A Study To Observe The Effect Of Intravenous Use Of Dexmedotomidine On Hemodynamic Response During Laryngoscopy And Intubation Under General Anaesthesia In Patients Posted For Functional Endoscopic Sinus Surgeries

Abstract

BACKGROUND :

Airway instrumentation in the form of direct laryngoscopy and intubation pose to be potentially invasive stimuli that can lead to detrimental hemodynamic responses in the form of tachycardia and hypertension. It is primarily due to an increase in the plasma concentration of catecholamines1. Induction of general anesthesia, direct laryngoscopy and endotracheal intubation induce marked cardiovascular changes as well as autonomic reflex activity2. Dexmedotomidine is a highly selective α2 adrenergic receptor agonist causes cardiovascular stability, reduces need for anaesthetics and narcotics17. So ,the current study is designed to observe the effectiveness of intravenous use of dexmedotomidine for attenuation of hemodynamic response to direct laryngoscopy and intubation in patients undergoing general anaesthesia posted for functional endoscopic sinus surgeries (FESS).

METHOD :

This observational study was conducted in 52 patients of either gender under ASA I & II scheduled for FESS surgeries under general anesthesia in Dhiraj hospital, Vadodara, Gujarat. All 52 patients were given intravenous(i.v.) dexmedotomidine (1μg/kg) in 100 ml normal saline over 10 minutes before induction16. All the patients were premedicated with inj. Glycopyrolate 0.04mg/kg i.v. , inj ondansetron 0.1mg/kg i.v. , inj midazolam 0.03mg/kg i.v. and inj tramodol 0.5mg/kg i.v. Anaesthesia was induced with inj propofol 2mg/kg i.v. followed by inj. Succinylcholine 2mg/kg i.v. All the parameters like pulse rate, systolic and diastolic blood pressure and mean arterial pressure were recorded at regular intervals.Complications (if any) were also observed and noted during perioperative period.

RESULT :

Pulse rate, mean arterial pressure (MAP), systolic (SBP) and diastolic pressure (DBP) were compared at baseline, after giving dexmedotomidine , at the time of induction , laryngoscopy and throughout the study period till 60 minutes. It was observed during the study that measured values of above parameters reduced following drug administration in compare to baseline. The measured value of all parameters increased following stress response due to laryngoscopy and intubation in compare to measured value of parameters observed after drug administration but the increment in all the parameters was below measured values of baseline. Side effects like hypotension and bradycardia were not noted due to slow infusion of  dexmedotomidine over 10 minutes.(p < 0.05)

CONCLUSION :

It is concluded that pre treatment with intravenous dexmedotomidine at a dose of 1μg/kg over 10 minutes prior to induction of anaesthesia is a safe and effective method to attenuate the hemodynamic stress response i.e rise in pulse rate, SBP, DBP & MAP to laryngoscopy and intubation in patients posted for FESS under general anaesthesia