Fig. 2. ( A ) Electric sensation (open symbols, filled boxes) and pain tolerance (filled symbols, open boxes) thresholds on the shoulder before (pre), 2 and 4 days (d2, d4) after, and 1 month (m1) after abdominal hysterectomy. Morphine or tramadol infusions were given 48 h after operation. Box whisker plots are shown (median = point; box = interquartile range; whiskers = range).*1, P = 0.04 for pain tolerance thresholds with morphine versus tramadol on postoperative day 2. *2, P < 0.05 for sensation thresholds in the morphine group on postoperative day 4 versus day 2 and at the 1-month follow-up evaluation. *3, P < 0.02 for pain tolerance thresholds in the morphine group on postoperative day 4 versus before operation and on postoperative day 2. ( B ) Electric sensation (open symbols, filled boxes) and pain tolerance (filled symbols, open boxes) thresholds in the dermatome of surgical incision before (pre), 2 and 4 days (d2, d4) after, and 1 month (m1) after abdominal hysterectomy. Morphine or tramadol infusions were given 48 h after operation. Box whisker plots are shown (median = point; box = interquartile range; whiskers = range), with no significant differences.