Endocrine Salt

Question 1

High urine osmolality after fluid deprivation:
High urine osmolality after desmopressin
Normal > 600

Answer 1

primary polydipsia

Question 2

LOW urine osmolality after fluid deprivation:
LOW urine osmolality after desmopressin

Answer 2

Nephrogenic DI

Question 3

LOW urine osmolality after fluid deprivation:
HIGH urine osmolality after desmopressin

Answer 3

Cranial DI

Question 4

Define DI

Answer 4

• is a lack of secretion of ADH (cranial)
• lack of response to ADH (nephrogenic).

Question 5

Function of ADH

Answer 5

= urine conc rises and water loss is reduced.

Question 6

5 Causes of Nephrogenic DI

Answer 6

1. AVPR2 gene (=ADH receptor abnormality
   2.aquaporin 2 channel gene mutation
   3.electrolytes: hypERcalcaemia, hypokalaemia
   4.Drugs - lithium & demeclocycline
2. tubulo-interstitial disease: obstruction, sickle-cell, pyelonephritis

Question 7

RX nephrogenic DI

Answer 7

Hydrochlorothiazide - inhibits NACL transport in the DCT = Na excretion.

Question 8

What is Cranial DI

Answer 8

ADH is produced

Question 9

3 causes PsudoHyponat.

Answer 9

Multi myeloma
hyperlipidaemia
TURP syndrome
Isotonic hyponat

Question 10

3 Causes of hypervol. HypoNa

Answer 10

1.cirrosis
2.HF
3. Nephrotic syndrome

Question 11

Causes HYPOvol hypoNa

Answer 11

1. D & V
2. diarretics
3. Cerebral salt wasting

Question 12

How to divide Euvol HypoNa (2)

Answer 12

1. Concentrated Urine - SIADH, Hypothyroid
2. Dilute urine : Causes Alcohol, drink too much hater

Question 13

Causes of Urinary sodium > 20 mmol (Not the same as osmolality)
-hypovolemic (5)
-EUvolemic ()

Answer 13

Peeing out salt
Na depletion, renal loss
1. hypovolaemic -diuretics: thiazides, loop diuretics
* Addison’s disease
* diuretic stage of renal failure
EUvolemic - SIADH, hypothyroid

Question 14

Causes of SIADH (5)

Answer 14

1. Malignancy- small cell lung ca
2. Neurological -stroke, SAH,SDH,Meningitis/encephalitis/abscess
3. Infections- TB, pneumonia
   4, Drugs
   sulfonylureas*
   * SSRIs, tricyclics
   * carbamazepine
   * vincristine
   * cyclophosphamide
4. Other causes -(PEEP)
   * porphyrias

Question 15

RX Severe Symptomatic hyPONa?

Answer 15

• 3%Hypertonic solution is given bolus of 300 ml then repeat Na measurement every 20min;
• bolous 150 over 20 min until increase of 5 mmol of serum sodium is achieved

Question 16

what IX is desmopressin use to investigate
what does Dexamethasone Ix

Answer 16

• DI
  -cushing