Fig. 1. Graph showing the cerebrospinal fluid (CSF) time course of prostaglandin E2(PGE2), interleukin 6 (IL-6), and interleukin 8 (IL-8) concentration in control hip surgery patients. Baseline values just before surgical incision (0 h value) were 40.0, 0.0, and 0.6 pg·ml–1, respectively. Asterisks indicate significant difference ( P < 0.05) from baseline. Note: PGE2values at 1 and 3 hour (h) and IL-8 values at 1, 24, and 30 hours are below the detection limit.