Effect of ultrasound-guided lumbar plexus block on emergence agitation in children undergoing hip surgery: study protocol for a randomized controlled trial

BACKGROUND: Emergence agitation (EA) is a common postoperative issue in children that causes self-injury, increases stress on healthcare team members, and even leads to postoperative maladaptive behavioral changes in children. Clear answers regarding a ‘gold standard’ for prevention of EA are not available. Pain is regarded as an important causative factor of EA, and ultrasound-guided lumbar plexus block is a safe and efficient anesthetic method that can provide satisfactory pain relief in pediatric hip surgery. The purpose of our study is to determine whether ultrasound-guided lumbar plexus block can reduce the incidence of EA in children undergoing hip surgery. METHODS/DESIGN: We designed a prospective, randomized, controlled, blinded trial to determine the effect of ultrasound-guided lumbar plexus block on EA. A total of 100 American Society of Anesthesiologists class I–II children (1–6 years old) scheduled for elective hip surgery will be recruited for this study. Participants will be randomized at a 1:1 ratio to receive either ultrasound-guided lumbar plexus block or fentanyl after the induction of general anesthesia. The primary outcome is the incidence of EA 30 min after emergence from anesthesia using the Pediatric Anesthesia Emergence Delirium (PAED) score. The secondary outcomes are the severity and duration of EA 30 min after emergence from anesthesia using the PAED score, postoperative pain evaluated by the Children’s Hospital of Eastern Ontario Pain Scale, and the incidence of postoperative adverse events. Randomization will be conducted using a computer-generated randomization schedule. Outcome assessors and data collectors will be blinded to the group allocations. Assessments will be performed before surgery, intraoperatively, and postoperatively at every time point. DISCUSSION: Our hypothesis in this trial is that ultrasound-guided lumbar plexus block can decrease the incidence of EA in children undergoing elective hip surgery. This trial will provide clinical answers to verify our hypothesis. If our hypothesis is confirmed, the results could provide a safe method to prevent EA. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR-INR-17011525. Registered on 30 May 2017. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13063-018-3140-3) contains supplementary material, which is available to authorized users.