ABSTRACT
Sixty patients of ASA physical status 1 or II aged 20-40 years scheduled for elective surgery under G.A. were classified into 3 groups: group I [n=20] where no local aneasthetics were injected or sprayed. group II [n=20] in which a bilateral superior laryngeal block SLN block was done 5 minutes before intubation and group III [n=20] in which a transtracheal injection of 5 ml of 1% xylocaine through the cricothyroid membrane 5 minutes before intubation. In the 3 groups blood pressure and pulse rate was measured before induction after induction before intubation. 1, 3, 5 and 10 minutes after intubation .In group I the mean arterial pressure showed significant increase [96. 75 +/- 11.09] after intubation from its basal value [87.45 + 12.1]. Also the mean pulse rate showed significant increase after 3 min [11 0.2 +/- l0.49].In group II the rise in mean arterial b.p was insignificant after intubation [82.9+8.230 to 98.80+ 10.51]. Also the increase in pulse rate after intubation was insignificant: [95.75 +/- 20.3 to 98.8 +/- 10.5] In group III the mean arterial pressure showed 11 significant reduction after intubation from induction values 72.30 + 6.57 from 91.20 + 8.21. Also the pulse rate didn't change much 1 min. after intubation, although it showed a significant reduction after words: from [97.6 + 14.76 to 69.3 +/- 094] 10 minutes after intubation. In conclusion: the transtracheal injection of xylocaine produced a pronounced attenuation of intubation response and is superior to SLN block in that respect