Table 2. Comparison of Postoperative Pain Intensity at Different Times in the Two Groups^a.

Different Time Points After Surgery	Pain Scores (Measured by VAS)		P Value
	Ketamine	Fentanyl
15 min	0.00 ± 00	0.00 ± 00	-
30 min	0.00 ± 00	0.00 ± 00	-
One hour	0.1 ± 0.0	0.1 ± 0.1	0.82
Two hours	0.1 ± 0.1	0.2 ± 0.1	0.302
Three hours	0.1 ± 0.1	0.2 ± 0.1	0.64
Four hours	0.5 ± 0.1	0.6 ± 0.2	0.668
Five hours	0.9 ± 0.2	0.8 ± 0.2	0.685
Six hours	1.4 ± 0.3	0.9 ± 0.2	0.154
Nine hours	3.4 ± 0.3	1.2 ± 0.3	< 0.0001b
12 hours	3.9 ± 0.3	1.5 ± 0.3	< 0.0001b
24 hours	3.9 ± 0.3	1.0 ± 0.2	< 0.0001b

^aValues are expressed as mean ± SE.

^bThe statistical test used was the t-test.