Hyperkalaemia Management

OVERVIEW

• Hyperkalaemia is a life-threatening emergency.

RESUSCITATION

• A, B, C
• Large bore IV access -> fluid resuscitation (to enhance renal perfusion and elimination)
• Bloods – FBC, U+E, CK, ABG/ VBG
• Monitoring – ECG and NIBP

MEMBRANE STABILSATION

Calcium

• 10mL of 10% Ca2+ gluconate or chloride
• calcium gluconate = 2.2mmol of Ca2+ in 10mL
• calcium chloride = 6.8mmol of Ca2+ in 10mL
• antagonises the membrane excitability of heart
• does not lower serum K+
• can cause: bradycardia, arrhythmias, tissue necrosis if extravasated

SHIFT K+ INTO CELLS

HCO3- infusion

• 1mmol/kg IV
• 100mL of 8.4%
• decreases the concentration of H+ in the extracellular fluid compartment -> increases intracellular Na+ via the Na+/H+ exchanger and facilitates K+ shift into cells via the Na+/K+ ATPase
• does require a metabolic acidosis
• doesn’t lower K+ independently but has been shown to be additive with insulin/dextrose and salbutamol
• don’t administer at same time as Ca2+ -> precipitation
• can cause: hypernatraemia, pulmonary oedema, tetany in patients with hypocalaemia

Insulin/Dextrose

• 10U actrapid, 50mL of 50% glucose
• insulin increases uptake by stimulating the Na+/K+ ATPase
• reduces K+ by 0.65-1mmol/L/hr
• can cause: hypoglycaemia

Salbutamol nebulisers/IV

• 0.5mg IV or 20mg neb
• binds to the beta-2-receptor -> stimulated adenylase cyclase converting ATP->cAMP -> stimulation of Na+/K+ ATPase with subsequent increase in intracellular K+
• IV slightly better than nebulised
• can cause: tachyarrhythmias, tremor, anxiety and flushing

INCREASE K+ ELIMINATION

Diuretics

• Mannitol, Frusemide
• theoretically work but no clinical trials to support use in hyperkalaemia

Dialysis

• IHD = best (can remove 25-40mmol/hr -> 1mmol/L/hr)
• faster if increase blood flow rate, dialysis flow rate, low K+ concentration in dialysate, high bicarbonate concentration-

Resonium – K+ binders

• calcium resonium (15-30g PO/PR) or sodium polysterene sulphonate
•  cation exchange resins
• negatively charged polymers than exchange the cation for K+ across the intestinal wall
• give a laxative at the same time
• caution: slow acting and ineffective -> unsuitable for emergency situations, constipation, intestinal necrosis

TREAT UNDERLYING CAUSE

HYPERKALAEMIC CARDIAC ARREST

• don’t stop until K+ normalised
• adrenaline helps drive K+ down
• Ca2+ chloride
• Na+ bicarbonate in acidosis
• @ ROSC start insulin/dextrose
• dialysis while undergoing CPR has well documented in case reports -> IHD, CVVH, CVVHDF and peritoneal with complete neurological recovery
• consider ECMO

References and Links

LITFL

• CCC – Hyperkalaemia management
• CCC – Hyperkalaemia DDx
• CCC – Hypokalaemia
• CCC – Hypokalaemia Mind Map
• ECG Library – Hyperkalaemia
• ECG Library – Hypokalaemia
• Clinical Case – Hyperkalaemia
• CCC – Potassium

Journals

• Parham WA, Mehdirad AA, Biermann KM, Fredman CS. Hyperkalemia revisited. Tex Heart Inst J. 2006;33(1):40-7. PMC1413606.