Inhalational anaesthetic technique is the usual method to induce anaesthesia in children without intravenous access. A smooth, struggle free induction not only provides a pleasant experience for the child and parent but also avoids behavioral disturbance at emergence and prevents psychological stress and combativeness due to forceful mask holding. This is particularly important in children requiring multiple examinations under anaesthesia like those with retinobalstoma. This study envisages to find the median effective dose of intranasal dexmedetomidine as a premedication to ensure satisfactory mask acceptance during inhalation induction. After a pre-anaesthetic assessment and informed parental consent, 40 children aged 1-60 months undergoing EUA for RB will be recruited for this study. After ensuring appropriate NPO, the child will be administered IN dexmedetomidine in the pre-operative waiting area. The starting dose of dexmedetomidine will be 1µg/kg. The score by Modified Observer’s Assessment of Agitation/ Sedation scale (MOAA/S) will be noted. The child will be taken to the operating room for anaesthesia induction. One parent will accompany the child. Anaesthesia will be induced using a mask and gradual incremental doses of sevoflurane in oxygen and various parameters including mask acceptance, time to loss of eyelash reflex and hemodynamic parameters will be noted. Successful mask acceptance is defined as a calm, co-operative (with or without reassurance) or asleep child during inhalational induction. An intravenous line is secured and anaesthesia is maintained using any technique as deemed appropriate by the attending anaesthesiologist. The details like mode of maintaining the airway (mask, LMA), use of fentanyl, propofol, need for focal therapy like LASER, cryotherapy or intravitreal injection and duration of procedure and anaesthesia are noted. The recovery characteristics like time to reach modified Aldrete score of 9, and any untoward event like coughing, laryngospasm, vomiting, desaturation, Bradycardia at induction , maintenance or recovery will be noted. The parental satisfaction score with regards to the induction technique as compared to any previous experience will be recorded prior to discharge of the child from the hospital

The end point of the study is at discharge of the child from the hospital. The dose of IN dexmedetomidine in the following child will depend on the mask acceptance in this child. A dose increment of 0.2µg/kg will be done if the score for mask acceptance is poor and the child is cryful and combative at induction. A decrement of 0.2µg/kg in dosing will be done for the next child if the mask acceptance was effective and successful and smooth.