Hypermagnesemia is a strong independent risk factor for mortality in critically ill patients: results from a cross-sectional study.

BACKGROUND: Patients with electrolyte imbalances or disorders have a high risk of mortality. It is unknown if this finding from sodium or potassium disorders extends to alterations of magnesium levels.

METHODS AND PATIENTS: In this cross-sectional analysis, all emergency room patients between 2010 and 2011 at the Inselspital Bern, Switzerland, were included. A multivariable logistic regression model was performed to assess the association between magnesium levels and in-hospital mortality up to 28days.

RESULTS: A total of 22,239 subjects were screened for the study. A total of 5339 patients had plasma magnesium concentrations measured at hospital admission and were included into the analysis. A total of 6.3% of the 352 patients with hypomagnesemia and 36.9% of the 151 patients with hypermagnesemia died. In a multivariate Cox regression model hypermagnesemia (HR 11.6, p<0.001) was a strong independent risk factor for mortality. In these patients diuretic therapy revealed to be protective (HR 0.5, p=0.007). Hypomagnesemia was not associated with mortality (p>0.05). Age was an independent risk factor for mortality (both p<0.001).

CONCLUSION: The study does demonstrate a possible association between hypermagnesemia measured upon admission in the emergency department, and early in-hospital mortality.