Comparison of the morphine-sparing effects of diclofenac sodium and ketorolac tromethamine after major orthopedic surgery.

Study Objectives: To compare the efficacy of diclofenac sodium with ketorolac tromethamine in reducing postoperative morphine use after major orthopedic surgery.

Design: Double-blind, randomized, placebo-controlled study.

Setting: Major teaching institution.

Patients: 102 ASA physical status II patients undergoing hip and knee replacement with general anesthesia.

Interventions: Before induction of anesthesia, patients were randomly allocated to receive intravenously either diclofenac sodium 75 mg (Group D), ketorolac tromethamine 60 mg (Group K), or placebo (Group P). Patient-controlled analgesia was supplied postoperatively using morphine.

Measurements: Visual analog scale (VAS), verbal pain score (VPS), sedation score, frequency of opioid side effects, and morphine consumption were recorded every 4 hours.

Main Results: There was a highly significant downward trend for VAS, VPS, and sedation scores over time, p = 0.001. The mean VAS and VPS scores were significantly lower in Groups D and K compared with Group P at time 0, p = 0.009 and 8 hours, p = 0.026. The mean (SD) 24-hour morphine requirements were 36.3 mg (16.9), 47.2 mg (34.9), and 51.6 mg (22.2) for Groups D, K, and P, respectively, p = 0.032. Fewer patients suffered from postoperative nausea and vomiting in the treatment groups (Groups D and K) compared with Group P (9, 8, and 19, respectively), p < 0.05. Fewer patients also suffered from pruritus in Groups D and K compared with Group P (3, 4, and 11, respectively), p < 0.01.

Conclusions: Preoperative administration of intravenous diclofenac 75 mg or ketorolac 60 mg significantly reduces morphine requirements and associated side effects after major orthopedic surgery.