Table 3.

Serum levels of BDNF and 5-HT at various timepoints after surgery.

Variables	High-dose S-ketamine, n=104	Low-dose S-ketamine, n=104	Racemic ketamine, n=104	Control, n=105	P value
BDNF
Before	23.24±1.29	23.08±1.29	23.23±1.36	23.23±1.18	0.775
1 d	22.58±1.52b,c,d	20.36±1.38a,d	20.17±1.32a,d	19.11±1.16a,b,c	<0.001
2 d	23.86±1.35b,c,d	21.55±1.42a,d	21.63±1.26a,d	20.04±1.15a,b,c	<0.001
3 d	24.95±1.54b,c,d	23.52±1.18a,d	23.36±1.21a,d	21.20±1.03a,b,c	<0.001
5 d	24.55±2.00d	24.71±1.52d	24.64±1.71d	23.46±1.49a,b,c	<0.001
7 d	27.01±1.36	26.47±1.14	26.59±1.17	26.61±1.15	0.035
5-HT
Before	228.83±17.70	228.10±16.84	226.40±16.91	222.87±17.22	0.059
1 d	252.38±15.89b,c,d	246.13±14.48a,d	248.25±13.32a,d	227.04±15.69a,b,c	<0.001
2 d	261.98±17.65b,c,d	247.81±18.57a,d	247.51±17.93a,d	232.16±19.31a,b,c	<0.001
3 d	270.39±23.61b,c,d	255.37±18.57a,d	250.13±18.58a,d	235.94±21.48a,b,c	<0.001
5 d	335.32±20.30d	336.47±21.63d	339.03±23.24d	305.02±21.48a,b,c
7 d	347.05±26.23	353.41±26.47	345.41±27.66	345.24±24.85	0.085

^aP<0.05, compared with the high-dose S-ketamine group;

^bP<0.05, compared with the low-dose S-ketamine group;

^cP<0.05, compared with the racemic ketamine group;

^dP<0.05, compared with the control group.

Continuous data were compared using ANOVA followed by Tukey post hoc test.