Endocrine Abstracts

Thyroid storm requires a multiple-step pharmacological approach. While there is limited evidence for it, plasmapheresis has been shown to be an effective treatment when patients fail conventional therapy and other comorbidities complicate the clinical course. A 65-year-old woman presented with 6 months of symptoms of thyrotoxicosis and dyspnea, treated initially as an outpatient for pneumonia with no improvement. Eventually requiring admission for her dyspnea, laboratory testing revealed a suppressed TSH of <0.01 mIU/L and FT4 of 36 (12–22 pmol/L) and a chest x-ray consistent with interstitial edema. The patient was started on propylthiouracil, lugol’s solution, hydrocortisone, cholestyramine and propranolol, however continued to have cardiac and neuropsychiatric symptoms. Further work-up for her hyperthyroid disease revealed anti-thyroid receptor antibodies consistent with Graves’ disease. Interesting to this case, a transthoracic and transesophageal echocardiograms performed to evaluate for her heart failure, that was initially felt to be secondary to her thyroid storm, revealed the presence of severe aortic stenosis with a bicuspid aortic valve and 3+ mitral regurgitation. Cardiac surgery evaluation recommended in-house dual valve replacement surgery as valvular disease was predicted to not entirely improve with current treatment of her thyrotoxicosis. Given the need for urgent in-house dual valve replacement, and her persisting symptoms despite being on adequate treatment for 6 days and, the patient was started on therapeutic plasma exchange (TPE). She underwent three rounds of TPE which improved both her clinical and biochemical markers. Her FT4 decreased from 36 to 19 pmol/L. Furthermore, in preparation for her cardiac surgery, the patient underwent definitive treatment of her hyperthyroid state with a complete thyroidectomy after completing the TPE treatments. She was started on levothyroxine post thyroidectomy. Repeat TEE post thyroidectomy showed significant improvement in the severity of mitral regurgitation and was likely secondary to her thyrotoxic state; however, there was persisting severe aortic stenosis. The decision was made to proceed with single valve replacement and, on day 29, the patient underwent open aortic valve replacement surgery without any complications. While the medical treatment of thyroid storm is well established, patients may not have the appropriate response in first 24–48 hours. In cases where medical management fails and/or patients require urgent surgical intervention, as discussed above, therapeutic plasma exchange can be used to achieve both clinical and biochemical improvement from their thyrotoxic state.