meglumine-ioxithalamate and Anaphylaxis

A rare case of anaphylaxis to iodinated contrast media is reported. The patient underwent two anaphylactic shocks to intravenous administration of radiocontrast agents. Specific IgE were suspected on the basis of positivity of intradermal tests and human basophil degranulation tests. The passive sensitization of basophils from donors was performed, comparing native and heated serum. Results agreed with the hypothesis of IgE antibodies, since heating 56 degrees C during two hours prevented the degranulation. Considering the chemical structure, iopamidol was thought to be innocuous. Two opacification procedures were further performed with iopamidol without any incident.

Topics: Aged; Anaphylaxis; Basophil Degranulation Test; Complement Activation; Contrast Media; Diatrizoate Meglumine; Drug Hypersensitivity; Heart Arrest; Humans; Immunoglobulin E; Intradermal Tests; Iothalamate Meglumine; Male; Molecular Structure; Preoperative Care

The occurrence of an anaphylactoid shock in a patient treated with beta-adrenergic blocking agents during a long time prior to surgery constitutes a high risk because beta-receptors are refractory to adrenergic substances and compensatory mechanisms are obtunded. The shock is characterized by severe hypotension and bradycardia, both resistant to adrenaline. These signs were observed in a patient treated with metoprolol for hypertension several months prior to surgery. The intravenous injection of an iodine containing contrast medium during general anaesthesia was followed by a lethal anaphylactoid shock resistant to adrenaline, atropine and isoprenaline. The treatment of the shock needs, besides adrenaline, massive vascular filling, high doses of beta-agonists and glucagon.

Topics: Adrenergic beta-Antagonists; Anaphylaxis; Anesthesia, General; Blood Pressure; Contrast Media; Humans; Hypertension; Iothalamate Meglumine; Male; Middle Aged