Fig. 4. Plasma concentrations of adrenal hormones in patients undergoing upper abdominal surgery in the acupuncture (n = 50, circles) and control (n = 48, squares) groups. Data are expressed as mean ± SD. 0 = before induction of anesthesia; 1 = immediately before surgery; 2 = 1 h after surgery; 3 = during recovery; 4 = first postoperative day. *Statistically significant differences (P < 0.01) between time zero and other time points within each group; #statistically significant differences (P < 0.01) from the control group.