BY

KANZA KHALID

BUSHRA KHAN

1866……

– “If a surgeon should be so

foolhardy as to undertake it

[thyroidectomy] … every step of

the way will be environed with

difficulty, every stroke of his knife

will be followed by a torrent of

blood, and lucky will it be for him

if his victim lives long enough to

enable him to finish his horrid

butchery.” Samuel David Gross Samuel

1920…. “feat which today can be

accomplished by any

competent operator

without danger of mishap”

(William Halsted)

The thyroid gland secretes two principal hormones –

THYROXINE (T3) AND TRIIODOTHYROXINE (3).

These major metabolic hormone are required for homeostasis of

all cell and influences cell differentiation ,growth , and

metabolism

HYPERTHYROIDISM Hyperthyroidism is the overproduction of thyroid

hormones by an overactive thyroid.

THYROTOXICOSISThyrotoxicosis is defined as the clinical syndrome of hypermetabolism resulting from increased free thyroxine (T4) and/or free triiodothyronine (T3) serum levels

CLINICAL FEATURES OF HYPERTHYROIDISMSudden weight loss

Rapid heartbeat (tachycardia) — commonly more than 100 beats a minute — irregular heartbeat (arrhythmia) or pounding of your heart (palpitations)

Increased appetite

Nervousness, anxiety and irritability

Tremor — usually a fine trembling in your hands and fingers

Sweating

Changes in menstrual patterns

Increased sensitivity to heat

Changes in bowel patterns, especially more frequent bowel movements

An enlarged thyroid gland (goiter)

Fatigue, muscle weakness

Difficulty sleeping

Skin thinning . Fine, brittle hair

WHAT IS GOITER?? A goitre is a swelling of

the neck or larynx resulting from enlargement of the thyroid gland (thyromegaly), associated with a thyroid gland that is not functioning properly.

INDICATIONS FORTHYROIDECTOMY

Thyroid cancer

Toxic thyroid nodule (produces too much thyroid hormone)

Multinodular goiter (enlarged thyroid gland with many nodules), especially if there is compression of nearby structures

Graves' disease, especially if there is exophthalmos (bulging eyes)

Thyroid nodule, if fine needle aspirate (FNA) results are unclear[

TYPES OF THYROID SURGERIES Thyroid lobectomy to remove a nodule (solitary hot or

cold nodules) and goitres that occur in one lobe. Partial thyroid lobectomy to remove a solitary nodule in

one specific part of the thyroid. Thyroid lobectomy with isthmectomy for benign

Hürthle cell tumours and for non-aggressive thyroid cancers.

Subtotal thyroidectomy (leaving enough of the gland to produce some hormones) is now little used and has been replaced by total thyroidectomy or thyroid lobectomy alone.

Total thyroidectomy for thyroid cancers, Hürthle cell tumours and also increasingly for multinodular goitres and patients with Graves' disease.

HISTORY History of onset, duration, rate of growth

History suggestive of primary or secondary thyroid toxicity

History of pain

History of palpitation, precordial pain, exhaustion

History of pressure effects- like dyspnoea, dysphagia, hoarseness of voice.

Past history/family history.

Personal history-diet, menstrual, mental attitude, sleep

PHYSICAL EXAMINATION General appearance

Vital signs

Respiratory system

CVS system

Abdomen

Extremities and spine

Neurologic system

GENERAL PHYSICAL EXAMINATION Built, nourishment

Fullness of thyroid region, pallor, icterus, cyanosis,

clubbing, oedema

Temperature, Sleeping pulse rate, blood pressure

Skin- hot and moist palm

Tremors

Mental status-anxiety, nervousness.

Airway assessment

Local examination Inspection :

Whether diffuse/ nodular swelling

Pizzillo's method : in obese and short necked patient hands are placed behind head and patient is asked to push head backwards against her clasped hand. Ask the patient to swallow, thyroid slowly moves upwards on deglutition.

Pemberton's sign : Patient is asked to raise both the arm over his head until they touch the ears. This is maintained for a while, congestion of face and distress becomes evident because of obstruction of great veins at thoracic inlet.

Palpation:

Percussion : Over manubrium sterni to exclude

presence of a retrosternal goiter.

Auscultation : A systolic bruit may be heard over

goiter due to increased vascularity in primary toxic

goiter.

Systemic examination CVS :

Enlarged heart

Atrial fibrillation

Signs of CCF.

Systolic murmurs

CNS :

Myopathy and tremors

Reflexes- hyperreflexia

INVESTIGATIONS Complete Blood Count, BT, CT to rule out

anemia, thrombocytopenia and agranulocytosis.

Urine Albumin, Sugar, Microscopy

RBS, B. Urea, Serum creatinine

ECG- Sinus tachycardia, ST elevation, QT shortening, atrial fibrillation/flutter, ventricular ectopics

INVESTIGATIONSTHYROID FUNCTION TESTS:

TSH Assay : single best test of Thyroid Hormone action at cellular level.

Normal level : 0.4-5.0 mU/L.

Subclinical hyperthyroidism : TSH level is 0.1-0.4mU/L with normal FT3 & FT4.

Overt hyperthyroidism : TSH level is <0.03mU/L with increased T3 & T4.

Thyroid Storm : TSH level is <0.01mU/L.

Free T4 (FT4) : approx 0.02% of total T4.

Elevated in 90% of patients with hyperthyroidism.

Decreased in 85% of patients with hypothyroidism

Radioactive iodine uptake : I123, I131 & Tc99

Varies directly with functional state of thyroid.

24 hr thyroid uptake is measured.

Normal value range – 10-25%

Used to confirm Hyperthyroidism

Ultrasonography: to differentiate between cystic, mixed or solid lesion in gland.

Thyroid scan using I123 or Tc99 evaluate nodules as

Warm/ Normal

Hot/ Hyperfunctioning.

Cold/ Hypofunctioning.

CHEST X-RAY PA view- position of trachea,

deviation, retrosternal goiter,

calcification.

Lateral view and barium

swallow- pressure effects on

trachea and oesophagus

CT scan and MRI scan-for airway evaluation and extension of thyroid.

Difficult tracheal intubation in thyroid surgery 6% of tracheal intubations for

thyroid surgery will be difficult.

When conventional methods of laryngoscopy and endotracheal intubation do not provide airway management. The best choice is

Fiberoptic intubation. If fiberoptic bronchoscope

is not available, mask ventilation, laryngeal mask, combitube, nasotrachealintubation, rigid bronchoscope intubation.

MEDICAL TREATMENT OBJECTIVES

Making the patient asymptomatic

Making a thyrotoxic patient euthyroid before surgery

WHAT IS EUTHYROIDISM?? Euthyroid is clinically assessed by-

◦ Sleeping pulse rate < 90/min

Progressive weight gain

◦ Disappearance of toxic symptoms like tremors, nervousness, anxiety etc .

◦ No requirement of sedation for sleep.

◦ Normal pulse pressure, sinus rhythm, disappearance of cardiac murmurs

Making the patient Euthyroid

• Anti thyroid drugs : Carbimazole vs. PTU

• Start Carbimazole 10-30 mg/day based on severity of symptoms and time left for surgery

• Call back after 6 weeks and reassess

MAKING THE PATIENT ASYPMTOMATIC

Beta blockers

• Reduces myocardial oxygen consumption, reduces heart rate, improves myocardial efficiency

• Used to prepare patients for surgery• Used with caution in patients with

congestive heart failure, bronchial asthma• Useful in thyrotoxic crisis

ANTITHYROID DRUGS CARBIMAZOLE: commonest drug used.

Dose: 5-10mg, 8hrly.

Maintenance Dose: 5mg 6-24 months.

Blocks the synthesis of thyroid hormones.

Suppresses the autoimmune process in Grave’s disease.

METHIMAZOLE: Alike carbimazole. Dose is 5-20mg daily.

ANTI THYROID DRUGS PROPYLTHIOURACIL:

Blocks thyroid hormone synthesis.

Blocks peripheral conversion of T4 to T3.

Decreases thyroid autoantibody levels.

Safe to be given in children and pregnancy.

Dose: 200mg 8hrly.

Side Effects: agranulocytosis and aplastic anemia

BETA BLOCKERS β-Blockers reduces the cardiac symptoms .

Blocks peripheral conversion of T4 to T3.

Propranolol 80 -160 mg once daily

Atenolol 25-100 mg once or twice daily

Metoprolol 50 - 200 mg divided 2 or 3 times per day

IODIDES Saturated solution of potassium iodide: 1-3 drops 3

times per day

Lugol’s solution (5%Iodine +10%KI) : 5 drops 3 times per day dissolve in a full glass of water

Iodide therapy added 1 wk before surgery and continued through the day of surgery

Involution of the gland

Decreases its vascularity, (decreased rate of

intraoperative blood loss)

• Contraindicated in toxic multinodular goiter and AFTN

BLOCK AND REPLACEMENT TREATMENT

It is giving high dose of carbimazole to inhibit T3 and T4 production completely with a maintainence dose of 0.1 mg of L Thyroxine .It reduces iatrogenic thyroid insufficiency.

For Emergency Surgery

Esmolol 100-300 mcg/kg/min IV until heart rate <100/min

Why should a toxic patient beEuthyroid before surgery ?To Prevent

Thyrotoxic crisis

Cardiac arrhythmias and tachycardia

Worsening of co existent medical conditions:

Cardiovascular

Diabetes mellitus

Blood pressure

Hemodynamic compromise

Anesthetic drug interactions

Thyroid Storm Is a life threatening emergency

Characterized by sudden appearance of clinical signs of hyperthyroidism due to the abrupt release of T4 and T3 into circulation.

Mortality is as high as 25% to 30%.

Commonly associated with Grave's disease.

Triggers Trauma

Infection

Surgery

THYROID STORMCLINCAL PRESENTATION 2 most important defining features :

High fever (usually over 40 degrees C)

Significantly abnormal mental status

Agitation, confusion, psychosis, coma

May also exhibit :

Marked tachycardia

Vomiting, diarrhea

Jaundice (in 20 %)

Associated signs of Graves' disease

TREATMENT OF THYROID STORM High flow O2

Rapid cooling if markedly hyperthermic

Ice packs, cooling blanket, mist / fans, nasogastric tube lavage, acetominophen (Salicylates contraindicated because cause peripheral deiodinationto T3)

IV fluid bolus if dehydrated

May need inotropes instead if in CHF

Propranolol 1 mg doses or labetolol 10 to 20 mg doses IV & repeat doses as needed

IV diltiazem +/- digoxin for rate control for atrial fib

IV diuretics if in CHF

IV hydrocortisone (or equivalent) 100 mg

Propylthiouracil (PTU) 600 to 1200 mg PO or by NG

Sodium iodide 1 gram IV one hour after the PTU

Find and treat the precipitating cause

PRE OP ORDERS………. Informed consent

Keep NPO.

Absolute bed rest.

Sedation : Diazepam 2mg-5mg

Resting pulse chart

Patient must be made euthyroid or near euthyroid at operation.

Sleeping pulse rate < 90/min

Progressive weight gain

THANK YOU!!