Ultrasonography-guided rectus sheath block in paediatric anaesthesia - A new approach to an old technique

Background. The purpose of this study was an anatomical and clinical evaluation of ultrasonography-guided rectus sheath blocks in children. Method. A total of 30 children were included in the sono-anatomical part of the study. The depth of the anterior and posterior rectus sheath was evaluated with a portable SonSite 180 plus ultrasound machine and a 5-10 MHz linear probe. In total, 20 consecutive children undergoing umbilical hernia repair were included in the clinical part of this study. After induction of general anaesthesia children received a rectus sheath block under real-time ultrasonographic guidance by placing 0.1 ml kg-1 bilaterally in the space between the posterior aspect of the sheath and the rectus abdominis muscle. Results. Ultrasonographic visualization of the posterior rectus sheath was possible in all children. The correlation between the depth of the posterior rectus sheath and weight (adjusted r2=0.175), height (adjusted r2=0.314) and body surface area (adjusted r2=0.241) was poor. The ultrasound-guided rectus sheath blockade provided sufficient analgesia in all children with no need for additional analgesia in the perioperative period. Conclusion. The bilateral placement of levobupivacaine 0.25% 0.1 ml kg-1 in the space between the posterior aspect of the rectus sheath and the rectus abdominis muscle under real-time ultrasonographic guidance provides sufficient analgesia for umbilical hernia repair. The unpredictable depth of the posterior rectus sheath in children is a good argument for the use of ultrasonography in this regional anaesthetic technique in children. © 2006 Oxford University Press.