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Published on: July 4, 2018
Pupillometry: a non-invasive technique for pain assessment in paediatric patients
Mark A Connelly1, Jacob T Brown2, Gregory L Kearns3
1Departments of Pediatrics, University of Missouri-Kansas City, Kansas City, Missouri, USA Department of Developmental and Behavioral Sciences, The Children's Mercy Hospital, Kansas, Missouri, USA.
Insights
Pupillometry shows promise for objectively measuring pain in children. This study found pupil changes correlate with pain intensity and opioid dosage in pediatric patients, suggesting its use as a pain assessment tool.
Area of Science:
- Pediatric Anesthesiology
- Pain Management
- Ophthalmology
Background:
- Pupillometry is established for pain assessment in adults.
- Objective pain measurement in children remains a challenge.
- Opioid pharmacodynamics require precise monitoring.
Purpose of the Study:
- To explore pupillometry as a proof-of-concept for objective pain assessment in pediatric patients.
- To evaluate changes in pupil parameters related to opioid exposure in children.
- To investigate the correlation between pupillary responses and self-reported pain intensity.
Main Methods:
- Prospective, single-center observational study at an academic pediatric medical center.
- Enrolled 30 children (9-17 years) undergoing elective pectus excavatum repair.
- Measured pupil size and reactivity with a handheld pupillometer; assessed pain using validated self-report scales.
Main Results:
- Each point increase on a 10 cm visual analogue pain scale correlated with significant changes in maximum pupil constriction velocity (0.11 mm/s) and pupil diameter (~0.4%).
- Total opioid dose (morphine equivalents) showed a positive association with pupil diameter.
- Age, sex, and baseline anxiety did not significantly correlate with pupillary response.
Conclusions:
- Pupillometry demonstrates potential as a non-invasive tool for objectively quantifying pain intensity and response in pediatric populations.
- The technique shows promise for assessing opioid pharmacodynamics in children.
- Pupil constriction velocity and diameter changes are associated with pain scores, supporting clinical utility.
Objective:
Pupillometry has been used to assess pain intensity and response to analgesic medications in adults. The aim of this observational study was to explore proof of concept for the use of this technique in paediatric patients. Changes in pupil parameters before and after opioid exposure also were evaluated.
Design And Setting:
This was a single-centre, prospective study conducted at an academic paediatric medical centre.
Patients:
Children 9-17 years of age undergoing elective surgical correction of pectus excavatum were enrolled into a protocol approved by the human ethical committee (institutional review board).
Interventions:
Pupil size and reactivity were measured using a handheld pupillometer. Pain was assessed using age-appropriate, validated pain self-report scales.
Results:
Thirty patients were enrolled. Each point change on a 10 cm visual analogue pain intensity scale was associated with a statistically significant mean change of 0.11 mm/s in maximum pupil constriction velocity, and of approximately 0.4% in pupil diameter. As expected, there was an association between total opioid dose (expressed as morphine equivalents) and pupil diameter. Age, sex and baseline anxiety scores did not correlate significantly with pupillary response.
Conclusions:
The association of maximum pupillary constriction velocity and diameter with pain scores illustrates the potential for using pupillometry as a non-invasive method to objectively quantitate pain response/intensity in children. The technique holds promise as a pharmacodynamic 'tool' to assess opioid response in paediatric patients.
