Evaluation of adverse reactions to contrast media in the hospital

Objective:

To determine and analyse the characteristics of contrast media adverse reactions (CM-ARs) reported in a hospital.

Methods:

A retrospective review of CM-ARs from the electronic spontaneous adverse drug reaction (ADR) report system between January 2011 and August 2012 was conducted. CM-ARs were evaluated in terms of causality, severity, preventability and affected organs. Also, agreement and correlation among the tools used to evaluate CM-ARs were analysed.

Results:

The overall reaction rate was 1.5% (n = 286). In total, 269 CM-ARs were identified. For ADR causality, 96.7% (n = 260) and 98.5% (n = 265) were evaluated as “probable” ADR using the Naranjo probability scale and the World Health Organization–Uppsala Monitoring Centre causality categories, whereas 98.1% (n = 264) were evaluated as “certain” with Korean algorithm v. II. Of these, 91.4% (n = 246) were mild in severity and 96.7% (n = 260) were unpreventable. Most patients (n = 233, 86.7%) could be managed with observation and/or simple treatment. The most frequent reaction (n = 383, 79.5%) was dermatological. Spearman''s correlation coefficient was 0.667 (p < 0.01), and the agreement was 98.1% between the Naranjo scale and the World Health Organization–Uppsala Monitoring Centre categories. No relationship was seen between CM-AR severity and gender or between in- and outpatients.

Conclusion:

In our study, most CM-ARs were mild and managed with simple treatment. However, as the number of patients undergoing CT procedures continues to increase, it is essential to identify and observe patients at risk for CM-ARs to prevent severe ADRs.

Advances in knowledge:

Continuous careful review of reporting and treatment protocols of CM-ARs is needed to prevent morbidity and mortality.Contrast media (CM) are intravascular pharmaceuticals that are used in approximately 75 million procedures annually and are among the most common pharmacological agents injected into the human body.¹ As the number of patients undergoing CT or MRI increases,² more patients are affected by CM-related adverse events (AEs).CM adverse reactions (CM-ARs) range from a mild inconvenience, such as itching associated with urticaria, to a potentially life-threatening emergency. Although low-osmolarity non-ionic CMs have been used to reduce such side effects since the mid-1970s, ARs to them have also been reported.^3–6Most CM-ARs are mild events that usually require only observation and supportive measures,^7,8 but sometimes severe and life-threatening ARs continue to occur unpredictably. Mortality was estimated at one death per 100 000 examinations on the basis of findings from 1991.⁹ Not only patient complications but also the cost of treating CM-related ARs, in total, are considerable.¹⁰ Although CM-ARs cannot always be predicted, studies have shown that certain patients are at greater risk. To decrease and prevent CM-ARs, there are several guidelines to prevent AEs, and they are partially successful.^11–13 For example, the American College of Radiology (ACR), Reston, VA, recommends that patients with a known history of CM-ARs be pre-medicated with corticosteroids and antihistamines before receiving CM.¹³Because patient safety should be the top priority, a spontaneous or automatic adverse drug reaction (ADR) reporting system would seem to be a useful tool. The introduction of regional pharmacovigilance centres in Republic of Korea and computerized surveillance systems have promoted the monitoring of ADRs; indeed, the number of ADRs reported is increasing rapidly. The purpose of this study was to determine and evaluate the CM-ARs reported from the spontaneous ADR reporting system of a single hospital in terms of type, severity, causality and preventability of CM-ARs.