Study will be conducted after approval by the Institutional Ethics Committee and will be registered with Clinical Trials Registry of India. Patients fulfilling the inclusion criteria will be recruited for the study. A careful pre-anaesthetic check-up including detailed history, physical examination, baseline investigations as per clinical requirements will be performed. A verbal assent from the subject and written informed voluntary parental consent will be obtained for anaesthesia, surgery and participation in the study. Randomisation and concealment of allocation will be done. This will be a double blind study in which the drugs as mentioned in the randomised envelopes will be prepared by a resident not involved in the study in identical syringes and volumes. The drug syringes will be labelled as per the code alloted to the patient. Ketamine and dexmedetomidine will be prepared in 20 ml syringes with a dilution of 2mg/ ml and 2mcg/ ml respectively. The observations of the study shall be made by an independent person not aware of the study groups.

Patients in Group I will receive ketamine@ 1mg/kg over 10 minutes (body weight of the patient over 10min).

Patients in group II will receive dexmedetomidine @ 1µg/kg  over ten minutes (body weight of the patient over 10min).

  This will be followed by flash induction of anaesthesia with propofol set at a target Cp of 3-6µg/ml to achieve BIS between 40-60. Airway shall be secured with weight appropriate 2^nd generation supraglottic device (SGD). The correct placement shall be confirmed with capnography and lungs will be mechanically ventilated with O₂+Air (FiO₂ - 0.4) to maintain an EtCO₂ of 30–35 mm Hg.

Under all aseptic precautions, caudal block will be administered using 0.75ml/kg of ropivacaine 0.2% with morphine (30µg/kg).

Anaesthesia will be maintained by infusion of propofol with a Fresenius Kabi target controlled infusion pump (Agilia SP TIVA), using the Paedfusor plasma model. Cp will be increased or decreased by 0.5µg/ml to maintain a BIS of 40-60. Analgesia will be maintained by either ketamine (Group I) @ 0.5mg/kg/hr (Body weight of the patient/ 4 ml/hr) or dexmedetomidine (group II) @ 0.5µg/kg /hr (Body weight of the patient/ 4 ml/hr) with an increment of 0.2mg/kg or 0.2µg/kg upto 1mg/kg or 1µg/kg respectively, if needed.

BIS will be recorded every 5 minutes. A record shall be maintained of the plasma concentration of propofol whenever it is changed and the number of changes made.

Haemodynamic parameters will be observed intraoperatively and side effects such as hypotension (BP < 20% baseline), bradycardia (fall in HR <20% from baseline or less than 50/ min),  hypertension (BP > 20% baseline) and tachycardia (HR >20% baseline) will be recorded and treated. Hypotension will be treated with either decreasing propofol if BIS is <40 or bolus of ringer lactate as required. Bradycardia will be treated by decreasing propofol rate if BIS <40, removing the surgical stimulus, or intravenous atropine 0.02mg/kg if HR< 60/min. Tachycardia and hypertension will be treated by increasing propofol Cp if BIS > 60 and then analgesic as required. Surgical causes and full bladder will be ruled out. In spite of these measures if tachycardia and/ or hypertension persists, it would be assumed due to pain and fentanyl 0.5µg/kg will be administered. If an opioid is administered intraoperatively, or the allocation code is broken at any point in the study, the case would be excluded from the analysis.

Ketamine or dexmedetomidine infusion will be stopped and intravenous paracetamol 15mg/kg over 15 min will be administered with the starting of skin sutures. With the last skin suture, Cp shall be noted and set to 1.5µg/ml. Time to awaken shall be noted from the pump, and infusion will be stopped. BIS shall be recorded at this point. This shall be denoted as T0. SGD will be removed when patient starts breathing spontaneously and regularly with adequate tidal volume. Time will be noted from T0 to removal of SGD (Te).  Time to spontaneous eye opening from T0 shall be considered as actual awake time. Modified Aldrete score will be observed every minute post removal of SGD and time taken to achieve modified Aldrete score  â‰¥ 9 (Annexure VI) from T0 will be noted (Tr) . Primary outcome i.e, the time to post-operative recovery (modified Aldrete score ≥ 9) will be taken from T0 to Tr. Presence of irrelevant talk and hallucination will be noted. Mean/median plasma concentration of propofol shall be calculated by �’plasma concentration/ n. Total propofol consumed will be noted at the end of procedure.

Multimodal analgesia will be provided with the help of paracetamol 15mg/kg 8 hourly. Pain assessment will done every 1/2 hourly for initial 2 hour then hourly for next 4 hours and then 6 hourly upto 24 hours using modified objective pain assessment score [MOPS (Annexure V)]. If the MOPS is ≥ 4 , or child demands analgesia, diclofenac 0.3mg/kg (max 50 mg)  will be administered intravenously. Total requirement of post-operative analgesia will be recorded. Patients will be asked if they remember any events during the procedure after recovery. A note shall also be made of the episodes of nausea and vomiting in 24 hours. Patients will be administered ondansetron 0.08 mg/ kg iv on demand for nausea and/ or vomiting keeping an interval of 8 hours between two doses. Total 24 hrs analgesic requirement will also be noted.