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

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

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Anaesthesia; Postoperative Sleep Quality; Postoperative Nausea and Vomiting (PONV); Postoperative Behaviour; Paediatric Surgery; Postoperative Recovery in Children
• Intervention / Treatment: Drug: Dexamethasone (IV); Drug: Ondansetron iv

Detailed Description

Postoperative nausea and vomiting (PONV) are a common complication after anaesthesia. Therefore, it is standard practice to administer either ondansetron and/or dexamethasone intraoperatively as prophylaxis. PONV affects up to 30-40% of the general surgical population and up to 80% of high-risk patients, making it one of the most distressing complications of the perioperative period.Uncontrolled PONV prolongs recovery room stay, increases unplanned hospital re-admissions, and is consistently identified by patients and families as one of the most undesirable aspects of the surgical experience. It was ranked in the top 10 research priorities in perioperative medicine in a recent large consumer engagement study involving over 350 children.

Ondansetron, a 5-HT3 receptor antagonist, and dexamethasone, a corticosteroid, are the two most widely used agents for PONV prophylaxis in paediatric anaesthesia, often administered in combination.Dexamethasone exerts well-documented glucocorticoid effects, including modulation of the hypothalamic-pituitary-adrenal (HPA) axis, suppression of endogenous cortisol secretion, and direct actions on brain structures involved in arousal and sleep regulation, including the hippocampus, hypothalamus, and limbic system.a single intraoperative dose of dexamethasone (0.1-0.5 mg/kg) has been shown to produce measurable HPA axis suppression lasting 24-48 hours postoperatively in children, as well as transient elevations in blood glucose and behavioural changes including hyperactivity, irritability, and emotional lability.

Sleep is a critical component of paediatric postoperative recovery. Disrupted postoperative sleep has been associated with increased pain perception, impaired immune function, heightened parental anxiety, and prolonged behavioural disturbance following surgery. Glucocorticoids are known to disrupt sleep architecture, including fragmentation of sleep, suppression of slow-wave sleep, and reductions in total sleep time. In children, the effects of a single perioperative dose of dexamethasone on sleep remain poorly characterised. In contrast, ondansetron does not directly affect the HPA axis or glucocorticoid receptors, and its central effects are limited primarily to 5-HT3 receptor blockade, with no established direct mechanism for sleep disruption. Postoperative negative behavioural changes (PNBC) in children, sometimes referred to as "new-onset behavioural problems", are a recognised sequela of paediatric anaesthesia and surgery, affecting up to 54% of children in the first 2 weeks following surgery. The potential role of perioperative dexamethasone in exacerbating these changes through glucocorticoid-mediated effects on the developing brain has not been systematically examined. Understanding whether the choice of PONV prophylaxis agent influences postoperative sleep quality and behaviour could have important implications for anaesthetic practice and family-centred postoperative care.

This study aims to investigate the impact of intraoperative intravenous dexamethasone vs ondansetron administered for prophylaxis of postoperative nausea and vomiting (PONV) on postoperative sleep, behaviour and recovery in children undergoing general anaesthesia.

• Study Type: Interventional
• Enrollment (Estimated): 500
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Britta S von Ungern-Sternberg, MD, PhD; Phone Number: +61864564806; Email: britta.regli-vonungern@health.wa.gov.au
• Study Contact Backup: Name: Lliana Slevin, Bsc; Phone Number: +61 864564806; Email: lliana.slevin@health.wa.gov.au

Study Locations

• Australia
  • Western Australia
    • Perth, Western Australia, Australia, 6009
      • Perth Children's Hospital
      • Sub-Investigator: David Sommerfield, MD
      • Sub-Investigator: Neil Hauser, MD
      • Sub-Investigator: Nazim Khan, PHD
      • Contact: Britta S von Ungern-Sternberg, MD, PhD; Phone Number: +61864564806; Email: britta.regli-vonungern@health.wa.gov.au
      • Contact: Lliana Slevin, Bsc; Phone Number: +61 864564806; Email: lliana.slevin@health.wa.gov.au
      • Sub-Investigator: Mon Ohn, MD
• Brazil
  • São Paulo
    • São Paulo, São Paulo, Brazil
      • Hospital das Clínicas
      • Contact: Vinícius Quintão, MD, PhD; Phone Number: +55 11 2661 5795; Email: vinicius.quintao@hc.fm.usp.br
      • Principal Investigator: Vinícius Quintão, MD PHD
    • São Paulo, São Paulo, Brazil
      • Santa Casa de Misericórdia de Ribeirão Preto
      • Contact: Ricardo Vieira Carlos, MD; Phone Number: +55 11 2661 5795; Email: ricardovieirac@gmail.com
      • Principal Investigator: Ricardo Vieira Carlos, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Dexamethasone Group; Dexamethasone will be sourced from the hospital pharmacy as standard registered medications. The study drug will be prepared by independent clinical staff to ensure individualised, correct dosing. Dexamethasone will be administered intravenously at 0.2 mg/kg (maximum 8 mg) at the start of procedure.The patient-specific dose of the investigational product will be diluted to 2ml with normal saline to ensure blinding of the anaesthetist in charge of the patient. The trial will mimic this institutional standard practice by providing two syringes to every treating anaesthetist. The first syringe will contain the patient's dose of dexamethasone diluted to 2mL, the second syringe will contain 2mL of normal saline.	Drug: Dexamethasone (IV); Dexamethasone (0.2 mg/kg, maximum 8 mg) will be diluted to 2mL with normal saline and administered intravenously at the start of procedure.
Active Comparator: Ondansetron Group; Ondansetron will be administered intravenously at 0.15 mg/kg (maximum 4 mg) 15-30 min before the end of surgery. The dose will be diluted to 2ml with normal saline to ensure blinding by the anaesthetist. The study drug will be prepared by independent clinical staff to ensure individualised, correct dosing. The first syringe will contain 2mL of normal saline, the second syringe will contain the patient's dose of ondansetron diluted to 2mL.	Drug: Ondansetron iv; Ondansetron (0.15mg/kg, maximum 4mg) will be diluted to 2mL with normal saline and administered intravenously 15-30 minutes before the end of surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Compare parent-reported sleep quality on day 1 post-op between children receiving intravenous dexamethasone and children receiving intravenous ondansetron during their anaesthetic.	Parent-reported sleep quality will be measured on a 0 - 10 point scale, where 0 is terrible sleep and 10 is excellent sleep.	Sleep quality will be assessed on day 1 post-surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Compare parent-reported sleep quality preoperatively and on postoperative days 2,3,5 and 7 between children who received dexamethasone and children who received ondansetron intraoperatively.	Sleep quality is measured on a 0 -10 point scale, where 0 is terrible sleep and 10 is excellent sleep.	Parent-reported preoperative sleep quality will be collected on the day of surgery and postoperatively on days 2,3,5 and 7.
Compare child-reported (if child is aged over 8 years) sleep quality on postoperative days 1, 2, and 7 between children receiving intravenous dexamethasone and children receiving intravenous ondansetron during their anaesthetic.	Child reported sleep quality will be measured on a 0 - 10 point scale, where 0 is terrible sleep and 10 is excellent sleep	child reported sleep quality will be measure don days 1, 2, and 7 postoperatively
Compare parent reported postoperative recovery on postoperative days 1, 2, 3, 5, and 7 between children in the dexamethasone group and children in the ondasetron group	Postoperative recovery will be measured using the Pediatric Scale for Quality of Recovery (PedSQoR). The overall score will range from 20 to 100, higher scores indicate a better quality of recovery or a more complete recovery.	Postoperative recovery will be measured postoperative days 1, 2, 3, 5, and 7
Compare parent reported postoperative behaviour on postoperative days 1, 2, 3, 5, and 7 between children in the dexamethasone group and children in the ondasetron group	Postoperative behaviour will be measured using the the Post-Hospitalisation Behaviour Questionnaire for Ambulatory Surgery (PHBQ-AS). The scores range from 11 - 55. Higher scores indicate increased behavioural changes post-surgery,	postoperative behaviour will be measured on postoperative days 1, 2, 3, 5, and 7
Compare parent reported average and maximum pain score on postoperative days 1, 2, 3, 5, and 7 or until the child has returned to normal function between children in the dexamethasone group and children in the ondasetron group	Parent reported post-operative pain will be measured using the Verbal Rating Scale 0 - 10 [VRS] where 0 is no pain and 10 is the worst possible pain.	postoperative pain will be measured on days 1, 2, 3, 5 and 7 or until the child returns to normal function.
Comparison of sleep disturbances at baseline and 7 days post-surgery between children in the dexamethasone group and children in the ondasetron group	Sleep disturbance will be measured using the Patient Reported Outcomes Information System (PROMIS) Parent Proxy Sleep Disturbance - Short Form 8a. Higher scores indicate more severe sleep disturbances as reported by the parent	Sleep disturbance will be measured at baseline on the day of surgery in the pre-operative holding area and on postoperative day 7
Comparison of the incidence of early postoperative nausea and vomiting between children in the dexamethasone group and children in the ondansetron group	Postoperative nausea and vomiting will as self-reported by the patient or parent reported	From PACU arrival until 6 hours postoperatively or hospital discharge, whichever comes first.
Comparison of the use of rescue medication for postoperative nausea and vomiting between children in the dexamethasone group and children in the ondansetron group	Rescue medications given will be as recorded on the patient's medication chart	from PACU arrival until 6 hours postoperatively or hospital discharge, whichever comes first
Determine the impact of the Snoring, Trouble Breathing and Unrefreshed (STUBR) questionnaire on postoperative recovery	postoperative recovery will be measured using the Pediatric Scale for Quality of Recovery (PedSQoR)	STUBR questionnaire will be administered preoperatively and recovery will be assessed on postoperative days 1,2,3,5, and 7
Determine the impact of the Snoring, Trouble Breathing and Unrefreshed (STUBR) questionnaire on postoperative sleep	Parent-reported and child-reported sleep quality will be measured on a 0 - 10 point scale, where 0 is terrible sleep and 10 is excellent sleep.	Parent reported sleep quality will be measured on postopeative days 1,2,3,5, and 7. Child reported sleep quality (if the child is older than 8 years) will be measured on postoperative days 1,2, and 7.
Impact of sedative premedication on postoperative delirium	Emergence delirium will be assessed by the post-operative recovery nurse using the WATCHA Scale. The WATCHA Scale is scored from 0 (asleep) to 4 (thrashing around). Scores greater than or equal to 2 on this scale are indicative of emergence delirium.	Delirium will be assessed from PACU arrival until PACU discharge criteria met

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Impact of sedative premedication on postoperative delirium	Emergence delirium will be assessed by the post-operative recovery nurse using the Pediatric Anesthesia Emergence Delirium (PAED) scale. The PAED scale consists of 5 items and is scored on a 5 point scale (not at all, just a little, quite a bit, very much, extremely). higher scores are indicative of emergence delirium, the maximum score is 20 and minimum score is 0.	Delirium will be assessed from PACU arrival until PACU discharge criteria met
Impact of sedative premedication on postoperative recovery	Postoperative recovery will be measured using the Pediatric Scale for Quality of Recovery (PedSQoR). The overall score will range from 20 to 100, higher scores indicate a better quality of recovery or a more complete recovery.	Postoperative days 1,2,3,5, and 7
Impact of sedative premedication on postoperative sleep	sleep quality will be measured on a 0 - 10 point scale, where 0 is terrible sleep and 10 is excellent sleep.	postoperative days 1,2,3,5, and 7
Impact of anaesthesia management on postoperative delirium	Emergence delirium will be assessed by the post-operative recovery nurse using the WATCHA Scale. The WATCHA Scale is scored from 0 (asleep) to 4 (thrashing around). Scores greater than or equal to 2 on this scale are indicative of emergence delirium.	Delirium will be assessed from PACU arrival until PACU discharge criteria met
Impact of anaesthesia management on postoperative recovery	Postoperative recovery will be measured using the Pediatric Scale for Quality of Recovery (PedSQoR). The overall score will range from 20 to 100, higher scores indicate a better quality of recovery or a more complete recovery.	Postoperative days 1,2,3,5, and 7
Impact of anaesthesia management on postoperative sleep	sleep quality will be measured on a 0 - 10 point scale, where 0 is terrible sleep and 10 is excellent sleep.	postoperative days 1,2,3,5, and 7
Impact of induction compliance on postoperative delirium	postoperative delirium will be measured using the Pediatric Anesthesia Emergence Delirium (PAED) scale. The PAED scale consists of 5 items and is scored on a 5 point scale (not at all, just a little, quite a bit, very much, extremely). higher scores are indicative of emergence delirium, the maximum score is 20 and minimum score is 0.	Delirium will be assessed from PACU arrival until PACU discharge criteria is met
Impact of induction compliance on postoperative recovery	Postoperative recovery will be measured using the Pediatric Scale for Quality of Recovery (PedSQoR). The overall score will range from 20 to 100, higher scores indicate a better quality of recovery or a more complete recovery.	Postoperative days 1,2,3,5, and 7
Impact of induction compliance on postoperative sleep	Sleep quality will be measured on a 0 - 10 point scale, where 0 is terrible sleep and 10 is excellent sleep.	Postoperative days 1,2,3,5, and 7
Time of first drink postoperatively between patients in the dexamethasone group and patients in the ondansetron group	time of first drink as recorded in medical records	Post-operatively on the day of surgery (day 0) from the time the patient is first awake in the post anaesthetic care unit until they are discharged from the hospital (day 0 or day 1 post-op) assessed in hours.
Time of first food postoperatively between patients in the dexamethasone group and patients in the ondansetron group	Time of first drink as recorded in medical records	Post-operatively on the day of surgery (day 0) from the time the patient is first awake in the post anaesthetic care unit until they are discharged from the hospital (day 0 or day 1 post-op) assessed in hours.
Assessment of the parental and child satisfaction with the perioperative experience.	Assessed on a 5-point Likert scale - very dissatisfied, somewhat dissatisfied, neutral, somewhat satisfied, very satisfied	Postoperative days 1 and 7
Compare the incidence of emergence delirium between patients in the dexamethasone group and patients in the ondasetron group	Emergence delirium will be measured using the WATCHA scale. The WATCHA Scale is scored from 0 (asleep) to 4 (thrashing around). Scores greater than or equal to 2 on this scale are indicative of emergence delirium.	Post-operatively from PACU arrival until PACU discharge criteria met
Compare the incidence of emergence delirium between patients in the dexamethasone group and patients in the ondansetron group	Emergence delirium will be assessed by the post-operative recovery nurse using the Pediatric Anaesthesia Emergence Delirium (PAED) scale in the post anaesthetic care unit (PACU). The PAED scale consists of 5 items and is scored on a 5 point scale (not at all, just a little, quite a bit, very much, extremely). higher scores are indicative of emergence delirium, the maximum score is 20 and minimum score is 0.	Post-operatively from PACU arrival until PACU discharge criteria met
Compare the incidence of perioperative respiratory adverse events between patients in the dexamethasone group and patients in the ondansetron group	Perioperative respiratory adverse events (PRAE) are defined as: Major PRAE: laryngospasm or bronchospasm (as determined by the anaesthetist or recovery nurse) or desaturation <85% SpO2 for more than 1 minute on pulse oximetry. Minor PRAE: desaturation (<95% SpO2 for more than 10 seconds on pulse oximetry), airway obstruction, severe coughing, post-operative stridor. Each individual PRAE (laryngospasm, bronchospasm, desaturation, airway obstruction, severe persistent coughing and post-operative stridor) will be considered separately. PONV will be assessed by observing any incidence of nausea or vomiting post-operatively, and any administration of antiemetic medication.	PRAE will be assessed by the anaesthetist intraoperatively - during anaesthetic induction, maintenance and emergence and postoperatively by the recovery nurse while in the post-anaesthetic care unit (PACU).
Compare the incidence of unplanned medical representations for pain or any other reason between patients in the dexamethasone group and patients in the ondansetron group	Parent-reported presentations to the emergency department, outpatient clinics or patient's GP	Postoperative days 1,2,3,5, and 7
Comparison of overnight actigaraphy monitoring between patients who opted in for monitoring in the ondansetron group and patients in the dexamethasone group	Actigraphy will be measured using the Actigraph GT9X	Patients will wear the monitor for 3 nights preoperatively and 3 nights postoperatively
Comparison of preoperative and post operative overnight pulse oximetry monitoring between patients in the dexamethasone group and patients in the ondansetron group	Pulse oximetry will me measured using a wrist-worn pulse oximeter device (WristOx 3150)	Patients will wear the oximeter for 3 nights preoperatively and 3 nights postoperatively
Compare the transcutaneous carbon dioxide levels on the night of surgery between patients in the dexamethasone group and patients in the ondansetron group	Transcutaneous carbon dioxide will be measured using the non-invasive digital monitoring system, SenTec.	Monitoring will be done postoperatively on the night of surgery for an estimate of 12 hours overnight from approximately 7pm day 0 to 7am on day 1 post surgery (if patient is admitted)
Compare the postoperative outcomes between neurotypical and neurodiverse children	Neurodiversity will be assessed via parent report of whether the child has a formal diagnosis of autism and/or ADHD, as well as parent completion of a brief item set based on DSM-5-TR criteria for autism and ADHD in childhood (Strengths and Difficulties Questionnaire) as well as the Perth Autism Scale.	Parent reported ADHD or Autism diagnosis will be collected preoperatively.
Impact of anaesthesia management on postoperative delirium	Emergence delirium will be assessed by the post-operative recovery nurse using the Pediatric Anesthesia Emergence Delirium (PAED) scale. The PAED scale consists of 5 items and is scored on a 5 point scale (not at all, just a little, quite a bit, very much, extremely). higher scores are indicative of emergence delirium, the maximum score is 20 and minimum score is 0.	Delirium will be assessed from PACU arrival until PACU discharge criteria met
Impact of induction compliance on postoperative delirium	postoperative delirium will be measured using the WATCHA scale. The WATCHA Scale is scored from 0 (asleep) to 4 (thrashing around). Scores greater than or equal to 2 on this scale are indicative of emergence delirium.	Delirium will be assessed from PACU arrival until PACU discharge criteria is met

Collaborators and Investigators

• Sponsor: Telethon Kids Institute
• Collaborators: University of Sao Paulo General Hospital; Child and Adolescent Health Service - Perth; Santa Casa de Misericórdia de Ribeirão Preto

Study record dates

Study Major Dates

• Study Start (Estimated): August 17, 2026
• Primary Completion (Estimated): August 17, 2029
• Study Completion (Estimated): August 17, 2029

Study Registration Dates

• First Submitted: July 23, 2026
• First Submitted That Met QC Criteria: August 18, 2026
• First Posted (Actual): August 20, 2026

Study Record Updates

• Last Update Posted (Actual): August 20, 2026
• Last Update Submitted That Met QC Criteria: August 18, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: surgery; sleep quality; postoperative nausea and vomiting; paediatric; postoperative recovery; paediatric anaesthesia
• Additional Relevant MeSH Terms: Nervous System Diseases; Mental Disorders; Postoperative Complications; Pathologic Processes; Signs and Symptoms, Digestive; Sleep Wake Disorders; Sleep Disorders, Intrinsic; Dyssomnias; Vomiting; Nausea; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Sleep Initiation and Maintenance Disorders; Postoperative Nausea and Vomiting; Polycyclic Compounds; Pregnadienes; Pregnanes; Steroids; Fused-Ring Compounds; Steroids, Fluorinated; Pregnadienetriols; Dexamethasone
• Other Study ID Numbers: RGS0000008604

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No