Hyponatraemia

Question 1

Approaching electrolyte abnormalities

Answer 1

Symptoms
Severity
Timeline
Intravascular volume

Question 2

Symptoms

Answer 2

Confusion mod
Nausea 
Vom severe
Seizures
LOC
Cerebral oedema
Coma, Resp arrest, Death

Question 3

Insidious confusion

Answer 3

Chronic hyponatraemia

Question 4

Severity

Answer 4

<135 mild
<130 moderate
<125 severe

Question 5

Chronic hyponatraemia

Answer 5

Risk of poor outcome if correction is too quick

Question 6

Timeline

Answer 6

Is it acute or chronic?

Question 7

Determining fluid status

Answer 7

In exam:
Dry-> hypovolaemic
Normal -> euvolaemic
Wet -> hypervolaemia

Question 8

Urine

Answer 8

Check urine sodium
Paired osmolality:
Check urine osmolality + blood osmolality

Question 9

High blood osmolality

Answer 9

Lab mistake: with lots of fat/protein/Ig

Question 10

High blood sodium

Answer 10

.?

Question 11

Serum osmolality

Answer 11

Should be 275 - 295 normally

Should be low if hyponatraemic

Question 12

Hypovolaemic causes

Answer 12

.?

Question 13

Diuretics which cause hyponatraemia

Answer 13

Thiazides diuretics -> stop diuretic allow it to increase alone

Question 14

Management of severe acute hyponatraemia

Answer 14

3% saline
Check again in an hour
4-6 mmol increase in a few hours
No >10 in trust 24 hrs!!

Question 15

Osmotic demyelination syndrome

Central pontine demyelination

Answer 15

If sodium rises too quickly
Confusion
Dysarthria
Dysphasia
Locked in syndrome

Question 16

Euvolaemic hyponatraemia

Answer 16

SIADH:
high urine osm >100
Hyperthyroidism

Question 17

Common causes

Answer 17

Diarrhoea vom
Thiazides
SIADH
Cirrhosis HF