Fluid & electrolyte imbalance

Question 1

What are the symptoms of hypernatramia. (normal value = 133 - 146 mmol/L)

Answer 1

Convulsions
Hypovolaemia - decreased volume of circulating blood in the body.
Thirst
Dehydration
Oliguria - low urine output
Postural hypotension
Tachycardia

Question 2

What are some drugs that cause hypernatraemia?

Answer 2

COC
Corticosteroids
Na bicarbonate
Na content in intravenous Abx
Li

Hypernatraemia caused by volume depletion, e.g. diabetes insipidus by IV gluclose

Question 3

What are the symptoms of hyponatraemia (normal value = 133 - 146 mmol/L)

Answer 3

Drowsiness
Confusion
Convulsions
N/V
Headaches
Cramps

Question 4

What are some drugs that can cause hyponatraemia?

Answer 4

Antidepressants
Loop and thiazide diuretics
Carbamazepine
Desmopressin

Question 5

What would you treat mild-moderate hyponatraemia.

Answer 5

ORAL NaCl / Na bicarbonate (add glucose if there is water depletion)

Question 6

What would you treat sever hyponatraemia?

Answer 6

IV Saline (isotonic: via. peripheral vein OR concentrated: via central vein)
Give slowly; risk of osmotic demyelination syndrome

Question 7

What would you give to a person for REHYDRATION and they have an electrolyte imbalance?

Answer 7

• Oral rehydration therapy (K+, Na+, glucose)
  This is given over 3 - 4 hours in diarrhoea
  Over 12h in hypernatraemic dehydration, e.g. diabetes insipidus

Question 8

What would you give a person for REHYDRATION if they have a water deficit?

Answer 8

• INTRAVENOUS GLUCOSE

Should not be given alone unless there is no significant loss of electrolytes, e.g. hypercalcemia or diabetes insipidus.

Question 9

What would you use to treat metabolic acidosis (hyperchloraemia)?

Answer 9

Normal value (Cl-) = 103 mmol/L

• Na bicarbonate
• If caused by low K+ = K bicarbonate

Question 10

What would you use to treat a Ca2+ imbalance? (Hypercalcaemia and hypercalciuria (secondary from high Ca2+)

Answer 10

Normal range = 2.10 - 2.58 mmol/L corrected

Hypercalcaemia = BISPHOSPHONATES or CORTICOSTEROIDS.

Question 11

What would you use to treat hypercalcaemia of malignancy?

Answer 11

Calcitonin

Question 12

What would you use to treat hypercalcaemia caused by hyperparathyroidism?

Answer 12

CINALCET reduces parathyroid hormone therefore Ca2+

PARACALCITOL - in chronic renal failure

Question 13

What would you use to treat hypercalciuria?

Answer 13

BENDROFLUMETHIAZIDE - increase fluid intake and reduce dietary Ca2+

Question 14

What would you use to treat milk-moderate hypocalcaemia?

Answer 14

Low Ca2+ can cause osteoporosis.

VITAMIN D & CA SUPPLEMENTS

Question 15

What would you use to treat severe acute hypocalcemia or hypocalcaemic tetany?

Answer 15

SLOW IV CA GLUCONATE (too rapid = arrhythmias)

Question 16

What would you treat for hypomagnesaemia?

Answer 16

Normal range = 0.7 - 1.05 mmol/L
IV/IM Mg sulphate

This is common in alcoholics.
Low Mg can lead to hypos in Ca2+, K+, and Na+

Question 17

What would you use to treat hyperphosphatemia?

Answer 17

CALCIUM CONTAINING PREPS
(phosphate-binding agent) = e.g. Ca acetate with MgCO3; lanthanum for ppl with chronic renal failure; Ca acetate.
Normal range = 0.85 - 1.45 mmol/L

Question 18

What would you treat patients with hypophosphataemia?

Answer 18

PHOSPHATE.

Give intravenously if moderate to severe.

Question 19

What are the symptoms of hyperkalaemia?

Answer 19

Normal range = 3.5 - 5.3 mmol/L
Ventricular fibrillation
Cardiac arrest

Question 20

What dugs can cause high K+?

Answer 20

Heparin
ACEi
ARBs
Digoxin
BB
Eplerenone
Amiloride
NSAIDs
Spironolactone

Question 21

What would you use to treat mild-moderate hyperkalemia with no ECG changes?

Answer 21

CALCIUM RESONIUM

Question 22

What would you use to treat acute, severe hyperkalemia > 6.5 mmol/L

Answer 22

SLOW IV CA GLUCONATE

• IV insulin, glucose and salbutamol can be given in addition
• Add Na bicarbonate to correct compounding acidosis. Don’t give via the same line; precipitation = thrombosis

Question 23

What are the symptoms of hypokalaemia?

Answer 23

Muscle hypotonia = decreased muscle tone

Arrhythmias = abnormality of the heart’s rhythm

Question 24

What are some drugs that can cause hypokalemia?

Answer 24

Diuretics
Insulins
B2 agonists
Theophylline
Corticosteroids

Question 25

What would you use to treat mild hypokalemia?

Answer 25

ORAL SLOW KCL

• N/V cause poor compliance
• Smaller doses in renal impairment
• If caused by diuretic = K+-sparing diuretic preferred

Question 26

What would you use for severe hypokalaemia?

Answer 26

IV KCL

• Don’t add glucose for initial K replacement as glucose causes hypokalemia
• KCL injection overdose is fatal = use read-mixed solution OR thoroughly mix concentrate

Question 27

What is acute porphyrias?

Answer 27

This is a genetic defect in haem biosynthesis.

If certain drugs are taken haemolytic anaemia and acute porphyric crises can occur.

Question 28

How would you treat acute porphyric crises?

Answer 28

Haem Arginate for moderate, severe or unremitting crises.

Question 29

What is SPN?

Answer 29

Supplementary Parenteral Nutrition.

This is given in addition to PO/enteral feeds

Question 30

What is TPN?

Answer 30

Total Parenteral Nutrition. This is the sole source of nutrition.

• Glucose is given via a central vein to avoid thrombosis
• Give enough phosphate to allow the phosphorylation of glucose
• Fructose and sorbitol are added to avoid hyperosmolar hyperglycaemia and nonketotic acidosis.
• Don’t add additives to fat emulsions unless compatibility known