Sodium

Question 1

Normal Sodium levels

Answer 1

135 to 145 mEq/L

Question 2

Hypernatremia

Answer 2

> 145 mmol/L.

Question 3

Causes of Hypernatremia

Answer 3

1. MCC -hypovolemia
2. diabetes insipidus
3. diarrhea
4. vomiting
5. diuretics
6. hypertonic saline
7. sodium bicarbonate administration
8. Cushing’s syndrome.

Question 4

How to calculate the free water deficit: formula

Answer 4

Freewater deficit (L)=
0.6 (weight (kg) x [(serum Na/140) - 1]

Question 5

Mgmt: mild hypovolemic hypernatremia

Answer 5

infusion of 0.45% saline or 5% glucose.

Question 6

Mgmt: severe hypovolemic hypernatremia

Answer 6

1. Do not correct Na+ concentration faster than 1mmol/L/hr
2. Initially 0.9% saline to correct hypovolaemia (patients who have tachycardia, hypotension, or postural hypotension).
3. Once the patient is euvolaemic, use an
   infusion of 0.45% saline or 5% glucose (preferred)

Question 7

Complications of rapid Na+ correction

Answer 7

Cerebral edema (worsening of neurological sx)
seizures,
subdural and intracerebral haemorrhages
ischaemic stroke
dural sinus thrombosis

Question 8

Mgmt: euvolemic/hypervolemic hypernatremia

Answer 8

5% dextrose in water in treatment of
choice

Question 9

Hyponatremia

Answer 9

130 mmol/l
can lead to seizures

Question 10

Rapid correction of Hyponatremia

Answer 10

correction or serum sodium
should not exceed 0.5 mEq/L/hr to avoid causing irreversible damage to brain by osmotic demyelination
or central pontine myelinolysis

Question 11

Patients with serum sodium

Answer 11

1. 130-135 mEq/L are usually asymptomatic
2. 120-130 mEq/L may be asymptomatic or display mild symptoms (lethargy,forgetfulness).
3. <120 mEq/L may have severe symptoms (eg, profound confusion, seizures, coma).

Question 12

Causes: hypovolemic Hyponatremia

Answer 12

acute blood loss
GIT: vomiting/diarrhea
Renal: diuretics
Primary adrenal insufficiency

Question 13

Causes: Euvolemic Hyponatremia

Answer 13

SIADH
Primary polydipsia
Secondary adrenal deficiency
Hypothyroidism

Question 14

Causes: hypervolemic Hyponatremia

Answer 14

CHF
Cirrhosis
CKD/nephrotic synd

Question 15

acute hyponatremia

Answer 15

<24 hours

Question 16

chronic hyponatremia

Answer 16

> 24 hours

Question 17

Mgmt: mild acute hyponatremia

Answer 17

Fluid restrictions

Question 18

Mgmt: symptomatic acute hyponatremia-seizures/raised ICP

Answer 18

200mL of 2.7% saline IV over 30min and recheck
serum Na+ levels.
The correction should not be more than 0.5 mmol/L/hr

Question 19

Mgmt: chronic hyponatremia

Answer 19

1. mostly seen in hypokalemia/chronic alcoholics
2. should not exceed d10 mmol/L in 24 hours
3. Treat the underlying cause
4. 200mL of 2.7% saline over 30min and recheck serum Na+). Aim to i serum Na+ by no more than 5mmol/L using
   this method.

Question 20

Mgmt: chronic Hypervolemic hyponatremia

Answer 20

Fluid restriction