Written informed consent will be obtained from parents of all participants prior to the study.
* Demographic information (age, sex, ethnicity).
* Clinical history and physical examination (Heart rate, Hypertension, Respiratory rate, burn percentage …. etc).
* Intervention:
* Group (1): Patients will receive nebulized ketamine (2 mg/kg)
* Group (2): Patients will receive nebulized combination of dexmedetomidine and ketamine (1 μg/kg + 1 mg/kg) Drugs will be prepared in 3 mL of saline 0.9% before administration by a standard hospital jet nebulizer via a mouthpiece, with a continuous flow of oxygen at 6 L/min for 10 to 15 minutes. Treatment will be stopped when the nebulizer begin to sputter. All solutions will be prepared in identical syringes with matching random codes by an independent investigator not involved in the observation or the administration of the anesthesia.
* Group (3): Patients will receive intramuscular ketamine (4 mg/kg, intramuscularly) 15 mins before starting the procedure. (Green et al., 1998).
* All patients will be admitted on the day of the surgery and will be instructed to fast 6 hours before surgery for older patients, as for breast fed patients, they will be instructed for 4 hours for breast feeding and for formula fed patients they will be instructed to fast for 6 hours as recommended by the American society of anesthesiologists. Preoperative assessment will be done before surgery by one of the members of the team who will make sure that the inclusion and exclusion criteria of the patients are considered, and baseline vital signs will be recorded. According to randomization that will be done by a computerized program, the drug will be administered to the patients in the preparation room by a researcher who will not participate in the evaluation of the patients before transfer to the operation room (OR).
* Parents are not allowed to accompany their children to the OR according to the hospital policy.
* Upon arrival to the OR department the Parental separation anxiety scale (PSAS) will be calculated.
Upon entering the operation room, standard monitoring will be commenced including ECG, non-invasive blood pressure and pulse oximetry and baseline measurement will be recorded. An attempt of cannulation will be done by an expert.
* During the length of the operation vital data will be recorded at 5 minutes interval. all patients will receive IV paracetamol 15mg/kg and patient would receive 3 mg/kg propofol as a rescue dose if vital data increased by \>20% of the baseline. Sedation will be assessed by University of Michigan Sedation Scale (UMSS) After the completion of procedure, patient will be discharged to post-anesthesia care unit (PACU) in for the first 15 min. During the stay in PACU pain will also be assessed by using FLACC score.
* Discharge from PACU will be done after meeting discharge criteria and the time of discharge will be documented. After discharge pain score will be measured using FLACC score at 15, 30, 60 minutes interval postoperative and the total combustion of postoperative analgesics will be calculated as well as the time of discharge from the hospital
