Objective: Effect of magnesium sulfate on intraoperative hemodynamic undergoing cerebral aneurism surgery and rate of postoperative cerebral vasospasm.
Design: Interventional, Randomized, Single blind (researchers were not aware), Target sample size : 46 People.
Setting and conduct:
The magnesium group received magnesium sulfate 50% (20 mg/per kg) (manufactured by Pasteur Institute of Iran), diluted in 100 cc normal saline over 15 min before anesthetic induction. Then, 10 mg/kg/h of magnesium sulfate with saline solution is infused within fifteen minutes for the patients after clip application. If the mean arterial pressure decreases to less than 80 mmHg, propofol infusion, fentanyl, and magnesium sulfate are reduced or stopped to maintain the arterial pressure in 80-100 mmHg range, before clip application. In the normal saline group, the same volume of magnesium sulfate is administered to the patients. Intraoperative fluid management is performed according to the standard procedures (4-2-1 rule); bleeding is compensated by a three-fold increase in magnesium and 0.9% normal saline.
Participants including major inclusion criteria:
candidate for brain aneurysm surgery after 3 days of aneurysm bleeding;
American Society of Anesthesiologists (ASA) class I and II.
Participants including major exclusion criteria:
pathology of cardiovascular system; heart failure [Ejection fraction (EF) less than 40%],
Previous history of hypertension; Liver or kidney diseases (impaired Liver function test (FT) and Glomerular filtration rate (GFR) less than 50 ml/min); Motor, neurological, and muscle disorders, coagulopathy [Prothrombin time (PT) more than 16, International Normalized Ratio (INR) more than 1.5; Partial thromboplastin time (PTT) more than 35]; Hypomagnesaemia, More than 60 years of age; History of allergy to any of the used medications in the experiment,
Overweight [Body mass index (BMI) more than 30]; Previous use of calcium channel blockers; Atrioventricular block.
Intervention group: Magnesium sulphate 50%, 20 mg/kg, during 15 minutes before infusion of anesthesia and 10 mg/kg/hour till 15 minutes after end of improvising the tresses.
Control group: Normal Saline 0.9%, Fluid therapy During surgery according to standard procedures (Rule 4-2-1) and compensation bleeding occurs with three times of Normal Saline 0.9%.
Primary outcome measure: Vasospasm after intervention, Daily, By angiography and transcranial Doppler