Parecoxib Supplementation to Morphine Analgesia Decreases Incidence of Delirium in Elderly Patients After Hip or Knee Replacement Surgery: A Randomized Controlled Trial

BACKGROUND: Severe pain and high-dose opioids are both associated with increased risk of postoperative delirium. The authors investigated whether parecoxib-supplemented IV morphine analgesia could decrease the incidence of delirium in elderly patients after total hip or knee replacement surgery. METHODS: In a randomized, double-blind, 2-center trial, patients of 60 years or older who underwent elective total hip or knee replacement surgery were assigned in a 1:1 ratio to receive either parecoxib (40 mg at the end of surgery and then every 12 hours for 3 days) or placebo (normal saline). All patients received combined spinal-epidural anesthesia during surgery and IV morphine for postoperative analgesia. The primary outcome was the incidence of delirium within 5 days after surgery. RESULTS: Between January 2011 and May 2013, 620 patients were enrolled and were included in the intention-to-treat and safety analyses. The incidence of delirium was significantly reduced from 11.0% (34/310) with placebo to 6.2% (19/310) with parecoxib (relative risk 0.56, 95% confidence interval 0.33–0.96, P = .031). The severity of pain and the cumulative consumptions of morphine at 24, 48, and 72 hours after surgery were significantly lower with parecoxib than with placebo (all P < .001), although the differences were small. There was no difference in the incidence of postoperative complications between the 2 groups (12.3% [38/310] with placebo versus 11.6% [36/310] with parecoxib; P = .80). CONCLUSIONS: For low-risk elderly patients undergoing elective total hip or knee replacement surgery, multidose parecoxib supplemented to IV morphine decreased the incidence of postoperative delirium without increasing adverse events.