Disorders of Sodium

Question 2

Describe the mechanisms involved in sodium homeostasis.

Answer 2

Question 3

Define the following terms:
1. hypernatremia
2. osmolality
3. osmolarity - how is it calculated?

Answer 3

Question 4

What clinical features on exam would indicate:
1. hypovolemia

Answer 4

Question 5

What clinical features on exam would indicate:
2. hypervolemia

Answer 5

Question 6

There are renal and non-renal causes of hypernatremia, where renal causes are more common.
What are the renal causes of hypernatremia? Explain how they result in hypernatremia.

Answer 6

Question 7

There are renal and non-renal causes of hypernatremia, where renal causes are more common.
What are the non-renal causes of hypernatremia?

Answer 7

Question 8

List some ddx for hypernatremia.

Answer 8

Question 9

What are the symptoms of hypernatremia ( not all the symptoms - just hypernatremia)

Answer 9

Question 10

What are the symptoms of Diabetes insipidus?

Answer 10

Question 11

What are ALL the common symptoms of hypernatremia?(not specific to hypernatremia).

Answer 11

Question 12

What are the common signs of hypernatremia?

Answer 12

Question 13

How would you investigate DI?

Answer 13

Question 14

List and justify all the investigations for hypernatremia.

Answer 14

Question 15

What is the target for serum sodium?

Answer 15

<145mmol/L

Question 16

What is hypovolemic, euvolemic and Hypervolemic in terms of plasma osmolality? How is it calculated?

Answer 16

Question 17

What is considered to be a diluted urine vs concentrated urine in term of urine osmolality?

Answer 17

Question 18

What measures can be taken to prevent hypernatremia?

Answer 18

Question 19

How is the desmopressin stimulation test and water deprivation test aid in the dx of DI?

Answer 19

Question 20

Outline the acute management of hypernatremia.

Answer 20

First we need to determine the diagnosis => random blood glucose and 24-hr urine collection,
Why don’t we want to correct faster than 1/hr or 10/24hrs? ———> osmotic demyelination syndrome (oedema)
If cranial DI -> desmopressin, if any other cause => rehydration + electrolytes

Question 21

Outline the management of DI.

Answer 21

Question 22

Outline the full management of hypernatremia.

Answer 22

Question 23

How would you quantify hyponatremia>

Answer 23

serum Na <135mmol/L

Question 24

What is the pathophysiology of hyponatremia?

Answer 24

Question 25

What are the causes of psuedo-hyponatremia?

Answer 25

Question 26

How would you classify the causes of hyponatremia?

Answer 26

1. Renal loss vs renal compensation (urine na < 20 vs >40) 2. hypovolaemia, euvolaemia and hypervolaemia.

Question 27

What the causes of a hypovolemic hyponatremia?

Answer 27

Question 28

What the causes of a euvolemic hyponatremia?

Answer 28

Question 29

What the causes of a hypervolemic hyponatremia?

Answer 29

Question 30

What are ALL the causes of hyponatremia?

Answer 30

Question 31

Define SIADH

Answer 31

Question 32

What is the diagnostic criteria for SIADH?

Answer 32

Question 33

What are the common symptoms of hyponatremia?

Answer 33

Question 34

What questions would you ask a patient presenting with a suspected hyponatremia? include symptoms.

Answer 34

Question 35

What are the common exam findings of hyponatremia?

Answer 35

Question 36

Give 6 investigations for hyponatremia?

Answer 36

Question 37

What other imaging investigations can be done to determine the cause of hyponatremia?

Answer 37

Question 38

Outline the acute management of hyponatremia. What is the aim of acute management?

Answer 38

aim - rise by 4-6mmol

Question 39

Outline the long-term management of hyponatremia. What is the aim of long-term management?

Answer 39

Question 40

Outline the full management of hyponatremia.

Answer 40

Question 41

What is the main complication of hyponatremia?

Answer 41