Endocrine Abstracts

A 35-year lady with Grave’s disease and brittle asthma presented to the Endocrinology team with symptoms and signs of thyrotoxic crisis. She was not on any anti-thyroid medication as she had previous suffered a severe rash in response to carbimazole, and profound gastrointestinal disturbance with propylthiouracil. It was suggested that she consider radioiodine to control her condition, but as a single parent with young children she was not prepared to undergo the isolation this would require.

The decision was made to commence Lugol’s iodine, and over 6 days her free T₄ improved from 66.2 to 31.7 pmol/l (normal range 9.1–23.8 pmol/l). There was some symptomatic improvement over this time, but due to concerns of rebound hyperthyroidism (Jod - Basedow phenomenon) a total thyroidectomy was performed on day 7.

This procedure was challenging for the surgical team who encountered adhesive tissue planes, but despite this, the parathyroid glands and recurrent laryngeal nerves were identified and preserved, and the operation was uneventful.

The anaesthetic challenge was to overcome the hypermetabolic state and control any catecholamine surge in the perioperative period in a patent with asthma who may experience profound respiratory compromise with beta blocker administration. A midazolam, propofol, vecuronium and remifentanil induction was used with sevoflurane and remifentanil maintenance anaesthesia. In addition, magnesium sulphate was infused to control arrhythmias as a consequence of hyperthyroidism, and hydrocortisone to inhibit further TSH release. It was decided that beta blockers should be trialled in the relatively controlled context of the intubated, ventilated patient in case required postoperatively. A short acting esmolol (6.1 μg/kg per min) infusion was administered without adverse effects.

This case demonstrates how with careful multidisciplinary input and endocrinology work up, a patient experiencing a complicated thyrotoxic storm can be safely managed surgically.