Association between Neurological Pupillary Index and Constriction Velocity in Traumatic Brain Injury Patients and Discharge Disposition: A Retrospective Project

Background: Autonomic pupillary dysfunction and neurological deterioration are common after both primary and secondary traumatic brain injury and require frequent pupillary and neurological assessment. An automated pupillometer has provided promising results in predicting pupillary changes and patient outcomes in Traumatic brain injury. Aim: This project aimed to explore the prevalence of automated pupillometer in the neurosurgical intensive care unit. This project hypothesized that there is no association between Neurological pupil index, constriction velocity, and discharge disposition. Methods: Automated pupillary assessment using an automated pupillometer (NPi-200) was performed on patients with traumatic brain injury between January 2014 and January 2022. Results: In this retrospective study, 8,034 quantitative pupillary assessments were performed (n=618; mean age= male 51 years, female 61 years, males, 72%). 307 (49.7%) had unfavorable outcomes among the included patients, with 230 (74.9 %) expired. Initial NPi (p \u3c 0.001), initial CV (p = 0.005), mean NPi (p \u3c0.001), and mean CV (p \u3c0.001) were noted among TBI patients with favorable outcome. Age was independently associated with discharge disposition (adjusted OR 0.94, 95% CI 0.93-0.95, p \u3c0.001). Conclusion: Serial pupillary assessment by an automated pupillometer could help provide a rapid and precise measurement in traumatic brain injury patients. There is a strong relationship between the lowest initial and mean NPi and CV and discharge disposition