TO STUDY THE EFFICACY OF INTRAVENOUS MAGNESIUM SULPHATE WITH AND WITHOUT LIGNOCAINE SPRAY IN ATTENTUATING THE PRESSOR RESPONSE TO LARYNGOSCOPY AND INTUBATION

Depending on the study drug to be administered, the chosen patients will be randomized into 2 Groups, ML and M by computer generated randomization using sealedenvelope.com. Concealment will be done using sealed envelope technique. Group ML will receive intravenous MgSO4 (30 mg/kg) and 10% lignocaine spray; Group M will get intravenous MgSO4 (30 mg/kg).

All patients will be pre-medicated with tab. Alprazolam 0.5 mg oral, the night before surgery and a minimum fasting state of six hours before anaesthesia will be ensured in all patients. On arrival in the operating room, standard monitoring such as electrocardiography, pulse oximetry (SpO2), non-invasive blood pressure monitoring will be connected to the patient and the baseline heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded.

Prior to induction, pre-medications such as inj. Midazolam 0.05 mg/kg IV and inj. Morphine 0.1 mg/kg IV will be given, and all patients will be preoxygenated with 100% oxygen for three minutes. Prior to induction, both the groups will receive intravenous magnesium sulphate 30mg/kg as slow iv over two minutes. Induction will be carried out with injection propofol till the loss of verbal response. Muscle relaxation will be achieved with inj. vecuronium 0.1mg/kg after assessing adequacy of mask ventilation.  Positive pressure mask ventilation will be provided to ensure adequate oxygenation and ventilation. Three minutes after giving vecuronium, laryngoscopy will be done, following which group ML patients will receive 10% Lignocaine spray. Positive pressure mask ventilation will be provided for two minutes after which laryngoscopy and tracheal intubation will be done. In group M, after administration of vecuronium, positive pressure mask ventilation will be done for three minutes. Then, laryngoscopy will be done followed by endotracheal intubation. An experienced anaesthesiologist will perform the laryngoscopy, and a suitable-sized cuffed endotracheal tube will be used for orotracheal intubation. Only patients whose intubation will be performed in a single try within 20 seconds and using a standard McIntosh curved blade laryngoscope will be included in the study. After intubation, surgical stimulation will not be allowed for 10 minutes. Maintenance of general anaesthesia, intraoperative monitoring and reversal of neuro-muscular blockade and extubation following the standard practice.

Parameters like Heart Rate (HR); systolic blood pressure (SBP); diastolic blood pressure (DBP); mean arterial pressure (MAP) will be recorded at Baseline; after administration of the study drug; after administration of propofol; at laryngoscopy with spraying, immediately after intubation; at two, four, six, eight and at 10 minutes after induction. Patients will be carefully monitored for any complications including hypotension and bradycardia which will be managed by Inj. Mephentermine and Inj. Atropine accordingly.