Risk factors and clinical characteristics associated with post-radioactive iodine thyroid storm

The occurrence of post-radioactive iodine thyroid storm among patients with hyperthyroidism is relatively rare and only a few cases have been reported. We conducted a literature review of cases reported from 1951 to 2023 and determined the risk factors and clinical characteristics of patients who developed thyroid storm. A total of 19 cases were documented and reviewed. The mean age was 51.2 ± 20.1 years (range 7.5 to 75). Approximately two-thirds were females. Major etiologies were diffuse toxic goiter (57.9%) and nodular disease (36.8%). Mean dose was 11.3 ± 7.7 mCi (range 3.3 to 35), with 52.6% receiving less than 10 mCi. Mean interval time from administration to development of thyroid storm was 6.6 ± 5.5 days (range 0.5 to 20). The most common preexisting conditions were weight loss, heart failure, atrial fibrillation, hypertension and coronary artery disease. Thyroxine levels were not routinely measured prior to and during storm. Among those with available data, only 26.3% had hormone levels prior to and during storm. Thyroxine levels during storm (range 19.8 to 65 µg/dL) were higher than levels prior to storm (range 9.6 to 45 µg/dL). Pretreatment regimens varied consisting of no intervention, beta blockers, steroids, reserpine, phenobarbital and anti-thyroid drugs. Treatment regimens are more uniform and consistent with American Thyroid Association recommendations. The mortality rate remains high at ~ 26.3%. Statistical analyses did not show any significant differences. Even though the frequency of this condition is quite rare, it is an important and potentially prognostic condition underscoring the value of this review. The inclusion of this severe adverse effect should be part of patient discussion with emphasis on the need to seek early consultation when severe symptoms appear.