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Quantitative Assessment of Pupillary Light Reflex in Acute Carbon Monoxide Poisoning

Completed
Conditions
Carbon Monoxide Poisoning
Interventions
Diagnostic Test: Automated quantitative pupillometer
Registration Number
NCT05110820
Lead Sponsor
Wonju Severance Christian Hospital
Brief Summary

Neurological complications after acute carbon monoxide (CO) poisoning can range from transient headache or dizziness to cognitive dysfunction, seizure, permanent anoxic brain damages or death. A recent study reported that a lack of standard pupillary light reflex (sPLR), assessed using a pen light, was a predictor of 30-day neurological sequelae in patients with CO poisoning. Given that the basic sPLR has a poor inter-rater reliability, more objective and quantitative methods are required in the assessment of PLR.

An automated pupillometer has been used in the intensive care unit to quantitatively assess the PLR. Therefore, we hypothesized that quantitative assessment of PLR might be associated with neurocognitive sequelae after acute CO poisoning. The purpose of this study was to assess the value of quantitative pupillary reactivity (NPi and qPLR) in comparison to that of sPLR in predicting neurocognitive outcome at 1 month after acute CO poisoning.

Detailed Description

Neurological complications after acute carbon monoxide (CO) poisoning can range from transient headache or dizziness to cognitive dysfunction, seizure, permanent anoxic brain damages or death. Although hyperbaric oxygen therapy (HBO2) has been tried to minimize the neurological complications, a significant percentage of patients still suffer from neurocognitive sequelae after acute CO poisoning. A recent study reported that a lack of standard pupillary light reflex (sPLR), assessed using a pen light, was a predictor of 30-day neurological sequelae in patients with CO poisoning. Given that the basic sPLR has a poor inter-rater reliability, more objective and quantitative methods are required in the assessment of PLR.

An automated pupillometer has been used in the intensive care unit to quantitatively assess the PLR. Quantitative PLR (qPLR), which is expressed as the percentage pupillary constriction in response to a calibrated light stimulus, was better in predicting neurological outcome after cardiac arrest (CA) compared to standard light reflex. In addition, the Neurological Pupil index (NPi) has been validated as a tool for assessing prognosis after CA because it is not influenced by medications (especially opioids and neuromuscular blocking agents) or small pupil size.

Therefore, the investigators hypothesized that quantitative assessment of PLR might be associated with neurocognitive sequelae after acute CO poisoning. The purpose of this study was to assess the value of quantitative pupillary reactivity (NPi and qPLR) in comparison to that of sPLR in predicting neurocognitive outcome at 1 month after acute CO poisoning.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
104
Inclusion Criteria
  • Acute CO poisoning
Exclusion Criteria
  • Age <19 years
  • Patients with a history of ophthalmic surgery which might have affected the PLR
  • Patients with baseline cognitive deficit
  • Refusal to enroll in this study
  • Discharge from the ED or transfer to another hospital within 24 hours
  • Expired in the ED
  • Co-ingestion of drugs, such as hypnotics, that may affect the PLR
  • No follow-up for the neurocognitive outcome

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
Acute CO poisoningAutomated quantitative pupillometerA diagnosis of CO poisoning was made according to medical history and carboxyhaemoglobin \>5% (\>10% in smokers).
Primary Outcome Measures
NameTimeMethod
The prediction of neurological pupil index (NPi) for poor neurocognitive outcomeWithin 3 days after acute CO poisoning

The predictive value of NPi for the 1-month poor neurocognitive outcome after acute CO poisoning

Comparison of predictive value for poor neurocognitive outcome between NPi and standard pupillary light reflex (sPLR)Within 3 days after acute CO poisoning

The value of NPi in comparison to that of sPLR in predicting neurocognitive outcome at 1 month after acute CO poisoning

Comparison of predictive value for poor neurocognitive outcome between qPLR and sPLRWithin 3 days after acute CO poisoning

The value of qPLR in comparison to that of sPLR in predicting neurocognitive outcome at 1 month after acute CO poisoning

The prediction of quantitative pupillary light reflex (qPLR) for poor neurocognitive outcomeWithin 3 days after acute CO poisoning

The predictive value of qPLR for the 1-month poor neurocognitive outcome after acute CO poisoning

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

Wonju Severance Christian Hospital

🇰🇷

Wonju, Gangwon, Korea, Republic of

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