Serum Magnesium Level in Critically Ill Patients in a Tertiary Care Centre

Background: Hypomagnesemia is reported in up to 20% of patients in medical wards and 65% of patients in ICUs. A potential relationship between low magnesium levels and increased mortality has been suggested in the literature. Because magnesium depletion may not be accompanied by hypomagnesemia, the incidence of magnesium deficiency is even higher than indicated by the surveys of hypomagnesemia.

Aims and Objectives: To study serum magnesium levels in critically ill patients and to correlate serum magnesium levels with patient outcome based on length of stay in ICU, need for and duration of ventilator support, APACHE score and mortality.

Materials and Method: A prospective observational study was conducted in a tertiary care hospital from April 2011 to Nov 2011. It included 250 seriously ill patients, suffering from various medical conditions. Estimation of serum total magnesium levels was done on admission. Normal deviate (z) test and Chi-square test was applied for quantitative and qualitative data respectively to find significant associations between two variables.

Results: Among 250 patients, 53.6% patients had hypomagnesemia, 43.6% had normal magnesium level and 2.8% had hypermagnesemia. The patients with hypomagnesemia had higher mortality rate (40%), more frequent need for ventilator support (62%), longer duration of mechanical ventilation (6.70±2.91) and higher incidence of sepsis (26.8%). The differences were statistically significant.

Conclusions: Our study has found high prevalence of hypomagnesemia(53.6%) in critically ill patients. There were associations between hypomagnesemia and duration of ventilation, higher incidence of mortality and sepsis.