Fig. 1

Consecutive target propofol concentrations during colonoscopy insertion for EC50 determination. The lines represent the mean propofol concentration when crossing from a failure to suppress patient movements. The average of these concentrations is defined as EC50. Propofol EC50 was 3.08 with 95 % CI of 2.78–3.42 μg.ml⁻¹ in control group (shown in Fig. 1a ); while EC50 in F0.5 group was 2.75 with 95 % CI of 2.50–3.02 μg.ml⁻¹ (shown in Fig. 1b ) and 2.05 with 95 % CI of 1.98–2.13 μg.ml⁻¹ in F1.0 group (shown in Fig. 1c )