Comparison Of Nebulized Lignocaine With Dexmedetomidine Versus Nebulized Lignocaine With Clonidine In Obtunding The Laryngoscopic Responses-A Prospective, Randomized, Double-Blind Study

Abstract

Background: Major autonomic responses produced by endotracheal intubation may cause dangerous cardiovascular complications, especially in patients with known heart diseases. These responses can be attenuated by local anaesthetics, such as lignocaine, which reduce afferent nerve stimulation. Adjunctive agents, namely the alpha-2 adrenergic agonists dexmedetomidine and clonidine, have recently been found to potently add to the effects of lignocaine to minimize the stress response during intubation.

Objective: The aim of this study was to compare the efficacy of nebulized lignocaine with dexmedetomidine versus nebulized lignocaine with clonidine in blunting hemodynamic response during laryngoscopy and endotracheal intubation on heart rate and blood pressure during and after the procedure.

Methods: This was a randomized, control, double-blind study in 60 adult patients who underwent any elective surgery under general anaesthesia with endotracheal intubation. The patients were randomly allocated to two groups. In Group A (Control Group), patients received lignocaine with dexmedetomidine 1ml (50µg) and Group B (Study Group) received lignocaine with clonidine 1ml (150µg). The two drug combinations were given by nebulization 15 minutes before induction. All the patients' hemodynamic parameters, like heart rate and mean arterial pressure, were monitored at baseline after nebulisation, during laryngoscopy, and at intervals at 1,5 and 10 min after intubation. Post Operative Sore Throat (POST) and other adverse events were also assessed.

Results: The reduction in heart rate at baseline in Group A 78.2 ± 8.1 bpm and in Group B 80.2 ± 8.8 bpm with significance of p value  < 0.05, during laryngoscopy Group A  was 92.3 ± 9.1 bpm and in Group B was 102.4 ± 10.2 with significance of p value 0.01, immediate laryngoscopy Group A  was 98.2 ± 9.6 bpm and in Group B was 110.4 ± 11 bpm with significance of p value 0.02, at post intubation 1min in Group A  was 95.4 ± 10.0 bpm and in Group B was 106.1 ± 10.8 with significance of p value 0.01, post intubation 5 min in Group A 84.9 ± 7.6 bpm and in Group B 90.2 ± 9.5 bpm with p value of < 0.05, post intubation 10 min in Group A 80.2 ± 7.1 bpm and in Group B 82.5 ± 8.9 bpm with significant p value  of 0.05. Mean arterial pressure  at baseline at baseline in Group A 87 ± 5 mm of Hg and in Group B 90 ± 4 mm of Hg with significance of p value  < 0.05, During laryngoscopy 104 ± 7 mm of Hg in Group A and in  Group B 116 ± 8 mm of Hg, immediately after intubation in Group A 117 ± 6 mm of Hg and in Group B 129 ± 7 mm of Hg with p < 0.05, at post intubation 1min in Group A  was 110 ± 5 mm of Hg  and in Group B was120 ± 6 mm of Hg with significance of p value 0.04 , post intubation 5 min in Group A 96 ± 4 mm of Hg and in Group B 106 ± 5mm of Hg with p value of < 0.05, post intubation 10 min in Group A 90 ± 3 mm of Hg and in Group B 99 ± 4 mm of Hg with significant p value  of < 0.05. Occurrence of Sore throat in 1 hour - 2 patients reported in Group A whereas 8 in Group B, at 6 hours 1 patient reported in Group A whereas 6 in Group B and in 24 hours 4 patients in Group B whereas in Group A no sore throat. Adverse event rates were comparable between the groups and therefore suggested a good safety profile for clinical use.

Conclusion: The combination of nebulized lignocaine with dexmedetomidine shows better hemodynamic stability compared to lignocaine combined with clonidine. Both treatments administered were effective and safe, but dexmedetomidine had a better profile when compared with clonidine in obtunding laryngoscopic response and reduction in post operative sore throat