Hypo/hypernatraemia

Question 1

How can hyponatraemia be categorised?

Answer 1

hypovolaemia, euvolaemia, hypervoloaemia

Question 2

Below what level of sodium is defined as hyponatraemic?

Answer 2

<130

Question 3

Which is the most common type of hyponatraemia?

Answer 3

euvolaemic

Question 4

How are the serum osmolality and urine osmolality affected in euovolaemic hyponatraemia?

Answer 4

Decreased serum osmolality and increased urine osmolality

Question 5

What is the calculation for serum osmolality?

Answer 5

2 (Na+) + Glucose + Urea (all in mmol/L)

Question 6

In which condition is urine osmolality particularly helpful in investigationg?

Answer 6

SIADH and diabetes insipidus (abnormalities of ADH)

Question 7

How is serum and urine osmolality affected in hypovolaemic hyponatraemia?

Answer 7

decreased serum, increased urine

Question 8

List four examples of hypovolaemic hyponatraemia?

Answer 8

diarrhoea, N/V, burns, shock

Question 9

Which is a serious risk of hypervolaemic hyponatraemia?

Answer 9

cerebral oedema- the resulting decrease in plasma osmolality causes water movement into the brain in response to the osmotic gradient

Question 10

Which fluid should be administered in hypovolaemia associated with hyponatraemia?

Answer 10

0.9% NaCl

Question 11

Provide three causes of hypervolaemic hyponatraemia

Answer 11

1. Heart failure
2. Nephrotic syndrome
3. Liver cirrhosis

Question 12

What is the fluid management of hypervolaemic hyponatraemia?

Answer 12

fluid restriction + diuretic (discuss with senior)

Question 13

Name three causes of euvolaemic hyponatraemia

Answer 13

SIADH, Addison’s!!, cancers

Question 14

What is the fluid management for euvolaemic hyponatraemia?

Answer 14

Severe hyponatraemia + symptomatic= 3%NaCl

fluid restriction in mild hyponatraemia 1.5L

Question 15

What is a serious risk of treating hyponatraemia?

Answer 15

pontine demyelination (irreversible). This results from a quick change in the body’s sodium levels, most commonly due to treatment for low blood sodium (hyponatremia) where the sodium is replaced too quickly. Sometimes, it occurs when a high level of sodium in the body (hypernatremia) is corrected too quickly.

Question 16

In euvolaemic hyponatraemia, what should be closely monitored?

Answer 16

U+Es every 4 hours. If Na+ rises too quickly then stop fluids altogether

Question 17

Three symptoms of hyponatraemia?

Answer 17

n/v, headache, confusion, irritability, pulmonary oedema, coma

Question 18

How can causes of hyponatraemia be divided?

Answer 18

hypovolaemic, hyper, euvolaemic

Question 19

Three causes of hypovolaemic hyponatraemia?

Answer 19

diarrhoea, vomiting
Burns
Diuretics
Addison's
Renal failure

Question 20

Two causes of hypervolaemic hyponatraemia?

Answer 20

cardiac failure
nephrotic syndrome
cirrhosis
renal failure

Question 21

Two causes of euvolaemic hyponatraemia?

Answer 21

SIADH
water overload
glucocorticoid insufficiency

Question 22

Two causes of SIADH?

Answer 22

Head injury, SAH, drugs, SCLC, TB

Question 23

Three symptoms of hypernatraemia?

Answer 23

  Thirst 
  Lethargy 
  Weakness 
  Irritability 
  Confusion, fits, coma 
  Signs of dehydration

Question 24

How can causes of hypernatraemia be divided?

Answer 24

hypo,hyper,euvolaemic

Question 25

Four causes of hypernatraemia?

Answer 25

diarrhoea, vomiting
diuretics
sweating, burns
reduced fluid intake
fever
hyperaldosteronism

Question 26

Three symptoms of diabetes inspidus?

Answer 26

polyuria, polydipsia, dehydration

Question 27

Two types of diabetic inspidus?

Answer 27

nephrogenic

cranial

Question 28

Water regulation impairment is associated with which hormone in diabetes insipidus?

Answer 28

vasopressin/ADH

Question 29

How do you exclude pseudo hyponatraemia?

Answer 29

measure serum osmolality- done in lab, and compare calculated to measured results