RN You interpret the cluster (which electrolyte, which system at risk), prioritize the lethal ECG change, implement orders (calcium gluconate then insulin/D50 for hyperkalemia, IV magnesium for torsades, controlled sodium correction), and reassess. Items punish delay when potassium is critical with ECG changes, when sodium is < 120 with neuro changes, or when magnesium is low with a prolonged QT. Classic forks: calcium gluconate protects the heart but does not lower potassium, magnesium must be fixed before potassium, correct sodium slowly in both directions, and never push IV potassium. Choose the option that stabilizes the rhythm and closes the safety loop first. For NCLEX-RN (United States), questions rarely announce the topic in the first sentence. They hide it inside vitals, labs, and a short story. Your job is to name the clinical problem, justify why it matters now, and select the safest next step for the role you are given—before you let distractors pull you toward busywork or out-of-scope heroics. When two answers feel partly right, pick the one that closes risk first and matches your license in the stem.