Efficacy and Optimal Time of Oropharyngeal Topical 10% Lignocaine Spray Before Induction of Anaesthesia in Attenuating the Pressor Response to Direct Laryngoscopy and Endotracheal Intubation

The study aimed to ascertain the efficacy of oropharyngeal topical 10% lignocaine spray applied prior to induction of anaesthesia and also to determine the optimal time for spraying to attenuate pressor response to laryngoscopy and endotracheal intubation. 80 patients of either sex, in the age group of 20-60 years (ASA I & II) undergoing different elective surgical procedures under general anaesthesia were taken up for the study. 10 puffs of Lignocaine 10% sprayed 1 min before induction in Group I, 3 min before induction in Group 2, 5 min before induction in Group 3 and normal Saline in Group 4 as control. Heart rate(HR), systolic (SBP), diastolic (DBP) and mean arterial pressure (MAP) were measured at baseline, after intubation, after 1min, 3 min and 5 min following intubation. There was statistically significant increase in HR, systolic, diastolic and MAP in control group when compared to baseline as well as to study groups. Following laryngoscopy and intubation attenuation of pressor response did not show a significant difference at 1min, 3min and 5min of 10% lignocaine spray within study groups. Lignocaine 10% when sprayed to the oropharynx prior to induction of anaesthesia attenuated the pressor response to laryngoscopy and intubation irrespective of timing of the spray.