A.    Study procedure: After approval of JIPMER scientific advisory committee, Institute Ethics committee, registration from CTRI. Informed written consent from patient or relatives will be taken. A total of 180 patients meeting inclusion criteria will be enrolled in the study and randomized into one of the 3 groups K, C, D. Regular Pre-medications will be given with tablet famotidine 20 mg, diazepam 5mg in the night the day before surgery and tablet famotidine 20mg, Perinorm 10mg, diazepam 5mg in the morning of the day of surgery. After securing IV line, connecting standard monitors, pre-oxygenation will be done. Standard intubation protocol will be followed by using fentanyl 2 ug/kg, propofol 2mg/kg, vecuronium 0.1mg/kg. Cervical spine immobilization will be maintained by using a rigid cervical collar or manual in line stabilization and tracheal intubation will be performed by one of these 3 video laryngoscopes following manufacturers’ recommendations. Standard endotracheal tube of size 8 for the male and size 7 for the female will be used for all the patients in the study.

B.   Data collection methods including settings and periodicity:

a)     First attempt success rate

b)     More than 2 attempts – failure of the intubation

c)     Time for intubation – from scope passing teeth to tube seen passing vocal cords                                                                                                                                         Grading of intubation difficulty – modified IDS score⁸,⁹

d)     Percentage of glottic opening (POGO) score¹⁰

e)     Cormack - Lehane grading of glottic view

f)      Alternative techniques used like Bougie, External laryngeal manipulation, or Specialist needed.

g)     Ease of insertion

h)     Complications – airway trauma, esophageal intubation