Adult Medical-Surgical
Nursing
Endocrine Module:
Hypersecretion of the
Thyroid
Secretions of the Thyroid Gland
 The
thyroid secretes Thyroglobulin,
the pre-cursor of:
 Thyroxine (T4)
 Tri-odothyronine (T3) (more potent)
 (under control of Hypothalamus →
TSH from Anterior Pituitary)
 Also
Calcitonin
Functions of Thyroid Hormones
T3 and T4:
 Energy metabolism and moderation of
Basal Metabolic Rate (BMR): oxygen
uptake and consumption at cellular level
 Cell replication and growth
 Brain and nervous development/ function


Calcitonin: Regulation of serum calcium
(lowers while Parathormone raises)
Importance of Iodine for
Thyroid Function
Iodine is essential to the thyroid for
synthesis of hormones (major uptake and
use of iodine in the body)
 Iodine in fish, added to salt, mostly in
H2O
 Iodine from diet + Tyrosine (amino acid)→
T3 and T4
 ↓ iodine in diet leads to ↓ thyroid function
 Most important cause of hypothyroidism
world-wide and enlargement (Goitre)

Hyperthyroidism:
Grave’s Disease (Thyrotoxicosis)
Increased synthesis and release of thyroid
hormones
 Affects metabolism increasing BMR
 Auto-immune condition
 Aetiology:
 Genetic tendency
 Unknown aetiology
 Exacerbated by stress, infection, ↓ iodine

Hyperthyroidism (Auto-immune)
 Thyroid-stimulating
antibodies act
like TSH stimulating thyroid:
 Hyperplasia
 Hypersecretion
 Leads
to gradual destruction of
gland, and eventually to exhaustion,
atrophy and hyposecretion, requiring
HRT
Hyperthyroidism: Pathophysiology
Hyperplasia: thyroid enlargement (“toxic
goitre” as hypersecretion)
 Hypersecretion: increased thyroid
hormone → increased BMR
 ↑ tissue sensitivity to sympathetic
stimulation (adrenoline/ noradrenaline)
 Ophthalmopathy: impaired venous
drainage from the eye orbit (auto-immune
effect), fat deposits and orbital oedema

Hyperthyroidism: Clinical
Manifestations (Thyrotoxicosis)
Goitre with increased pressure on trachea
 Excitability, restlessness, nervousness,
tremor
 Rapid weight loss
 Much increased appetite and thirst
 Fatigue from over-activity → muscle
weakness and exhaustion
 Cannot tolerate heat, flushed, sweating

Hyperthyroidism:
Clinical Manifestations (cont)
 Tachycardia/
tachypnoea: bounding
very rapid pulse (90 – 160/min)
 Increased resting pulse
 Palpitations (dysrhythmias) and
increased pulse pressure
 ↑ peristalsis, diarrhoea, frequent
stools
 Exophthalmos: staring, protruding
eyes (vision not affected)
Hyperthyroidism: Diagnosis
 History
and clinical picture
 Immuno-assay or radio-assay of
hormone levels: TSH, T3 and T4 and
FT4 (free unbound thyroxine)
 Radio-active iodine uptake test
 Needle biopsy of thyroid
 Ulrasound scan
 ECG
Hyperthyroidism:
Medical Management


Anti-thyroid medication (Carbimazole* or
Propylthiouracil): inhibit synthesis of
thyroid hormones by blocking utilisation of
iodine until “euthyroid state” (non-toxic)
Radio-active iodine (I131) gradually
destroys some of thyroid cells. (Patient
must be euthyroid prior. May need 2
treatments. Risks hypothyroidism)
Hyperthyroidism:
Surgical Management
Sub-total thyroidectomy (small amount of
tissue left to regenerate slowly)
 Leaves parathyroid glands intact
 Avoids damage to recurrent laryngeal
nerve
 Pre-op: Patient must be in euthyroid
condition prior to surgery, prepared with
anti-thyroid drugs, iodine (↓ size /
vascularity) and B - blockers (Propanalol)

Sub-total Thyroidectomy:
Risks related to surgery
Airway obstruction from:
 Oedema and pressure on trachea or
stridor (damage and oedema to recurrent
laryngeal nerve)
 Bleeding and haematoma (very vascular)
 Damage/ removal of parathyroids → low
blood calcium levels (Tetany)
 Thyroid crisis (hyperpyrexia, extreme
tachycardia and dysrhythmias, delirium)

Hyperthyroidism:
Nursing Considerations
Patient education
 Monitoring/ supervision during tests
 Pre- and post-operative care especially be
prepared for any post-op emergency:
 At bedside, O2 and suction ready and clipremovers
 Semi-sitting position, well-supported with
pillows
 Careful monitoring all vital signs, wound.
