Effect of early intraoperative magnesium sulfate application on the incidence of vasospasm and postoperative clinical outcome  –a retrospective cohort study

Weidinger C1, Sommer B2, Buchfelder M2, Schmitt H1

1Department of Anaesthesiology, 2Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany

Background and Goal of Study: The benefit of magnesium in patients with aneurysmal subarachnoid haemorrhage (SAH) is under active debate. We investigated the effect of intraoperative intravenous magnesium sulfate (MgSO4) application and compared the rate of vasospasm, delayed ischaemic deficit and neurological outcome in two patient groups.

Materials and Methods: Patient group 1 was a cohort of 20 individuals (15 female, 5 male, age 49.0 ±11.0 yrs) that suffered from aneurysmal SAH and underwent microsurgical clipping in 2005 without MgSO4. The second group included 20 patients (15 female, 5 male, age 56.0 ±11.0 yrs) treated in 2014 with early intraoperative application of magnesium sulfate 10% 50 mg/kg body weight as a continuous infusion with a infusion rate depending on blood pressure (MAP 60-65 mmHg) over a time period of max. 60 minutes. In group 1, general anesthesia was maintained with sufentanil (0,15-0,30 µg kg-1) or remifentanil (0,1µg kg -1 min-1-0,5µg kg-1 min-1), propofol 1% (6 mg kg-1 h-1) . In group 2, general anesthesia was maintained with sufentanil (0,15-0,30 µg kg-1) or remifentanil (0,1µg kg -1 min-1-0,5µg kg-1 min-1), esketamine (1mg kg-1 h-1) and sevoflurane 1,5-2,0 Vol%. Clinical endpoints were 1) incidence of vasospasm, 2) DIS, 3) neurological outcome using the modified Rankin Scale (mRS) 3 and 12 months after SAH.  

Results and Discussion: Both groups had SAH Hunt and Hess grade I-III in 11 of 20 and grade IV-V in 9 of 20 patients. In the first group, cerebral vasospasm occurred in 10 patients (50%), in the second group in 9 patients (45%) as defined by transcranial ultrasound or digital subtraction angiography. Eight patients (40%) of group 1 had an associated delayed ischemic deficit, whereas in group 2, only 5 patients (25%) had an ischaemic deficit. Neurological outcome after 3 months was mRS 2.9±1.5 and 12 months mRS 2.0±1.8 in group 1, whereas group 2 had an 3 month mRS of 2.3±1.5 and 12 months mRS of 1.8±1.5.  

Conclusion: In this retrospective cohort study, the incidence of a delayed ischaemic deficit due to cerebral vasospasm was lower in the group treated with early intravenous MgSO4. Neurological outcome showed a tendency of better recovery from ischaemic deficits in the magnesium group, however, sample sizes are too small to show statistical significance.

Effect of early intraoperative magnesium sulfate application on the incidence of vasospasm and postoperative clinical outcome in patients with aneurysmal subarachnoid haemorrhage – a retrospective cohort study