Na+ K+ Ca2+ Mg2+ PO4-

Question 1

Normal range for sodium?

Answer 1

135-145 mmol/L

Question 2

Normal range for potassium?

Answer 2

3.5- 5.3mmol/ L

Question 3

List three drugs that may cause hypernatraemia?

Answer 3

Mineralocorticoids- hydrocortisone, fludrocortisone
Phenytoin
Lithium

Question 4

What are the signs and symptoms of hypernatraemia?

Answer 4

Thirst 
Lethargy 
Confusion 
Irritability 
Restlessness 
Nausea and vomitting 
Fever

Question 5

Can you think of a class of drugs that can cause hyponatreamia?

Answer 5

Antidepressants:
TCAs
SSRIs
MAOIs
Carbamazepine 
Haloperidol

Question 6

What are the signs and symptoms of hyponatreamia?

Answer 6

Can show no symptoms at all until under 120 mmol/ L
Muscle Weakness
Nausea and vomitting
Lethargy 
Seizures/ neurological signs/ coma

Question 7

What does hypervolemia mean?

Answer 7

It is a state of decreased blood volume; more specifically, decrease in volume of blood- Hypovolemia is characterized by sodium depletion (salt depletion)

Hypovolemic shock, also known as hemorrhagic shock, is a life-threatening condition that results when you lose more than 20 percent (one-fifth) of your body’s blood or fluid supply.

Question 8

What can too rapid correction of sodium lead to?

Answer 8

Brain swelling and raised intracranial pressure

Question 9

Hyperkalaemia can be caused by excessive cellular breakdown. What are some examples of this?

Answer 9

Haemolysis
Burns
Surgery
Infection 
Rhabdomylosis

Question 10

How does hyperkalaemia result in arrhythmias?

Answer 10

Abnormal levels affect excitability of nerve and muscle tissue (myocardial tissue), leading to arrhythmias (NB this also caused by hypokalaemia)

Question 11

What drugs can cause hyperkalaemia? How?

Answer 11

ACE inhibitors

K+ sparing diuretics- 
Amiloride
Triamterene
Eplerenone
Spironolactone
Trimethoprim

Heparins

Theophylline

Renal K+ excretion is mediated by aldosterone and sodium (Na+) delivery.. These drugs impair aldosterone synthesis

Question 12

How do we manage hyperkalaemia?

Answer 12

1) protect the myocardium using Calcium GLUCONATE 10%
2) Move K+ back into cells using INSULIN (Actrapid- give in 20% dextrose to counteract hypoglycaemia)
3) 10mg Salbutamol neb- causes hypokalaemia

Question 13

What can be used to REMOVE K+ in hyperkalaemia?

Answer 13

Dialysis

Calcium resonium

Question 14

What are the signs and symptoms of hyperkalaemia?

Answer 14

Muscle weakness
ECG changes/ arrhythmia
Sudden death

Question 15

Can INSULIN cause hyperkalaemia or hypokalaemia?

Answer 15

Hypokalaemia

Question 16

Do beta-2 adrenergic receptor agonists (e.g. salbutamol), cause hypokalaemia or hyperkalaemia?

Answer 16

hypokalaemia

Question 17

What are the symptoms of hypokalaemia?

Answer 17

Fatigue
Drowsiness
Dizziness
Confusion
Electrocardiographic changes
weakness
Muscle pain.
Arrythmias

Question 18

Hypokalaemia can be corrected through administration of IV potassium 40mmol/L fluids. Why is central administration preferred?

Answer 18

Due to risk of thrombophlebitis with peripheral administration.

Question 19

How can metabolic acidosis result in hyperkalaemia?

Answer 19

acidosis – K+ exchanged for H+ across cell membrane. K+ leaves cells and causes hyperkalaemia.

Question 20

What is the normal range for calcium?

Answer 20

2.15 to 2.6 mmol/L

Question 21

What drugs may cause hypercalcaemia?

Answer 21

Thiazide diuretics

Tamoxifen

Question 22

What is the role of potassium with regard to physiological function?

Answer 22

it is responsible for cellular processes:

resting cell membrane potential and action potentials in neuronal, muscular, and cardiac tissues

Question 23

What is the role of sodium with regard to physiological function?

Answer 23

Osmolarity balance

It regulates blood volume, blood pressure, osmotic equilibrium and pH.

Question 24

What is the role of phosphate with regard to physiological function?

Answer 24

Energy metabolism- Important in energy (ATP) formation and for the structural integrity of cell membrane

Question 25

What is the role of calcium with regard to physiological function?

Answer 25

Calcification of bones and teeth and regulation of metabolism/excitation of nerve cells in cardiac conduction.

Question 26

What is the role of magnesium with regard to physiological function?

Answer 26

Hormone regulation (thyroxine, GH, PTH, aldosterone, ADH, calcium magnesium pump)

Question 27

What are the signs/ symptoms of hypocalcaemia?

Answer 27

``` Numbness or burning in the extremities Tingling General malaise Confusion Prolonged QT interval/ ECG changes Muscle cramps ```

Question 28

What is the normal range of magnesium?

Answer 28

0.7-1.0 mmol/L

Question 29

What drugs can cause low magnesium?

Answer 29

Diuretics Digoxin Amphotericin Aminoglycosides- gentamicin, amikacin

Question 30

What are the signs and symptoms of low magnesium?

Answer 30

``` Irritability Tremor (remember on-call baby scenario) Ataxia- muscle jerks Hallucinations Prolonged QT interval Epilepsy Tachycardia ```

Question 31

What electrolyte deficiency does hypo-magnesia commonly occur with?

Answer 31

Often occurs with hypocalcaemia, and must be treated in order to fully treat low calcium

Question 32

what are the signs and symptoms of Hypermagnesia?

Answer 32

``` Weakness drowsiness Respiratory paralysis Muscle paralysis Nausea and vomiting Bradycardia cardiac arrest ```

Question 33

What class of drugs can cause hyper magnesia?

Answer 33

Antacids

Question 34

What is the normal range for phosphate?

Answer 34

0.8 to 1.4 mmol/L

Question 35

What disease states can give rise to hyperphosphataemia?

Answer 35

Renal insufficiency (especially relate to rhabdomyolysis) HYPOCALCEAMIA Hypoparathyroidism Rhabdomylosis

Question 36

What are the symptoms of hyperphosphataemia?

Answer 36

``` Itching The other symptoms are due to hypocalceamia: Numbness or burning in the extremities Tingling Confusion Prolonged QT interval/ ECG changes Muscle cramps ```

Question 37

Phosphate plasma levels are related to the other electrolyte ________. As the levels of one rises, the levels of the other decline.

Answer 37

Plasma levels are related to calcium | So if calcium levels decrease, phosphate levels rise

Question 38

What disease states can cause hypophosphateamia?

Answer 38

Respiratory acidosis Hyperparathyroidism Chronic diarrhoea Malnutrition- refeeding syndrome

Question 39

What are the methods of replacing potassium or reducing levels if too high?

Answer 39

``` Replace with sando K or IV potassium if required quickly Reduce with: calcium gluconate insulin and glucose salbutamol ```

Question 40

What are the methods of replacing sodium ?

Answer 40

Replace with slow sodium or NaCl 30%

Question 41

What are the methods of replacing calcium ? What can be used if levels are too high?

Answer 41

Replace with calcichew, sandocal or calcium gluconate. If levels too high: Bisphosphonates can be use (Most effective when caused by malignant disease): Pamidronate-After rehydration

Question 42

What are the methods of replacing magnesium ?

Answer 42

Replace with magnesium glycerophosphate or aspartate sachets or magnesium IV

Question 43

What are the methods of replacing phosphate? What if levels are too high?

Answer 43

Replace with Phosphate Sandoz or IV phosphate Calcium salts as phosphate binders Sevelamer (phosphate binding agents) Lanthanum