Effect of Manual mask ventilation Vs Mechanical mask ventilation with oxygen and isoflurane during induction for post operative nausea and vomiting in adult patients posted for general endotracheal anaesthesia.

70 adult patients of both gender who will be posted for surgeries required to undergo general endotracheal (ET) anaesthesia will be evaluated thoroughly as a part of preanaesthetic evaluation. The Apfel scoring for PONV will also be evaluated & the scores will be noted. All patients will be included in the study after obtaining informed consent. On the day of surgery, patients will be randomised into two groups using shuffled sealed opaque envelop technique.

GROUP PCV: Case group will receive 100% oxygen with 1% Isoflurane and pressure control ventilation with 15 cmH2O and PEEP 5cms H2O after induction with propofol and vecuronium before intubation.

GROUP MMV : Control group will receive 100% oxygen with 1% Isoflurane and manual mask ventilation after induction with propofol and vecuronium before intubation.

The anaesthetist who is involved in randomization of patients will also be involved in induction and intubation of both the groups of patients and further management and observation of the incidence of post operative nausea and vomiting will be by another anaesthesiologist. Thus the observer and the patient will be blinded for the study drug. Inj dexamethasone 4mg, Inj Midazolam 0.01mg/kg body weight and Inj. Fentanyl 1microgram/kg body weight will be given as a part of premedications. All the patients after preoxygenation with 100% oxygen for 3 minutes, will be induced with propofol 2mg/kg body weight till the loss of eye lash reflexes. 0.1 mg/kg body weight of vecuronium will be administered for all patients. All patients will be mask ventilated with 100% oxygen and 1% isoflurane and the mode of ventilation changes depending on the group they belong to for 5 minutes and intubated with appropriate ET tubes. Patients will be maintained on O2&N2O and Isoflurane. Intaroperative heart rate (HR) and blood pressure (BP) will be monitored and any haemodynamic instability will be managed as per the institutional protocol. Patients will be administered with Paracetamol 1gm IV and 75mg diclofenac IV 20 minutes before extubation. Inj. Ramosetron 0.3 mg IV will be administered in both the groups 20 minutes before the end of surgery. At the end of surgery, patients will be reversed with Neostigmine 0.05mg/kg and Glycopyrrolate 0.01mg/kg body weight. Time of recovery will be noted from the time of administering reversal drugs and patients satisfying the extubation criteria are extubated. All patients will be shifted to post anaesthesia care unit (PACU) and monitored. Incidence of post operative nausea and vomiting will be noted at 0 hour and every 2nd hourly upto 6 hours and every 6th hourly upto 24 hours in both groups. Incidence of post-operative vomiting will be noted and treated with Inj.Metoclopramide 10mg IV (as a rescue antiemetic) and the number of injections will be noted. Post operative nausea will be assessed with VAS (visual analogue scale). Post op analgesic requirement will be also noted. All patients will be interviewed regarding the occurrence of nausea and vomiting 2nd hourly upto 6 hours and every 6th hourly upto 24 hours in both groups and were asked to rank their nausea using a four-point verbal rating scale (0 = none, 1 = mild, 2 = moderate, 3 = severe). Patient satisfaction at 24 h post-surgery will be quantified using a three-point scale (0 = dissatisfied, 1 = neither satisfied nor dissatisfied, 2 = satisfied).

9.2 Study population and source of data: After receiving ethical clearance, a total of 35 subjects in each group will be enrolled into this study who are adults of ASA physical status I/II aged 18 to 60 years undergoing laparoscopic surgeries.