Comparison of Dexmedetomidine and Clonidine Infusion on Depth of Anaesthesia and Blood Glucose Levels in PSI (Patient State Index) Guided General Anaesthesia in Thoracoabdominal Surgeries

Abstract

Background: Surgical stress induces haemodynamic instability and stress-related hyperglycaemia, which may adversely affect perioperative outcomes. Alpha-2 adrenergic agonists such as dexmedetomidine and clonidine are used as anaesthetic adjuvants to attenuate this response. Patient State Index (PSI) monitoring allows objective assessment of the depth of anaesthesia and precise titration of anaesthetic agents. Methods: This prospective randomised comparative study included 62 adult patients (18–60 years), ASA physical status I–II, undergoing elective thoracoabdominal surgeries under general anaesthesia. Patients were randomly allocated to receive dexmedetomidine (1 μg/kg loading dose followed by 0.5 μg/kg/h infusion) or clonidine (1 μg/kg loading dose followed by 0.5 μg/kg/h infusion). Anaesthesia was maintained with desflurane and titrated to maintain PSI values between 25 and 50. Results: PSI values remained within the recommended range in both groups with no significant intergroup difference (p > 0.05). Dexmedetomidine provided significantly lower heart rate and more stable mean arterial pressure compared to clonidine (p < 0.05). Blood glucose levels were comparable between groups except at 30 minutes after induction. Conclusion: Dexmedetomidine offers superior haemodynamic stability and may be preferred when cardiovascular stability is desired.