Fig. 3. This figure shows the entire progress of patient-controlled sedation (PCS) and the overall vital signs for one patient in group 1 (low dose group), as well as presenting the calculated plasma concentration (Cp) and effect site concentration (Ce) of dexmedetomidine. BIS, bispectral index; ETCO₂, end-tidal CO₂; LOR, loss of responsiveness point; ROR, return of responsiveness point.