systemic arteries. The chief causes of failure were impaired cardiac performance (2.4%) and poor patient cooperation (1.4%). Premature termination was caused by angina pectoris in 1.6% of our cases. These limitations apply also to central venous injection.

Adult↗
PubMed1985

Inability of caliper measurement to enhance observer agreement in the interpretation of coronary cineangiograms.

Important clinical decisions are made on the basis of the interpretation of the degree of stenosis in the coronary cineangiogram. Thus, minimization of observer variation (both intra and inter) is crucial. The purpose of this investigation was to determine if measurement of stenotic lesions by caliper (CM) as compared with the usual eyeball method (EM) would reduce observer variation. Five observers, using the AHA scoring system, estimated maximal luminal narrowing in 14 segments on 10 films providing 2 reports on each film by EM and 2 by CM, thus making observations on 2800 segments. This allowed analysis of intraobserver variation for each reporter for method EM and CM, and for interobserver variation by each method. Since chance agreement is an important component in an observational study, a correction for this was made using the Kappa statistic. The results revealed that the mean Kappa by EM was 0.71 compared to 0.63 by CM (1 being perfect agreement and 0 no agreement). Agreement was much greater in proximal rather than distal segments. Interobserver agreement was consistently higher by EM K = 0.62 than CM K = 0.53 (p = 0.0007). A delineation of the types of disagreement and their clinical significance are important considerations in the evaluation of observer variation. It is concluded that the use of a caliper does not enhance either intra or interobserver agreement.

Cineangiography↗
PubMed1978

Relief of coronary artery spasm by nitroglycerin: time-dependent variability in drug action.

The arteriographic distinction between a fixed atheromatous obstruction and localized vasospasm in the coronary artery is often decided by the response of the lesion to nitroglycerin. We studied the time course of nitroglycerin in four patients with coronary artery spasm as revealed by selective angiography. Following complete dissolution of a 0.6 mg tablet of nitroglycerin sublingually a slight increase in heart rate occurred as early as two minutes, variable changes in overall vessel diameter were observed within four minutes, but the localized spasm remained fixed. It was not until six minutes had elasped that reinjection showed disappearance of spasm and uniform patency of the vessel in all cases. These observations stress the importance of waiting an appropriate period of time (at least six minutes) following complete absorption of sublingual nitroglycerin before any conclusion can be rationally drawn regarding the nature of a stenotic lesion as seen angiographically.

Adult↗
PubMedDate not supplied

Ionic versus nonionic contrast use.

It has taken many years of research, development and intense scientific investigation to produce intravascular contrast media. Research on relations between chemical structure, animal toxicity, and water-solubility has produced a number of highly water-soluble, iodinated compounds for use in diagnostic radiology as intravascular contrast agents. The currently used intravascular agents may be classified into four groups according to their chemical structure: 1. Ionic monomers 2. Ionic monoacid dimers 3. Nonionic monomers 4. Nonionic dimers It is the objective of this publication to review the history and development of intravascular contrast media as well as their properties, general effects and clinical use. The four types of contrast media differ significantly in their chemical structure and physico-chemical properties, and these differences determine their osmotoxicity, chemotoxicity, and ion toxicity. We analyze the organ specific toxic effects of intravascular contrast media upon the central nervous system, the cardiovascular system, and the renal system. We also review the secondary effects, clinical manifestations, and the incidence of adverse events associated with different types of contrast. The choice of contrast media has become critical since the introduction of nonionic agents because their toxicological and pharmacological properties differ from those of the ionic agents. The application of basic concepts involved in the use of contrast media in excretory urography, computed tomography, angiography, and angiocardiography is discussed, and the advantages of the use of nonionic contrast agents are outlined. Economic and ethical issues are presented with emphasis upon strategies to reduce the risk associated with the injection of intravascular contrast and to curtail consumption according to rational principles of use.

Contrast Media↗