An observational study in Emergency Delirium, Postoperative Delirium (POD) and Adenotonsillectomy, sponsored by Universitair Ziekenhuis Brussel. Not yet recruiting at 1 site in Belgium. Open to participants aged 2 Years to 12 Years. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by Universitair Ziekenhuis Brussel · Observational
Emergence delirium (ED) is a frequent complication in children undergoing general anesthesia, particularly following ENT procedures such as adenotonsillectomy. Alpha-2 adrenergic agonists, such as clonidine and dexmedetomidine, are commonly used in pediatric anesthesia for their sedative, analgesic, and ED-reducing properties.The purpose of this prospective observational study (CLONIDEX) is to evaluate and compare the occurrence of emergence delirium, Post-Anesthesia Care Unit (PACU) length of stay, and overall time to hospital discharge in pediatric patients undergoing (adeno)tonsillectomy with or without placement of myringotomy tubes who receive intravenous dexmedetomidine, intravenous clonidine, or no alpha-2 agonist as part of their standard anesthetic care.
Background:
Emergence delirium (ED) in pediatric patients leads to increased post-anesthesia care unit (PACU) complications, distress for parents and staff, and potential physical injury. While both clonidine and dexmedetomidine are widely utilized alpha-2 agonists in pediatric practice, real-world prospective comparative data regarding their relative efficacy on ED incidence and recovery timelines remain limited.
Study Design and Methodology This is a single-center, prospective observational cohort study conducted at UZ Brussel. Because this is an observational study evaluating standard-of-care practices, the administration and choice of alpha-2-agonist (IV dexmedetomidine, IV clonidine, or no alpha-2-agonist) are left entirely to the discretion of the attending pediatric anesthesiologist.
Data Collection and Outcomes:
Pediatric patients undergoing elective (adeno)tonsillectomy with or without placement of myringotomy tubes will be observed. Key demographic data, anesthetic techniques, and intraoperative co-analgesics will be recorded. Upon arrival in the PACU, emergence delirium will be systematically assessed using the Pediatric Anesthesia Emergence Delirium (PAED) scale at set time intervals (arrival, 15, 30, 45, and 60 minutes). Secondary endpoints include PACU length of stay (measured against standardized discharge readiness criteria), total time to hospital discharge, requirement for rescue medication, and incidence of perioperative adverse events (such as postoperative nausea and vomiting, desaturation, or laryngospasm).
795 studies on the registry are indexed under Emergence Delirium; 257 are open to participants now.
This study's planned enrollment of 150 is close to the median of 153 across 290 observational studies indexed under Emergence Delirium.
Browse Emergence Delirium studies →Universitair Ziekenhuis Brussel is the lead sponsor of 375 studies on the registry; 107 are open to participants now.
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The study population consists of pediatric patients aged 2 to 12 years (ASA I-II) scheduled for elective ambulatory (adeno)tonsillectomy with or without placement of myringotomy tubes under general anesthesia at UZ Brussel. Participants are selected from the daily operating room list in the day-surgery unit.
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Exclusion Criteria:
Pediatric patients undergoing elective (adeno)tonsillectomy with or without placement of myringotomy tubes who receive intraoperative intravenous dexmedetomidine as part of standard anesthetic care, at the discretion of the attending anesthesiologist.
Drug: Intravenous dexmedetomidine
Pediatric patients undergoing elective (adeno)tonsillectomy with or without placement of myringotomy tubes who receive intraoperative intravenous clonidine as part of standard anesthetic care, at the discretion of the attending anesthesiologist.
Drug: Intravenous clonidine
Pediatric patients undergoing elective (adeno)tonsillectomy with or without placement of myringotomy tubes who do not receive any intraoperative alpha-2 adrenergic agonist (dexmedetomidine or clonidine) as part of standard anesthetic care.
Other: Standard Anesthetic Care Without Alpha-2 Agonist
Standard of care intraoperative intravenous administration of dexmedetomidine. Dose, timing, and administration are determined solely by the attending anesthesiologist.
Standard of care intraoperative intravenous administration of clonidine. Dose, timing, and administration are determined solely by the attending anesthesiologist.
Standard anesthetic care during pediatric (adeno)tonsillectomy without administration of intraoperative alpha-2 adrenergic agonists.
Incidence and Severity of Emergence Delirium (ED)
Emergence delirium will be assessed using the Pediatric Anesthesia Emergence Delirium (PAED) scale. The PAED scale consists of 5 items, with total scores ranging from 0 to 20, where higher scores indicate greater severity of delirium. A PAED score \>= 10 (or \>= 12) is defined as the presence of emergence delirium.
Time frame: Assessed at PACU arrival (T0), and at 15 (T15), 30 (T30), 45 (T45), and 60 (T60) minutes post-operatively until PACU discharge.
Post-Anesthesia Care Unit (PACU) Length of Stay
Time duration (in minutes) from arrival at the PACU until meeting formal criteria for discharge readiness (e.g., modified Aldrete or PADSS score).
Time frame: From arrival at PACU until discharge readiness, assessed up to 2 hours post-operatively.
Total Time to Hospital Discharge
Time duration (in hours) from the end of anesthesia/surgery until actual discharge from the day-surgery clinic.
Time frame: From end of surgery until hospital discharge on Day 1 (up to 24 hours).
Incidence of Rescue Medication Administration
Proportion of patients requiring rescue medication in the PACU for severe emergence delirium or acute postoperative pain (e.g., propofol, opioids, or additional alpha-2 agonists).
Time frame: During the PACU stay, up to 2 hours post-operatively.
Incidence of Perioperative Adverse Events
Occurrence of airway or recovery complications including laryngospasm, oxygen desaturation (\<92%), severe postoperative nausea and vomiting (PONV), or excessive sedation.
Time frame: From anesthesia induction until discharge from the day-surgery clinic (up to 24 hours).
Plan to share: No — Patient Privacy \& GDPR Compliance: The study involves a vulnerable pediatric population. Full individual participant data sets, even if pseudonymized, carry a risk of re-identification when combined with detailed clinical and surgical variables, which violates strict European General Data Protection Regulation (GDPR) standards and institutional patient privacy policies. Absence of Informed Consent for Broad Public Data Sharing: The informed consent process and ethics committee approval approved for this study specifically cover data collection and analysis by the designated investigation team at UZ Brussel. Participants' legal guardians did not consent to open-access public repository sharing or secondary use of their children's raw individual data by external third parties. Institutional \& Regulatory Restrictions: In accordance with hospital policy and national regulatory frameworks governing single-center observational clinical research, raw patient-level data remain restricted.
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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