An observational study in Opioid-Induced Respiratory Depression, Postoperative Complications (Cardiopulmonary) and Respiratory Complications Due to Anesthesia, sponsored by NeurOptics Inc. Recruiting at 2 sites in United States. Open to participants aged 3 Years to 17 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-08.
Sponsored by NeurOptics Inc · Observational
This study will evaluate whether quantitative pupillometry measurements can be used to identify children at risk for postoperative opioid-induced respiratory depression (OIRD) following tonsillectomy. Opioid-induced respiratory depression is a serious and potentially life-threatening complication that can occur after surgery, and current monitoring approaches are limited in their ability to predict which patients are at highest risk.
In this prospective observational cohort study, approximately 300 pediatric patients undergoing tonsillectomy will undergo non-invasive pupillometry measurements at defined perioperative time points, including preoperative, intraoperative, and postoperative periods. Pupillometry measurements will be collected using a commercially available, FDA-regulated infrared pupillometer. These measurements will include pupil size, constriction and dilation velocities, and latency in response to light stimulation.
Pupillometry data will be collected for research purposes only and will not be used to guide clinical care or treatment decisions. Standard clinical care will not be altered as part of this study. Clinical outcomes, including the occurrence of postoperative opioid-induced respiratory depression, opioid use, sedation levels, pain scores, and other postoperative events, will be recorded from the medical record.
The goal of this study is to evaluate the relationship between pupillary response patterns and the occurrence of postoperative respiratory depression, and to support the development of predictive models that may improve early identification of patients at risk for opioid-related adverse events.
This is a prospective, observational cohort study designed to evaluate the relationship between perioperative pupillary responses and postoperative opioid-induced respiratory depression (OIRD) in pediatric patients undergoing tonsillectomy.
Approximately 300 participants aged 3 to less than 18 years will be enrolled across participating clinical sites. Pupillometry measurements will be obtained using a portable, automated infrared pupillometer at predefined perioperative time points, including preoperative baseline, intraoperative periods, and postoperative recovery. Measurements will include resting pupil diameter, pupillary light reflex parameters (including percent constriction, constriction velocity, dilation velocity, and latency), and pupillary unrest in ambient light.
Pupillometry measurements will be collected solely for research purposes and will not be used to guide clinical management. All patients will receive standard perioperative care as determined by the clinical team.
The primary outcome is the occurrence of postoperative opioid-induced respiratory depression, defined as persistent oxygen desaturation (SpO2 \<90%) or respiratory rate \<8 breaths per minute in the absence of airway obstruction in the post-anesthesia care unit. Secondary outcomes include opioid consumption, sedation scores, pain scores, and postoperative complications such as nausea and vomiting.
Data will be analyzed to assess the association between pupillary response parameters and the occurrence of respiratory depression, and to support development of predictive models for identifying patients at increased risk of opioid-related adverse events.
1,332 studies on the registry are indexed under Postoperative Complications; 311 are open to participants now.
This study's planned enrollment of 300 is above the median of 251 across 537 observational studies indexed under Postoperative Complications.
Browse Postoperative Complications studies →This is the only study on the registry with NeurOptics Inc as lead sponsor.
Counted across the registry records on this site, refreshed daily.
The study population will consist of pediatric patients aged 3 to less than 18 years undergoing tonsillectomy with or without adenoidectomy at participating clinical sites. Participants will be enrolled from routine clinical care settings and will receive standard perioperative management. The study will include patients across a range of clinical characteristics representative of the typical pediatric tonsillectomy population.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Pediatric participants aged 3 to less than 18 years undergoing tonsillectomy. Participants will undergo non-invasive pupillometry measurements at predefined perioperative time points. Pupillometry data are collected for research purposes only and will not be used to guide clinical care. All participants will receive standard perioperative management as determined by the clinical team.
Device: Infrared Pupillometry
Non-invasive pupillometry measurements will be performed using a commercially available, FDA-regulated infrared pupillometer. Measurements will be collected at predefined perioperative time points for research purposes only and will not be used to guide clinical care.
Also known as: Quantitative Pupillometry
Occurrence of Postoperative Opioid-Induced Respiratory Depression
Postoperative opioid-induced respiratory depression is defined as the occurrence of either (1) oxygen saturation (SpO2) \<90% for a sustained period, or (2) respiratory rate \<8 breaths per minute, in the absence of airway obstruction, during the post-anesthesia care unit stay. Events will be identified from clinical monitoring data and medical record documentation.
Time frame: From arrival in post-anesthesia care unit (PACU) through PACU discharge (up to 4 hours postoperatively)
Opioid Consumption
Total opioid dose administered during the intraoperative and immediate postoperative period, recorded from the medical record and normalized to body weight where appropriate.
Time frame: From induction of anesthesia through transfer to the post-anesthesia care unit (PACU) (up to 2 hours) through PACU discharge (up to 4 hours postoperatively); data collection across these periods may extend up to 6 hours in total.
Sedation Level
Sedation level assessed using clinically documented sedation scales recorded during routine care in the post-anesthesia care unit (PACU), including scales such as the Richmond Agitation-Sedation Scale (RASS; range -5 to +4, where more negative values indicate deeper sedation) or equivalent institution-specific scales. Higher levels of sedation correspond to lower (more negative) scores.
Time frame: During PACU stay (up to 4 hours postoperatively)
Pain Scores
Pain intensity scores measured using age-appropriate validated scales (e.g., Numeric Rating Scale or FLACC) as recorded during routine clinical care. The Numeric Rating Scale (0 to 10, where 0 indicates no pain and 10 indicates worst possible pain) and for the Face, Legs, Activity, Cry, Consolability (FLACC) scale (0 to 10, where higher scores indicate greater pain), as recorded during routine clinical care in the post-anesthesia care unit (PACU). Scale selection will be based on patient age and clinical appropriateness.
Time frame: During PACU stay (up to 4 hours postoperatively)
Postoperative Nausea and Vomiting
Occurrence of nausea and/or vomiting documented in the medical record during the PACU stay.
Time frame: During PACU stay (up to 4 hours postoperatively)
Plan to share: Undecided — The study team has not yet determined whether individual participant data will be shared. Any future data sharing will be evaluated following study completion and will consider participant privacy, institutional policies, intellectual property considerations, and applicable NIH and regulatory requirements.
No publications or documents are linked to this record.
Started May 2026 (actual). Primary completion is estimated for Apr 2027, 11 months after the start.
Of 281 observational studies under Postoperative Complications, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 39. This study's planned 11 months is below that.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.