What is the initial action to take when observing tall, peaked T waves on the ECG of a client with end-stage kidney disease (ESKD)?

Tall, peaked T waves on an ECG are often indicative of hyperkalemia, which is a common complication in patients with end-stage kidney disease (ESKD). In ESKD, the kidneys are unable to effectively excrete potassium, leading to its accumulation in the bloodstream. This accumulation can result in significant cardiac changes, including alterations in the T wave morphology.

By checking the potassium level, healthcare providers can confirm whether hyperkalemia is present, allowing for timely intervention if potassium levels are indeed elevated. This action is critical because hyperkalemia can lead to life-threatening cardiac arrhythmias. Identifying the underlying cause, in this case, elevated potassium levels, is essential for guiding appropriate treatment and preventing serious complications.

The other options do not directly address the immediate need to assess potassium levels to manage potential life-threatening consequences associated with ESKD. While preparing to give sodium bicarbonate to correct acidosis or repeating the ECG can be part of a subsequent approach, initially confirming the potassium level is vital.