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

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 < 0.001) and 48 (difference -12 mg, 95%CI -19.5 mg to -5 mg, P = 0.001) hours. The pain numerical rating scales at rest were lower in the paravertebral block than control group at postoperative 4 h (difference -2, 95%CI -3 to -1, P < 0.001). The active pain numerical rating scales were lower in the paravertebral block than control group at postoperative 12 h (difference -1, 95%CI -2 to 0, P = 0.005). Three months postoperatively, the paravertebral block group had lower rates of hypoesthesia (OR 0.28, 95%CI 0.11 to 0.75, P = 0.009) and numbness (OR 0.26, 95%CI 0.07 to 0.88, P = 0.024) than the control group. Conclusions Intermittent bolus paravertebral block provided an opioid-sparing effect and enhanced recovery both in hospital and after discharge in patients undergoing hepatectomy. Trial registration clinicaltrials.gov (NCT04304274), date: 11/03/2020.