Descriptive analyses of the variables, comparisons of means, and proportions using Student's t and chisquare tests, and logistic regressions were conducted.
Patients who experienced adverse events and patients who did not were compared to evaluate differences in age, sex, dose of contrast agent (in grams of iodine), patient's status during study (i.e., inpatient vs outpatient vs emergency department patient), and time of study (i.e., month and season).
Adverse events were observed in 111 patients (14.4%) and were categorized as follows: urticaria (n = 87), facial or laryngeal edema (n = 7), bronchospasm (n = 6), severe nausea or vomiting (n = 3), or other (n = 8). 89% were rated mild, 9%, and 2%, including one fatality. Adverse events required treatment in 42%.
72 females, 39 males; age range, 24–80 years; mean age, 50.5 years experienced adverse events. Of these, 73% were outpatients, 10% were inpatients, and 17% were emergency department patients.
Analysis of the subgroup of patients with adverse events (40.8%) scanned after June, 2009, showed that the dose of iodine was 22.5–30 g in 85% and 46.25–55.5 g in 15%.
Despite immediate treatment, the patient experienced cardiac arrest soon after and died. 59% were treated with observation only and 41% with a specific treatment.
Diphenhydramine was administered to 71 patients, methylprednisone to five patients, and epinephrine to five patients.
Three patients were immediately transferred to the emergency department, and the code team was called for three patients. Information on treatment was not available for four patients.
No statistically significant relationship was found between the incidence of adverse events and patient age (p = 0.69), contrast agent dose (p = 0.41), or time of study (month [p = 0.9], season [p = 0.58]. However, a statistically significant relationship was present between the incidence of adverse events and the female sex (p < 0.001).
Also, outpatients were more likely to experience adverse events after iopromide administration than were inpatients and emergency department patients (p < 0.001).
The logistic regression analysis shows that the incidence of adverse events was 3.6 times higher (statistically significant) in females than males and 5.5 times higher in outpatients than others.
Colored contrast media (p < 0.001) had a statistically significant higher incidence of adverse events.
We noted that patient who received colored oral contrast media had higher incidence of mild type of contrast reaction, however the incidence of moderate to severe grade of contrast reactions were equal to those who received noncolored oral media.