SAT-499 Myxedema Coma Presenting as Large Pericardial Effusion with Cardiac Tamponade

Background Myxedema coma is a life-threatening decompensated form of hypothyroidism. Current treatment recommendation is intravenous levothyroxine. However, in areas where parenteral form of levothyroxine is unavailable, levothyroxine tablet is the only option. Clinical Case A 48-year old male known to have chronic glomerulonephritis and hypertension, came in due to lacerated scalp wound sustained after falling asleep. Pertinent laboratory exams showed mild anemia, hemoglobin 10.6 g/dL (reference range 13–17) and hyponatremia 128mmol/L (reference range 136–145). His estimated creatinine clearance was 60mL/min. Cranial CT scan showed no signs of acute hemorrhage or fracture. There was scalp swelling and laceration with subgaleal hematoma over the frontal region. Electrocardiogram showed low voltage complexes. Chest radiograph showed an enlarged cardiac silhouette suggesting pericardial effusion. Transthoracic echocardiography was requested revealing a massive pericardial effusion with tamponade physiology. Patient underwent emergency pericardial window with pericardiostomy tube placement, debridement and suturing of scalp laceration under general anesthesia. He was able to tolerate the procedure well but noted to have decreased sensorium post-operatively. ABG revealed respiratory acidosis with pH 6.9 and incalculable pCO2. He was subsequently intubated. Further laboratory investigations showed undetected FT4 0.0ng/dL (reference range 0.58–1.64) and elevated TSH 23.87µIU/mL (reference range 0.38–5.33). Anti-TPO was elevated 333 µIU/ml (reference range 0–35). He was started on hydrocortisone followed by levothyroxine 200 µg tablet through NGT daily. His condition improved after few days and was weaned off from mechanical ventilator. Repeat echocardiogram showed resolution of previously noted massive pericardial effusion with preserved systolic and diastolic functions. He was eventually discharged after a month on levothyroxine. Follow-up after 1 month, patient was clinically stable with normal thyrotropin level at 0.67µIU/mL. Conclusion Myxedema coma is a life threatening form of hypothyroidism and may be difficult to recognize initially especially in patients with pre-existing kidney disease due to overlap in clinical findings. Treatment with levothyroxine administered enterally is possible especially if the intravenous form is unavailable.