The effect of pre-incision field block versus post-incision inguinal wound infiltration on postoperative pain after paediatric herniotomy

BACKGROUND: The Ilioinguinal/iliohypogastric nerve block has been shown to significantly decrease opioid analgesic requirements and side effects after inguinal herniotomy. We compared the effect of pre-incisional field block with 0.25% bupivacaine and post-incisional wound infiltration with 0.25% bupivacaine for postoperative pain control after inguinal herniotomy. PATIENTS & METHODS: This was a randomized controlled double blind study in 62 ASA I and II children aged 1-7 years scheduled for inguinal herniotomy. They were assigned to receive either pre-incision field block (group I) or post-incision wound infiltration at the time of wound closure (group II). The pain score was assessed in the recovery room using mCHEOPS score and VAS or FLACC score at home by the parents for 24 hours. RESULTS: The mean pain scores during the 2 hour stay in the recovery room, at 12 and 18 hours at home were similar in both groups, p > 0.05. However, the mean pain scores were significantly lower at 6 hours at home in group I (1.22 ± 0.57) than in group II (1.58 ±0.90), p <0.001, but significantly higher at 24 hours at home in group I (3.29 ± 0.46) than in group II (2.32 ± 0.24), p = 0.040.There was no difference in mean paracetamol requirement, and in the number of patients who required paracetamol for pain relief at home in both groups, p > 0.05. CONCLUSION: We have demonstrated that both pre-incisional ilioinguinal/iliohypogastric field block and post incisional wound infiltration provided adequate postoperative analgesia for 24 hours after inguinal herniotomy.