Serum Magnesium Test: Clinical Importance, Normal Range & ICU Relevance
Serum Magnesium Test: Clinical Importance, Normal Range & ICU Relevance Introduction A 58‑year‑old patient in the intensive care unit suddenly develops a polymorphic ventricular tachycardia. Potassium is replaced aggressively, yet the arrhythmia persists. The team checks a magnesium level — it is critically low at 1.0 mg/dL. Within minutes of magnesium infusion, the cardiac rhythm stabilises. Scenarios like this play out daily in ICUs, yet magnesium is often the forgotten electrolyte. While sodium and potassium receive most of the attention, the serum magnesium test holds the key to understanding many otherwise unexplained clinical disturbances. This article explores why magnesium matters, what the normal magnesium range truly means, and why hypomagnesemia and hypermagnesemia are critical contributors to ICU electrolyte imbalances . What is Magnesium and Why is it Important? Magnesium is the fourth most abundant cation in the body and the second most abu...