Pitfalls

You should keep the following points in mind when treating patients in the Emergency Department:

Patient statistics

• The majority of patients with disturbances of potassium balance are asymptomatic
• The majority of patients with hyperkalaemia have some underlying renal dysfunction
• Mortality as an inpatient is tenfold higher in hypokalemic patients. Careful monitoring and correction +/- supplementation must be achieved prior to discharge

Serum levels

• Serum levels can be raised, normal or low in excess or deficiency of total body potassium
• If a serum potassium level is raised in a well patient with normal renal function, take a repeat sample to check the first result was not spuriously elevated
• Rapidly rising levels of serum potassium are more serious than slower rising levels

Treatments

• Remember medications are common causes of potassium disturbance
• Potassium balance is intimately related to sodium, water, acid base balance and cannot be interpreted in isolation
• ECG findings in hyperkalaemia are non-specific and the ECG is not a predictor of the presence or severity of hyperkalaemia
• Remember to monitor glucose levels and administer glucose during treatment with insulin
• Renal replacement therapy with haemofiltration or haemodialysis is the treatment of choice for life threatening hyperkalaemia refractory to medical management.