Effects of Milrinone continuous intravenous infusion on global cerebral oxygenation and cerebral vasospasm after cerebral aneurysm surgical clipping

Background
Cerebral vasospasm (CVS) is a disabling disease with high morbidity and mortality risk. Milrinone (phosphodiesterase III inhibitor) has inotropic and vasodilator effects, noninvasive transcranial cerebral oximetry (rSO%) useful in estimating the effect of triple-H therapy preventive measures against CVS.
Objective
of the study is to clarify the value of the use of Milrinone continuous IV infusion as a cerebral vasodilator in post-clipping spasm prevention during the period of maximum vasospasm incidence, guided by noninvasive rSO%.
Methods
Post-clipping all patients extubated in the operative room, shifted to Neurosurgical ICU, and fully monitored. Then, in the period from 4th till the 11th day post-clipping, they were divided into two groups 15 patients each: Group 1: control group, given Norepinephrine continuous IV infusion alone in a dose ranges from 0.05 to 0.2 μg/kg/min. Group 2: given Norepinephrine continuous IV infusion 0.05–0.2 μg/kg/min, Plus Milrinone starting with 50 μg/kg bolus dose, followed by IV infusion at a rate of [0.5–0.75 μg/kg/min]. IMAP, ICP CPP, GCS, Norepinephrine dose, rSO2%, were recorded every 6 h for the next 168 h. Any attack of cerebral vascular spasm recorded as number and % in each group as an incident.
Results
MBP, rSO2%, ICP, CPP, Norepinephrine Infusion dose, and GCS were significantly increased in Group (2) in comparison with Group (1) mostly during the period of the study. CVS occurrence was significantly lower in group (2), i.e., (20%) cases compared to (46.6%) in group (1).
Conclusions
Milrinone improved significantly the global cerebral oxygenation and reduced the incidence of cerebral vasospasm during the dangerous period of cerebral spasm after cerebral aneurysm clipping.