Endocrinology Flashcards
Symptoms and signs of Hyperthyroidism
Symptoms
- Nervous, anxious, increased perspiration
- Heat intolerance, hyperactivity
- Palpitations
- Diarrhoea
- Wieght loss despire increase in appetite
- oligomenorrhoea
Signs
- Tachycardia or atrial arrhythmia
- Systolic hypertension - wirth wide pulse pressure
- Warm, moist skin
- Lid lag
- Hand tremor
- Muscle weakness
Graves Disease
- Ophthalmopathy –> Exophthalmos, periorbital oedema –> lid lag, lid retration, diplopia
- Goitre
- Pretibial myxedema (hyaluronic acid in the subcutis of the shins)
Causes of hyperthyroidism
Primary hyperthyroidism
- Graves Diseae
- Hyperfunctional Multinodular Goitre
- Hyperfuctnional thyroid adenoma (most carcinomas are not functional)
- Hashitoxicosis (early phase of hashimotos)
- Iodine overload
- Drugs - lithium, thyroixine
- Paraneoplastic syndrome (germ cell tumour e.g. teratoma)
Secondary hyperthyroidism
- Pituitary adenoma –> increase production of TSH
How do you differentiation secondary and primary hyperthyroidism through investigations
- Serum free T4, T3 –> elevated in hyperthyroidism
- TSH –> suppressed in primary disease, not suppressed in TSH mediated disease (secondary)
What are the investigations for thyroid disease
Blood tests
- Free T4, T3
- TSH
- Serum thyroglobulin levels (Tg) –> low levels if exogenous thyroid hormone
- Serum thyroid antibodies
i) Thyroid receptor antibodies –> Grave’s Disease
ii) Thyroid peroxidase –> Hashimotos, Graves
iii) Thyroglobulin antibodies –> Hashimotos, Graves, T1DM, thyroid cancer
Imaging
- Thyroid U/S
- Thyroid scintigraphy (nuclear medicine scan)
- -> Normal thyroid - diffuse uptake of RAI
- -> Graves - enlarged gland with increased RAI uptake
- -> Toxic MNG - multiple nodules both hot and cold
- -> adenoma - hot nodule
Treatment of hyperthyroidism
First line of Graves and MNG:
- Carbimazole 10-45mg orally, daily 2-3 doses (inhibits thyroperoxidase)
Second line of Graves and MNG:
- Propylthiouracil 200-600mg orally, daily 2-3 doses (inhibits thyroperoxidase and periopheral deiodination of T4)
Sympatheric NS treatment e.g. tremor, tachycardia, eyelid retraction
- Propranolol 10mg orally
Other treatments:
- Thyroidectomy and replace T4
- Irradiate gland and replace T4
- Potassium iodide (prevent peripheral deiodination of T4)
Adverse effect of thyroid drugs –> agranulocytosis
Causes of hypothyroidism
Primary
- Hashimoto’s - autoimmune thyroiditis
- Iodine deficiency/ Maternal def.
- Surgery/ irradiation
Secondary
- pituitary adenoma
- pituitary apoplexy
- Sheehan’s syndrome
- head trauma
Symptoms and signs of hypothyroidism
- Weakness, lethargy
- Weight gain
- Dry skin
- cold intolerance
- Constipation
- Depression
- Ammenorrhoea
- Facial oedema
- Bradycardia
- Goitre
Two serious complications of hypothyroidism in childhood and adulthood
Childhood –> Cretinism (Impaired development of skeleton and CNS)
- Short stature, course facial features, protruding tongue and severe mental impairment
Adulthood –> Myxoedema
- Slowing of physical and mental activity
Treatment of hypothyroidism
Thyroxine (T4) 30-100ug/day
*T3 is available as IV formulation, for rapid treatment of life threatening hypothyroidism
Adverse effects - sinus tachycardia, arrhythmias, angina, restlessness, tremor
Causes of hypernatraemia
Hypovolemic
- Dehydration (poor flood intake, diarrhoea)
- Diuretics, osmotic diuretics (hyperglycaemia, uraemia)
Euvolemic
- Diabetes inspidus
Hypovolemic
- Primary hyperaldosteonism
- Cushing’s syndrome
- Iatrogenic - excess NaCl
Clinical features of sodium imbalance
Mild
- Anorexia
- N + V
- Headache
- Muscle cramps
Moderate
- Muscle weakness
- Lethargy
- Confusion
Severe
- Seizures
- Altered consiousness
Symptoms also depend on the onset of sodium imbalance
- Acute onset (<48hrs) usually symptomatic event even with mild sodium derangements
Subacute (>48hrs) usually asymptomatic unless severe derangements are present
Orthostatic hypotension, oliguria, impaired thirst
Investigations and results for hypernatraemia
- Serum sodium concentration - increased
- Serum osmolarity - increased
- Haematocrit - increased in hypovolaemia, dehydration
- Urinalysis - osmolarity > 800mOsmol/kg in extra-renal loss and < 800mOsmol/kg in renal loss
Treatment of hypernatraemia
- Treat underlying cause
- Patients with serum sodium values <>160mEq/L require intensive care
- Careful correction of sodium levels: maximum correction within 24 hours is 10mEq/L (rate of correction: 0.5-1mEq/L per hour)
- Effects of rapid correction - Rapid decrease in serum sodium à risk of cerebral oedema
Correct free water deficit
- Mild hypernatraemia à oral rehydration
- Moderate to severe hypernatraemia à hypotonic saline or 5% dextrose
Hypovolaemia hypernatraemia
- Fluid resuscitation
- Once adequately resuscitation à correct free water deficit
Euvolemic hypernatremia
- Correct free water deficit
Hypervolemic hypernatraemia
- Loop diuretic + 5% dextrose
Causes of hyponatraemia
Investigations in hyponatraemia
Blood tests
- Serum Sodium
- Serum osmolality
- Haematocrit
- ¯ - possibly fluid overload
- - hypovolaemia, dehydration
Urine examination
- Urine sodium concentration
- >20Eq/L implies renal sodium loss
- <20Eq/L implies extra renal sodium loss
Treatment for hyponatraemia
- Treat underlying cause
- Patients with serum sodium values < 120mEq/L require intensive care
- Careful correction of sodium levels: maximum correction within 24 hours is 10mEq/L (rate of correction: 0.5-1mEq/L per hour)
- Effects of rapid correction - Rapid increase in sodium levels à risk of central pontine myelinolysis
Hypovolemic hyponatraemia
- Mild – moderate –> normal saline
- Severe symptoms –> hypertonic saline
Euvolemic hyponatraemia
- Mild – moderate –> fluid restriction
- Severe à hypertonic saline
Hypervolaemia hypnatraemia
- Mild – moderate à fluid restriction +/- loop diuretic
- Severe –> isotonic saline
Symptoms of T1DM
- polydipsia
- polyuria
- weight loss
- blurred vision
- nausea and vomiting
- abdominal pain
- lethargy
Acute complications of T1DM and T2DM
- DKA –> T1DM
- Hypoglycaemia –> over treatment
- Hyperglycaemic hyperosmotic state –> T2DM
Chronic complications of Diabetes
1) Predisposition to infection
2) Microangiopathy
- Diabetic nephropathy - decreased GFR + albuminuria
- Neuropathy - peripheral and autonomic
- Retinopathy - proliferative and non-proliferative
3) Macroangiopathy
- CVD, cerebrovascular disease
- PAD
- HTN
- Diabetic foot
Investigations for diabetes
- Fasting and random plasma glucose
- Fasting glucose - (>7mmol/L – should be between 3.5-5.5mmol/L)
- Casual - 11.0mmol/L
- Plasma or urine ketones
- HbA1c
- >6.5%
iv. Urinalysis
Treatment for T1DM
- Diet and Exercise - Low GI foods
- Monitoring - finger-prick blood test, specialist
- Insulin
First line –> Basal-bolus regiment - Bolus - Aspart 100 units/mL
- Basal - Glargine 100 units/mL
Total insulin 0.5-0.8units/kg for an adult
Side effects –> hypoglycaemia, weight gain, injection site scaring
Can also add sotaglifozin –> SGLT1/2 inhibitor
Causes of DKA
- Insufficient insulin replacement
- Under administration – insulin pump failure, forgotten injection, non-compliance
- Undiagnosed, untreated diabetes
- Increased insulin demand
- Stress –> infection, illness, surgery, trauma, MI
- Drugs etc. –> Glucocorticoid therapy, cocaine use, alcohol abuse
Symptoms and signs of DKA
Symptoms
- Nausea and vomiting
- Fatigue
- Abdominal pain
- Ketotic breath
- Laboured Breathing
- LOC
- Polydipsia and polyuria
Signs
- Dry mucus membranes
- Decreased skin turgor
- Tachycardia, tachypnoea
- Abdominal tenderness
Investigation results in DKA
- Plasma glucose - elevated
- ABG and electolytes
- pH < 7.3
- Increased pO2, K+
- decreased pCO2, bicarbonate, K+ - Capillary or serum ketones - elevated
