Cardiovascular responses include increase in blood pressure and heart

   rate is a common event after laryngoscopy and tracheal intubation, and it

   has potentially adverse side effects especially in high risk patients. The cause

   of cardiovascular responses is stimulation   of receptors in autonomic nervous

   system  with  plasma  increase  in noradrenalin and other catecholamines.

   Sometimes   this   response  is  in  from  of  parasympathic and vagus nerve

   stimulation and  lead to bradycardia especially in children . The purpose of

   this study is comparison  and  survey of  lidocaine and  fentanyl  effects on

   prevention  or  attenuating  cardiovascular  responses  after  laryngoscopy

   and tracheal intubation in patients who  referred to Hamadan hospitals for

   elective surgery in 1998.

          We studied   a  total  of  96  patients ,   ASA   class  I  and  II  received a

   balanced  anesthesia  were   randomly  divided  into  three  groups. In the

   induction of anesthesia and  before laryngoscopy and tracheal intubation,

   group 1 received saline 5 ml , group  2 received  lidocaine 1.5  mg/kg  and

   group 3 received fentanyl 2    g/kg.  Patients  and investigator was blinded

   to it.Blood pressure and heart rate were recorded at following times:before

   induction ,  after  induction  but  before laryngoscopy and intubation , and

   1,3,5 minutes after intubation.Then the mean of hemodynamic parameters

   in  steps  one  and  two  compared  with  the  same  parameters   in   three

   following steps.

         Fentanyl     effectively     blunted   the    hemodynamic     responses   to

   laryngoscopy and tracheal intubation but saline and lidocaine were found

   to be ineffective in abolish or attenuating these same response.

         So according to this study fentanyl is more useful adjunct for preventing

   hemodynamic responses after laryngoscopy and tracheal intubation than

   lidocaine.