Epidural morphine improves postoperative analgesia in patients after total knee arthroplasty: A randomized controlled trial.

ABSTRACT: BACKGROUND:Patients after total knee arthroplasty (TKA) often develop moderate to severe pain. This study compared the analgesic effect of low-dose epidural morphine vs. a comparable saline injection in patients following TKA surgery. METHODS:This randomized, double-blinded, and placebo-controlled trial was conducted in a tertiary hospital in Beijing between July 1, 2017 and May 30, 2018. One hundred and ten patients following TKA under combined spinal-epidural anesthesia were randomized to receive either epidural morphine (2 mg diluted to 5 ml normal saline, the epidural morphine group) or placebo (5 ml normal saline, the placebo group). For all patients, single-injection femoral nerve block was performed, and a supplementary patient-controlled intravenous analgesia pump was provided. The severity of pain was assessed with the numerical rating scale (NRS, an 11-point scale where 0 = no pain and 10 = the worst pain) at 6, 12, 24, 36, and 48 hours after surgery. The primary endpoint was moderate to severe pain (NRS pain score ?4) within 48 hours after surgery. RESULTS:The percentage with moderate to severe pain within 48 hours was lower in the epidural morphine group than in the placebo group (58.2% [32/55] with epidural morphine vs. 76.4% [42/55] with placebo; OR 0.43, 95% CI 0.19-0.98; p = 0.042). Furthermore, the cumulative morphine consumption within 48 hours was lower (18.4±6.1 mg vs. 22.4±7.3 mg; p = 0.002) whereas the mental component summary score of 30-day quality of life was higher (63.8±2.9 vs. 61.9±4.2; p = 0.008) in the epidural morphine group than in the placebo group. CONCLUSIONS:For patients following TKA, the addition of epidural morphine to single-injection femoral nerve block improves the quality of analgesia within 48 hours, without increasing adverse events. TRIAL REGISTRATION:ClinicalTrials.gov NCT03203967.

SUBMITTER: Meng ZT 

PROVIDER: S-EPMC6602200 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature