Before arrival to the operating room, the patient will be assessed preoperatively in preoperative room and gastric volume will be calculated using antral cross sectional area using ultrasound.  

Conduct of anesthesia

Upon arrival to the operating room, the patient will be positioned supine and advanced multipara monitor, including electrocardiogram, blood pressure, and SpO2, to all the patients included in the study. All patients will be premedicated with midazolam 1mg.General anesthesia will be induced with Fentanyl 2µg/kg, Propofol 1-2.5mg/kg and Vecuronium 0.1mg/kg. Patients Will be mask ventilated for 3 min using the anaesthesia machine, with controlled ventilation set to a tidal volume of 7mLkg�’ 1, frequency of 12 -16 breaths per minute and an inspiratory:expiratory ratio of 1:2 to maintain an end tidal carbon dioxide of 35-45mmHg.Thereafter respective airway device will be inserted accordingly to the group assignment as follows- Group E (Endotracheal intubation) and Group P (ProSeal laryngeal mask airways).If satisfactory insertion of proseal LMA is not achieved with three attempts, or there is respiratory embarrassment, the patient will be intubated using direct laryngoscopy and will be excluded from study. The ventilation will be set to Volume control mode delivering air: oxygen mixture (2:1) at a frequency of 12-16breadths/min, TV of 7 ml/kg, Inspiratory:expiratory(I:E) ratio of 1:2,  to maintain EtCO₂ at 35-45 mm Hg, by adjusting the respiratory rate. Anesthesia will be maintained with Sevoflurane at a Minimum Alveolar Concentration (MAC) of 1.0 initially, and titrated further to keep the Mean arterial pressure and heart rate  within ±20% of the baseline values. Muscle relaxation will be achieved with vecuronium 1 mg intermittently according to NMT monitoring.  .The difference between inspired tidal volume (ITV) and ETV will be used to calculate leak volume (LV), i.e. LV=Inspired Tidal Volume – Expired Tidal Volume. The leak fraction is defined as leak volume divided by ITV (i.e. leak fraction=LV/ITV). At the end of surgery, anesthesia will be discontinued, Muscle relaxation will be reversed with neostigmine and glycopyrollate. The tracheal tube, ProSeal LMA, will be removed when the patient will be spontaneously breathing and able to open their mouth to command. Any blood staining on the laryngoscope, tracheal tube, or ProSeal LMA will also be documented.

Patients and post-anaesthesia care unit nurses will be unaware of the airway device used. A single trained observer, who is blinded to the airway device used, will document post operative events at 2, 6, and 24 h after surgery. Patients will be asked if they had any of the following symptoms (yes/no): nausea, vomiting (at any time), sore throat (constant pain, independent of swallowing), dysphonia (difficulty speaking and pain on speaking), and dysphagia (difficulty or pain provoked by swallowing). Anaesthesia time will be from mask ventilation to removal of the airway device. Surgical time will be from incision to insertion of the last stitch.