Efficacy of Oral Gabapentin for Attenuation of Haemodynamic Responses to Laryngoscopy & Endotracheal Intubation

Abstract

BACKGROUND Laryngoscopy and endotracheal intubation are basic skills to be acquired by an anaesthesiologist. For many years, laryngoscopy has been used as a conventional way to facilitate endotracheal intubation. These are the most critical events because, they provoke a marked rise in sympathoadrenal response as hypertension and tachycardia. There is an absolute need to decrease these haemodynamic responses, for which various drugs were used, with varying degrees of success. Gabapentin, initially used as an anticonvulsant has extended its role into anaesthesia practice with its multimodal effects. This study was conducted to evaluate the efficacy of oral gabapentin 800 mg in attenuation of haemodynamic responses to laryngoscopy and endotracheal intubation. METHODS After obtaining institutional ethical clearance, a prospective randomised comparative study was undertaken. Written and informed consent was obtained from 80 patients belonging to American Society of Anaesthesiologists (ASA) class I & II scheduled for various elective surgeries under general anaesthesia. They were divided into two groups of 40 each using computer generated random number table. Group G received oral gabapentin 800 mg and group C received empty capsules with sips of water, 2 hours prior to induction. Haemodynamic parameters – heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) were noted and rate pressure product (RPP) was calculated at baseline, at laryngoscopy and then at 1, 3, 5, 10 & 15 minutes after laryngoscopy and endotracheal intubation. RESULTS In Group G there was significant attenuation of HR, SBP, DBP, MAP at 1, 3 and 5 minutes after laryngoscopy and endotracheal intubation as compared to Group C. Hence, in Group G there was significant attenuation of RPP at 1 minute (12673.60 ± 1691.25, 11769.08 ± 1146.02, P = 0.01), 3 minutes (12546.85 ± 1123.78, 11759.98 ± 1358.02, P = 0.01) and 5 minutes (12411.68 ± 1270.04, 11537.03 ± 1230.06, P = 0.002) after laryngoscopy and endotracheal intubation as compared to Group C. No statistical difference was seen at 10 and 15 minutes. CONCLUSIONS Oral gabapentin 800 mg given preoperatively can attenuate haemodynamic responses to laryngoscopy and endotracheal intubation without significant side effects. KEY WORDS Oral Gabapentin, Laryngoscopy, Endotracheal Intubation, Haemodynamic Changes, Attenuation, Pressor Responses