Electrolyte Disturbances

Question 1

Normal Potassium Levels

Answer 1

3.5 - 5.2 mmol/L

Question 2

Classic Causes of Hyperkalemia

Answer 2

• increased intake (K+ supplements, diet)
• increased production (hemolysis, rhabdomyolysis, burns, trauma, intense physical activity)
• decreased excretion (acute or end-stage CRF, NSAIDs)
• shifts from intracellular to extracellular as a result of acidosis, insulin deficiency, or some drugs (b-blockers, digoxin, succinylcholine)

Question 3

ECG features of hyperkalemia

Answer 3

• tall tented T waves
• flattened or absent P waves
• prolonger PR interval
• wide QRS
• bradycardia

*may progress to bizarre QRS complexes, sine waves, asystole

Question 4

Pre-hospital treatment for hyperkalemia

Answer 4

• Calcium chloride to stabilize cellular action potential (Indicated for hyperkalemia with cardiovascular toxicity as seen in ECG)
• Sodium Bicarbonate to shift K+ intracellularly (if suspicion of underlying metabolic acidosis)
• Salbutamol to shift K+ intracellularly

Question 5

Calcium Chloride dose for Hyperkalemia

Answer 5

1-2g IV infusion over 10 min, may repeat once if still indicated