An earlier review to evaluate the quality and outcomes of studies assessing ultrasound imaging in regional anesthesia for the pediatric population considered articles published from 1994 to 2009 and showed some evidence in support of block-related outcomes (block onset, success, duration) and process-related outcomes (performance time, local anesthetic dose, and spread). At that time, strong evidence in the form of randomized controlled trials and well-designed prospective observational studies was limited, leading to a call for additional research. The current systematic review (2009–2014) compares and updates the evidence for ultrasound-guided pediatric regional anesthesia published since our last review. Using the MEDLINE and EMBASE databases, we included in this review studies examining ultrasound imaging for nerve localization in the pediatric population between 2009 and March 2014 (meta-analyses, systematic reviews, randomized controlled trials, controlled studies without randomization, observational studies, comparative studies, and case series involving at least 10 patients). In the current review, we identified 24 and 13 articles evaluating peripheral nerve blocks and neuraxial anesthesia, respectively.

What's New Studies in the current review provide stronger evidence and have addressed a number of outcomes that were previously inconsistent or lacked strength in evidence. In the current systematic review, we identified more studies in a shorter period compared with the previous review, and these studies contain higher levels of evidence compared with what we previously found. Randomized controlled trials and well-designed prospective observational studies have replaced case series. Stronger evidence from the literature suggests that ultrasound-guided peripheral blocks decrease block performance time when compared with nerve stimulation (but take longer than the landmark technique), increase block success, and increase block quality (as measured by analgesic consumption, block duration, and pain scores). Ultrasound guidance in neuraxial blocks improves needling time, predicts epidural depth, allows visualization of the catheter and local anesthetic spread, and improves block quality. Furthermore, we identified 2 large-scale prospective studies describing the incidence of adverse events and complications in pediatric regional anesthesia. The increase in evidence presented in this review reflects the efficacy and prevalent use of ultrasound imaging in pediatric regional anesthesia.