The median scores of the grade of duration of spontaneous pain (SP) and number of pain attack (PA) during study days. (A) ^*The grade by the duration of SP during the past 24 h was lower, and (B) ^*the grade of the number of PA during the past 24 h was lower in NFP group from the day 2 to 6 of hospitalization (P < 0.05 compared to those of NS group). All data are expressed SD ± error. NFP: nefopam, NS: normal saline. Grade by duration of SP: grade 1 (less than 1 h), grade 2 (between 1 and 3 h), grade 3 (between 4 and 7 h), grade 4 (8 and 12 h), and grade 5 (permanently). Grade by frequency of PA: grade 0 (no pain attack), grade 1 (between 1 and 5), grade 2 (between 6 and 10), grade 3 (between 11 and 20), and grade 4 (more than 20).