Fluids and electrolytes

Hyperkalaemia

Reviewed Nov 2026·2 references
New· views rounded down, updated weekly

Five steps (UKKA): protect the heart with IV calcium if ECG changes, shift K+ into cells with insulin-glucose (± salbutamol), remove K+ (binders, diuresis, dialysis), monitor glucose and K+, and prevent recurrence.

Definition
UKKA: mild 5.5-5.9, moderate 6.0-6.4, severe ≥ 6.5 mmol/L.

At the bedside

Timed steps
  1. 1

    ECG and confirm

    0 min

    12-lead ECG, continuous monitoring; repeat sample if haemolysed but do not delay treatment if ECG changes.

  2. 2

    Protect the heart

    Step 1

    ECG changes: 30 mL 10% calcium gluconate over 10 min (10 mL 10% calcium chloride over 5 min in peri-arrest). Repeat if changes persist after 5-10 min.

  3. 3

    Shift K+

    Step 2

    K+ ≥ 6.0: soluble insulin 10 units + 25 g glucose over 15 min. If pre-treatment glucose < 7 mmol/L (126 mg/dL): then 10% glucose 50 mL/h for 5 h. K+ ≥ 6.5: add salbutamol 10-20 mg nebulised.

  4. 4

    Remove K+

    Step 3

    Sodium zirconium cyclosilicate 10 g three times daily (or patiromer); loop diuretic if passing urine and volume replete; urgent dialysis for refractory hyperkalaemia, anuric AKI or ESKD.

  5. 5

    Monitor

    Step 4

    K+ at 1, 2, 4, 6 and 24 h; capillary glucose 0, 30, 60, 90, 120, 180, 240, 300, 360 min after insulin.

  6. 6

    Prevent

    Step 5

    Stop K+ supplements, ACEi/ARB/MRA, NSAIDs, trimethoprim, heparin; treat rhabdomyolysis, tumour lysis, acidosis.

Hyperkalaemia with ECG changes

Calcium gluconate 10%

IV, large vein
Dose
30 mL of 10% over 10 min; repeat if ECG unchanged

Onset 3 min, lasts 30-60 min; does not lower K+.

K+ ≥ 6.0 mmol/L

Insulin + glucose

IV
Dose
Soluble insulin 10 units + 25 g glucose (50 mL 50% or 250 mL 10%) over 15 min
Target
K+ falls 0.6-1.0 mmol/L within 30-60 min
Worked example
70 kg, K+ 7.1, glucose 90 mg/dL (5 mmol/L): insulin 10 units + 50 mL 50% dextrose; then 10% dextrose 50 mL/h for 5 h

Adjunct, K+ ≥ 6.5

Salbutamol (nebulised)

Nebulised
Dose
10-20 mg

ECG changes of hyperkalaemia (not reliably sequential)

ChangeComment
Peaked T wavesEarliest, but insensitive
PR prolongation, flattened/absent PAtrial conduction slows
Broad QRS, bundle branch blockHigh risk
Bradycardia, high-grade AV block, junctional rhythmPeri-arrest; atropine often ineffective
Sine wave, VF, asystole, PEACardiac arrest: calcium chloride, insulin-glucose, consider bicarbonate, dialysis

BRASH syndrome (Bradycardia, Renal failure, AV nodal blockade, Shock, Hyperkalaemia) can occur with K+ < 6.5.

Red flag · call your senior now
Broad QRS or bradycardia with high K+: calcium now, then everything else.
Pitfall
Hypoglycaemia hours after insulin, especially in CKD (no glucose monitoring).
Pitfall
Relying on sodium polystyrene / calcium resonium for acute treatment (slow; not recommended).
Pitfall
Sodium bicarbonate as routine therapy: insufficient evidence except in cardiac arrest or severe acidosis.
Pearl
Calcium gluconate 30 mL of 10% contains the same calcium as 10 mL of 10% chloride.

References

  1. 1

    UK Kidney Association. Clinical practice guideline: Treatment of acute hyperkalaemia in adults (October 2023; updated July 2026)

  2. 2

    Clase CM, Carrero JJ, Ellison DH, et al. Potassium homeostasis and management of dyskalemia in kidney diseases: conclusions from a KDIGO Controversies Conference. Kidney Int. 2020;97(1):42-61

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