Evaluating the utility of quantitative pupillometry in a neuro-critical care setting for the monitoring of intracranial pressure: A prospective cohort study.

Ali, Ahmad M S; Gul, Wisha; Sen, Jon; Hewitt, Sarah-Jane; Olubajo, Farouk; McMahon, Catherine

Abstract

Assessment of the pupillary light reflex (PLR) is key in intensive care monitoring of neurosurgical patients, particularly for monitoring intracranial pressure (ICP). Quantitative pupillometry using a handheld pupillometer is a reliable method for PLR assessment. However, many variables are derived from such devices. We therefore aimed to assess the performance of these variables at monitoring ICP. Sedated patients admitted to neurocritical care in a tertiary neurosurgical centre with invasive ICP monitoring were included. Hourly measurement of ICP, subjective pupillometry (SP) using a pen torch device, and quantitative pupillometry (QP) using a handheld pupillometer were performed. 561 paired ICP, SP and QP pupillary observations from nine patients were obtained (1122 total pupillary observations). SP and QP had a moderate concordance for pupillary size (κ=0.62). SP performed poorly at detecting pupillary size changes (sensitivity=24%). In 40 (3.6%) observations, SP failed to detect a pupillary response whereas QP did. Moderate correlations with ICP were detected for maximum constriction velocity (MCV), dilation velocity (DV), and percentage change in pupillary diameter (%C). Discriminatory ability at an ICP threshold of >22 mmHg was moderate for MCV (AUC=0.631), DV (AUC=0.616), %C (AUC=0.602), and pupillary maximum size (AUC=0.625). QP is superior to SP at monitoring pupillary reactivity and changes to pupillary size. Although effect sizes were moderate to weak across assessed variables, our data indicates MCV and %C as the most sensitive variables for monitoring ICP. Further study is required to validate these findings and to establish normal range cut-offs for clinical use. [Abstract copyright: Copyright © 2024. Published by Elsevier B.V.]

Citation

Ali, A. M. S., Gul, W., Sen, J., Hewitt, S.-J., Olubajo, F., & McMahon, C. (in press). Evaluating the utility of quantitative pupillometry in a neuro-critical care setting for the monitoring of intracranial pressure: A prospective cohort study. Clinical Neurology and Neurosurgery, 239, Article 108215. https://doi.org/10.1016/j.clineuro.2024.108215

• Journal Article Type: Article
• Acceptance Date: Feb 28, 2024
• Online Publication Date: Mar 2, 2024
• Deposit Date: May 21, 2024
• Publicly Available Date: May 21, 2024
• Journal: Clinical neurology and neurosurgery
• Print ISSN: 0303-8467
• Electronic ISSN: 1872-6968
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 239
• Article Number: 108215
• DOI: https://doi.org/10.1016/j.clineuro.2024.108215
• Keywords: critical care, traumatic brain injuries, pupil, intracranial pressure
• Public URL: https://keele-repository.worktribe.com/output/784639