Neonatal thyrotoxicosis associated with the hyperviscosity syndrome

Abstract

Baby S.M. was the 2,230-gram, 36-week product of a 28-yearold gravida 1 para 0 black woman with a previous history of hyperthyroidism, treated by subtotal thyroidectomy one year prior to her pregnancy. Clinically, she was euthyroid, with a normal T, value and a negative long-acting thyroid stimulator titer. No thyroid or anti-thyroid medications were taken during pregnancy. Labor and delivery were uneventful Shortly after birth, however, the infant developed acrocyanosis, tachypnea (100/ minute), tachycardia (180/minute), and hyperactivity with marked irritability and tremulousness. At 13 hours of age, his blood glucose value, measured by Dextrostix, was 25 mg/dl; 10% dextrose solution was administered intravenously, and he was transferred to St. Louis Children's Hospital. On arrival, he was moderately icteric (total bilirubin 10.4 rng/dl; direct bilirubin 2.52 mg/dl) and was noted to have generalized petechiae, purpura, and hepatosplenomegaly. Diffuse cardiomegaly was noted radiographically; right heart enlargement was shown electrocardiographically. Sixty percent inspired oxygen was required to maintain normal arterial blood gas values. Serum calcium was decreased to 6.8 mg/dl, but the concentrations of the other electrolytes were normal. Venous microhematocrit was 73%. Initial platelet count was 170,000/ mm', but it fell to 56,000/mm :~. Blood smear revealed 2,880 nucleated red blood cells/mrn ~, but was otherwise unremarkable.