Object: Recent data from both experimental and clinical studies have supported the use of intravenous magnesium as a potential therapy in the setting of cerebral ischemia. This study assessed whether intraoperative magnesium therapy improves neuropsychometric testing (NPT) following carotid endarterectomy (CEA).
Methods: One hundred eight patients undergoing CEA were randomly assigned to receive placebo infusion or 1 of 3 magnesium-dosing protocols. Neuropsychometric testing was performed 1 day after surgery and compared with baseline performance. Assessment was also performed on a set of 35 patients concurrently undergoing lumbar laminectomy to serve as a control group for NPT. A forward stepwise logistic regression analysis was performed to evaluate the impact of magnesium therapy on NPT. A subgroup analysis was then performed, analyzing the impact of each intraoperative dose on NPT.
Results: Patients treated with intravenous magnesium infusion demonstrated less postoperative neurocognitive impairment than those treated with placebo (OR 0.27, 95% CI 0.10-0.74, p = 0.01). When stratified according to dosing bolus and intraoperative magnesium level, those who were treated with low-dose magnesium had less cognitive decline than those treated with placebo (OR 0.09, 95% CI 0.02-0.50, p < 0.01). Those in the high-dose magnesium group demonstrated no difference from the placebo-treated group.
Conclusions: Low-dose intraoperative magnesium therapy protects against neurocognitive decline following CEA.