Mild, moderate, and sometimes severe adverse reactions may occur associated with the procedure and/or the contrast media. Reactions known to occur with parenteral administration of iodinated ionic contrast media (see the listing below) are possible with a nonionic agent. Approximately 95 percent of adverse reactions accompanying the use of other water-soluble intravascularly administered contrast agents are mild to moderate in degree. However, severe and life-threatening reactions and fatalities, mostly of cardiovascular origin, have occurred.
Reported incidences of death from the administration of other iodinated contrast media range from 6.6 per 1 million (0.00066 percent) to 1 in 10,000 patients (0.01 percent). Most deaths occur during injection or 5 to 10 minutes later, the main feature being cardiac arrest with cardiovascular disease as the main aggravating factor. Isolated reports of hypotensive collapse and shock are found in the literature. The incidence of shock is estimated to be 1 out of 20,000 (0.005 percent) patients.
Nausea, vomiting, flushing, or a generalized feeling of warmth are the reactions seen most frequently with intravascular injection. Symptoms which may occur are chills, fever, sweating, headache, dizziness, pallor, weakness, severe retching and choking, wheezing, a rise or fall in blood pressure, facial or conjunctival petechiae, urticaria, pruritus, rash, and other eruptions, edema, cramps, tremors, itching, sneezing, lacrimation, etc. Antihistaminic agents may be of benefit; rarely such reactions may be severe enough to require discontinuation of dosage.
Although local tissue tolerance is usually good, there have been a few reports of a burning or stinging sensation or numbness and of venospasm or venous pain, and partial collapse of the injected vein. Neutropenia or thrombophlebitis may occur.
Severe reactions which may require emergency measures may take the form of a cardiovascular reaction characterized by peripheral vasodilatation with resultant hypotension and reflex tachycardia, dyspnea, agitation, confusion and cyanosis progressing to unconsciousness. Or, the histamine-liberating effect of these compounds may induce an allergic-like reaction which may range in severity from rhinitis or angioneurotic edema to laryngeal or bronchial spasm or anaphylactoid shock.
Temporary renal shutdown or other nephropathy may occur.
Adverse reactions may sometimes occur as a consequence of the procedure for which the contrast agent is used. Adverse reactions in excretion urography have included cardiac arrest, ventricular fibrillation, anaphylaxis with severe asthmatic reaction, and flushing due to generalized vasodilatation. Reactions following higher doses for nephrotomography are usually mild and transitory and do not appear to occur more frequently or severely than those induced by doses for excretion urography. Nausea, vomiting, flushing, or a generalized feeling of warmth are the reactions seen most frequently. In aortography, the risks of procedures include injury to the aorta and neighboring organs, pleural puncture, renal damage including infarction and acute tubular necrosis with oliguria and anuria, accidental selective filling of the right renal artery during the translumbar procedure in the presence of preexistent renal disease, retroperitoneal hemorrhage from the translumbar approach, spinal cord injury and pathology associated with syndrome of transverse myelitis, generalized petechiae, and death following hypotension, arrhythmia, and anaphylactoid reactions. Adverse reactions in pediatric angiocardiography have included arrhythmia and death. During peripheral arteriography, complications have occurred including hemorrhage from the puncture site, thrombosis of the vessel, and brachial plexus palsy following axillary artery injections. During selective coronary arteriography and selective coronary arteriography combined with left ventriculography, most patients will have transient ECG changes. Transient arrhythmias may occur infrequently. Ventricular fibrillation may result from manipulation of the catheter during the procedure or administration of the medium. Other reactions may include hypotension, chest pain, and myocardial infarction. Transient elevation of CPK (creatine phosphokinase) has occurred in approximately 30 percent of the patients tested. Fatalities have been reported. Complications due to the procedure include hemorrhage, thrombosis, pseudoaneurysms at the puncture site, and dislodgment of arteriosclerotic plaques. Dissection of the coronary vessels and transient sinus arrest have occurred rarely.
Adverse reactions in selective renal arteriography include nausea, vomiting, hypotension and hypertension. Post-arteriographic changes in laboratory studies include transient elevations in BUN, serum creatinine and glucose.
Complications due to the procedure during selective visceral arteriography include hematomas, thrombosis, pseudoaneurysms at injection site, and dislodgment of arteriosclerotic plaques. Other reactions may include urticaria, hypotension, hypertension, and insignificant changes in renal function and liver chemistry tests.