A 28-year-old male with arm pain presents to the emergency department. He is diaphoretic and anxious, but in no apparent distress. His vital signs include a BP of 90/65, HR of 125, RR of 16, and temperature of 38.8°C. The patient has a history of occasional back pain and has been taking ibuprofen 800 mg PRN for the last three days. He has used cocaine occasionally and smokes tobacco. The patient’s primary and secondary surveys reveal rhabdomyolysis, heat exhaustion, and acute kidney injury. The candidate should aggressively hydrate the patient, treat hyperthermia, obtain renal consultation, and consider intravenous bicarbonate therapy. The patient should be admitted to the hospital. The use of NSAIDs should be avoided as they can cause renal artery vasoconstriction and reduce GFR. The patient’s EKG shows sinus tachycardia. The complications of rhabdomyolysis include electrolyte abnormalities and acute kidney injury.

This chapter discusses a critical diagnosis, hyperkalemia, and how to figure out the cause of seemingly vague complaints. It emphasizes the importance of the history and the EKG interpretation to get to the diagnosis rapidly and initiate treatment. After making the diagnosis, this chapter reviews the pharmacologic treatment of hyperkalemia, which all emergency physicians should know to prevent arrhythmias and even death. It also provides a nice review of the causes of hyperkalemia.