Paravertebral somatic nerve block compared with peripheral nerve blocks for outpatient inguinal herniorrhaphy

Abstract

Background: Inguinal herniorrhaphy (IH) is a common outpatient procedure, yet postoperative pain and anesthetic side effects remain a problem. Paravertebral somatic nerve blocks (PVB) have the potential to offer unilateral abdominal wall anesthesia and long-lasting pain relief with minimal side effects. We compared PVB with peripheral neural blocks for outpatient IH.

Methods: Forty-six patients scheduled for IH were entered into this prospective, single-blind study. All patients underwent a standardized general anesthetic. Patients were randomly assigned to receive a PVB (levels T10-L2) preoperatively (n = 24) or an intraoperative peripheral block (PB) by the surgeon (n = 22), using 0.5% ropivacaine (40 mL). Opioid use, verbal analog pain scores, and side effects were documented for 72 hours.

Results: The use of opioids during surgery was less for the PVB group 162 +/- 70 mg than the PB group, 210 +/- 60 (P =.02). Need for opioids in PACU was less for the PVB group (39%) than the PB group (61%) (P =.002). Time until first pain after discharge was not different between groups, 312 +/- 446 minutes (PB) and 425 +/- 384 minutes (PVB) (P =.12). Of the PVB patients, 29% used no opioids at all compared with 18% of PB patients (P =.12). Mean time until first oxycodone use was similar between groups, 303 +/- 469 minutes (PB) and 295 +/- 225 minutes (PVB) (P =.18). Oxycodone use was also similar; 35 +/- 34 mg (PVB) versus 49 +/- 42 mg (PB) (P =.30). More patients in the PB group (50%) required antiemetic treatment in the postanesthesia care unit than the PVB group (21%) (P <.001). Side effects were similar at all other measurements.

Conclusions: This study shows that PVB provides analgesia equivalent to extensive peripheral nerve block for inguinal herniorrhaphy, offering an alternative method of postoperative pain management and perhaps fewer side effects.