Comparison of Systemic Opioid (Morphine) and Pre-Incision Bilateral Scalp Nerve Block for Pain Management in Craniotomy Patients

Overview

The goal of this randomized controlled clinical trial is to compare the effectiveness of systemic opioids versus pre-incision bilateral scalp nerve block in managing intraoperative noxious stimuli and postoperative pain in adult patients (18-75 years) undergoing elective supratentorial craniotomy. The main questions this study aims to answer are: Does pre-incision bilateral scalp nerve block provide better intraoperative hemodynamic stability compared to systemic opioids? Does it result in lower postoperative pain scores and reduced opioid consumption during the first 24 hours after surgery? Researchers will compare Group M (systemic morphine) with Group S (bilateral scalp nerve block) to see if the scalp nerve block offers superior analgesia and fewer opioid-related side effects. Participants will: Be randomly assigned to receive either systemic morphine or bilateral scalp nerve block before incision. Undergo standard general anesthesia for craniotomy. Have postoperative pain managed using a patient-controlled analgesia (PCA) morphine pump and be monitored for 24 hours for pain, sedation, and nausea/vomiting scores

This double blinded, randomized controlled trial was conducted at Aga Khan University Hospital, Karachi, over a period of three to six months after obtaining approval from the institutional ethics committee. Non-probability consecutive sampling was used. Eligible patients were randomly assigned using computer-generated randomization into two groups: Group M (morphine) and Group S (scalp nerve block). Pre-operatively, all patients were given explanations of the visual analogue scale (VAS) scores for pain assessment and how to operate the patient-controlled analgesia (PCA) machine for post-operative analgesia. Baseline heart rate and blood pressure were recorded after applying standard ASA monitors. Group M was given IV Morphine at induction 0.1mg/kg. In Group S, a bilateral scalp nerve block was performed after arterial line insertion using a mixture of lidocaine 0.1%, ropivacaine 0.25%, adrenaline 1:200,000, and dexamethasone 4 mg. The supraorbital, supratrochlear, auriculotemporal, zygomaticotemporal, greater, and lesser occipital nerves were blocked. In Group M, only pin sites were infiltrated with the same solution. Intraoperative heart rate, systolic, diastolic, and mean arterial pressures were recorded at multiple surgical stages. Postoperatively, all patients received PCA morphine (1 mg/ml, 1 mg bolus, 10-minute lockout, no background infusion). Pain (VAS), sedation, and nausea/vomiting scores were assessed up to 24 hours postoperatively by a blinded observer.