A randomized, double-blinded controlled trial was conducted to evaluate the analgesic efficacy of MgSO4 as an adjuvant to ropivacaine in scalp blocks for craniotomy, focusing on its impact on hemodynamic parameters and intraoperative remifentanil consumption.

A prospective, randomized, double-blinded controlled trial was conducted at Hospital Universiti Sains Malaysia (HUSM). Twenty-four patients scheduled for elective supratentorial craniotomy under general anesthesia were randomized into two groups: the control group (ropivacaine alone) and the treatment group (ropivacaine with MgSO4). Hemodynamic parameters, including mean arterial pressure (MAP) and heart rate (HR), were recorded at seven predefined intraoperative time points corresponding to critical surgical stimuli. Total intraoperative remifentanil consumption was also measured.

Inclusion Criteria:

• 1. Scheduled for elective supratentorial craniotomy under general anaesthesia 2. ASA I-III physical status 3. Aged 18 years and above

Exclusion Criteria:

• 1. Traumatic brain injury 2. Aneurysmal clipping 3. GCS <14 4. Contraindication to scalp block 5. Known adverse reaction to magnesium sulphate or LA from previous exposure 6. Heart block 7. History of drug dependence or alcohol abuse 8. Pregnancy