Single-dose dexamethasone reduces dynamic pain after total hip arthroplasty.

BACKGROUND: Preoperative glucocorticoids reduce postoperative nausea but may also improve analgesia and decrease opioid consumption.

METHODS: Fifty consecutive patients undergoing elective, unilateral, primary total hip arthroplasty under spinal anesthesia with propofol sedation received in a randomized, double-blind, placebo-controlled manner either 40 mg of dexamethasone or saline placebo i.v. before the start of surgery. I.v. patient-controlled analgesia morphine, ibuprofen 400 mg p.o. q6 h and acetaminophen 650 mg p.o. q6 h were given for 48 h. Pain (0-10 numeric rating scale, NRS) at rest, side effects, and total cumulative patient-controlled analgesia morphine consumption were recorded q4 h for 48 h. Dynamic pain NRS score was recorded at 24 h. C-reactive protein levels were measured in a subgroup of 25 patients at 48 h.

RESULTS: The intraoperative sedation requirement with propofol was significantly increased in the dexamethasone group (234.6 +/- 160.1 vs 138.8 +/- 122.7 mg, P = 0.02). Dynamic pain was greatly reduced in the dexamethasone group (NRS score: 2.7, 95% CI: 2.2-3.1 vs 6.8, 6.4-7.2; P < 0.0001). There was no significant effect on pain at rest or cumulative morphine consumption at any time. C-reactive protein levels at 48 h were markedly reduced by dexamethasone (52.4 mg/mL, 28.2-76.6 vs 194.2, 168.9-219.4; P < 0.0001). Seven patients in the control group, but only one in the dexamethasone group, were treated for nausea (P = 0.05).

CONCLUSIONS: A single, preoperative i.v. dose of dexamethasone 40 mg has a prolonged suppressive effect on the inflammatory response and decreases dynamic pain 24 h after total hip arthroplasty.