Table 2.

Comparison of the incidence of postoperative POCD between the two groups [n (%)]

Group	Number of cases	1 d after operation	4 d after operation	7 d after operation
Group A, fentanyl	51	16 (31.37)	8 (15.69)	0 (0.00)
Group B, ropivacaine	52	2 (3.82)*	1 (1.92)*	0 (0.00)
X2		13.638	4.797	-
P		0.000	0.029	-

^*indicates comparison with group A, P < 0.05.