A Comparative Study of Clonidine and Lignocaine for Attenuating Pressor Responses to Laryngoscopy and Endotracheal Intubation in Neurosurgical Cases

BACKGROUND AND AIMS: Laryngoscopy and endotracheal intubation are associated with reflex sympathetic stimulation, known as pressor response and can cause major complications. We compared the attenuating effect of time-tested lignocaine versus clonidine on the hemodynamic response to laryngoscopy and intubation in neurosurgical cases. DESIGN: A prospective, randomized, comparative, double-blind study with a sample size of sixty patients. METHODS: Sixty patients undergoing elective neurosurgery were randomly allocated into one of the two groups: Group L (n = 30) received lignocaine 1.5 mg/kg intravenous (i.v.) before induction and Group C (n = 30) received clonidine 2 μg/kg i.v. before induction. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded at baseline, after drug, after induction and 1, 2, 3,5,10, and 15 min after intubation. STATISTICAL ANALYSIS: Statistical software, namely, SPSS, version 15.0 by SPSS Inc., Chicago, USA was used for the analysis of data with Chi-square test to compare intergroup hemodynamic parameters. RESULTS: Mean HR remained above baseline at all times after intubation in lignocaine group but decreased at 2 min after intubation and remained below baseline at all times in the clonidine group. SBP, DBP, and MAP all increased above baseline at 1 min after intubation in lignocaine group, and decreased below baseline at 2 min after intubation, whereas in the clonidine group they all decreased below baseline after drug administration and remained below baseline at all times. Therefore, clonidine is very effective in attenuating pressor responses and this difference between the groups is statistically very significant with P < 0.001. CONCLUSION: Clonidine is more effective than lignocaine for attenuating the pressor responses to laryngoscopy and endotracheal intubation in neurosurgical cases.