Early DC reduces mortality but does not appear to improve favourable outcomes in patients younger or older than 60 years after MCI. RCTs incorporating quality of life assessments are warranted for MCI patients, in addition to defining the optimal timing and benefits of DC in older patients.

Introduction: Assessment of the pupillary light reflex (PLR) is a key part of intensive care monitoring of neurosurgical patients, particularly for detecting abnormalities in intracranial pressure (ICP). Quantitative pupillometry using a handheld pupillometer is a reliable method for assessing the PLR. However, many variables are derived from such devices. We therefore aimed to assess the performance of these variables at monitoring ICP. Methods: Sedated patients admitted to a neurocritical care unit in a tertiary neurosurgical centre with invasive ICP monitoring were eligible for inclusion. Hourly measurement of ICP, subjective pupillometry (SP) using a pen torch device, and quantitative pupillometry (QP) using a handheld NeuroOptics NPi-200 Pupillometer system were performed. Results: 561 paired ICP, SP and QP pupillary observations from nine patients were obtained, amounting to 1122 pupillary observations in total. SP and QP had a moderate concordance for measuring pupillary size (κ = 0.62). SP performed poorly at detecting changes in pupillary size (sensitivity = 24%). In 40 (3.6%) observations, SP failed to detect a pupillary response whereas QP did. Moderate correlations against 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 > 22mmHg was moderate for MCV (AUC = 0.631), DV (AUC = 0.616), %C (AUC = 0.602), and pupillary maximum size (AUC = 0.625). MCV and %C values were significantly different at different ICP thresholds on ANOVA testing. Conclusion: 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.