Thyroid Disorders: Hyper and Hypothyroidism Year II, Unit II Unit-directed Activity AMEL ARNAOUT,...

Thyroid Disorders: Hyper and Hypothyroidism

Year II, Unit II

Unit-directed Activity

AMEL ARNAOUT, MD

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Disclosure

Unit II – Thyroid Disorders: Hyper and Hypothyroidism

Describe important signs & symptoms of hyperthyroidism Describe important signs & symptoms of hypothyroidism Discuss the use of thyroid function tests in the diagnosis of

hypothyroidism Discuss common causes of primary & secondary hypothyroidism Discuss the use of thyroid function tests in the diagnosis of

hyperthyroidism Describe the pathophysiology of hyperthyroid Graves’ disease Outline and describe acute, subacute & chronic thyroiditis Describe the clinical course of postpartum thyroiditis Describe the three phases of subacute thyroiditis

Objectives

Unit II – Thyroid Disorders: Hyper and Hypothyroidism – D. Liu

Case 1


Ms. Lee is a 56-year old woman who has been your patient for 10 years.

She is normally healthy and active. During a routine check-up, she complains of

fatigue and 10 lb weight gain in 6 months.

Hypothyroidism is on the differential diagnosis. What other information will you ask for on history?

Case 1: Ms. Lee


Additional History: Chronic constipation Hot flashes since menopause Weight increased despite stable diet &

activity PMHx: Borderline HTN & dyslipidemia Meds: Multivitamin, no other supplements FHx: Hypothyroidism in aunts

Case 1: Ms. Lee


What signs might you expect to find on physical exam?

General appearance: Vitals: Head & neck: Resp: CVS: Abdo: MSK: Neuro:

Case 1: Ms. Lee


BP 135/90, HR 65

Small, firm thyroid – no nodule

Which of the following tests would you order?

Case 1: Ms. Lee


TSH Free T3 Total T3 Free T4 Total T4 Thyroid ultrasound Thyroid uptake &

scan

Anti-microsomal antibodies

Anti-thyroglobulin antibodies

Thyroxine binding inhibitory immunoglobulin (TBII)

Investigations

Case 1: Ms. Lee


Test Result Reference Range Units

TSH 34.3 0.35 – 5.0 mU/L

Free T4 5.7 7.0 - 17.0 pmol/L

Free T3 3.2 3.3 – 6.0 pmol/L

What treatment would you recommend?

What is your plan for follow up?

What is the diagnosis?

Diagnosis: Primary hypothyroidism Treatment: Levothyroxine (T4) titrated to achieve a

normal TSH Repeat blood work (TSH) 6 weeks after initiating

treament

What if these were her lab results?

Case 1: Ms. Lee



TSH 9.5 0.35 – 5.0 mU/L

Free T4 10.8 7.0 - 17.0 pmol/L

Free T3 4.3 3.3 – 6.0 pmol/L

What are the indications for treating subclinical hypothyroidism?

• Indications for treatment of SCH:• TSH >10• Significant symptoms of hypothyroidism• Hyperlipidemia• Depression• Women of childbearing age• Positive anti-TPO antibodies

Case 2


Case 2: Mrs. Healthnut

40 yr old female with small goitre (symmetric enlargement, no palpable nodules).

Surgeon advised she does not need surgery.

She read on the internet that taking kelp might shrink her thyroid gland.


Case 2: Mrs. Healthnut

What are possible consequences of taking kelp and the mechanisms involved?


HO O CH2 CHCOOH

NH2

I

I I

I

T4: 4 iodine atomsRemoved when converted to T3

• Kelp contains iodine which acts as a substrate for thyroid hormone synthesis

• An increase in iodine in the diet MAY cause an increase in formation of thyroid hormones T4 and T3 which MAY cause a slight increase in circulating Free T4 and Free T3 levels which MAY suppress TSH.

• A lower TSH causes gland to shrink

Case 3


Case 3: Ms. Newmum

Ms. N has a 5-month old baby. She was coping well, but now has symptoms suggestive of thyrotoxicosis.

Describe symptoms of thyrotoxicosis.


What signs might you expect to find on physical exam?

General appearance: Vitals: Head & neck:

Resp: CVS: Abdo: MSK: Neuro:

Case3: Ms. Newmum


BP 140/80, HR 95

Eyes: Lid lag, no proptosisThyroid 2 x normal size, no nodule

S1 S2 & systolic flow murmur

Fine tremor in hands

Which of the following tests would you order?

Case 3: Ms. Newmum


TSH Free T3 Total T3 Free T4 Total T4 Thyroid ultrasound Thyroid uptake &

scan

Anti-microsomal antibodies

Anti-thyroglobulin antibodies

Thyroxine binding inhibitory immunoglobulin (TBII)

Investigations

Case 3: Ms. Newmum



TSH 0.06 0.35 – 5.0 mU/L

Free T4 33 7.0 - 17.0 pmol/L

Free T3 10.4 3.3 – 6.0 pmol/L

What is the differential diagnosis?

Which test(s) will you order next?

Case 5: Mrs. New Baby


Case 3: Ms. Newmum

24 hr uptake: 47% (6-22%)

What is her diagnosis?

What is the pathophysiology of this condition?

How can this condition be treated?

What are potential adverse effects of the treatment options?


Case 3: Ms. Newmum

Thyroid Gland

I- I-

MIT T3 T3

Po Po P

DIT T4 T4

Thyroglobin

MIT

I- DIT

ID

T4 5’deiodinase T3Periphery

Periphery

PTU, MMI

Iopanoic Acid, Ipodate

Inorganic Iodine

PTU Steroids

Iodine

Na+ Na+

With plans to have another pregnancy, Ms. N opted to be treated with 131-iodine. She is euthyroid on thyroid hormone replacement 4 months after thyroid ablation.

She is worried about how Graves’ disease will affect her pregnancy and baby. What would you advise?


Case 3: Ms. Newmum

Case 4


Case 4: Mr. Payne

Mr. Payne is normally stoic

He presents with new neck pain, irritability, rapid weight loss in the last week, heat intolerance and palpitations.

What is the likely cause of his thyrotoxicosis?


THYROIDITIS

Thyroiditis with pain and tenderness:

• acute infectious (rare)

• subacute granulomatous thyroiditis (common)

SUBACUTE GRANULOMATISTHYROIDITIS

• subacute thyroiditis or DeQuervains’ thyroiditis, likely viral

• three phases: hyperthyroid,hypothyroid recovery phase

• treatment: NSAID or prednisone for pain, b-blocker for hyperthyroid symptoms, L-T4 not usually necessary

Thyroiditis

Case 4: Mr. Payne

What investigations are appropriate? Discuss the expected results. What treatments would you consider

recommending for this condition? What is the expected clinical course for Mr. N? Discuss the clinical course of acute and chronic

thyroiditis.


Case 5


Case 5

• 26 yr old woman with 6 wk history of agitation, tremors, palpitations, 20 lb wt loss, diarrhea

• PHX: unremarkable• no meds• O/E

– BP 170/62, HR 132 irreg irreg, RR 23, temp 39o

– agitated, flight of ideas, tremulous– exophthalmus, lid lag, stare, chemosis– thyroid 4x normal, diffuse with bruit– few basilar crackles

Thyroid Storm

• Very rare• high mortality (20-30%)• When to suspect

– often have a history of thyroid disease– have all the usual features of thyrotoxicosis– often have very large goiter– often a ppting illness/event

• surgery, infection, pregnancy, iodinated contrast dye

Thyroid Storm

• Life threatening exacerbation of the hyperthyroid state• Decompensation of organ systems• Fatal if untreated• Mortality rate of 20 - 30%• Most common in patients with thyrotoxicosis secondary to Graves disease

Thyroid Storm:Clinical Presentation

• Features of thyrotoxicosis• History of thyroid disease, or symptoms

consistent with prolonged thyrotoxicosis• Fever• Systolic Hypertension, widened pulse preassure• Tachycardia, Atrial arrythmias• Mental status change• GI, CVS or Neurologic symptoms may

perdominate

Thyroid Storm:Clinical Presentation

• Infection• Surgery• Radioiodine Therapy• Iodonated Contrast

Dyes• Withdrawal of

Antithyroid drug therapy

• Amiodarone

• DKA• CHF• Hypoglycemia• Stroke• Trauma• Tooth extraction• Bowel infarction• Pulmonary embolism

Precipitating event:

THYROID STORMCLINICAL FEATURES

• Hyperpyrexia (>380C) • Tachycardia or cardiac dysrhythmia• Dehydration and dry skin• Restlessness, anxiety, or delirium• Goitre with or without exophthalmos• Stupor, coma or shock• Look for precipitating illness

Laboratory

• Elevated T3 and T4

• Suppressed TSH• Hyper or hypo glycemia• Leukocytosis• Elevated calcium• Increased transaminases, LDH, CK, Alk phos

Diagnosis of thyroid storm

• A clinical diagnosis, no lab criteria• febrile• CNS effects

– agitation, delirium, psychosis, extreme lethargy, seizure, coma

• GI/hepatic effects– diarrhea, N, V, jaundice

• CV effects– tachy, a fib, high output failure

Thermoregulatory DysfunctionTemperature

99-99.91 5100-100.9 10101-101.9 15102-102.9 20103-103.9 25 >=104.0 30

CNS EffectsMild 10AgitationModerate 20 Delerium, PsychosisExtreme lethargySevere 30Seizure, Coma

Precipitant HistoryNegative 0Positive 10

GI/Hepatic DysfunctionModerate 10Diarrhea, N&V Abd. PainSevere 30 Unexplained jaundice

CVS DysfunctionTachycardia99-109 5 110-11910 120-129 15130-139 20 >=140 25CHF Mild 5 Moderate 10 Severe 15Afib 10

Score > 45 Suggest thyroid storm 25-45 impending thyroid storm < 25 unlikely thyroid storm

Burch & Wartofsky 1993.

Treatment

• Monitored bed• Correct the hyperthyroidism

– PTU 600-1000 mg x 1 then 300 mg q. 4h– iodine after 1st dose of PTU– lugols 10 drops tid

• block the effects of thyroid hormone– large doses of B-blockers

• treat ppting event

THYROID STORMTREATMENT

• Lower temperature with cooling blanket, acetaminophen, or chlorpromazine• SSKI 5-10 gtts po tid or qid, or Na I I g iv infusion q12h• Propranolol 1 mg iv/min up to 2-10 mg, or 40-80 mg po q4-6h• PTU 800 mg po, and 200-300 mg q6h, or methimazole 80 mg po, and 40 mg q8h• Hydrocortisone 100 mg iv q8h or equivalent• Fluids and electrolyte replacement• Plasmaphoresis or peritoneal dialysis

Thyroid Disorders: Hyper and Hypothyroidism Year II, Unit II Unit-directed Activity AMEL ARNAOUT,...

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Transcript of Thyroid Disorders: Hyper and Hypothyroidism Year II, Unit II Unit-directed Activity AMEL ARNAOUT,...