The median effective concentration of remifentanil to inhibit pupillary reflex dilation induced by endotracheal intubation.

The EC of remifentanil to inhibit PRD induced by endotracheal intubation was 4.41 ng/mL and the EC was 5.24 ng/mL. The time to reach the maximum pupillary diameter change was shorter than the time needed for heart rate, blood pressure, and Bispectral index. This prospective study was registered in the China Clinical Trials Registration Center (ChiCTR2100043771, https://www.chictr.org.cn).