Effects of Low Dose Dexmedetomidine Infusion on Intraoperative Haemodynamic Stress Response in Patients Undergoing Oral Oncological Surgeries: A Randomised Control Study

Abstract

Introduction: Maintaining stable haemodynamics throughout oral and maxillofacial surgeries helps to decrease intraoperative bleeding and thus improves the surgical field avoiding unnecessary damage to vital structures and tissues. Dexmedetomidine improves haemodynamic stability when used as an adjuvant during general anaesthesia. Limited studies have been done using low dose of dexmedetomidine for the attenuation of haemodynamic stability perioperatively in oral oncological surgeries. Aim: To study the effect of two doses of dexmedetomidine, 0.4 mcg/kg/hr, 0.2 mcg/kg/hr and normal saline (0.9%) on haemodynamic stress response in patients undergoing elective oral oncological surgeries. Materials and Methods: The present study was a randomised control study. After institutional Ethical Committee clearance, one twenty patients of American Society of Anaesthesiologists (ASA) physical grades I and II aged between 18-65 years, undergoing elective oral oncological surgeries under general anaesthesia were enrolled. Patients were randomly assigned to 3 groups with 40 patients in each group. Group A received dexmedetomidine 0.4 mcg/kg/hr, Group B received dexmedetomidine 0.2 mcg/kg/hr and Group C received normal saline. The infusion was initiated 15 minutes prior to pre-oxygenation and continued intraoperatively till the beginning of skin closure. Parameters noted were Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP) and Mean Arterial Pressures (MAP). Any adverse effects during the observation period were also noted. Statistical tests done were analysis of variance (ANOVA), Post-Hoc Tukey’s test, Chi-square, Nonparametric setting for Qualitative data analysis. Results: Intravenous (lV) dexmedetomidine 0.4 mcg/kg/hr effectively attenuated haemodynamic stress response to intubation and surgical stimuli throughout the observation period compared to 0.2 mcg/kg/hr and saline, being statistically significant (p<0.05). No significant side effects were noted. Conclusion: Inj. dexmedetomidine 0.4 mcg/kg/hr IV is the minimum effective dose required to attenuate the haemodynamic stress response to both intubation and surgical stimulus intraoperatively in patients undergoing oral oncological surgeries.