To assess the efficacy and safety of three different doses of fentanyl in attenuating haemodynamic stress response to laryngoscopy and endotracheal intubation. To assess the sedative effect of fentanyl.To observe complication if any, in three groups.

 After approval from the institutional review board (IRB No. 504/2015) and informed written consent from patient, this prospective, randomized, double blind clinical study was carried out in 90 patients of either gender aged 18 to 40 years of ASA Physical status I and II scheduled for elective surgery under general anaesthesia requiring endotracheal intubation were enrolled in this study. After thorough preanaesthetic evaluation, patients with cardio respiratory diseases, diseases affecting autonomic system, taking medication affecting hemodynamic variables and sedation score, anticipated difficult intubation and Intubation attempt lasting longer than 15 seconds and antenatal females and body mass index more than 25 were excluded from study.   Patients were fasted for 6 hours before surgery. In pre-anaesthetic preparation    room monitoring for Heart Rate (HR), Non Invasive Blood Pressure (systolic, diastolic and mean arterial pressure) and peripheral oxygen saturation (SpO₂), were established and baseline vital parameters were recorded.Patients were randomly divided into three groups 30 patients of each using computer generated random number sequence. Fentanyl in the doses of 2mcg/kg, 3mcg/kg and 4mcg/kg   intravenously was given 5 minutes before induction of anaesthesia in group I, II and III respectively.All patients received a standard anaesthetic protocol. All the parameters selected (HR, SBP, DBP, MAP) were recorded at various specific timings-at baseline, 5minutes after fentanyl administration, at the time of intubation, and then at 1,3,5,10,15 and 20 minutes after intubation.At the end of surgery, neuromuscular blockade was reversed with neostigmine 50µg/kg and glycopyrrolate 10µg/kg intravenously. After satisfying the extubation criteria, trachea was extubated and patients were transferred to post anaesthesia care unit. Sedation score was recorded at base line, 5 minutes after fentanyl injection, at the time of extubation, and then at 5,10,15,20,30,60,90 and 120 minutes after extubation in the postoperative period.