The iodine molecule is an effective x-ray absorber in the energy range where most clinical systems operate. Patients usually present with persistent burning and swelling at the injection site. Steroids and H1 blockers are the basic components of most premedication regimens for patients at high risk for an anaphylactoid reaction. These agents often are essential to providing accurate diagnoses, and are nearly always safe and effective when administered correctly. Blood volume replacement in acute anaphylactic cardiovascular collapse related to anesthesia.
Less-frequent manifestations are parotitis, joint pain, and depression. The items also include information about other side effects when using contrast media. Anxiety, apprehension, and fear may play a part in this type of reaction. Ann Int Med 1991;115 4 :270-276. N Engl J Med 2003; 349:1333-1340. Unlike anaphylactic reactions, the exact mechanism of the nonimmune-mediated anaphylactoid reaction is not well worked out, but is most likely histamine-mediated. Smaller extravasations may be managed with elevation and cold compresses.
Members of the Laboratory Standards Committee: Frederick A. Although minor allergies are common and do not appear to increase overall risk, a history of severe atopy, such as multiple allergies or a prior major anaphylactic response, should heighten concern before administration of contrast material. The higher the iodine concentration, the greater the risk of an adverse reaction. Low osmolarity nonionic contrast media has been evaluated in patients with prior contrast reactions. However, they may progress to life-threatening reactions, so patients should be treated and monitored until symptoms have resolved completely.
Simultaneous hemodialysis during coronary angiography fails to prevent radiocontrast-induced nephropathy in chronic renal failure. Ann Intern Med 1999; 130:461-470. If you have kidney disease or diabetes, you will need to have a recent kidney function test result before contrast is given, unless the test or procedure is an emergency. Acute renal failure after coronary intervention: incidence, risk factors, and relationship to mortality. But a history of allergy to food containing iodine, such as seafood, is of no predictive value, 12,13 and the same holds true for skin reactions to betadine.
Generally, these symptoms occur only for a short period of time and do not require treatment. Pathophysiology An anaphylactic reaction is an IgE-mediated hypersensitivity reaction requiring prior sensitization of the patient by a given antigen. Recurrent severe reaction to iodinated contrast media during cardiac catheterization. Niell et al used a didactic module to improve knowledge and comfort levels for physicians, nurses, and technologists; however, a considerable percentage of personnel still reported feeling uncomfortable treating an adverse reaction to a contrast agent, and the authors concluded that didactic instruction alone may be inadequate. Since certain radiographic procedures, such as myelography, cannot use ionic contrast media, the discovery of nonionic contrast media in 1974 e.
Patient Selection, Preparation, and Special Circumstances Before administering contrast media, one should assess the medical history for factors predisposing a patient to contrast reactions. Should I Obtain Serum Urea Nitrogen and Creatinine Values for Every Patient before I Inject Contrast Media? It is well established that these agents are safer than the older high-osmolar or ionic contrast media. Although in theory all of the iodine in contrast agents is organically bound rather than free, it is not clear that no free iodide is present or to what extent there is thyroid uptake in the fetus or newborn and what the effect on thyroid function might be. Nonionic monomers do not break up in solution; a single molecule delivers 3 iodine atoms ratio, 1:3 , whereas a single nonionic dimer delivers 6 iodine atoms ratio, 1:6. Areas of focus include screening and patient selection strategies, premedication, and treatment of adverse events, including those related to renal function.
These are rare in premedicated patients who are given injections of a low-osmolar contrast agent and usually develop in those already identified as being at high risk. Otherwise, it is only possible to determine that a person is at increased risk of a reaction to contrast media based on the risk factors outlined below. With clearer images, the radiologist can provide your doctor with a more accurate diagnosis of the symptom or condition, to assist in deciding what treatment will be most appropriate. Therefore, training to maintain familiarity with methods for evaluation and treatment of reactions and indications for and doses of medications used is crucial. It is, therefore, wise to avoid administering them in women who are pregnant particularly in the first trimester when possible.
With these minor reactions, only recognition may be required. In most cases, these adverse effects are delayed cutaneous reactions discussed later that may be severe but are not life threatening. Invest Radiol 1994;29 suppl 1 :S37—S45. Management of hypersensitivity reactions to iodinated contrast media. Iodinated contrast media is a contrast media containing iodine that is used in radiography to increase the clarity of the image.