Introduction
Scenario setup K+ 6.8 mmol/L in a dialysis client with malaise and paresthesias. ECG shows peaked T waves. Severe hyperkalemia with ECG changes requires urgent collaboration and preparation for stabilization therapies per orders. Traps: minimizing ECG, delaying team activation. This case-study format is intentional: boards reward trajectory thinking—what changed, what is unstable, and what you do next for the role named in the stem. For REx-PN (Canada), read the assignment line before you eliminate answers. Slow read: re-scan the stem for vitals trends, oxygen settings, allergies, and time since onset—case items often hide the decisive clue in a single line. On the exam, writers often pair stable-sounding options with unstable data—notice the mismatch before you commit. If the stem names a license or role, reread that line; scope errors are classic trap answers even when the clinical topic is familiar. Run a 60-second scan: breathing work and oxygenation, perfusion and end organs, neuro baseline, likely infection sources, and devices that can fail quietly. When two answers feel partly right, pick the one that reduces imminent harm and for...