Potassium normal: 3.5-5.5
Hypokalemia:
- Mild: 3.0-3.5, moderate: 2.5-3.0, severe=<2.5
- Common causes: thiazide and loop diuretics, kidney injury, GI loss, sweating, burns, Beta blockers, insulin, sodium bicarbonate
- Every 0.3 mEq decrease is a 100 mEq deficit
- Symptoms start at < 3.0
- Correct Mg too. It’s used in potassium transport.
- Seen in EKG as U waves.
Hyperkalemia:
- Arrhythmias when >6.5, peaked T-waves: 5.5-6.5, wide QRS: 6.5-7.5
- Drugs that can cause: ACEI, ARB, Beta blockers, digoxin, triamterene, spironolactone, NSAIDs, renin inhibitors, succinylcholine.
- Treatment:
- If no EKG changes: insulin and D50.
- EKG Changes: CaCl or CaGluconate and Insulin and D50 +/- albuterol (increases tachycardia). Calcium stabilizes the cardiac membrane. You don’t need it if not symptoms.
- Bicarb is useful if acidotic.
- Kayexeltae isn’t good for acute hyperkalemia, it only decreases K+ by 0.4-1 over 24 hours.
- In digoxin toxicity, DO NOT GIVE CALCIUM (“stone heart” – but may not really be a risk, don’t give anyway). Give digibind, and can give dextrose and insulin.