This study will be conducted as a prospective, randomized, longitudinal, double-blinded trial at a single ambulatory surgery centre with 3 groups of 20 children. Group 1 will receive oral acetaminophen (15 mg/kg) 1 hour pre-operatively and high-dose intravenous dexamethasone (0.5 mg/kg, max. dose 10 mg) immediately after induction of anesthesia. Group 2 will receive oral acetaminophen elixir (15 mg/kg) 1 hour pre-operatively and low-dose intravenous dexamethasone (0.15 mg/kg, maximum of 8 mg) immediately after induction of anesthesia. Group 3 will receive an oral placebo 1 hour pre-operatively and low dose intravenous dexamethasone (0.15 mg/kg, maximum of 8 mg) immediately after induction of anesthesia. Dose of dexamethasone is a potential confounder if patients in the low-dose dexamethasone groups weigh enough to obtain the maximum dose (8 mg). We expect this occurrence to be rare, as dexamethasone will be dosed for ideal bodyweight, but subgroup analysis by actual dose received will be performed to compare the two dosing regimens (0.15mg/kg and 0.5 mg/kg).

In addition to these medications, patients will receive the standard peri-operative care at our centre, which consists of intra- operative ondansetron at the discretion of the anesthesiologist, and standing orders for acetaminophen (15 mg/kg) and ibuprofen (10 mg/kg) around the clock. Patients older than five years also receive morphine elixir (0.1 mg/kg rounded down to the nearest 0.5 mg) p.r.n (when necessary) at the discretion of the nurse. Thus, patients of all three groups will receive adequate post-operative symptom control. The Pediatric Otolaryngologist (Dr. Josee Paradis, Dr. Julie Strychowsky, or Dr. Murad Husein) who is the patient's physician and will be performing the tonsillectomy, will initially approach the participant and substitute decision maker (SDM) to describe the study. If the patient and SDM agree to consider the study, the study will be described in more detail and study consent/assent will be obtained by a research assistant or a physician (who is not the primary physician). We will recruit a convenience sample of 60 patients aged 3-13 years scheduled for tonsillectomy to be performed by the principal investigator or co-investigators (J.P., M.H. or J.S.). For children aged 3 to 6 years, SDM informed consent will be obtained; for children aged 7 to 12 years, SDM written consent and child assent will be requested; for children 13 years of age, written consent will be obtained from a SDM and from the child. The patients will be randomized to one of the three treatment groups by a computerized randomization table. Data from the tonsillectomy procedure, including whether analgesia was needed intraoperatively, and in the post-anesthesia care unit, will be recorded. Self-reported pain intensity will be scored on the Oucher tool, a number and picture scale validated in children age 3-13. A research assistant or nurse will be trained to obtain Oucher reports at the patient's bedside at specific post-operative events, which correspond to time points. The Oucher tool is simple to learn and takes minimal time to administer. The first pain report will be obtained once the patient wakes from anesthesia (15 - 45 min post- operation), then upon transfer to step-down care (1 - 2 hrs hour post-operation), then at 3 hours post-operation, and finally upon discharge (or at 5 hours post-operation, if the patient is not anticipated to be discharged by this time). Many of the details surrounding the operation will be gathered in post-hoc review of the patient's chart by the research assistant. If the patient is transferred from the PACU to the day surgery unit (i.e. discharge is anticipated before the end of the day), the information from the entire stay in the day surgery will be collected. If the patient is admitted to the floor (i.e. staying overnight in the hospital for observation), information will be collected from the first 4 hours after admission. The information gathered from the chart will include complications of surgery, whether or not the patient had post-operative bleeding requiring a change in management, and also whether or not the patient had post-operative bleeding that required an operating room procedure. Time to first oral fluid intake, as well as amount of oral intake (measured in quantity of popsicles) in the post-anesthesia care unit and total oral intake before discharge will also be gathered from the patient's chart, as well as the time to first administration of morphine, the dose of morphine required, and the frequency of post-operative vomiting until time of discharge. For home pain management, all patients are advised to take acetominophen (15mg/kg) every 6 hours as needed, alternating with ibuprofen (10mg/kg) every 6 hours as needed. At discharge (average 5 hours post-operation), parents/guardians will be provided with a package including the Pediatric Quality of Life Inventory with questions about oral intake and activity, as well as a space to record any incidents of vomiting, the Oucher tool to evaluate the patient's pain severity, and a medication log to keep track of the pain medication (over the counter or prescribed) that the patient has taken. Parents/guardians will be given a measured cup to record quantity of oral fluid intake for the day. Parents will be asked to fill out the first questionnaire at discharge (average 5 hours post-operation) time point, and they will be encouraged to raise any questions or concerns they have about how to complete the questionnaires. Subsequently, these instruments will be completed by parents/guardians (relationship to patient will be noted on each form and they will be encouraged to have the same parent/guardian complete the form each time) on post-operative days 1, 2, 3, 4, 5, 6, and 7 before bedtime. The research assistant will contact parents/guardians and patients by telephone on the first postoperative day to follow-up with any questions or concerns about the survey. On the last weekday before the patient's follow-up appointment, a reminder call will be made to ask the parent/guardian to bring their completed questionnaire to the appointment. On the 14th post-operative day patients will attend a follow-up visit where they will be assessed and their completed forms will be collected. If the patient had any emergency department visits related to the procedure, the research assistant will consult the hospital database to obtain information about the emergency department visit, including date, chief complaint, and management.