Serum K+ 5.5 mmol/L or higher
v
Exclude pseudohyperkalaemia
- Suspect with haemolysis, delayed sample processing, very high platelets or white cells, or a difficult draw
- Repeat as paired lithium heparin and clotted samples from a large vein with gentle traction
- Do not delay treatment if the ECG is abnormal
1. Initial assessment (all patients)
- ABCDE approach. Give empirical treatment for arrhythmia if hyperkalaemia is strongly suspected
- Point-of-care blood gas K+ while awaiting the lab result
- Urgent 12-lead ECG if K+ is 6.0 mmol/L or higher
- Continuous cardiac monitoring if K+ is 6.5 or higher, if ECG changes, or if K+ 6.0 to 6.4 and unwell or rising fast
- Identify and treat the cause: AKI, drugs, acidosis, tissue breakdown, adrenal insufficiency
v
ECG changes of hyperkalaemia?
v
YES
Step 1. Protect the heart: IV calcium
- Calcium gluconate 10%, 30 mL IV over 10 min via a large vein (contains about 6.8 mmol calcium), OR
- Calcium chloride 10%, 10 mL over 5 min (preferred in cardiac arrest or peri-arrest, give via central access)
- Onset 1 to 3 min, lasts 30 to 60 min. Repeat ECG and give a further dose after 5 min if changes persist
- Calcium protects the myocardium but does NOT lower K+. Still proceed to shift and remove
NO
Assess by potassium level (below)
- No ECG changes does not mean safe. Treat by level, rate of rise and clinical state
- Recheck K+ and keep on monitoring if rising
vCLASSIFY SEVERITY (UKKA)
Mild: 5.5 to 5.9
- Emergency treatment not usually needed
- Find and treat the cause
- Review and stop K+ raising drugs; withhold RAASi if acutely unwell
- Recheck K+ and go to Step 5
Moderate: 6.0 to 6.4
- Treatment guided by clinical state, ECG and rate of rise
- Consider insulin-glucose and salbutamol (Step 2)
- Consider a K+ binder (Step 3)
- Monitor and seek senior or renal review
Severe: 6.5 or higher
- Emergency treatment indicated now
- Continuous cardiac monitoring
- Give IV calcium if any ECG changes
- Urgent renal or critical care opinion. Dialysis patients: urgent dialysis
v
2
Shift K+ into cells (severe: give; moderate: consider)
- Insulin-glucose: 10 units soluble insulin in 25 g glucose IV over 15 to 30 min (25 g = 50 mL of 50%, or 125 mL of 20%, or 250 mL of 10% glucose)
- If pre-treatment glucose is below 7.0 mmol/L, follow with 10% glucose at 50 mL/h for 5 h
- Consider sodium bicarbonate only on specialist advice if significant metabolic acidosis
Adjunct: salbutamol 10 to 20 mg nebulised. Give with insulin-glucose in severe cases; may be used in moderate. Never as sole treatment in severe hyperkalaemia (beware tachycardia).
v
3
Remove K+ from the body
- Sodium zirconium cyclosilicate 10 g three times daily for up to 72 h (severe: give; moderate: consider)
- Or patiromer 8.4 g once daily if K+ is 6.0 or higher (not routinely available in Scotland)
- Loop diuretic (for example furosemide) if fluid overloaded and passing urine
- Calcium resonium is no longer routinely used
- Haemodialysis if refractory, anuric, or life-threatening. Discuss early
v
4
Monitor
- Serum K+ at least at 1, 2, 4, 6 and 24 h after treatment
- Blood glucose at 0, 30, 60, 90, 120, 180, 240, 300 and 360 min after insulin-glucose
- Watch for rebound hyperkalaemia and for hypoglycaemia
v
K+ still 6.5 or higher despite treatment?
v
YES
Life-threatening hyperkalaemia
- Seek expert help now: urgent nephrology or critical care review
- Consider dialysis (timing and modality decided by a nephrologist or intensivist)
- Critical care first if ABCDE or conscious-level problems
5
Prevent recurrence (NO)
- Review K+ raising medicines; withhold RAASi during acute illness and weigh recurrence risk before restarting
- Dietary K+ advice once constipation, acidosis and poor diabetes control are addressed
- Arrange community K+ monitoring on discharge
v
Hyperkalaemic ECG changes (reference)
| K+ (mmol/L) | Typical change |
|---|
| 5.5 to 6.0 | Peaked, tented T waves (compare with an old ECG) |
| 6.0 to 6.5 | PR prolongation, flattened or absent P waves, broadening QRS |
| Above 6.5 | Sine wave pattern, bradyarrhythmia, VT or VF, asystole |