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

Abstract

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. 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. 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. 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.