A Comparative Study of Nitroglycerine and Dexmedetomidine for Induced Hypotension in Functional Endoscopic Sinus Surgery

Abstract

Shruthi M. Shah1 , Nidhi Shrenikbhai Reshamwala2 , Aakanksha Sanjay Raval3 , Krimal Rahulkumar Shah4 , Yash Rajendrabhai Joshi5

BACKGROUND We wanted to evaluate the efficacy of IV nitroglycerine and IV dexmedetomidine in achieving and maintaining induced hypotension in patients undergoing FESS under general anaesthesia, compare haemodynamic response in terms of heart rate, blood pressure, mean arterial pressure, compare clarity of the surgical field, compare the effect on duration of surgery and study the intraoperative and postoperative complications, if any. METHODS This is a randomised control trial conducted from 01/01/2018 to 31/12/2018 among 50 patients, ASA 1 & 2 undergoing FESS. They were randomly divided into 2 groups - group D (an infusion of dexmedetomidine was started with a loading dose of 1 μg / Kg over 10 min and thereafter was maintained between 0.5 - 1.0 μg / Kg / h) and group N (an infusion of nitroglycerine was started at the rate of 0.5 μg / Kg / min and was maintained between 0.5 - 2.0 μg / Kg / min). Haemodynamic data was recorded. Both the infusions were titrated to maintain a MAP between 65 and 75 mmHg. The visibility of the surgical site was checked by the surgeon at every 30 minutes using the Fromme and Boezaart scale. RESULTS Both groups consisted of 25 patients each and were demographically similar. In both groups heart rates remained within normal physiological limits, not requiring any pharmacological treatment. Both groups had comparable average MAP during surgery. The group D showed desirable attenuation of haemodynamic response at the time of intubation as well as at extubation. Both groups had comparable duration of surgery. Both the drugs were equally effective in creating clear surgical fields to the surgeons’ satisfaction. Dexmedetomidine provided better intraoperative analgesia and reduced requirement of incremental fentanyl as compared to nitroglycerine. Emergence time was significantly higher in dexmedetomidine group. CONCLUSIONS Both the groups provided comparable clarity of surgical field with comparable haemodynamic parameters during surgery. dexmedetomidine provided better haemodynamic stability and an additional benefit of reduced requirement of intraoperative supplemental analgesia.

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