COMPARISION OF EASE OF ENDOTRACHEAL INTUBATION WITH POLYVINYL CHLORIDE ENDOTRACHEAL TUBE AND REINFORCED TUBE THROUGH THE INTUBATING LARYNGEAL MASK AIRWAY IN ADULT PATIENTS UNDERGOING SURGERIES UNDER GENERAL ANAESTHESIA

With approval from the Institutional Ethical Committee, informed and written consent will be taken from 60 patients of adult American Society of Anaesthesiologists (ASA) Physical Status of I/II of either sex, scheduled for elective surgery requiring general anesthesia.

A thorough pre-anaesthetic evaluation will be performed 24 hours prior to the scheduled procedure. Patients will be kept in an NPO status overnight, allowing only for sips of water for taking Tablet Alprazolam 0.5 mg and Tablet Ranitidine 150 mg the night before the surgery.

In the operating room, an intravenous infusion will be started, and patients will be randomly allocated to one of the two groups – Group I – intubation with cuffed PVC ETT, Group II – intubation with the flexo-metallic tube. Standard monitors will be applied – baseline parameters will be recorded including heart rate, arterial oxygen saturation, and non-invasive blood pressure recording. Patients are pre-medicated, and pre-oxygenated for 3 minutes with 100% oxygen. Anaesthesia will be induced with Inj. Fentanyl 1.5 mcg/kg and Inj. Propofol 2 mg/kg. Muscle Relaxant Inj. Vecuronium 0.1 mg/kg will be given. After complete relaxation, with the head in neutral position, an appropriate sized ILMA will be inserted. Several maneuvers and adjustments to ensure optimal positioning of the ILMA such as extension of the ILMA handle up/down movement, optimization maneuver, head-neck maneuver, rotation in the sagittal plane, or lifting away from the posterior pharyngeal wall (Chandy maneuver) will be made. A well lubricated cuffed PVC tube or flexo-metallic tube will be passed through the ILMA uptil 16 cm (the epiglottis elevating bar). The tube will be advanced into the trachea, and confirmation will be based on square-wave capnography, and prescence of bilateral breath sounds. The ILMA will then be deflated and removed using the stabilizing rod to maintain the tube in place. The ETT tube cuff will be inflated, and patient will be connected to closed circuit. The time taken for intubation is defined as the time from disconnection of the breathing circuit from the ILMA up to successful tracheal intubation.

Optimization maneuvers will be done if initial tracheal tube passage is unsuccessful. A maximum of 3 attempts will be allowed; in case of failure, airway will be secured with direct laryngoscopy alternatively. All ILMA placement attempts and tracheal intubations will be performed by the same anaesthesiologist. After intubation, anaesthesia will be maintained with Isoflurane 0.6-1%, and 66% Nitrous oxide with closed circuit and controlled ventilation.

After endotracheal intubation, and confirmation of correct placement with auscultation and square-wave capnograph, heart rate, arterial oxygen saturation, non invasive blood pressure and end tidal CO2 will be monitored at 1 minute intervals for the first 5 minutes following successful tracheal intubation. Thereafter, these parameters will be recorded every 5 minutes for 15 minutes after successful intubation. After extubation, all patients were evaluated for sore throat and hoarseness of voice during the first 24 hours at 1, 2, 4, 12 and 24 hours post extubation.