A total 120 patients will be enrolled for the study after obtaining a written consent from these patients. These patients will be randomly allocated by rapid sampling into 2 groups of 60 patients each by using computer generated random number table. Two types of coloured balls Red and Yellow would be given to each patient when allocated initially for the study. The patient can pick up any ball at their own discretion.  Group A –Red ball – Allocated for iv Lignocaine Group B –Yellow ball – Allocated for iv Magnesium sulphate  Group A will receive 2%Lignocaine(without preservative) 1.5 mg/kg IV bolus given over 1 min before induction. Group B will receive 50% Magnesium sulphate 30 mg/kg diluted and made upto 20 ml IV bolus with normal saline, IV bolus over 3 minutes before induction of anaesthesia.  Pre-anesthetic evaluation will be done day before OT. All patients will be on NPO for solid food for 8 hours, for light meal up to 6 hours, for non clear fluid up to 4 hours and for clear fluids up to 2 hours before the anaesthesia.  In the operation theater, the patient’s body weight, fasting status, consent, and preanaesthetic check up will be checked, i.v cannula will be established. Standard monitors like ECG, Pulse oximeter, NIBP will be connected to the patients and baseline heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), Rate Pressure Product (RPP) will be noted.  Rate pressure product will be calculated from recordings of SBP and HR (formula: SBP x HR), which will be recorded at various time intervals. The RPP is an index of myocardial oxygen demand.  All patients will be premedicated by midazolam 0.2 mg/kg IV and patients according to their respective group will receive (without preservative) Lignocaine or Magnesium sulphate and hemodynamic parameters will be recorded after 10 minutes from the time of administration of the Lignocaine or Magnesium sulphate. Then after 10 minutes of initiation of infusion of (without preservative) Lignocaine or Magnesium sulphate, general anaesthesia will be induced by IV Fentanyl 1-1.5 μg/kg, Propofol 1- 2 mg/kg. After achieving proper mask ventilation Atracurium 0.5 mg/kg will be given 16 to facilitate tracheal intubation. Then the patient will be mask ventilated for 3 minutes followed by laryngoscopy and endotracheal intubation; then Atracurium 0.1 mg/kg will be given as maintenance at regular intervals.  According to patient haemodynamics, anaesthesia will be maintained with Nitrous oxide 60%, Isoflurane 0.6-1.0% in 40% oxygen. The lungs will be mechanically ventilated and the end-tidal carbon dioxide concentration will be maintained at 30-40 mm Hg. No surgical or any other stimulus will be applied during 10 minutes of study period.  Hemodynamic parameters including HR, SBP, DBP, MAP, RPP and any adverse effect will be recorded at intubation and 1, 2, 4,6,8, 10 minutes after intubation. At the end of the surgery, neuromuscular block will be reversed with Neostigmine at a dosage 0.05 mg/kg iv and Glycopyrrolate at a dose of 0.004 mg/kg/iv dose.  Premedication with iv Lignocaine or iv Magnesium sulphate before induction of general anesthesia during Laryngoscopy and Tracheal intubation helps in attenuation of haemodynamic stress response and have no as such side effects per say, both these drugs can be used interchangeably without affecting the safety of the patients.  |