Table 1.

Demographic Characteristics and Perioperative Data

	Group N (n=115)	Group O (n=115)
Age (yr)	49 ± 9	53 ± 10
Weight (kg)	63.3 ± 9.4	67.8 ± 10.1
Gender (M/F)	64/51	73/42
ASA I/II	93/22	102/13
Duration of surgery (min)	78 ± 23	71 ± 17
Starting time of PCIA (min)	28 ± 17	24 ± 20
Baseline pain intensity (VAS scores at postoperative 0 hour), n (%)
Slight pain (10 - 30 mm)	26 (22.6%)	21 (18.3%)
Moderate pain (40 - 60 mm)	82 (71.3%)	89 (77.4%)
Severe pain (70 - 100 mm)	7 (6.1%)	5 (4.3%)

ASA: American Society of Anaesthesiologists physical status; PCIA: patient-controlled intravenous analgesia; VAS: visual analog scale.

Data are presented as mean ± SD, number or number (percent).

No statistically significant between-group differences (P ≥ 0.05).