Continuous intravenous diclofenac does not induce opioid-sparing or improve analgesia in geriatric patients undergoing major orthopedic surgery

Study Objective: To assess the analgesic efficacy and perioperative opioid-sparing effects of adjuvant intravenous (IV) diclofenac. Design: Prospective, controlled, double-blind study. Setting: Large referral hospital. Patients: 40 ASA physical status I, II, and III geriatric patients (>65 years) undergoing open reduction and internal fixation of subcapital fracture of the femur. Interventions: A standardized general anesthetic was administered. On induction of anesthesia, patients in the diclofenac group received an IV bolus of diclofenac (0.7 mg/kg) followed by a constant infusion (0.15 mg/kg/hr) until the end of surgery. In the saline group, an equal volume of saline was administered. "Rescue" fentanyl was administered in response to an increase in mean arterial pressure or heart rate (exceeding 20% of the patient's preinduction "baseline" values) that did not respond to a 30% increase in the inspired isoflurane concentration. Postoperative pain was assessed using a four-point patient-generated pain score (1 = none, 2 = mild, 3 = moderate, 4 = severe) as well as number of attempts and actual morphine delivered via a patient-controlled analgesia (PCA) device. Measurements and Main Results: The two treatment groups were demographically comparable. The perioperative hemodynamic variables, as well as the induction and "rescue" fentanyl dosages, were unaffected by the treatment modality. Pain scores, PCA attempts, and actual morphine delivered were statistically similar between the two groups. Conclusions: Adjuvant IV diclofenac does not improve intraoperative stability or decrease postoperative opioid requirements in geriatric patients undergoing internal fixation of subcapital fracture of the femur.