Preadministration of flurbiprofen suppresses prostaglandin production and postoperative pain in orthopedic patients undergoing tourniquet inflation

Abstract

Study Objectives To evaluate the effect of preadministration of flurbiprofen on the plasma concentrations of prostaglandin E2 (PGE2) and postoperative pain. Design Prospective, randomized, controlled and double-blind study. Setting Inpatient surgery at Nagasaki Rosai Hospital. Patients 32 ASA physical status I to II patients scheduled for total knee arthroplasty or open anterior cruciate ligament reconstruction. Interventions Patients were randomly assigned to two groups. Five minutes before tourniquet inflation (350 mmHg), group A (n = 16) received placebo (intralipid, one mL · kg −1), and group B (n = 16) received flurbiprofen one mg · kg −1 IV. Catheters were placed in the ipsilateral femoral vein for collection of local blood and in a cubital vein for sampling of systemic blood. Measurements Prostaglandin E2 (femoral vein and cubital vein) was measured before tourniquet inflation (T1), before tourniquet deflation (T2), and immediately after tourniquet deflation (T3). Postoperative analgesia was provided with intravenous buprenorphine, 0.1 mg, on patient demand. Pain (Visual Analog Scale) was assessed at 0.5, one, two, 4, 6, 12 and 24 hours after surgery. Main Results Visual Analog Scale and buprenorphine consumptions in group B were significantly lower than those in group A during the first 4 postoperative hours. In group A, PGE2 in femoral vein increased significantly at T2 (359 ± 105 pg mL −1, P < 0.0001), compared with T1 (211 ± 61 pg mL −1) and returned to control values at T3 (252 ± 77 pg mL −1), whereas PGE2 in the cubital vein showed no change. In group B, PGE2 in either the femoral vein or cubital vein showed no change throughout the time course. Conclusions Preadministration of flurbiprofen suppresses the local production of PGE2 during tourniquet ischemia, resulting in reduced early postoperative pain in patients undergoing knee surgery.