Ultrasonography for ilioinguinal/iliohypogastric nerve blocks in children

Background. The ilioinguinal/iliohypogastric nerve block isa popular regional anaesthetic technique for children undergoinginguinal surgery. The success rate is only 70–80% andcomplications may occur. A prospective randomized double-blindedstudy was designed to compare the use of ultrasonography withthe conventional ilioinguinal/iliohypogastric nerve block technique. Methods. One hundred children (age range, 1 month–8 years)scheduled for inguinal hernia repair, orchidopexy or hydrocelerepair were included in the study. Following induction of generalanaesthesia, the children received an ilioinguinal/iliohypogastricblock performed either under ultrasound guidance using levobupivacaine0.25% until both nerves were surrounded by the local anaestheticor by the conventional ‘fascial click’ method usinglevobupivacaine 0.25% (0.3 ml kg^–1). Additional intra-and postoperative analgesic requirements were recorded. Results. Ultrasonographic visualization of the ilioinguinal/iliohypogastricnerves was possible in all cases. The amount of local anaestheticused in the ultrasound group was significantly lower than inthe ‘fascial click’ group (0.19 (SD 0.05) ml kg^–1vs 0.3 ml kg^–1, P<0.0001). During the intraoperativeperiod 4% of the children in the ultrasound group received additionalanalgesics compared with 26% in the fascial click group (P=0.004).Only three children (6%) in the ultrasound-guided group neededpostoperative rectal acetaminophen compared with 20 children(40%) in the fascial click group (P<0.0001). Conclusions. Ultrasound-guided ilioinguinal/iliohypogastricnerve blocks can be achieved with significantly smaller volumesof local anaesthetics. The intra- and postoperative requirementsfor additional analgesia are significantly lower than with theconventional method.