Comparison of effects of volatile and intravenous anesthetics on pupillary function during general anesthesia in...

The light reflex, which reflects central nervous system dysfunction, can also be affected by anesthetic agents.

We evaluated whether these effects differed according to the anesthetic agent in pediatric patients.

Twenty children aged 3-12 years who were scheduled to undergo elective surgery under general anesthesia were randomly allocated to propofol and sevoflurane groups and underwent pupillometric assessments at five points during anesthesia: T1, after confirming loss of consciousness; T2, after endotracheal intubation; T3, at the time of skin incision; T4, 1 h after skin incision; and T5, before endotracheal extubation. The primary outcome was the Neurological Pupil index at T4, and the secondary outcomes were other pupillometric parameters, including pupil diameter, percentage of change in pupil diameter, dilation velocity, and constriction velocity.

At T4, the Neurological Pupil index was significantly lower in the sevoflurane group (median difference, 0.30; 95% CI, 0.00 to 0.70; p = .036). Furthermore, the Neurological Pupil index at all time points was lower in the sevoflurane group. The time-and-group interaction effects on constriction velocity and dilation velocity were significantly different [F(1, 4) = 16.68, p = .002; F(1, 4) = 14.78, p = .008, respectively] but were not different on the Neurological Pupil index, pupil diameter, and percentage of change in pupil diameter. No intergroup differences were observed in the baseline characteristics, the flow rate of remifentanil at each time point, and total infused remifentanil.

The Neurological Pupil index value in pediatric patients under general anesthesia is affected by the anesthetic agent used; this factor requires consideration in evaluations of the Neurological Pupil index during general anesthesia.