Ultrasound-guided transversus abdominis plane block versus caudal block for pain relief in children

Caudal block (CB) is the gold standard technique for analgesia in children undergoing surgical interventions in the groin. Although the efficacy and the safety of this technique is high, nonetheless, there are several caveats such as unwarranted motor blockade of the lower limbs and disturbances of the bladder function, potentially resulting in delayed demission in the ambulatory setting. An alternative method to block neural structures which innervate lower abdominal wall has been described: the transverse abdominal plane block. The ultrasound guided technique improves the safety of margin. However, although this new technique seems to offer substantial advantages so far only experience from small case series are available. In particular, the TAP block has not been compared in a systematic trial with the "gold standard", the caudal block. The aim of this study is to evaluate potential differences in the effectiveness of postoperative analgesia and to test the hypotheses that the duration of pain relieve is prolonged after a TAP block when compared with an epidural caudal technique.