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

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.