Table 2.

Number of Patients Who Needed Additional Rescue Analgesics (Pethidine) During 36 h After Surgery

Interval	E-PCA group (n = 47)	dIV-PCA group (n = 54)	IV- PCA group (n = 52)	P value
0 - 2 h	16 (34%)	22 (41%)	28 (54%)	0.054
2 - 6 h	12 (26%)	10 (19%)*	23(44%)	0.012
6 - 12 h	9 (19%)†	8 (15%)*	24(46%)	<0.001
12 - 24 h	12 (26%)†	12 (22%)*	33(63%)	<0.001
24 - 36 h	6 (13%)	4 (7%)	10 (19%)	0.199

Data are presented as number of patients (proportion).

^† P <0.01, vs. IV-PCA group (Bonferroni corrected), ^* P <0.01 vs. IV-PCA group (Bonferroni corrected)