Sleep Quality - Comparing the Effect of Ondansetron or Dexamethasone Given as Routine Prophylaxis Intraoperatively to Prevent Post Operative Nausea and Vomiting (SCORPION)

Nausea and vomiting are common complications after anaesthesia, and anaesthetists routinely give medications to prevent them. Dexamethasone and ondansetron are the two most commonly used agents and have a long safety record. However, their effects on sleep, behaviour, and overall recovery are not well studied. Understanding these will guide future care. The aim of this study is to determine if dexamethasone or ondansetron given during an anaesthetic affect post-operative sleep, behaviour and recovery in children. Patients enrolled in the study will be randomised to receive either dexamethasone or ondansetron during their procedure. This randomisation will be blinded to patients, their families and their treating anaesthetist. Information about the patient's pain, recovery and sleep will be collected over 7 days post-operatively using online surveys. A subset of patients will also be asked to complete additional pre-operative non-invasive monitoring using an oximeter and an actigraph to measure their sleep quality before and after surgery. In addition to the postoperative surveys, these patients will be asked to wear the oximeter and actigraph for 3 nights before and immediatey after surgery. Patients who are admitted overnight postoperatively will also have additional transcutaneous carbon dioxide monitoring on the night of their surgery.

Inclusion Criteria: * Children aged 2 - 15 years, * Undergoing general anaesthesia for minor ambulatory surgery or procedures with a maximum of 1 overnight stay postoperatively * ASA I or III Exclusion Criteria: * Currently taking regular dexamethasone or ondansetron * Currently taking regular steroids, including inhaled corticosteroids * Anaesthetic plan to give dual PONV prophylaxis * Known hypersensitivity to the active substance or to any of the excipients listed * Language barriers impeding data collection * Department for Child Protection and Family Support is involved in their care * Planned admissions to the Paediatric Intensive Care Unit (PICU) * Oncology patients * Severe developmental delay * ASA III or above * Significant cardiorespiratory conditions