Prehospital Care
A patient with known hyperkalemia or a patient with renal failure with suspected hyperkalemia should have intravenous access established and should be placed on a cardiac monitor. [4] In the presence of hypotension or marked QRS widening, intravenous bicarbonate, calcium, and insulin, given together with 50% dextrose, may be appropriate, as discussed in Medication. Avoid calcium if digoxin toxicity is suspected. Magnesium sulfate (2 g over 5 min) may be used alternatively in the face of digoxin-toxic cardiac arrhythmias.
Emergency Department Care
Perform continuous ECG monitoring with frequent vital sign checks when hyperkalemia is suspected or when laboratory values indicative of hyperkalemia are received.
Initial management includes assessment of the ABCs and prompt evaluation of the patient's cardiac status with an ECG.
Discontinue any potassium-sparing drugs or dietary potassium.
If the hyperkalemia is known to be severe (potassium >7.0 mEq/L) or if the patient is symptomatic, begin treatment before diagnostic investigation of the underlying cause. Individualize treatment based upon the patient's presentation, potassium level, and ECG. Not all patients should receive every medication listed in Medication. Patients with mild hyperkalemia, for example, may need only excretion enhancement.
Some studies are emerging that suggest sodium polystyrene sulfonate (SPS), also known as Kayexalate, may be unhelpful in hyperkalemia and may increase the chance of colonic necrosis (especially when used with sorbitol). [19, 20, 21, 22] A retrospective study by Lee and Moffett, however, found SPS to be a safe and effective treatment for hyperkalemia in most pediatric patients. However, the investigators suggested that the drug may not be an appropriate first single-line agent when patients with severe acute hyperkalemia need their serum potassium level reduced by over 25% or when patients have a high cardiac arrhythmia risk. [23] Generally, SPS is considered safe orally but is not recommended as a retention enema, which has a higher rate of colonic necrosis. Effects are expected to be minor and not adequate to reduce potassium levels to normal levels.
Phase II and III clinical trials have indicated that patiromer and sodium zirconium cyclosilicate (ZS-9) have a dose-dependent ability to lower potassium levels. In 2015, patiromer (Veltassa) was approved by the US Food and Drug Administration (FDA) for the treatment of hyperkalemia in adults, although its labeling specified that, owing to its delayed onset of action, it "should not be used as an emergency treatment for life-threatening hyperkalemia." In 2018, ZS-9 (Lokelma) became FDA approved for adults with hyperkalemia as well, but like patiromer, it is also not to be used for the emergency treatment of life-threatening hyperkalemia. [24, 25, 26, 27]
A study by Jacob et al of adult patients who received intravenous regular insulin during emergency department treatment for hyperkalemia found the incidence of hypoglycemia and severe hypoglycemia to be 19.8% and 5.2%, respectively. The median blood glucose level at baseline was significantly lower in patients who developed hypoglycemia than in those who did not. The investigators suggested that standard insulin doses may not be suitable for hyperkalemic patients with low baseline glucose. [28]
Consultations
Consult a nephrologist or the dialysis team for patients with either severe symptomatic hyperkalemia or renal failure. Admit these patients to an ICU.
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Widened QRS complexes in hyperkalemia.
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Widened QRS complexes in a patient whose serum potassium level was 7.8 mEq/L.
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ECG of a patient with pretreatment potassium level of 7.8 mEq/L and widened QRS complexes after receiving 1 ampule of calcium chloride. Notice narrowing of QRS complexes and reduction of T waves.
