Feasibility of USG Guided Objective Initial Assessment of Pupillary Size and Pupillary Reflexes Versus Clinical Examination in Patients With Altered Mental Status A Cross-Sectional Study

Background - Pupillary assessment is an important part of the neurological assessment which provides vital information in critically ill patients. However, clinical pupillary assessment is subjective. The ultrasound-guided pupillary examination is objective. There are limited pieces of literature regarding its use in assessing patients with altered mental status. So, we studied the extent of agreement of B-mode ultrasound with clinical examination for assessment of the pupillary size and reflex in patients with altered mental status. Objectives - The primary objective was to determine the extent of agreement between clinical examination and ultrasound-based examination for assessing pupillary reflex and size in patients with altered mental status in two settings (trauma and non-trauma patients). Methods - Exactly 200 subjects (158 males, mean [range] age 43.56 [18-92 years]) with no history of partial globe rupture or dementia were included in this cross-sectional study from March 2019 to March 2020. B-mode ultrasound was performed with the subject's eyes closed using a 7-12 MHz linear probe and a standardized light stimulus. ICC score, paired t-test, kappa, Wilcoxon signed-rank test, and Bland-Altman plots were used for statistical analysis. Results - The clinical-USG agreement for pupillary light reflex examination (Pupillary Diameter [PD] at rest, after direct light stimulation [D-stim] and consensual light stimulation [C-stim]) was excellent (ICC, 0.93-0.96). The Kappa coefficient (0.74 +/- 0.07) showed an agreement of 87.36% between clinical and USG examination for pupillary reflex (reactive or non-reactive). Conclusion - USG-guided pupillary examination proves to be a better adjunct to neurological assessment in patients with altered mental status.