PUPD + other Endocrine disorders Flashcards
1
Q
What are the main Ddx for PUPD?
A
- Diabetes insipidus
- Osmotic diuresis
- Iatrogenic
- Renal medullary washout - loss of hypertonicity of medulla because of long term PUPD
- Primary polydipsia - problem of thirst centre of brain
2
Q
What can cause diabetes insipidus?
A
- Central DI
- Primary NDI
- Secondary NDI =
-Renal failure
-Hyperadrenocorticism
-Pyometra
-Hypercalcaemia
-Hyperthyroidism
-Pyelonephritis
-Hypoadrenocorticism
-Liver failure
-Hypokalaemia
-Acromegaly
3
Q
What can cause osmotic diuresis?
A
- Diabetes mellitus
- Primary renal glucosuria
- Fanconi’s syndrome - glucose + amino acids in urine
- Post-obstructive diuresis
4
Q
What are iatrogenic reasons for PUPD?
A
- Glucocorticoids
- Diuretics
- Phenobarbitone
- High salt diet
- Levothyroxine
- Vitamin D toxicity
5
Q
What classes as polydipsia?
A
- drinking >100ml/kg/day
6
Q
What would you initial work-up for PUPD be?
A
- History (rule out iatrogenic)
- Physical examination (evidence of renal dz, pyometra…)
- Haematology (evidence of pyometra / pyelonephritis?)
- Biochemistry (hyperCa? hypoNa? renal disease? diabetes?)
- Bile acids (liver disease?)
- T4 (hyperthyroidism?)
- Urinalysis (diabetes, Fanconi’s, renal glucosuria?. Culture to rule out pyelonephritis
- Rule out cushings = dexamethasone suppression test
- Differentiate CDI, primary NDI + primary polydipsia with DDAVP (desmopressin test)
7
Q
What hormones are release from the hypothalamus?
A
- TRH
- GnRH
- CRH
- PRH
- Dopamine
- Somatostatin
8
Q
What hormones are released from pituitary gland?
A
- Anterior lobe = (FLAT PEG)
- TSH
- FSH / LH
- GH
- Prolactin
- Endorphins
- ACTH
- Posterior lobe =
- Oxytocin
- Vasopressin (ADH)
9
Q
What is the pathogenesis of pituitary dwarfism?
A
- Rare congenital lesion (developmental defect in pituitary gland)
- Almost exclusive GSDs
- Failure of GH secretion
- Isolated GH deficiency or combined deficiency
- FSH, LH, TSH
10
Q
What are clinical features of pituitary dwarfism?
A
- Proportionate dwarfism
- Failure to develop adult coat
- Delayed dental eruption
- Delayed growth plate closure
- Thin, fragile, hyperpigmented skin
- Pyoderma
- Immature gonads
11
Q
How is pituitary dwarfism diagnosed + treated?
A
- Dx = rule out other causes of retarded growth,
- Dynamic test to assay GH
- Tx = Progestagens = induce GH secretion - adverse effect
- GH - adverse effects
- Do NOT breed
12
Q
What is pathogenesis of acromegaly?
A
- Excess growth hormone
- cats = pituitary tumour (Older males)
- dogs = mammary tissue (intact females)
13
Q
What are clinical features of acromegaly?
A
- Insulin resistant DM
- Excessive growth of the extremities
- Prognathism, wide interdental spaces
- Soft tissue proliferation
14
Q
Dx + Tx of acromegaly?
A
- Dx =
- Diabetes mellitus
- Liver enzyme elevation
- Elevated IGF-1
- MRI/CT
- Tx = Bitch = OVH / stop progestagens (bony changes irreversible)
- Cat = attempt to control DM, surgery, radiation
15
Q
What is central diabetes insipidus?
A
- Complete / partial deficiency in ADH
- renal collecting tubules = impermeable to water
- Neoplasia / trauma of hypothalamus / posterior pituitary = cause
16
Q
What does PTH do?
A
- Increase calcium reabsorption from kidneys
- increase calcium release from bones
- Increase absorption of dietary calcium in SI
17
Q
What is primary hyperparathyroidism? What does it cause? Dx? Tx?
A
- Functional tumour producing PTH
- Causes hypercalcaemia =
- PUPD
- dehydration
- dystrophic calcification
- Renal damage (AKI)
- Dx =
- High total calcium and iCa
- Normal to low PO4
- High or normal PTH
- Detect mass in thyroid/parathyroid area
- Tx = restore normal calcium level + surgical removal of parathyroid tumour
18
Q
What is secondary hyperparathyroidism?
A
- Renal secondary hyperparathyroidism
- Nutritional - unbalanced diet
19
Q
What is pseudohyperparathyroidism?
A
- Caused by tumour secreting PTH-rp
- Anal sac adenocarcinoma
20
Q
What is hypoparathyroidism? CS? Dx? Tx?
A
- Failure to produce PTH
- CS = hypocalcaemia =
- Anxiety
- Muscle twitching, spasm, tetany
- Weakness, ataxia
- Seizures
- Tachycardia, weak pulses
- Dx = Low calcium + high PO4, Low PTH
- Tx = EMERGENCY = IV fluids + calcium gluconate
- maintenance = oral calcium + Vit. D
21
Q
What are differentials for hypocalcaemia?
A
- Hypoalbuminemia (low total Ca, ionised Ca normal)
- CKD
- AKI
- Eclampsia (puerperal tetany)
- Acute pancreatitis
22
Q
What are pancreatic endocrine diosrders?
A
- Insulinoma - functional tumour of pancreatic B-cells producing insulin = hypoglycaemia
- Gastrinoma - tumour producing gastrin = gastric hyperacidity + risk of ulceration + can have severe signs
23
Q
CS, Dx + Tx of insulinoma?
A
- CS =
- Often episodic (fasting, exercise, excitement)
- Weakness, trembling, ataxia, seizures
- +/- other neurological signs
- May have weight gain
- Dx = Persistent hypoglycaemia, Normal glucose does not exclude, Elevated insulin, Pancreatic mass
- Tx = IV glucose if needed, frequent small meals, prednisolone, surgery
24
Q
Dx + Tx of gastrinomas?
A
- Dx = Elevated gastrin levels, imaging, endoscopy
- Tx = surgical removal - BUT frequent metastases
25
Q
What are signs of phaechromocytoma? Dx? Tx?
A
- CS =
- anxiety
- tachycardia
- tachypnoea
- vomiting
- diarrhoea
- weight loss
- hypertension (retinal detachment)
- Dx = US + urinary / plasma metanephrines
- Tx = Radical excision - BUT frequent metastases
26
Q
What are signs of hyperaldosteronism? Tx?
A
- Adrenal tumour producing aldosterone
= CS = - PUPD
- weakness
- neck ventroflexion (hypokalaemia)
- hypertension (sodium retention)
- Tx =
- restrict sodium and supplement potassium
- surgical excision
- spironolactone (aldosterone antagonist)
Hyperaldosteronism
27
Q
A
