Final answer:
The most appropriate next step in managing a patient with an ECG suggesting hyperkalemia is the administration of calcium gluconate to temporarily stabilize the cardiac membranes and prevent arrhythmias.
Step-by-step explanation:
The ECG of a 67-year-old man with hypertension and end-stage renal disease who presents with symptoms following an incomplete dialysis session suggests hyperkalemia. Hyperkalemia is a condition characterized by an elevated level of potassium in the blood, which can severely impact the heart's function, leading to arrhythmias and the potential for cardiac arrest. Given the patient's symptoms and the ECG findings, the most appropriate next step in management would be the administration of calcium gluconate. Calcium gluconate works by temporarily stabilizing the myocardial cell membranes against the effects of hyperkalemia, providing protection against arrhythmias while more definitive treatment for hyperkalemia is implemented.
Cardiology consultation, defibrillation, and transcutaneous pacing may be necessary in different scenarios but are not the immediate next steps in managing this clinical presentation. Calcium gluconate is chosen to stabilize the cardiac membrane and prevent fatal arrhythmias while the patient is further assessed and treated for the underlying causes of their symptoms, which could stem from their incomplete dialysis and pre-existing medical conditions.