Absence of Iodinated Contrast Hypersensitivity and Characterization of Gadolinium Utilization in an Interventional Pain Population.

Abstract

Iodinated contrast media (ICM) allergy labels pose a unique clinical problem for the interventional pain physician due to the drawbacks of gadolinium for enhancement during pain procedures, as well as the reluctance to add to the cumulative steroid burden with steroid premedication. However, the risks of ICM hypersensitivity specific to this setting have not been previously described. We aimed to describe the incidence of ICM-induced hypersensitivity during the performance of epidural injections in a large healthcare system. We also sought to characterize preexisting ICM allergy labels and how these affected consequent gadolinium utilizations in this population. 6,471 epidural pain procedures requiring contrast enhancement were performed during the 18-month study period. There were no reported contrast-induced hypersensitivity reactions in this time. 108 patients (1.6%) had a preexisting ICM allergy; a shellfish/seafood allergy was recorded in 118 patients (1.82%), and 51 charts (0.78%) were labeled with "iodine" allergy. 183 individuals received gadolinium for enhancement during epidural steroid injections. 96.7% of gadolinium utilization occurred in the context of preexisting allergy labels in the electronic medical record. Of note, 20 patients (18.5%) with ICM allergy labels also received iodinated contrast, and this was uneventful in all cases. Our results suggest that ICM-associated hypersensitivity is very rare during epidural procedures and the incidence is significantly lower than expected based on reaction rates during intravascular administration. This may be related to both dose as well as route of administration. The establishment of a protocol for safe workup of ICM allergy labels would be useful in optimizing pain procedures.