Eligible studies were randomised controlled trials (RCTs) in children that compared either ultrasound guided neuraxial blocks or peripheral nerve blocks with other techniques. Additional study types were also included in the review, including prospective, descriptive and case studies.
Outcomes reported for included studies comprised: success rate; performance time of blocks; vertebral/bone contact; direct visualisation of dura; onset of blocks; complications; duration and local anaesthetic volume.
Neuraxial blocks included: lumbar/thoracic epidural placement; intraoperative or postoperative epidural placement; and lumbar/thoracic epidural puncture). Peripheral nerve blocks included: brachial plexus; sciatic and femoral blocks; ilio-inguinal and ilio-hypogastric blocks. In included studies, ultrasound guidance varied in terms of percentage, duration and volumes.
Three independent reviewers selected the studies for inclusion, and disagreements were resolved by consensus.