Fig. 3
Variations of Targeted concentrations of propofol in group CLTD and CLTN. Note: Data are presented as mean ± standard deviation. *, compared with the concentration of propofol in the group CLTN at each time point, p < 0.05. Abbreviations: CLT, Closed-loop TCI. CLTD, Closed-loop TCI during the day (8:00–18:00). CLTN, Closed-loop TCI during the night (22:00–5:00). T1 (5 min after induction), T2 (beginning of ventilation), T3 (mechanical ventilation for 5 min), and T4 (beginning of operation), T5 (operation for 10 min), T6 (operation for 30 min) and T7 (end of operation)