Quantitative Pupillometry

Study Overview
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Brief Summary
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The aim of this study is to assess the diagnostic ability of quantitative pupillometry for the early detection of hydrocephalus during the weaning process of the external ventricular drain.

Detailed Description
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Acute hydrocephalus is an emergency often requiring the insertion of an external ventricular drain (EVD). In the aftermath, the patient is transferred to an intensive care unit (ICU) for close monitoring. Ensuring optimal cerebral perfusion through efficient drainage of cerebrospinal fluid while minimizing drainage duration are the objectives of care. Assessing pupillary light reflex is a key test for the detection of neurological deterioration. For long, this assessment has been grossly performed via a qualitative approach (present/absence of pupillary light reflex). For a more precise assessment, quantitative pupillometry has been proposed. Pupil size and constriction speed in response to a standard light are recorded by an automatic portable and user-friendly device. This device is increasingly used in the ICU, mostly for prognostication after acute brain injury. We hypothesized that quantitative pupillometry parameters may vary when hydrocephalus occurs. The aim of this study is to assess whether quantitative pupillometry parameters vary when hydrocephalus occurs. The investigators focused on the early detection of hydrocephalus during the EVD weaning process.

Official Title
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Quantitative Pupillometry During External Ventricular Drain Weaning - An Observational Study

Conditions
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Hydrocephalus, Critical Care

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria : Patient older than 18 years old Admitted to the ICU With an external ventricular drain Consenting to participate (or consent from his/her next of kin, if unable to consent). Exclusion Criteria : Patient with pre-existing bilateral pupillary pathology Pregnant or breast-feeding patient Moribund patient or patient with decision of withholding or withdrawing life-sustaining treatment Patient with no health insurance Patient under guardianship

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| NPi (Neurological Pupil index) and EVD (external ventricular drain)occlusion test | NPi will be compared between two groups of patients (constituted a posteriori): success and failure of the EVD occlusion test. Independently of this study, the EDV occlusion test starts as soon as prescribed by the physician as a prerequisite before its withdrawal. Failing an occlusion test is defined by the need for reopening the EVD. | 5 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic evaluation | Pupillometer ability to detect an EDV occlusion test failure will be studied. The area under the ROC curve (AUCROC) will be determined. We define, a priori, that the detection performance will be, respectively, honorable, good or excellent if the AUCROC is higher than 0.70, 0.80 and 0.90. | 5 days | 
| Pupillometry and EVD occlusion test | Constriction velocity will be compared between two groups of patients (constituted a posteriori): success and failure of the occlusion test. | 5 days | 
| Dilatation velocity | Dilation velocity will be compared between two groups of patients (constituted a posteriori): success and failure of the occlusion test. | 5 days | 
| Maximum constriction velocity | Maximum constriction velocity will be compared between two groups of patients (constituted a posteriori): success and failure of the occlusion test. | 5 days | 
| Latency of contraction | Latency of contraction will be compared between two groups of patients (constituted a posteriori): success and failure of the occlusion test. | 5 days | 
| Pupil size variation | Pupil size variation will be compared between two groups of patients (constituted a posteriori): success and failure of the occlusion test. | 5 days | 
| Pupillometry and clinical scores | The association between pupillometry parameters and clinical scores (Glasgow Coma Scale, FOUR score, RASS and CAM-ICU) will be studied | 5 days | 
| The association between pupillometry parameters and ventricular volume will be studied. | A relationship between, measurements of ventricular volumes (via brain imaging examinations performed regardless of this study) and pupillometry parameters will be sought | 5 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pupillometry, External ventricular drain, Weaning, Brain injury, Pupillary reactivity