Pupillary reflex dilation and pain index evaluation during general anesthesia using sufentanil: a double-blind randomized controlled trial.

Communication with patients under general anesthesia is impossible. A potential solution is to measure pain. One of seven commercially available options is to use a pupillometer. Automated painful stimuli are given and the dilation of the pupil is measured. We hoped to use this method to better control the dose of the opioid sufentanil. During daycare gynecological and abdominal procedures, we had a 25% higher sufentanil usage in the intervention group. We experienced difficulties in reaching the right pain score in both groups. The well-being of the patients, namely pain and painkiller usage at day 1 after surgery, did not show any significant difference. With our protocol, there is no benefit to controlling the dose of sufentanil by pupillometer measurement.