Analgesic Effect of Ropivacaine Combined with Hydromorphone following Surgery for Mixed Hemorrhoids: A Pilot Study

Table 2

Numerical rating scale (NRS) pain scores.

Time post operation (h)	Hydromorphone group (n = 40)	Morphine group (n = 40)	Z-value	value
6	0 (0–1)	0 (0–0)	−1.198	0.228
12	1 (0–2)	0 (0–2)	−2.056	0.044
18	2 (1–3)	2 (0–2)	−1.891	0.060
24	2 (2–3)	2 (1–3)	−1.751	0.081

Data are expressed as the median (interquartile range). The Wilcoxon rank-sum test was used for statistical comparisons between groups.