Systemic reactions to intravascular contrast media. A guide for the anesthesiologist.

Intravascular contrast media reactions are not uncommon. They occur frequently in relatively young and healthy patients, and are more likely to occur in patients with strong allergic, atopic, asthmatic, or cardiac histories. Five different types of reactions occur: Vasomotor, vasovagal, dermal, osmotic, and anaphylactoid. These different manifestations are seen both individually and in various combinations. The seriousness of a reaction depends not only on the extent of the reaction, but also upon the patient's cardiovascular status. Most severe reactions are idiosyncratic, and the history of reaction to contrast media always will not predict the current response to contrast media. ICM reactions occur commonly enough so that most anesthesiologists will at some time be asked to help prevent or treat them. Knowledge about their incidence, risk factors, mechanisms of pathogenesis, treatment, and prevention should decrease the morbidity and mortality of these unfortunate occurrences. Anesthesiologists should actively seek out radiologists to suggest the following: 1. Increased use of routine blood pressure and ECG monitoring 2. Routine visits by anesthesia staff to the radiology suite to review available drugs and equipment 3. Regularly scheduled cardiopulmonary resuscitation drills for new radiology personnel 4. Availability of emergency respiratory care equipment, oxygen, suction, atropine, diphenhydramine, and epinephrine in every radiology suite.