Effect of ilioinguinal and iliohypogastric nerve block and wound infiltration with 0.5% bupivacaine on postoperative pain after hernia repair

We have compared, in 40 adult males, the effect on pain in the first 24 h after herniorrhaphy of preincisional ilioinguinal and iliohypogastric nerve block and wound infiltration with 0.5% bupivacaine or saline. After operation, patients received morphine i. v. via a patient-controlled analgesia machine and visual analogue pain scores (VAS) at rest and on movement were recorded. The bupivacaine group consumed less morphine in the first 6 h after operation. There was no difference in morphine consumption between the two groups in the next 18 h. The time to first analgesia was delayed in the bupivacaine group and was not followed by a rebound increase in requirement for analgesia. There was no significant difference in VAS scores at rest but there was a significantly higher pain score with movement in the saline group. We have shown that the combination of nerve block and wound infiltration reduces consumption of morphine in the first 24 h after herniorrhaphy. We have failed to show any effect of 0.5% bupivacaine beyond the first 6h after operation.