8630 Cardiorespiratory Failure in Thyroid Storm After C-section in a Patient with Untreated Hyperthyroidism

Abstract Disclosure: I.C. Arroyo: None. M. Ramirez: None. M. Alvarado: None. L.R. Sepulveda-Garcia: None. L. El Musa Penna: None. W. Medina-Torres: None. Z. Maisonet -Feliciano: None. J. Segarra-Villafane: None. Unrecognized hyperthyroidism during pregnancy increases the risk of maternal and fetal complications, including miscarriage, pre-eclampsia, maternal congestive heart failure, and intrauterine growth restriction (IUGR). Thyroid storm is a rare but life-threatening complication that can occur as well. Furthermore, it can present with cardiopulmonary failure which increases risk of death. Recognizing it early and providing intensive and ongoing therapy is imperative for a positive outcome.We report a case of a 29-year-old female G4P2A0 with triplet pregnancy who developed thyroid storm after an emergency C-section at 27 weeks of gestation due to sinus tachycardia and IUGR in one of the fetuses.Past medical history was remarkable for hyperthyroidism diagnosed on first pregnancy that did not require treatment.Upon questioning, she referred unintentional weight loss, palpitations, tremors, and heat intolerance in the past months.Physical examination showed sinus tachycardia, fine hand tremors, non-tender goiter, and thin/brittle hair.One day after C-section thyroid function tests (TFT) were remarkable for suppressed TSH <0.008uIU/mL, FT4 at 4.30 (0.89-1.76ng/dL) and positive thyroid stimulating antibodies. Burch-Warsofsky Point Scale (BWPS) for Thyrotoxicosis of 20 points didn’t indicate current or impending thyroid storm. Methimazole and propranolol were started. Two days after C- section patient developed worsening FT4 at 5.63ng/dl, worsening sinus tachycardia, increased temperature and respiratory failure requiring mechanical intubation. 2 D echocardiogram showed right ventricular overload with pulmonary hypertension, while CT angiogram of thorax suggested thyrotoxic cardiomyopathy. BWPS was now at 45 points compatible with thyroid storm (positive criteria for temperature of 38.4, heart rate of 117 bmp and heart failure). At this time methimazole was switched to propylthiouracil (PTU), propranolol was adjusted, and hydrocortisone, in addition to cholestyramine, were started. After these changes in therapy, TFTs improved markedly and a stable clinical state was achieved, with successful extubation.Untreated hyperthyroidism during pregnancy and post-partum period poses significant risks, including thyroid storm. Our patient had a C-section with worsening TFTs despite methimazole therapy, developing thyroid storm with cardiopulmonary failure. Cardiopulmonary failure is a rare, but deadly presentation of thyroid storm. In this case C-section was identified as a stressor for thyroid storm and cardiorespiratory failure as a complication. Prompt recognition and aggressive treatment of this potentially lethal condition is warranted to improve survival in thyrotoxic cardiomyopathy. Presentation: 6/1/2024