The patient’s arm mass with palpable thrill is an arteriovenous fistula for hemodialysis. The patient likely experienced ventricular fibrillation related to excessively high potassium levels related to inadequate dialysis. Therefore, the patient must have the potassium level decreased safely. Fluid resuscitation is a part of this treatment, but this is not the most accurate aim. The patient has not necessarily had a STEMI; the patient condition points to hyperkalemia-induced ventricular fibrillation. Drug overdose does not fit the patient’s symptoms.