Final answer:
For severe or life-threatening hypomagnesemia, intravenous magnesium is the recommended treatment for immediate correction of low magnesium levels, not oral supplements, diet, or topical lotions.
Step-by-step explanation:
To treat severe (<1.2 mg/dL) or life-threatening (seizure/arrhythmia) hypomagnesemia, the recommended intervention is intravenous magnesium (IV) administration. This approach is immediate and allows for the control of magnesium dosage, which is critical in an emergency situation. Oral magnesium supplements, a magnesium-rich diet, or topical magnesium lotion are not suitable for rapid correction in severe cases.
Severe hypomagnesemia constitutes a medical emergency, and delays in treatment can lead to significant morbidity and mortality. While less severe cases might be treated with diet and oral supplementation, life-threatening hypomagnesemia requires IV administration to quickly restore serum magnesium levels and prevent complications such as seizures and cardiac arrhythmias. This is a condition often encountered in acute clinical settings and should be managed by healthcare professionals with appropriate monitoring of vital signs and serum magnesium levels.