Table 1.

Baseline demographic and clinical characteristics

	Group Alf2 (n = 57)	Group Alf4 (n = 57)	Group Sal (n = 58)	P value
Age (range) (years)	4.5 (3–6)	4.5 (3–6)	4.4 (3–6)	0.919
Weight (kg)	18.79 ± 3.34	17.94 ± 2.86	18.56 ± 3.17	0.324
Height (cm)	107.72 ± 8.97	107.53 ± 8.42	108.59 ± 7.29	0.644
Male/female	27/30	30/27	32/26	0.779
mYPAS	51.56 ± 21.53	52.49 ± 21.53	47.59 ± 23.75	0.457
Duration of surgery (min)	115 (90, 150)	115.5 (90, 150)	120 (90, 144)	0.409
Duration of anesthesia (min)	131 (102, 165)	130 (103, 165)	135 (105, 160)	0.496

Alf2 0.2 μg/kg/min alfentanil, Alf4 0.4 μg/kg/min alfentanil, mYPAS modified Yale Preoperative Anxiety Scale, Sal saline