NHS FORTH VALLEY Thyroid Storm

Transcription

1 NHS FORTH VALLEY Thyroid Storm Date of First Issue 01 August 2006 Approved 01 August 2006 Current Issue Date 1 st July 2016 Review Date 1 st July 2018 Version EQIA Yes 01/08/2010 Author / Contact Group Committee Final Approval Dr Linda Buchanan Diabetes Consultant Group This document can, on request, be made available in alternative formats Version 1 st July 2016 Page 1 of 6

2 NHS Forth Valley Consultation and Change Record Contributing Authors: Linda Buchanan, John Doig, Chris Kelly, Alison Mackenzie Nick Barwell Consultation Process: Reviewed at Diabetes Consultant Meeting Distribution: Change Record Date Author Change Version 26/07/12 LMB Removed Norman Peden as author and added Nick Barwell 26/07/12 LMB Added endocrine COW bleep number page 4 and removed secretaries numbers /07/2016 LMB Added sentence Para 2, page 4 re critical care 01/07/2016 LMB Added sentence re bile acid sequestrants, para 4 page 4 01/07/2016 LMB Final paragraph on thionaamides amended to make PTU first choice therapy 01/07/2016 LMB Page 5 paragraph added on Bile Acid Sequestrants 01/07/2016 LMB Page 5 para added regarding surgery Version 1 st July 2016 Page 2 of 6

3 MANAGEMENT OF THYROID STORM Precise criteria for the diagnosis of thyroid storm have been introduced by Burch and Wartofsky. Patients with severe and life-threatening thyrotoxicosis typically have an exaggeration of the usual symptoms of hyperthyroidism. Cardiovascular symptoms include tachycardia to rates that can exceed 140 bpm, along with congestive heart failure in many patients. Hyper-pyrexia to is common. Agitation, delirium, psychosis, stupor, or coma are common and are considered by many to be essential to the diagnosis. Severe nausea, vomiting, or diarrhoea, and hepatic failure with jaundice can also occur. DIAGNOSTIC CRITERIA FOR THYROID STORM Thermoregulatory dysfunction Cardiovascular dysfunction Temperature Tachycardia > >40 30 Central nervous system effects Congestive heart failure Mild 10 Mild 5 agitation pedal oedema Moderate 20 Moderate 10 delirium bi-basilar crackles psychosis Severe 15 extreme lethargy pulmonary oedema Severe 30 Atrial Fibrillation 10 seizure coma Gastro-intestinal-hepatic dysfunction Precipitant history Moderate 10 Negative 0 diarrhoea Positive 10 nausea/vomiting abdominal pain Severe 20 unexplained jaundice A score of 45 or more is highly suggestive of thyroid storm A score of supports the diagnosis and a score below 25 makes thyroid storm unlikely Version 1 st July 2016 Page 3 of 6

4 TREATMENT Diagnosis and treatment should be discussed with a consultant Endocrinologist if possible at an early stage. Contact consultant of the week on bleep The therapeutic options for thyroid storm are the same as those for uncomplicated hyperthyroidism, except that the drugs are given in higher doses and more frequently. In addition, full support of the patient in an intensive care unit is essential, since the mortality rate of thyroid storm is substantial. The principles of treatment outlined below are more often applied to patients with severe hyperthyroidism who do not fully meet the criteria for thyroid storm. In addition to specific therapy directed against the thyroid gland, supportive therapy may be critical to the final outcome. Patients should be managed in a critical care setting. The therapeutic regimen typically consists of multiple medications, each of which has a different mechanism of action: beta-blocker to control the symptoms induced by increased adrenergic tone. thionamide, such as carbimazole, to block new hormone synthesis. iodinated radiocontrast agent to inhibit the peripheral conversion of T4 to T3. iodine solution to block the release of thyroid hormone. glucocorticoids to reduce T4-to-T3 conversion and possibly treat the autoimmune process in Graves' disease. Bile acid sequestrants to decrease entero-hepatic recycling of thyroid hormones ß- Blocker Oral Propranolol is given orally or via nasogastric tube at a dose of 60 to 80 mg every four hours. IV An alternative regimen is to utilize the short-acting beta-blocker esmolol. A loading dose of 250 to 500 µg/kg is given, followed by an infusion at 50 to 100 µg/kg per min. This regimen permits rapid titration of the drug to achieve adequate beta-blockade while minimizing adverse reactions. Thionamides Thionamides block de novo thyroid hormone synthesis within one to two hours after administration. However they have no effect on the release of preformed hormone from the thyroid gland. Propylthiouracil (PTU) has certain advantages over carbimazole as PTU but not Carbimazole blocks T4-to-T3 conversion in the periphery. It is reasonable to administer 200 mg of PTU every four hours, orally or via nasogastric tube (an alternative if no PTU available is 20 mg of Carbimazole every six hours). When the patient s thyroid function is stable the consultant endocrinologist (bleep 1965) will switch the patient to carbimazole due to the risk of severe hepatic dysfunction with PTU. Version 1 st July 2016 Page 4 of 6

5 Iodinated radiocontrast agents Iopanoic acid and other iodinated radiocontrast agents used for oral cholecystography have been used to treat hyperthyroidism, but there is little published data on their efficacy in thyroid storm. They are, however, potent inhibitors of T4-to-T3 conversion, and they have been extremely useful in treating severe hyperthyroidism or in preparing hyperthyroid patients for urgent surgery. Because they are iodinated, they should be given at least one hour after the thionamide to prevent the iodine from being used as substrate for new hormone synthesis. Iodine Iodine blocks the release of T4 and T3 from the gland. It is likely that sufficient iodine is released from the iodinated radiocontrast agents to achieve an adequate effect; however, no data are currently available that satisfactorily address this issue. It is therefore prudent to treat patients in thyroid storm with iodide. The doses that are given are considerably higher than the dose needed to block hormone release, eg, Lugol's solution, 10 drops three times daily, or SSKI, five drops every six hours. Glucocorticoids Glucocorticoids also reduce T4-to-T3 conversion, and may have a direct effect on the underlying autoimmune process if the thyroid storm is due to Graves' disease. Their use for the treatment of thyroid storm appears to have improved outcome in at least one series. It is therefore reasonable to administer hydrocortisone 100 mg intravenously every eight hours in patients with life-threatening, hyperthyroidism. Bile Acid Sequestrants Thyroid hormones are metabolised in the liver and excreted in the bile. Free thyroid hormones are released in the intestine and reabsorbed. Cholestyramine 4g orally qds has been found to reduce thyroid hormones in thyrotoxic patients. Surgery For patients with contraindications to thionamides surgery is the treatment of choice once the patient has been stabilised and treated with iodine. Version 1 st July 2016 Page 5 of 6

6 Publications in Alternative Formats NHS Forth Valley is happy to consider requests for publications in other language or formats such as large print. To request another language for a patient, please contact For other formats contact , text , fax or - fv-uhb.nhsfv-alternativeformats@nhs.net Version 1 st July 2016 Page 6 of 6