*Thyroid storm

dr.Pandji M,SpPD,KEMD, FINASIM

THYROID STORM

*Anatomy of the thyroid gland The thyroid is one of the largest endocrine gland in the bodyThe thyroid gland is located in the front of the neck, below the larynx (voice box). The small, two-inch gland consists of two lobes, one on each side of the windpipe, connected by tissue called the isthmus.The thyroid tissue is made up of two types of cells: follicular cells and parafollicular cells. Most of the thyroid tissue consists of the follicular cells, which secrete iodine-containing hormones called thyroxine (T4) and triiodothyronine (T3). The parafollicular cells secrete the hormone calcitonin. The thyroid needs iodine to produce the hormones.

*Anatomy of thyroid gland

*Functions& Physiology of the thyroid glandThe thyroid plays an important role in regulating the body's metabolism and calcium balance. The T4 and T3 hormones stimulate every tissue in the body to produce proteins and increase the amount of oxygen used by cells. The harder the cells work, the harder the organs work. The calcitonin hormone works together with the parathyroid hormone to regulate calcium levels in the body.Levels of hormones secreted by the thyroid are controlled by the pituitary gland's thyroid-stimulating hormone, which in turn is controlled by the hypothalamus.

*Physiology of thyroid hormones

*Thyroid diseaseDefinitionHyperthyroidismOverproduction of hormone from the thyroid glandThyrotoxicosisAny cause of excessive thyroid hormone concentrationGraves' disease Autoimmune disease and a metabolic imbalance resulting from overproduction of thyroid hormones Euthyroidism Normal functioning of the thyroid gland , normal serum levels of thyroid hormone

*Thyroid storm or Thyroid crisisDefinitionExacerbation of hyperthyroidismAcute, life-threatening, hypermetabolic stateThyroid storm may be the initial presentation of thyrotoxicosisLess than 10% of hospitalized thyrotoxicosisMortality: 20-30%

*EtiologyGraves disease (most common)Solitary toxic adenoma or toxic multinodular goiterRare causehypersecretory thyroid carcinomathyrotropin-secreting pituitary adenomastruma ovarii/teratomahuman chorionic gonadotropiasecreting hydatidiform mole.Other causesinterferon alpha interleukin-2induced thyrotoxicosis

*Precipitating eventSystemic insultsSurgery, trauma, myocardial infarction, pulmonary thromboembolism, DKA, severe infectionDiscontinuation of antithyroid drugsExcessive iodine (eg, radiocontrast dyes, amiodarone)Radioiodine therapyPseudoephedrine and salicylate use

*Thyroid Storm- diagnosisA score of 45 or more is highly suggestive of thyroid storm; a score of 25 to 44 supports the diagnosis; and a score below 25 makes thyroid storm unlikely. 40C37.2 37.7C

*Clinical presentation

*Symptoms of Thyroid StormIncreased body temperature Tachycardia (rapid heart rate)Nausea/vomitingFrequent loose bowel movements Heart palpitations Heart failurePulmonary edema Confusion

*LAB free T4 and free T3TSHHyperglycemia, elevated alkaline phosphatase, leukocytosis, Mild hypercalcemia,and elevated liver enzymesCortisol (normal level adrenal insufficiency)

*Storm TreatmentsTreatments directed at thyroid gland and hormonesInhibition of new hormone synthesis with Thioamide drugs such as PTU and methimazoleInhibition of hormone release with Iodine & potassium iodide (Lugols solution) & Lithium carbonate

*Storm TreatmentsTreatments directed at preventing hormones affects on the bodyPolythiouracil (PTU)CorticosteroidsBeta blockers (most importantly Propanolol)AmiodaronePlasmapheresis

*Storm TreatmentsTreatments directed at maintaining homeostasisHyperthermia: acetaminophen, cooling blanketsFluid and electrolyte testing/replacementGlucoseVasopressorsDigoxin & diuretics if appropriate

Efek Wolff ChaikoffEfek ini ditemukan oleh Dr Jan Wolff dan Lyon Chaikoff pada tahun 1948. efek WC adalah suatu bentuk pengurangan level hormon tiroid yang disebabkan oleh proses pencernaan iodine dalam jumlah besar. Hasil penelitian Wolff dan Chaikoff menunjukkkan bahwa injeksi iodine yang dilakukan pada tikus akan menghambat organification (oksidasi iodide ) pada kelenjar tiroid.Pasien yang memiliki penyakit Graves lebih sensitif dibanding pasien dengan eutyroid, dan iodine telah digunakan untuk pengobatan penyaki Grave*

Efek WC adalah fenomena autoregulator yang menghambat organification dari kelenjar thyroid, pembentukan hormon tyroid didalam folikel tyroid dan melepaskan hormon tyroid ke peredaran darah. Hal ini menjadi bukti adanya peningkatan sirkulasi iodideEfek WC berlangsung kurang lebih 10 hari., dan diikuti oleh escape phenomenon, suatu kondisi yang digambarkan dengan adanya pengulangan dari normal organification dan fungsi peroksida tyroid yang normal.Escape phenomenon dipercaya akan muncul karena penurunan konsentrat inorganic iodine ke regulation ofsodium-iodide symporter(NIS) on the basolateral membrane of the thyroid follicular cell.

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Efek WC dapat digunakan sebagai treatment dasar terhadap hypertyroidism (khususnya thyroid storm) dengan cara memasukkan sejumlah iodine (dalam jumlah besar) untuk menekan kelenjar thyroid. Iodide telah digunakan untuk merawat hyperthyroidism sebelum pemberian obat-obatan antithyroid spt asppropylthiouracil dan methimazole. Pasien yg diberi iodide akan mengalami penurunan pada angka basal metabolic yang dpt dibandingkan setelah thyroidectomyEfek WC juga menjelaskan hypothyroidism yang etrjadi pada beberapa pasien dengan konsumsi obat-obatan yang mengandung iodine seperti amiodarone. Efek WC adalah juga bagian dari mekanisme untuk penggunaan dari potassium iodide pada pada keadaan nuclear emergencies *

*Treatment SummaryOverall Goal: Reduce circulation thyroid levels and control symptomBeta blockers: decreases adrenergic hyperactivity (sympathetic outflow)PTU (large amounts): prevents synthesis of the hormoneGlucocorticoids: inhibit hormone production and decrease peripheral conversion from T4 to T3. Sodium iodide solution (Lugols solution): High levels of iodide will initially suppress release of thyroid hormoneTreat cardiac symptoms, fever and hypertension

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