potassium abnormalities

Question 1

Name non iatrogenic causes for hypokalaemia

Answer 1

• GI losses
• ectopic ACTH secretion
• renal tubular acidosis
• hyperaldosteronism
• hyperthyroidism

Question 2

Name iatrogenic/ drug causes of hypokalaemia

Answer 2

• IV fluids without K+
• thiazide/ loop diuretics
• corticosteroids
• salbutamol
• theophylline

Question 3

what are the symptoms of hypokalaemia

ECG findings

Answer 3

• asymptomatic
• muscle weakness, cramp, tetany, polyuria
• small/ inverted T waves
• prominent U waves (after T wave)
• prolonged PR
• ST depression

-VF/ VT/ Torsades/ SVT

Question 4

what is classed as mild and severe hypokalaemia?

Answer 4

• mild > 2.5mmol K+ no symptoms

- Severe <2.5mmol K+ or symptomatic

Question 5

how do you treat mild hypokalaemia?

Severe hypokalaemia?

Answer 5

• oral K+
• “Kay- Cee- L/ Sando-K” syrup
• Give 20mmols IV K+ in 500ml NaCl 0.9% over 4 hours
• rate of infusion shouldn’t exceed 20mmol/hr
• ECG monitoring essential
• never give as a bolus

Question 6

What must you never do to treat hypokalaemia?

what may hypokalaemia increase the risk of with other medication?

Answer 6

• IV potassium bolus, causes fatal arrhythmias

- digoxin toxicity, keep levels above 4.0

Question 7

what are the non drug causes of hyperkalaemia?

Answer 7

• renal failure
• burns
• Addisons
• rhabdomyolysis
• hyperglycaemia
• metabolic acidosis

Question 8

what are the drug causes of hyperkalaemia?

Answer 8

• ACE inhibitors
• cotrimoxazole
• K+ sparing diuretics

Question 9

what are the symptoms of hyperkalaemia?

what is the cut off for hyperkalaemia?

Answer 9

• asymptomatic
• Tall tented T waves
• small P waves
• wide QRS complexes
• VF
• > 5.3

Question 10

What is the treatment for hyperkalaemia?

Answer 10

1) Protect myocardium: Give 10mls of 10% calcium gluconate IV bolus over 5-10 mins until ECG improves
2) Drive K+ into cells: 10 units Actrapid and 50mls of 50% glucose IV over 15- 30 mins
3) Nebulised salbutamol 5mg 4x a day

Question 11

what is the indication for refractory hyperkalaemia?

what should be given for maintenance of normal K+?

what monitoring do you need?

Answer 11

• hypertonic IV sodium bicarb
• dialysis
• Calcium resonium (binds K+ in gut), until K+ is <5
• 12 lead ECG
• Daily K+
• renal function and electrolytes
• monitor blood glucose in insulin used