Comparison of laryngeal position using ultrasound imaging vs direct laryngoscopy in neutral and sniffing position

The study protocol will be explained to the patients and informed consent will be obtained. Ultrasound examination of upper airway will be done in sniffing and neutral position. Hyomental distance will be measured. Anterior neck soft tissue thickness will be seen at level of vocal cords. The transverse processes of cervical vertebrae corresponding to the vocal cords will be noted. That will be taken as laryngeal position. After shifting the patient to the OT standard protocol for induction of anaesthesia will be followed. Muscle relaxation will be achieved with inj vecuronium in all patients. Laryngoscopy will be done with Macintosh blade,size 3 in female patients and size 4 in male patients. Laryngoscopy will be done first in neutral position and modified Cormack Lehane grading (CML) will be noted. If CML is more than I then backward upwards rightwards pressure (BURP) will be applied and if there is change in CML due to BURP will be noted. Same procedure will be repeated in sniffing position. After confirming the CML with BURP, trachea will be intubated with appropriate size entotracheal tube. Capnographic confirmation of entotracheal intubation will be end point of study. Inability to visualize vocal cords after optimal sniffing position with BURP will be manage according to difficult airway management protocol and findings will be noted.