Efficacy of continuous peri-operative infusion of dexmedetomidine for smooth emergence from general anaesthesia in laparoscopic surgeries.

After Obtaining ethical committee approval and patient’s written and informed consent, patients of ASA I/II/III physical status who will be undergoing elective laparoscopic surgery under general anaesthesia with estimated time of 1-3 hours will be recruited to participate in randomized controlled trial. The participant would be randomly allocated to group C or group D by computer generated random numbers. Results of randomization will be kept in concealed opaque envelopes and opened sequentially immediately before study drug administration. Routine monitors will be applied including BP cuff, electrocardiogram leads, Pulse oximeter probe, capnometry , esophageal temperature probe , peripheral nerve stimulator using Train of four(TOF) throughout the surgery. In all patients Inj dexmedetomidine loading dose (1µg/kg) over 15mins will be given followed by an infusion, at the rate of 0.4µg/kg/hr started 20mins prior to induction. Anaesthesia will be induced using IV Glycopyrrolate 0.04mg/kg mg, IV fentanyl 2 µg/kg, IV xylocard 1.5 mg/kg, IV Propofol and 1.5-2 mg/kg, Vecuronium 0.1 mg/kg or scoline 2mg/kg depending on the airway management. After orotracheal intubation and Ryles tube insertion, anaesthesia will be maintained using O2+air, sevoflurane 1%-3% , using low flows (1-2 lits) in close circuit and volume controlled ventilation with tidal volume 7ml/kg and respiratory rate of 10-14 in order to maintain the ETCO2 around 30mmHg with FIO2 of 50%. Intermittent doses of Inj fentanyl will be given every hourly to keep the blood pressure and heart rate within 20% of baseline and Inj. vecuronium will be titrated according to TOF monitoring i.e. will be repeated on appearance of three twitches. In control group, when pneumoperitoneum will be deflated by surgeon, dexmedetomidine infusion will be stopped. In experimental group D, dexmedetomidine infusion will be continued till the time of administration of neostigmine(reversal agent), when all four twitches of equal amplitude will be obtained on TOF stimulation. In all patients, at the end of surgery (skin suturing completed), Sevoflurane will be stopped (Defined as time zero or baseline of emergence process), fresh gas flow will be increased to 4-6lit/min, and Ondansetron 4 mg IV will be given and Orogasric suction will be performed. From Time zero till 15 minutes post extubation, systolic BP, Diastolic BP , heart rate, Spo2 and end tidal CO2, Agitation, Cough Scores and no. of coughing episodes will be recorded every 5 minutes. Patient will be reversed with Inj neostigmine 0.05 mg/kg and glycopyrrolate 0.01 mg/kg,.Trachea will be extubated when patient will be awake, spontaneous eye opening and reflexes present. The following will be recorded: total duration of anaesthesia and duration of surgery and time to extubation. Time to Extubation is defined as Time from switching off the sevoflurane to removal of the endotracheal tube. Duration of surgery will be defined as time of skin incision to completion of skin suturing. Duration of anaesthesia will be defined as time from induction by propofol to reversal with inj neostigmine and glycopyrrolate.