RETRACTED ARTICLE: The effects of intermittent bolus paravertebral block on analgesia and recovery in open hepatectomy: a randomized, double-blinded, controlled study

Abstract Background We aimed to investigate the effects of intermittent bolus paravertebral block on analgesia and recovery in open hepatectomy. Methods Eighty 18–70 years old, American Society of Anesthesiologists level I-III patients scheduled for hepatectomy with a J-shaped subcostal incision were enrolled and randomized to receive either intermittent bolus paravertebral ropivacaine (0.5% loading, 0.2% infusion) or 0.9% saline infusion at 1:1 ratio (25 ml loading before surgery, 0.125 ml/kg/h bolus for postoperative 48 h). The primary outcome was set as postoperative 48 h cumulative intravenous morphine consumption recorded by a patient-controlled analgesic pump. Results Thirty-eight patients in each group completed the study. The cumulative morphine consumptions were lower in the paravertebral block than control group at postoperative 24 (difference -10.5 mg, 95%CI -16 mg to -6 mg, P