Lidocaine versus ropivacaine for postoperative continuous paravertebral nerve blocks in patients undergoing laparoscopic bowel surgery: a randomized, controlled, double-blinded, pilot study

BACKGROUND AND OBJECTIVES Lidocaine could provide many advantages in continuous regional anesthesia techniques, including faster onset, greater titratability, and lower cost than long-acting local anesthetics. This prospective, randomized, double-blinded, pilot study is therefore intended to compare lidocaine to ropivacaine in bilateral continuous paravertebral blocks using a multimodal approach for postoperative pain management following laparoscopic bowel surgery. METHODS Thirty-five ASA I-III consecutive patients undergoing elective laparoscopic bowel surgery and bilateral thoracic paravertebral continuous blocks were analyzed: bilateral thoracic paravertebral infusions of ropivacaine 0.2% (Group Ropi, n=18) or lidocaine 0.25% (Group Lido, n=17) were started at 7 mL/h in the postanesthesia care unit. For each patient, we collected numerical rating scores (NRS) for pain at rest and during movement at baseline, at postanesthesia care unit discharge, at 24 hours and 48 hours after the end of surgery, as well as hydromorphone patient-controlled analgesia requirements, local anesthetic consumption, side effects, postoperative complications, and functional outcomes. RESULTS No effect of group distribution on NRS scores for pain at rest or at movement (P=0.823 and P=0.146), nor on hydromorphone (P=0.635) or local anesthetic consumption (P=0.063) was demonstrated at any analyzed time point. Hospital length of stay and spontaneous ambulation were comparable between groups (P=0.636 and P=0.148). In the context of a multimodal approach, the two drugs showed comparable safety profiles. DISCUSSION Lidocaine 0.25% and ropivacaine 0.2% provided similar analgesic profiles after elective abdominal surgeries, without any difference in terms of functional outcomes. The easier titratability of lidocaine together with its lower cost induced our clinical practice to definitely switch from ropivacaine to lidocaine for postoperative bilateral paravertebral continuous infusions.