thyroid disorders a practical approach

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Some interesting cases commonly Some interesting cases commonly seen in practiceseen in practice

1. Govindammal – Persistant diarrhea2. Sridhar – Cachexia 70 kg to 40 kg 3. Kavitha – Weight loss – lung shadow 4. Sulochana – Severe anaemia – CHF5. Laxmi – Infertility after 16 yrs of ML6. Siva – Atrial fibrillation – cachexia7. Kadirvelu – uncontrolled diabetes 8. Annaji – dyspnea – tracheal compression

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Clinical Exam. of ThyroidClinical Exam. of Thyroid Have patient seated on a stool / chair Inspect neck – also while drinking water Examine with neck in relaxed position Palpate from behind the patient Remember the rule of finger tips Use the tips of fingers for palpation Palpate firmly down to trachea Pemberten”s sign for RSG

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Clinical Exam of ThyroidClinical Exam of Thyroid

PEMBERTEN”S SIGNPEMBERTEN”S SIGN

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LOOK HIS FACE

Difficult situationsDifficult situations

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The Thyroxines

Tri iodo Thyronine – T3

- 10% is from thyroid gland

- 90% derived from conversion of T4 to T3

Tetra iodo Thyronine – T4

- is exclusively from thyroid glandFrom the thyroid gland

- 90% of hormone secreted is T4

- 10% of hormone secreted is T3

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Thyroid Function Tests

1. TSH2. Free T43. Free T3

4. Anti-Thyroid Antibodies

5. Nuclear Scintigraphy

6. FNAC of nodule

Ultra sound is the basic test to see for thyroid nodule and goitre

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Thyroid Antibodies

Anti-TPO antibodies are commonly associated with Hashimoto's thyroiditis and TRAbs are commonly associated with Graves' disease

The most clinically relevant anti-thyroid autoantibodies are

Anti-thyroid peroxidase antibodies (anti-TPO ), &Thyrotropin receptor antibodies (TRAbs)

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What tests should I order ?

As per the Guidelines of the AACE

1. TSH alone if Hypothyroidism is suspected

2. TSH and Free T4 only if Hyperthyroidism is suspected or for routine evaluation

3. Free T3 if T3 toxicosis is suspected

4. For follow-up of treatment only TSH

5. Don’t order for Total T4 or Total T3

6. Never order RAIU in pregnancy

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THYROID HORMONES

TEST REFERENCE RANGE

TSH Normal Range 0.3 - 4.0 mU/L

Free T4 Normal Range 0.7-2.1 ng/dL

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How to interpret How to interpret results ?results ?

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The Nine Square Game

To evaluate our Thyroid patient

As per the AACE Guidelines

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LOW NORMAL HIGH

THYROID STIMULATING HORMONE - TSH

LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4

BASIC THYROID EVALUATION

15

LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4

EUTHYROID

LOW NORMAL HIGH



16

LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4

PRIMARYHYPOTHYROID

LOW NORMAL HIGH



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LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4 PRIMARYHYPERTHYROID

LOW NORMAL HIGH



18

LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4

SECONDARYHYPOTHYROID

LOW NORMAL HIGH



19

LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4 SECONDARYHYPERTHYROID

LOW NORMAL HIGH



20

LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4

SUB-CLINICALHYPERTHYROID

LOW NORMAL HIGH



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LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4

SUB-CLINICALHYPOTHYROID

LOW NORMAL HIGH



22

LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4

NON THYROIDILLNESS or NTI

LOW NORMAL HIGH



23

LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4

NTI or Pt.on ELTROXIN

LOW NORMAL HIGH



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LO

W

N

OR

MA

L

HI G

H

FREE

TH

YRO

XIN

E o

r FT

4

EUTHYROIDSUB-CLINICALHYPERTHYROID

NON THYROIDILLNESS - NTI

NTI or Pt.on ELTROXIN

SUB-CLINICALHYPOTHYROID

SECONDARYHYPERTHYROID

SECONDARYHYPOTHYROID

PRIMARYHYPERTHYROID

PRIMARYHYPOTHYROID

LOW NORMAL HIGH



CASE DISCUSSIONCASE DISCUSSION

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A 26 year old female presented to her obstetrician with complaints of palpitations. She states the palpitations have been constant over the past two weeks but seem worse at nighttime.


She recently delivered a normal baby 45days before this visit. Her review of system is remarkable except for loose stools occurring approximately 4 times/day. . She denies any nausea, vomiting or abdominal pain.. She denied heat or cold intolerance

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Her blood pressure was 146/90. Pulse 96 and regular and a normal temperature of 37 degrees . Her review of systems revealed clear lungs, normal heart rhythm, normal abdomen and she showed a fine tremor of the hands

Her thyroid was approximately 1.5 times normal in size, symmetrically enlarged, firm, non-tender with carotids palpable bilaterally without bruits

Lab investigationsLab investigations

She also had a thyroid panel that included , Free T4 15.2 ng /dl(Normal Range 0.7-2.1 ng/dL)and a TSH of <0.05 (NL 0.3 5.0).

28Primary hyperthyroidismDIAGNOSIS


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The patient had a radioactive iodine uptake scan which was normal and subsequently had thyroid auto-antibodies determined which were positive for Anti TPO and neg for TRAbs .

Diagnosis - GRAVES DISEASE ??


A thyroid biopsy was also performed and revealed diffuse, lymphocytic infiltration, a characteristic histologic picture of post partum thyroiditis.

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In this case the patient was simply treated with beta blockers to reduce the palpitations. Inside three months, the thyroiditis had resolved and the patients' symptoms disappeared with normal thyroid function test results.

DISCUSSIONDISCUSSION

Post partum thyroiditis (PPT) is a relatively common disorder expressed in 5 to 15% of post partum women.

This disorder initially presents as thyrotoxicosis from 6 weeks to 3 months post partum, is associated with an auto immune component and usually resolves spontaneously after 1-2 months of expression.

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In some patients, the thyrotoxic phase can be followed by a hypothyroid phase before spontaneous disease resolution occurs. This thyroid disorder is more prevalent in patients with a family history of Hashimoto's thyroiditis. Over 50% of patients will have a mild goitre

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The symptoms of thyrotoxicosis are generally milder than that of Graves disease,however the presenting symptoms can be similar and it is important to distinguish thyrotoxicosis due to PPT and Graves disease since the approach to treatment is quite different between the two.

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The radioactive iodine uptake or thyroid scan can be used to differentiate Graves disease from PPT. A normal scan or uptake is observed in patients with PPT in contrast to Graves where there is a marked elevation in radioactive iodine uptake

Anti TPO &TRAbs Anti TPO &TRAbs

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Tt has been suggested that screening with TPO antibodies in high risk pregnancy could identify those patients at risk of developing post partum thyroiditis.

To distinguish PPT from Graves disease, measurement of TRAbs and the use of the thyroid scan are approaches that can help confirm the diagnosis. Both are abnormal with Graves disease and normal in the patients with PPT.

HOW TO DIFFERENTIATEHOW TO DIFFERENTIATE

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Question # 1Question # 1

Should a serum TSH & F T4 be a routine component

of the health exam in pregnant women?yes

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What is the appropriate biochemical end point for adequate thyroid hormone replacement in hypothyroid patient?

TSH starts showing decrements from the high values TSH returns to normal eventually

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Are there risks associated with over

replacement?

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Over-replacement risksReduced bone density / osteoporosis

Tachycardia, arrhythmia. atrial fibrillation

In elderly or patients with heart disease, angina,

arrhythmia, or myocardial infarction

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Are all L-thyroxine products therapeutically equivalent? Should combination T4/T3

preparations be used?

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Treatment of choice is levothyroxin Brand consistency recommended No divided doses - illogical Not recommended for use :

Desiccated thyroid extractCombination of thyroid hormones

T3 replacement except in Myxedema coma

Many Causes, One Treatment

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What is the impact of pregnancy on Thyroxine replacement

therapy in a hypothyroid women?

Pregnancy ( 25% ↑ in dose),

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safe in lactating mother

Safety in lactating mother

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Should women with sub-clinical hypothyroidism

be treated with L-Thyroxine?

Normal FT4 & TSH elevated from 5 to <10

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Co-morbidity

HypercholesterolemiaDepressionInfertility – Menstrual Irregularities Recent Wt gainHigh TPO levels

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Should euthyroid patient with benign thyroid

nodules be placed on thyroid hormone

suppression therapy?

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Thyroid hormone suppression therapy

This involves treating a benign nodule with levothyroxine . The idea is that supplying additional thyroid hormone will signal the pituitary to produce less TSH, the hormone that stimulates the growth of thyroid tissue. Although this sounds good in theory, levothyroxine therapy is a matter of some debate. There's no clear evidence that the treatment consistently shrinks nodules

SURGERY SURGERY

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Occasionally, a nodule that's clearly benign may require surgery, especially if it's so large that it makes it hard to breathe or swallow.

Surgery is also considered for people with large multinodular goiters, particularly when the goiters constrict airways, the esophagus or blood vessels.

Nodules diagnosed as indeterminate or suspicious by a biopsy also need surgical removal, so they can be examined for signs of cancer.

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The Commandments

Highly suspect hypothyroidism Growth and pubertal delay Unexplained depression TSH is the test in Hypothy. TSH, FT4 to confirm Dx. Nine square magic

All obese patients TSH a must For all pregnant -test TSH, FT4 Postmenopausal 15% Hypothy Start low and go slow Use Levothyroxine only Always on empty stomach Thyroxine - avoid empirical use

Thank u Thank u

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thyroid disorders a practical approach

Health & Medicine