Evaluation of the Effect of Preemptive Oral Pregabalin in the Attenuation of Cardiovascular Response to Direct Laryngoscopy and Endotracheal Intubation during General Anesthesia: A Randomized Placebo-Controlled Trial

Background: Pregabalin ameliorates neuro humoral stress response by inhibitory modulation of neuronal excitation. The primary objective of this study was to evaluate the effect of pre-emptively administered oral Pregabalin (150mg) in attenuating the pressor response to laryngoscopy and endotracheal intubation and secondary objective to evaluate its’ safety profile. Methods: Following institutional ethics committee approval, 80 patients of ASA grade I and II aged 20- 50 years of either sex undergoing surgeries under general anesthesia were allocated randomly into two groups of 40 each in this prospective randomized, double-blinded, placebo-controlled study. Group I and II received oral capsules of Pregabalin 150mg and Vitamin respectively, with sips of water, 90 minutes before induction of general anesthesia. All patients were anesthetized using standard anesthesia protocol. Hemodynamic parameters were observed at baseline, pre-induction, and 1,2,4,6,8,10 and 15 minutes following laryngoscopy and intubation. Results: Demographic parameters were comparable between groups. The mean heart rate, blood pressures were higher in group II compared to group I, following intubation (p<0.001). The maximum magnitude of increase in heart rate [Group I 15.67 ± 1.54 (95% CI 15.4 – 16.1), group II 29.7 ± 2.5 (95% CI 28.9 – 30.5) (P<<0.001)], systolic [group I (5.95 ± 1.63, 95% CI 5.45 to 6.46), group II (24.75 ± 2.21, 95% CI 24.1 to 25.4) (p<0.001)], diastolic [group I (5.45 ± 0.87, 95% CI 5.18 to 5.72), group II (22.45 ± 1.42, 95% CI 22 to 22.9) (p<0.001)] and mean arterial pressures [Group I (5.33 ± 1.02, 95% CI 5.01 to 5.65), group II ( 24.15 ± 3.87, 95% CI 22.9 to 25.3), (p<0.001)] were greater in group II compared to group I. The incidence of tachycardia was higher in group II (p<0.001). Conclusion: Administration of pre-emptive oral Pregabalin 150 mg, 90 minutes prior to induction of general anesthesia effectively attenuates the hemodynamic stress response to laryngoscopy and intubation without significant adverse effects.