In a case of suspected hyperkalemia, what is the first diagnostic step in management?

In cases of suspected hyperkalemia, the first diagnostic step is to perform an electrocardiogram (EKG). This is crucial because hyperkalemia can cause significant changes in cardiac conduction, which can be life-threatening. The EKG can reveal characteristic changes such as peaked T waves, widening of the QRS complex, and even potential progression towards ventricular arrhythmias.

Identifying these cardiac changes early can guide subsequent management, as severe hyperkalemia may require urgent intervention such as calcium administration, insulin and glucose administration, or dialysis. Although other tests like a complete blood count, a CT scan, or troponin levels might provide useful information in different clinical contexts, they do not directly address the immediate risks associated with hyperkalemia. The EKG serves as a rapid assessment tool to ascertain the impact of potassium levels on the heart and is therefore prioritized in this scenario.