Effect of needle insertion site on ilioinguinal-iliohypogastric nerve block in children

Three different sites of needle insertion have been proposed for ilioinguinal-iliohypogastric (ILIH) nerve block. This double-blind study was designed to assess the quality of analgesia produced from these different sites.

One hundred and thirty-two children of ASA grade I and II were randomly allocated into four groups to receive no nerve block (control group, n = 30) or ILIH block at 1 cm inferio-medial to the anterior superior iliac spine (ASIS) in group IM (n = 34), 1-2 cm medial to the ASIS in group M (n = 34) and 2 cm superio-medial to the ASIS in group SM (n = 34) with 0.25 ml/kg of 0.25% bupivacaine after induction of anaesthesia. Pain was assessed using the All India Institute of Medical Sciences (AIIMS) pain discomfort scale (APDS) score. The amount and pattern of fentanyl consumed over the ensuing 24-h period was noted.

APDS score and fentanyl requirement were similar in all the study groups but significantly higher until 8 h after surgery in the control group, P < 0.05. Twenty-two out of 102 children in the study groups and all patients in the control group received additional fentanyl during the post-operative period. Only 6 out of 22 children required additional fentanyl supplementation beyond the 30-min interval. Overall failure rate of ILIH nerve block was 6%.

ILIH block can be successfully accomplished from any point if the needle bevel lies between the two muscle planes above and below the internal oblique.