Effect of Pre-vs. Post-incisional Lidocaine Infiltration on Postoperative Pain after Inguinal Herniorrhaphy

Lee, Sang Rock; Cho, Sung Jung; Ko, Hwall Young; Lee, In Bae; Chung, Chang Woo; Kim, Hong Youl

Abstract

BACKGROUND: Recently many studies reported that the postoperative pain was prevented or decreased from preoperative regional anesthesia by preventing the establishment of central sensitization(pre-emptive analgesia). Therefore, we evaluated the efficacy of preincisional lidocaine infiltration on the postoperative pain.
METHODS
We conducted a study to compare preinfiltrating group with 1% lidocaine (30 ml), postinfiltrating group with 1% lidocaine (30 ml) and non-infiltrating group in 45 patients scheduled for elective inguinal herniorrhaphy. During operation, all patients received a general anesthesia with thiopental, isoflurane and nitrous oxide in oxygen. Postoperatively, pain scores on visual analogue scale (VAS) and on verbal rating scale(VRS) at rest, coughing and movement from supine into sitting position were assessed. Also the time to first request for an on-demand postoperative analgesics and the total dose of postoperative analgesics were assessed. And the number of patients who didn't require any analgesics during postoperative period was assessed.
RESULTS
The VAS and VRS at rest, coughing, movement were low in preinfiltrating group than in non-infiltrating group and postinfiltrating group postoperatively, but it was statistically significant only in early postoperative period. The time to first request for an on-demand postoperative analgesics occurred later in preinfiltrating group than in non-infiltrating group and in postinfiltrating group and the total dose of supplemental analgesics (ketorolac) was smaller in the preinfiltrating group than in non-infiltrating group and postinfiltrating group, and the patients without analgesic treatment was less in the preinfiltrating group than in non-infiltrating group and postinfiltrating group, but it was not statistically significant.
CONCLUSIONS
In patients with inguinal herniorrhaphy, we can not support the pre-emptive analgesia clinically with preincisional lidocaine infiltration.