Hemodynamic Responses to Microlaryngoscopy in ENT Patients -A Comparative Study of Premedication with Oral Clonidine and Metoprolol

Introduction: Attenuation of the hemodynamic responses to microlaryngoscopy in ENT patients is achieved using various drugs. Premedication with clonidine and metoprolol produce stable hemodynamics and a reduction in the amount of anaesthetic required. Materials and Methods : This is a prospective randomized double-blind study conducted to compare the effects of two such drugs clonidine and metoprolol given as oral premedication. Forty patients were premedicated 90 minutes prior to the procedure with oral clonidine and placebo in one group and metoprolol and diazepam in the other group and were anaesthetised using a standardised anaesthetic technique. Heart rate, systolic, diastolic and mean arterial blood pressures were recorded and the changes from baseline to those values during and after scopy were compared. The time interval from reversal to extubation and the sedation score at the end of the surgery were also noted. The statistical analysis of the data was done using student’s T-test. Results : The mean of the differences in heart rate from baseline value to scopy at 5 minutes was 13.6 ± 11.26 for clonidine and 12.05 ± 9.42 for metoprolol P=0.64 and that of mean blood pressure was 16.5 ± 8.75 and 13.45±9.69 P=0.30. There were no statistically significant differences between the two groups in the attenuation of cardiovascular response. The sedation produced by clonidine was comparable with that of diazepam. Conclusion: Both clonidine and metoprolol were equally effective in attenuating the hemodynamic responses to the procedure.