Thyroid disorder: Emergencies Dr Hiren Patt D.M. (Endocrinology)

Myxoedema Coma

What is Myxoedema Coma? Severe hypothyroidism Slowing of functions of multiple organs Medical emergency High mortality rate (up to 40 %) Rare nowadays (because of early diagnosis)

Coma: Must for Diagnosis ? Confusion Lethargy Obtundation Drowsiness Stupor Coma Rarely, myxoedema madness (Psychosis)

Pathogenesis Old age, female Severe long-standing hypothyroidism Precipitating factors: Infection MI Cold exposure Sedative drugs

Clinical features Decreased mental status Hypothermia Hypoventilation Bradycardia Hypotension Hyponatremia Hypoglycemia

Investigations Total T4/ Free T4 TSH Cortisol ACTH Before starting any treatment

Hypothyroidism + Cortisol deficiency Primary hypothyroidism: Addison disease TSH: high ACTH: high Secondary hypothyroidism: Panhypopituitarism TSH: low/normal ACTH: low/normal

Management If the results for TSH, T4 & Cortisol are delayed, treatment can be started before results Hydrocortisone dose: 100 mg i.v. stat 100 mg i.v. 8 hourly for 2 days Tapering dose to minimum required dose Supportive measures: ABC Rx of coexistent illness (e.g. infection)

Problems with T4 Rx T4 to T3 conversion: slow T4 absorption: slow (GI motility: affected)

Management T4 + T3 preferred than T4 alone T4 (intravenously) 200-400 mcg i.v. stat 50-100 mcg i.v./day Till patient starts taking orally T3 (intravenously) 5-20 mcg i.v. stat 2.5-10 mcg 8 hourly Till patient is stable

Case 1 60 yrs/F, Altered sensorium: 2 days Hypoglycemia, but no improvement even after correction K/c/o: Hypothyroidism: 10-12 years Stopped Rx: 1 year P: 60/min, BP: 80/40 mm Hg

Rx: Thyroxine 50 mcg/day & Biochemistry Normal range TSH 0.08 0.4 – 4 T4 0.4 4.5 – 12.5 Na 130 135 – 145 Rx: Thyroxine 50 mcg/day & referred to us

Provisional Diagnosis Myxoedema crisis with panhypopituitarism (TSH + ACTH deficiency) Pituitary Profile: ACTH, Cortisol, FSH, Prolactin Inj. Hydrocortisone 100 mg i.v. stat and then 8 hourly started

Pituitary Profile Normal range ACTH 6 18-46 S.Cortisol 0.8 5-25 FSH NDT > 10 Prolactin 0.2 5-20 MRI: Empty sella

Final Diagnosis TSH deficiency ACTH deficiency FSH/LH deficiency Prolactin deficiency Myxoedema crisis + Pahypopituitarism

Management: Issues T4 & T3 (i.v.): Not available T4 (oral): Only option T4: Dose ?

Management Tab.Thyroxine (400 mcg) stat through RT No RT feeds for next 4 hours to improve absorption

Management Day Tab.Thyroxine Free T4 (normal range: 0.8-1.8) 1 400 mcg 0.4 2 300 mcg 0.7 3 250 mcg 0.9 4 150 mcg 1.0 5 1.2 6 100 mcg

Discharged: Tab. Thyroxine 100 mcg 1-0-0 Tab. Prednisolone 2.5 mg 1-0-0 with stress cover

Thyrotoxic crisis

Introduction Medical emergency High mortality rate (up to 30 %) Rare nowadays (due to early diagnosis)

Etiology Long standing untreated hyperthyroidism Precipitating factors: Trauma Infection Surgery (thyroid/non thyroid) Acute iodine load

T3, T4, TSH Required to diagnose hyperthyroidism Doesn’t differentiate b/w compensated hyperthyroidism & Thyrotoxic crisis

Clinical features Tachycardia Nausea/vomiting/abdominal pain Hepatic failure with jaundice Hypotension/CHF/Arrythmia Hyperpyrexia (Temp. upto 104 to 106) Agitation/psychosis/delirium/stupor/coma

Management Beta blockers Methimazole/PTU Iodine solution Glucocortisoids Bile acid sequestrants Supportive measures: ABC Rx of coexistent illness (e.g. infection)

Beta blockers Propranolol: 60-80 mg every 4-6 hourly Adjusted by Heart rate/BP To improve symptoms/signs related to sympathetic overactivity

Thionamides Carbimazole: 30 mg every 4-6 hourly Methimazole: PTU 200 mg every 4 hourly PTU > Methimazole: Preferred, because it inhibits conversion of T4 to T3 as well

Glucocorticoid Hydrocortisone 100 mg i.v. 8 hourly Interferes with T4 to T3 conversion Possibly, halts autoimmune process in Grave’s disease.

Iodine solution SSKI: 5 drops every 6 hourly Lugol’s iodine: Start 1 hour after the thionamide dose

How to make SSKI ? 144 gms potasium iodide 100 ml water

Iodinated contrast agents Iopanoic acid 0.5-1 gm/day Interferes with T4 to T3 conversion Inhibits release of thyroid hormones from thyroid gland

Bile Acid Sequestrants Cholestryramine 4 gm every 6 hourly Interferes with enterohepatic circulation & recycling of thyroid hormones

Conclusion Thyroid emergencies: rare, but fatal Myxoedema coma: Can use high dose oral T4 Rule out cortisol deficiency Thyrotoxic crisis: comprehensive management with beta blockers, thionamides, iodide, steroids etc.

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