Use of Mayfield skull clamp during craniotomies; results in a sharp and intense noxious stimulus which results in a severe hemodynamic pressor response. Many strategies have been reported to blunt this undesirable pressor effect. This prospective, double blind, and randomized study is the first to evaluate the effect of MgSo4 on attenuation of hemodynamic pressor activity after head clamp application during craniotomies.

Background: Use of Mayfield skull clamp during craniotomies; results in a sharp and intense noxious stimulus which results in a severe hemodynamic pressor response. Many strategies have been reported to blunt this undesirable pressor effect. This prospective, double blind, and randomized study is the first to evaluate the effect of MgSo4 on attenuation of hemodynamic pressor activity after head clamp application during craniotomies.

Methods: This randomized, double blind, and prospective study was done in Neurosurgical department at ElSahel Teaching Hospital in Cairo from February 2016 till august 2017. All adult patients aged from 18 to 60 years of both genders, ASA physical status I and II scheduled for craniotomies were assessed to enter this study. Seventy one patients were assessed preoperatively, sixty of them were enrolled and assigned in two groups (n=30 each). Group M received 50 mg/kg MgSo4 in 100 ml 0.9 sodium Chloride 15 minutes prior to anesthesia induction over 15 minutes. Group S received 100ml 0.9% Sodium Chloride over the same period with the same rate.Mean HR was recorded as a primary outcome , meanwhile; MAP and the need for a bolus dose of fentanyl was considered a secondary outcome.

Inclusion Criteria:

• All adult patients aged from 18 to 60 years
• of both genders
• ASA physical status I and II
• scheduled for craniotomies

Exclusion Criteria:

• history of MgSo4 consumption or allergy
• renal disease
• hepatic or endocrine disorder
• cardiovascular dysfunction
• calcium channel blocker intake
• drug abuse were excluded from this study.