Hypomagnesemia: a potassium that will not rise, and a number inside the range
Educational use only. Not clinically reviewed71-year-old woman for Cardiac monitoring and qualified QT review, exposure cessation, context review, qualified magnesium repletion, reassessment, and unresolved-risk handoff. About 60 simulated minutes.
What you will practise
- Protect the patient and stop the suspected exposure without waiting for a repeat number.
- Read the exposure and the losses alongside the results that have not corrected.
- Separate what the magnesium value shows from what it excludes.
- Distinguish a partial recheck from a current picture, and know where a response would show.
- Transfer an unresolved problem with explicit ownership of repletion, drug review, and surveillance.
Review and sources
Not clinically reviewed. No clinician has signed this scenario.
- Huang CL, Kuo E. Mechanism of hypokalemia in magnesium deficiency. Journal of the American Society of Nephrology. 2007;18:2649–2652. doi:10.1681/ASN.2007070792. A mechanistic review of distal potassium secretion, not a trial; its own abstract states that magnesium deficiency alone does not necessarily cause hypokalemia, which is why this lesson keeps the causal claim bounded and prescribes nothing.
- Micke O, Vormann J, Kraus A, Kisters K. Serum magnesium: time for a standardized and evidence-based reference range. Magnesium Research. 2021;34:84–89. doi:10.1684/mrh.2021.0486. Supports only the weaker claim used here — an in-range value does not rule out deficiency. Its central proposal, to raise the lower reference limit to 0.85 mmol/L, comes from officers of a magnesium research society with a manufacturer-affiliated author, is contested, and is not adopted.
- Okamoto N, Onishi S, Manabe T, Satoh S, Nara S. Vonoprazan-associated hypomagnesemia presenting to the emergency department with altered mental status and a suspected seizure. American Journal of Emergency Medicine. 2026;101:131–134. doi:10.1016/j.ajem.2025.12.034. One retrospectively reported patient. It establishes no threshold, repletion protocol, expected time course, or attribution rule; only the clinical shape is taken.
Open Sim Lab is an educational simulator, not for clinical use. It is not a clinical decision-support tool, not a dosing calculator, and is not validated for any decision affecting a real patient.