A Comparative Study Of Intraoperative Infusion Of Dexmedetomidine Versus Nitroglycerin For Controlled Hypotension In Elective Functional Endoscopic Sinus Surgeries(Fess) - A Randomized Controlled Study

Abstract

Introduction: FESS (Functional Endoscopic Sinus Surgery) is an approach to manage both acute and chronic conditions of paranasal sinuses. One of the key benefits of using a controlled hypotensive anesthetic technique during FESS is the reduction in blood loss, which in turn minimizes the need for blood transfusions, enhances the visibility of the surgical field, and shortens the overall duration of procedure. Both dexmedetomidine and Nitroglycerin have been shown to achieve desired level of hypotension without causing tachycardia, thus improving surgical conditions by reducing bleeding and facilitating a clearer operative view.

Aims & Objectives: This study aims to compare the efficacy of intravenous (IV) dexmedetomidine and Nitroglycerin infusions in producing controlled hypotension during elective Functional Endoscopic Sinus Surgery (FESS) in adults under general anesthesia. The comparison will focus on several key factors: the quality of the intraoperative surgical field, intraoperative heart rate (HR), the need for additional vasoactive drugs (such as ephedrine and atropine), recovery profile, duration of recovery, postoperative sedation scores, surgeon satisfaction, and any adverse effects associated with two agents.

Methods: A double-blind, randomized, prospective study was conducted involving 60 patients with paranasal sinus pathologies scheduled for functional endoscopic sinus surgery at Adichunchanagiri Institute of Medical Sciences and Research Centre. The patients were randomly assigned to two groups, with 30 patients in each group: Group D received dexmedetomidine, while Group N received nitroglycerin as the hypotensive anesthetic agent. Key parameters such as heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and oxygen saturation were monitored from the onset of drug administration until the end of the surgery. Additionally, Ramsay sedation scores, surgical satisfaction scores, and bleeding scores were used to assess and compare the effectiveness of the two agents in achieving controlled hypotension.

Results: The mean age of the study participants was 31.48 years, with a standard deviation of ±8.27 years. The majority of participants were female, and both groups consisted predominantly of patients classified as ASA Grade 1. When comparing the changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) from baseline to thriteen different time intervals (5, 10, 20, 30, 60, 90,105,120,135 and 150 minutes), repeated measures ANOVA revealed a statistically significant difference favoring dexmedetomidine.

The mean duration for rescue analgesia was significantly longer in the dexmedetomidine group (619.87 minutes) compared to the nitroglycerin group (356.60 minutes). Additionally, the mean Ramsay Sedation Score and Surgical Satisfaction Score were higher in the dexmedetomidine group (2.77 and 2.70, respectively) compared to the nitroglycerin group (1.73 and 2.33, respectively). The mean Bleeding Score was lower in the dexmedetomidine group (2.33) compared to the nitroglycerin group (2.63). All of these differences were statistically significant, indicating that dexmedetomidine was more effective in inducing controlled hypotension during surgery.

Conclusion: The study found that dexmedetomidine was more effective than nitroglycerin in inducing controlled hypotension and providing postoperative sedation. While nitroglycerin was associated with a shorter recovery time, dexmedetomidine demonstrated superior performance in achieving higher surgeon satisfaction scores and better control of bleeding during surgery.