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Abstract
BACKGROUND
Various agents like lignocaine, opioids, calcium channel blockers have been used to attenuate symptho-adrenal pressor response to laryngoscopy & endotracheal intubation. Dexmedetomidine-a newer highly specific α2 adreno-receptor agonist is also been tried for the same purpose.
Hence, this study is undertaken to compare the efficacy of Dexmedetomidine against the established Lignocaine in attenuating the hemodynamic responses to laryngoscopy and intubation.
AIMS AND OBJECTIVES
1) To compare the efficacy of IV lignocaine (1.5mg /kg) with that of IV Dexmedetomidine (1 µg /kg) in attenuating the following pressor reflexes .
2) To compare the rate pressure product (RPP) between the groups.
METHODOLOGY
A randomized double blinded prospective study involving 60 patients of both sexes of 18-65 years of age undergoing elective surgeries under general anesthesia were included. Each group (n=30)
Group D: Dexmedetomidine 1µg/kg diluted to 10ml with normal saline given over 10 minutes just before induction.
Group L: 2% lignocaine (preservative free) 1.5mg/kg made up to 10ml in normal saline 3 minutes before laryngoscopy
Anesthetic techniques:
A regular pre-anesthetic checkup done previous night. On the day of surgery, patients were given inj. Fentanyl 1.5µg/kg IV, inj. Glycopyrolate 0.2mg IV, inj. Thiopentone 5mg/kg IV, inj. Scoline 1.5 mg/kg IV. Laryngoscopy and intubation was accomplished in less than 30 seconds.
Heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure noted soon after inj. Fentanyl (before induction) and at laryngoscopy and 3 min ,5 minutes,15 minutes and 30 minutes post intubation.
All patients were maintained with O2, N2O, Isoflurane (0. 5%). and vecuronium as required. ECG, NIBP, HR were monitored throughout the procedure until recovery. All patients were monitored for 24 hours post operatively.
RESULTS
In Group D patients had significant attenuation of pressor response to laryngoscopy and intubation with lesser rise of HR, BP-Systolic, Diastolic, Mean & RPP at intubation and 1 min post intubation (P VALUE <0.05) when compared to Group L. The % increase in Mean BP in Group D was 19.3 % whereas it was 36.6 % in Group L.
At 1 min post intubation, the HR Increase in Group D was 1.1 % whereas In Group L, it was 22.3 % rise above the baseline. Similarly, again Mean BP rise in Group D was 9.3 % as compared to Group L which showed 22.4 % rise above baseline showing significant attenuation of stress response in Dexmedetomidine group.
In Dexmedetomidine group there was a minimal change in RPP with 20.5% at intubation and 6.6 % rise above baseline at 1 min post intubation compared to Lignocaine which showed poor attenuation of stress response with a maximum rise of 63.7 % at intubation above baseline and a rise of 44.6 % at 1 min post intubation.
From 3 mins post intubation all the 3 parameters HR, BP, RPP started coming down and reached baseline levels at 3 mins in Group D and at 5 min in Group L.
