Prediction of the level of consciousness using pupillometer measurements in patients with impaired consciousness brought to the emergency and critical care center

Abstract

Aim We investigated whether the level of consciousness can be predicted using pupillometer measurements in patients with severe disturbance of consciousness. Methods Patients with a Glasgow Coma Scale (GCS) of 3–8, except for those after cardiac arrest, were included. Pupillary contraction rate and contraction velocity were each measured using a pupillometer. Results Thirty‐five patients were analyzed. At the time of discharge or changing hospitals, 16 patients had a GCS score of 3–13 and 19 patients had a GCS score of 14–15. In the non‐sedative group at about the time of arrival at our hospital, average pupillary contraction rates were 18.36% in the GCS 3–13 group and 19.67% in the GCS 14–15 group ( P = 0.739), and average pupillary contraction velocities were 1.02 and 1.48, respectively ( P = 0.182). Approximately 48 h after arrival, average pupillary contraction rates were 21.18% and 29.27%, respectively ( P = 0.058), and average pupillary contraction velocities were 1.37 and 1.91, respectively ( P = 0.172). Among the sedative group, at about the time of arrival, average pupillary contraction rates were 8.75% in the GCS 3–13 group and 19.75% in the GCS 14–15 group ( P = 0.032). Average pupillary contraction velocities were 0.34 and 1.48, respectively ( P = 0.001). Approximately 48 h after arrival, average pupillary contraction rates were 13.50% and 13.50%, respectively ( P = 1.00), and average pupillary contraction velocities were 0.80 and 0.82, respectively ( P = 0.93). Conclusions Pupillometer measurements could predict level of consciousness of patients with severe consciousness disorder.

New Behavioral Signs of Consciousness in Patients with Severe Brain Injuries

“…Recent studies, beyond the scope of this article, suggest that electrophysiological findings [64][65][66][67][68][69][70][71][72][73][74] , neuroimaging findings 16,44,75 , pupil responses 76,77 , and autonomic nervous system correlates 78,79 might also reflect the level of consciousness in patients with DoC. Thus, we emphasize the need to further investigate and validate these parameters within the framework of a multimodal assessment (behavioral and neuroimaging) in DoC patients.…”

“…Habituation had the highest prevalence and sensitivity, 55 and 75% , respectively, among all MCS items. The accuracy of habituation was 70%, second highest after visual pursuit (75% [65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83]). The mechanism of habituation of auditory startle reflex could be of cortical origin, as shown with FDG-PET and high-density EEG data.…”

Automated Pupillometry Value Differences Serve as a Prognostic Indicator Even When They are Within Normal Range

“…The top 2 primary diagnoses included 813 (29.54%) patients with brain tumor and 479 (17.41%) patients with stroke. Mean GCS was 12.06 (3.41) with a median of 14 (10)(11)(12)(13)(14)(15). The mean ICU length of stay (LOS) was 4.60 (6.65) days and the mean hospital LOS was 8.38 (9.66) days.…”

Discussion on the prediction model of early judgment of critical risk in emergency patients

“…Pupil size and re ex are important monitoring parameters for patients with consciousness disorder. Minami Y and others think that pupil measurement in emergency is simpler and faster than EEG and imaging in early prediction of patients' consciousness level, but the accuracy of direct examination with ashlight is lower than that of automatic pupillometer [22][23] . so the availability and accuracy of tools for measuring pupils in actual emergency work need to be further evaluated [24] .…”