Prevention of generalized reactions to contrast media: a consensus report and guidelines

The aim of this study was to document, using consensus methodology, current practice for prevention of generalized reactions to contrast media. to ide ntify areas where there is disagreement or confusion and to draw up guideli nes for reducing the risk of generalized contrast media reactions based on the survey and a review of the literature. A document with 165 questions wa s mailed to 202 members of the European Society of Urogenital Radiology. Th e questions covered risk factors and prophylactic measures for generalized contrast media reactions. Sixty-eight members (34%) responded. The majority indicated that a history of moderate and severe reaction(s) to contrast me dia and asthma are important risk factors. The survey also indicated that p atients with risk factors should receive non-ionic contrast media. In patie nts at high risk of reaction, if the examination is deemed absolutely neces sary, a resuscitation team should be available at the time of the procedure . The majority (91%) used corticosteroid prophylaxis given at least 11 h be fore contrast medium to patients at increased risk of reaction. The frequen cy of the dosage varied from one to three times. Fifty-five percent also us e antihistamine Hl, mainly administered orally and once. Antihistamine H2 a nd ephedrine are rarely used. All essential drugs are available on the emer gency resuscitation trolley. Patients with risk factors are observed up to 30 min by 48% and up to 60 min by 43% of the responders. Prophylactic measu res are not taken before extravascular use of contrast media. Prophylactic drugs are given to patients with a history of moderate or severe generalize d reaction to contrast media. In patients with asthma, opinion is divided w ith only half of the responders giving prophylactic drugs. Aspirin, beta -b lockers, interleukin-2 and non-steroid anti-inflammatory drugs are not cons idered risk factors and therefore are not stopped before injection of contr ast media. The survey showed some variability in rating of risk factors for generalized contrast medium reactions, and marked variability in the proph ylactic measures used. There remain major areas of uncertainty, and there i s insufficient data in the literature to guide practice. Some simple guidel ines for prophylaxis of generalized contrast medium reactions are proposed.