Development of a life-threatening anaphylactoid reaction following administration of ioversol in a child

Enhancing Pediatric Safety: Using Simulation to Assess Radiology Resident Preparedness for Anaphylaxis from Intravenous Contrast Media

PURPOSE

To prospectively develop and test a simulation model for assessing radiology resident preparedness for pediatric life-threatening events in the radiology environment.

MATERIALS AND METHODS

This study was institutional review board approved. Nineteen radiology residents (10 men, nine women; mean age, 28.5 years) participated in two simulated contrast material reaction scenarios: one with and one without resuscitation aids available. Each resident examined and managed two mannequins-simulating a 1-2-year-old patient and an 8-9-year-old patient-for type, sequence, dose, and administration route for any intervention, including administering medication, calling a code team, and providing oxygen. The time to order each intervention was documented. Resident responses (time to order intervention, appropriateness of intervention, and intervention route) were evaluated. The paired t test was used to compare the time to intervention between the resuscitation-aid-available and resuscitation-aid-not-available scenarios and between the scenario performed first and the scenario performed second. The McNemar test was performed to compare the percentage of appropriate interventions between the two resuscitation aid scenarios.

RESULTS

The average time to call the code team was shorter when no resuscitation aids were available than when resuscitation aids were available (98 vs 149 seconds, P=.08). The average times to request oxygen and epinephrine were shorter when resuscitation aids were available (40 vs 89 seconds to request oxygen, P=.016; 121 vs 163 seconds to request epinephrine, P=.21). Appropriate medication dosing was not significantly different between the two scenarios. In only five of the 38 simulated scenarios was calling the code team the first intervention. The correct sequence of interventions (calling code team, providing oxygen, and then providing epinephrine) was performed by only one resident in one scenario. Only five residents recognized that they were encountering a contrast material reaction.

CONCLUSION

Simulation training for radiology residents is valuable and suggests that resident preparedness for pediatric anaphylaxis from intravenous contrast media is insufficient. Clear step-by-step resuscitation aids are needed in the radiology environment.

Drug-induced anaphylaxis : case/non-case study based on an italian pharmacovigilance database

OBJECTIVE

To identify the number of cases of anaphylaxis reported in association with different classes of drugs and compare it with other reports contained in the same database.

METHODS

The data were obtained from a database containing all of the spontaneous reports of adverse drug reactions (ADRs) coming from the Italian regions of Emilia Romagna, Lombardy and the Veneto, which are the main contributors to the Italian spontaneous surveillance system. The ADRs reported between January 1990 and December 2003 with a causality assessment of certainly, probably or possibly drug related (according to the WHO criteria) were analysed using a case/non-case design. The cases were defined as the reactions already coded by the WHO preferred terms of 'anaphylactic shock' or 'anaphylactoid reaction' (this last term also included anaphylactic reaction) and those with a time of event onset that suggested an allergic reaction and involved at least two of the skin, respiratory, gastrointestinal, CNS or cardiovascular systems; the non-cases were all of the other ADR reports. The frequency of the association between anaphylaxis and the suspected drug in comparison with the frequency of anaphylaxis associated to all of the other drugs was calculated using the ADR reporting odds ratio (ROR) as a measure of disproportionality.

RESULTS

Our database contained 744 cases (including 307 cases of anaphylactic shock with 10 deaths) and 27 512 non-cases. The percentage of anaphylaxis cases reported in inpatients was higher than that among outpatients (59.1% vs 40.9%). This distribution is significantly different from that of the other ADR reports that mainly refer to outpatients. After intravenous drug administrations, anaphylactic shock cases were more frequent than anaphylactoid reactions or other ADRs, but more than one-third of these reactions were caused by an oral drug. Blood substitutes and radiology contrast agents had the highest RORs. Among the systemic antibacterial agents, anaphylaxis was disproportionally reported more often for penicillins, quinolones, cephalosporins and glycopeptides, but diclofenac was the only NSAID with a significant ROR. As a category, vaccines had a significantly lower ROR, thus indicating that anaphylaxis is reported proportionally less than other ADRs.

CONCLUSIONS

Anaphylaxis is a severe ADR that may also occur with commonly used drugs. It represents 2.7% of all of the ADRs reported in an Italian spontaneous reporting database.

« Allergie à l’iode » : le point sur la question

OBJECTIVE

The aim of this literature review is to suggest a diagnostic and a preventive attitude in patients having presented an immediate hypersensitivity reaction due to an iodinated drug.

DATA SOURCES

Literature review. Data were searched in the Medline database from 1967 to 2004 in English and French language. Complementary references were selected from the bibliography of selected references or from authors' personal databases. The following key-words were used separately or combined: Hypersensitivity, Immediate; Allergy; Contrast Media; Povidone-Iodine; Iodine; Iodine Compounds; Iodides; Amiodarone; Seafood, Parvalbumins; Tropomyosin.

STUDY SELECTION

Randomized studies, epidemiological studies, original articles, clinical cases, and letters to the editor were selected.

DATA SYNTHESIS

The implication of iodine has never been demonstrated during allergic hypersensitivity reactions due to iodinated drugs. However, IgE-mediated allergic hypersensitivity reactions have been published with contrast media or iodinated antiseptics and will be described in this development. In a wider sense, allergic hypersensitivity reactions due to seafood are evoked because often improperly considered as a risk factor of allergic reaction to iodinated drugs. The allergenic determinant responsible of patient sensitization is not known for iodinated contrast media, but is probably due to povidone in case of iodine povidone. In fish, the allergen is described as the protein M. There has also been strong immunological evidence that tropomyosin is a cross-reactive allergen among crustaceans and molluscs (shellfishs). In case of hypersensitivity reaction occurring with iodinated drug, an allergological assessment is required to confirm the immune mechanism, to identify the culprit drug or substance and to identify cross-reactivity especially with iodinated contrast media.

CONCLUSION

Asking a patient if he/she is "allergic to iodine" is a question that should be avoided because its significance is null. A diagnosis of drug allergy, essentially relying on clinical symptoms, biological tests and cutaneous tests, is required to take adequate preventive measures.

[Anaphylactoid reactions and late skin reactions to iodinated contrast media: present state of the question--idea development]

PURPOSE

Adverse reactions to iodinated contrast media (ICM) share various mechanisms. Anaphylactoid reactions are among the most serious reactions when they are characterized by the elevation of seric tryptase. Pretreatment with corticosteroids and anti-H1 or the use of non-ionic contrast media do not prevent anaphylaxis. Late skin reactions could be mostly related to delayed hypersensitivity. Previous reactions to contrast media, cardiovascular disorders, beta-blockers, asthma, and atopy are risk factors. Female gender and age increase the severity.

CURRENT KNOWLEDGE AND KEY POINTS

Anaphylaxis can be demonstrated by intradermal tests and the identification of specific IgEs. Delayed hypersensitivity is shown by the results of epicutaneous tests and the immunohistology of the skin.

FUTURE PROSPECTS AND PROJECTS

Allergologic tests are advised in the case of previous reactions. In case of emergency, gadopentetate dimeglumine can be alternatively used. The other risk factors lead to the combination of pretreatment and use of non-ionic monomeric contrast media. Immediate hypersensitivity to iodinated media might increase in the near future with the use of divalent molecules.