Thyrotoxic crisis following eclampsia and induction of labour.

Case report A 28-year-old Indian woman presented to the surgical out-patient clinic with complaints of weightloss and a neck swelling. On examination the surgeon found that the patient had a smooth goitre, lid lag and a tachycardia of 120 per min. The serum thyroxine (T4) level was 215 nmol/l (normal 60-135). She was started on carbimazole 10 mg three times daily. It was however, not known that she was 13 weeks pregnant at this time. She did not turn up for review 4 weeks later. Nine weeks after initial presentation to the surgical out-patient department, she attended the antenatal booking clinic in her 5th pregnancy at 22 weeks gestation. She had had four previous uneventful pregnancies. The uterine size corresponded with dates and the blood pressure was 120/80 mmHg and the pulse rate 110 per min. She had a smooth goitre and lid lag was present. She claimed to be taking carbimazole regularly (though this later proved to be false). Thyroid function tests were not done. Three weeks after booking she had two fits and was admitted as an obstetric emergency. On arrival blood pressure was 190/105 mmHg, pulse rate was 140 per min, and there was heavy proteinuria with ankle oedema. Eclampsia was diagnosed and treatment started with a constant infusion of 0-8% chlormethiazole and hydralazine 40 mg in 50 ml of 5% dextrose intravenously. After an epidural anaesthetic block, labour was induced with extraamniotic prostaglandin. Eight hours later a female fetus was aborted. Following delivery her condition was stable for approximately 7 hr, when she developed extreme restlessness despite the chlormethiazole. She was tachypnoeic with a tachycardia of 200 per min, blood pressure was 170/95 mmHg, and there were bilateral basal lung crepitations. She became unrouseable and chlormethiazole was stopped. There were no localizing signs in the central nervous system. Cardiac failure was treated initially with digoxin 0 5 mg and frusemide 40 mg intravenously, but her condition did not improve. Thyrotoxic crisis was suspected and treatment started with propranolol 40 mg four times daily, carbimazole 15 mg three times daily, digoxin 0 25 mg (two doses), and 5 drops of Lugol's iodine, all given through a Ryle's tube. She gradually improved and 40 hr postpartum was fully conscious with a normal blood pressure and no signs of cardiac failure, although a tachycardia of 100 per min persisted. She had passed 12-5 litres of urine in the preceding 24 hr. Carbimazole and propranolol were continued during the puerperium and she was discharged 7 days after admission. Thyroid function tests on admission confirmed thyrotoxicosis-T4 146 nmol/l (60-135), T3 uptake 66% (93-117), free thyroxine index (FTI) 17 (34-13).