Impact of Dexmedetomidine Infusion during Functional Endoscopic Sinus Surgery: A Randomised Controlled Trial

Abstract

Introduction: Functional Endoscopic Sinus Surgery (FESS) requires a surgical field with minimal bleeding, and numerous pharmacological agents have been used to achieve this. Dexmedetomidine has been widely used as a sedative, analgesic, and as a supplement to general anaesthesia. It has been found to decrease norepinephrine release, thereby decreasing heart rate (HR) and blood pressure. These properties, along with its opioid-sparing analgesic effects, make it an attractive drug to use during FESS. Aim: The aim of this study was to determine if dexmedetomidine infusion during FESS improves the visibility of the surgical field, provides stable haemodynamics, and alters the consumption of sevoflurane and other anaesthetic agents. Materials and Methods: This randomised, double-blinded controlled trial was conducted at the Otorhinolaryngology Operation Theatre, BYL Nair Charitable Hospital, Mumbai, India, from July 2018 to December 2019. The study included 100 patients of either sex, with American Society of Anaesthesiologists (ASA) I and II classification, aged 18-55 years, who were randomly divided into two groups. Group D received a dexmedetomidine infusion (0.5 mcg/kg/hour), while group C (control group) received a saline infusion. Haemodynamic parameters, Minimum Alveolar Concentration (MAC) of sevoflurane, surgeon’s grading of the operative field, and the requirement of additional hypotensive agents were compared. Statistical analysis was performed using Student’s unpaired t-test to evaluate the significance of normally distributed variables, Mann-Whitney U test and Chi-square test for ordinal data and categorical variables. Results: The groups were comparable with respect to age, weight, gender, and ASA grade. The average mean MAC of sevoflurane at various time intervals was 1.135±0.664635 in group D and 1.9675±0.438 in group C, which was statistically significant. The surgeon’s grading of the surgical field using the Fromme and Boezaart scale was significantly better in group D (1.53±0.45625 versus 2.907±0.5835 in the control group). Although not statistically significant, more number of patients in group C needed additional drugs to lower HR and blood pressure. Conclusion: Dexmedetomidine infusion during FESS is effective in maintaining stable haemodynamics with a lesser need for additional agents to lower HR and Mean Arterial Pressure (MAP). It improves the visibility of the surgical field and decreases the MAC of sevoflurane required to maintain anaesthesia.