Transcript Hyperthyroidism

Hyperthyroidism
Dr. Januchowski
2012
Picture courtesy: Hyperthyroidism Stephanie L Lee, MD, PhD; Chief Editor: George T Griffing, MD, Medscape reference library
Objectives
• Name the most common causes of
hyperthyroidism
• Distinguish between the different causes by use
of labs and imaging
• List the clinical features associated with
hyperthyroidism
• Name the treatment options for hyperthyroidism
• Identify complications of hyperthyroidism
Etiology
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Autoimmunity (Graves disease)
Toxic multinodular goiter (Plummers disease)
Toxic adenoma
Subacute thyroiditis (deQuervains thyroiditis)
Struma ovarii
Iodide induced thyrotoxicosis (Jod-Basedow)
Molar pregnancy
Metastatic follicular thyroid carcinoma
Comparing the most common causes
Cause
%
Sex
Peak Age
Graves
50-60%
7.5>1
20-40
Higher thyroid levels seen
Subacute
15-20%
2>1
Varies
Tenderness noted / decreased
uptake on scan
Toxic MN goiter 15-20%
3>1
>50
More common if iodine def.
Toxic adenoma
3>1
20-50
Single nodule
3-5%
Graves Disease
• Most common cause
• Autoimmune modulated
– Thyroid stimulating immunoglobulin (TSI)
– Anti thyroid peroxidase (anti-TPO)
• Diffusely enlarged gland
• Can be associated with other autoimmune disease
• Can remit with oral medications***
Subacute thryoiditis
• Destructive release of preformed thyroid
hormone
• No 123I uptake in thyrotoxic phase
• Granulomatous infiltration noted***
• Can have spontaneous remission
Toxic multinodular goiter
• Usually in older individuals with long
standing goiter
• Usually only mild elevation in thyroid
hormones
• Can be worsened with iodine exposure
(contrast / amiodarone)
– Can set off thyroid storm
• apathetic hyperthyroidism
• No spontaneous remission
Toxic adenoma
• Single hyperfunctioning follicular thyroid
adenoma
• 123I usually shows the hot nodule
• Does not remit spontaneously
Clinical Presentation
• Symptoms
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Nervousness
Anxiety & Hyperactivity
Diarrhea
Increased perspiration
Heat intolerance
Tremor
Palpitations
Weight loss despite increased
appetite
– Reduction in menstrual flow or
oligomenorrhea
• Signs
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Hyperactivity
Tachycardia or atrial arrhythmia
Systolic hypertension
Warm, moist, smooth skin
Lid lag
Stare
Tremor
Muscle weakness
Physical Exam
• General
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• Neck exam
Anxious
Tachycardia
Elevated blood pressure
Tremor
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• Derm
– Thickening of skin
– Enlarged thyroid
– Pain vs. no pain
– Bruits
HEENT
– Periorbital edema
– Proptosis
Evaluation – Labs
• Thyroid Stimulating Hormone (TSH)
– most reliable screening method for assessing thyroid function
• T4, T3
– 99% protein bound
– Used to estimate degree of thyrotoxicosis
• Anti-Thyroid peroxidase (TPO)
• Thyroid stimulating Immunoglobulin (TSI)
– More impt than TPO if thinking about graves disease
Goldman’s Cecil Medicine, 24th Ed. Figure 233-3
Evaluation - Imaging
Common Forms (85-90% of cases)
Radioactive iodine uptake
Diffuse toxic goiter (Graves disease)
Increased
Toxic multinodular goiter (Plummer disease)
Increased
Thyrotoxic phase of subacute thyroiditis
Decreased
Toxic adenoma
Increased
Less Common Forms
Iodide-induced thyrotoxicosis
Variable
Thyrotoxicosis factitia
Decreased
Uncommon Forms
Pituitary tumors producing thyroid-stimulating hormone
Increased
Excess human chorionic gonadotropin (molar pregnancy/choriocarcinoma)
Increased
Pituitary resistance to thyroid hormone
Increased
Metastatic thyroid carcinoma
Decreased
Struma ovarii with thyrotoxicosis
Decreased
Imaging Views
Complications
• Non-specific changes
– Weight loss
– Fatigue
• Cardiac
– Atrial fibrillation
– High output cardiac
failure
– Right heart failure
– Pulmonary HTN
• Eyes
– Proptosis
– Extraocular muscle
dysfunction
• Pretibial edema (pain)
Subclinical hyperthyroidism
• No symptoms
• Low TSH, normal T4
• Risks
– Osteoporosis
– Atrial fibrillation
– Hypercalcemia
• Medications
Treatment
– Symptomatic relief
– Antithyroid drugs
• Surgery
• Radioactive 131I
• Note the difference for
treatment:
– Subclinical thyroiditis
– Subacute thyroiditis
(DeQuervain’s)
Treatment – Symptomatic care
• Tachycardia, tremors
– -blockers or Calcium channel blockers
• Eyes
– Artificial tears, protection
– Corticosteroids, surgery and radiation for severe
cases
Antithyroid medications
• Methimazole
– More potent and longer acting
• Propylthiouracil (PTU)
– Can be used during pregnancy (1st trimester)
– Severe liver problems noted
– Usually second line drug
• Titrated every 4 weeks
Surgery
• Severe hyperthyroidism in children
• Pregnant women who are noncompliant or intolerant of
antithyroid medication
• Patients with very large goiters or severe ophthalmopathy
• Patients who refuse radioactive iodine therapy
• Refractory amiodarone-induced hyperthyroidism
• Patients who require normalization of thyroid functions
quickly, such as pregnant women, women who desire
pregnancy in the next 6 months, or patients with unstable
cardiac conditions
Surgery
• Preoperatively
– Antithyroid medications until stable TSH
– -blockers for heart rate < 80
– Iodine (as super saturated potassium iodide SSKI)
• Risks
– Recurrent laryngeal nerve damage
• Damage 1 – trouble talking
• Damage both – pt gonna die by suffocation
– Damage to parathyroid glands
• Hypoparathyroidism – low calcium in the blood
Radioactive
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131I
Most common treatment in US
Single oral dose
Expected to become hypothyroid with treatment
Cannot use in pregnancy or breastfeeding
Can worsen eye disease if present
– reduced by glucocorticoid therapy
• Can exacerbate thyrotoxicosis transiently
Thyroid Storm
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Thyrotoxicosis
Acute, life-threatening hypermetabolic state
Adult mortality is ~90% untreated (20%)
Bimodal peak 10-15 year old and 30-40 year
olds
Presentation of thyroid storm
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Fever
Sweating
Weight loss
Respiratory distress
Diarrhea
Jaundice
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Anxiety
Mental status change
Seizures
High output CHF
Hypertension to
hypotension (shock)
Causes of thyroid storm
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Bodily stressors
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Sepsis
Surgery
Anesthesia induction
Radioactive iodine (RAI) therapy
DKA
Drugs (anticholinergic and adrenergic drugs such as pseudoephedrine; salicylates;
nonsteroidal anti-inflammatory drugs [NSAIDs]; chemotherapy)
Excessive thyroid hormone (TH) ingestion
Withdrawal of or noncompliance with antithyroid medications
Direct trauma to the thyroid gland
Vigorous palpation of an enlarged thyroid
Toxemia of pregnancy and labor in older adolescents; molar pregnancy
Differential of thyroid storm
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Anxiety Disorder or Panic Disorder
Congestive Heart Failure
Hypertension
Hyperthyroidism
Pheochromocytoma
Supraventricular Tachycardia, Atrial Ectopic
Tachycardia
Evaluation of thyroid storm
• TSH will be low
• T4 will be high
• Other studies to rule things out
Treatment of thyroid storm
• Stabilize the patient’s CV status
• Control hyperthermia as needed
• Antiadrenergic drugs (beta blockers)
– Propranolol
• High dose PTU
– Blocks T4 output and T4-T3 conversion
• SSKI to block thyroid hormone release (start after antithyroid medicine)
• Glucocorticoids to decrease peripheral conversion
References
• Goldman’s Cecil Medicine, Chapter 233
• http://emedicine.medscape.com/article/9217
07-overview