Effect of magnesium on the incidence of delirium occurrence in the ICU

Introduction

Sedation agents and opioids present an important subgroup of medications known to promote delirium. This study was designed to test the hypothesis that intravenous magnesium administration reduces the incidence of delirium occurrence by causing less sedative consumption in a mixed population of ICU patients.

Methods

Sixty-three adult medical and surgical ICU patients requiring mechanical ventilation were randomized to receive magnesium (2 g bolus intravenously, continued by 16 g/day infusion, target range 1.0 to 2.0 mmol/l) or saline. Patients were sedated with remifentanil and midazolam titrated to achieve the desired level of sedation measured by the Richmond Agitation and Sedation Scale (RASS). Those patients achieving a RASS score of ± 1 or 0 were monitored daily for delirium using the Confusion Assessment Method for the ICU (CAM-ICU). The incidence of delirium, delirium duration, daily remifentanil and midazolam consumption were compared between groups. Statistical performance was compared using Mann–Whitney U and chi-square tests.

Results

The groups were comparable in terms of age, gender, and admission APACHE II (17.2 ± 5 vs. 18.5 ± 8) and Sequential Organ Failure Assessment (4.9 ± 2 vs. 5.6 ± 3) scores. The incidence of at least one episode of delirium occurrence was 25% in the magnesium group and 27.3% in the control group. The magnesium group achieved the desired level of sedation of RASS score ± 1.0 much earlier than the control group and spent more time within that level of RASS score (68% vs. 36%) Addition of magnesium resulted in more days without delirium (89% vs. 55%). There was a reduction in the daily remifentanil and midazolam consumption in the magnesium group.

Conclusion

This is a preliminary report of an ongoing study. Our results demonstrated that addition of magnesium to the sedation protocol lowers both the remifentanil and midazolam consumption and resulted in more days without delirium in a mixed population of ICU patients.