Enteral vs IV Magnesium Replacement in Critically Ill Patients: A Randomized Noninferiority Trial

Background

Magnesium is an essential mineral involved in nerve function, muscle contraction, heart rhythm, and energy production. In critically ill patients, low magnesium levels, or hypomagnesemia, are common because of poor intake, gastrointestinal losses, diuretics, kidney dysfunction, sepsis, and the stress of critical illness. Even mild deficiency can matter in the intensive care unit because magnesium disturbances may contribute to arrhythmias, weakness, and difficulty correcting other electrolyte problems such as low potassium or low calcium.

The usual way to replace magnesium in critically ill patients is intravenously. IV magnesium is fast and familiar in intensive care, but it has drawbacks. It requires infusion equipment, nursing time, and often extra IV fluid. Much of the administered magnesium may also be lost in urine, especially when kidney handling of magnesium is altered. An enteral approach, meaning magnesium given through the gastrointestinal tract by mouth or feeding tube, could be simpler, cheaper, and potentially more sustainable. However, it has been unclear whether enteral replacement corrects magnesium deficiency as effectively as IV treatment in the ICU.