Postoperative analgesia of scalp nerve block with ropivacaine in pediatric craniotomy patients: a protocol for a prospective, randomized, placebo-controlled, double-blinded trial.

BACKGROUND Moderate-to-severe postoperative pain following craniotomy has a high incidence in pediatric patients. Such pain may cause agitation, intracranial hypertension, epileptic seizures, and postoperative hematoma, which affect morbidity and mortality. Although scalp nerve block (SNB) achieves satisfactory pain relief except for suboccipital mid-craniotomy in adults and ropivacaine is widely used as a long-acting peripheral nerve block agent in children, there are few studies of SNB with ropivacaine in pediatric patients undergoing craniotomy. In addition, the neurosurgery operation time is relatively long, but the duration of action of SNB is limited. It is generally believed that postoperative SNB is better than preoperative SNB for postoperative analgesia. However, considering the concept of preemptive analgesia, we believe that preoperative SNB may achieve a longer postoperative analgesia effect than we expected. METHODS This trial is a single-institution, prospective, randomized, controlled, double-blind study. A total of 180 children aged between 1 and 12 years who are undergoing elective craniotomy will be randomly allocated in a 1:1:1 ratio to three groups: group B (preoperative ropivacaine block group), group A (postoperative ropivacaine block group), and group N (nonblocking control group). This randomization will be stratified by age in two strata (1-6 years and 7-12 years). The primary outcome is the total consumption of sufentanil within 24 h after surgery. The secondary outcomes include assessment of pain scores, total consumption of sufentanil and emergency-remedy medicine consumption at observation points, the occurrence of postoperative complications, and the length of hospitalization after surgery. DISCUSSION This study is designed to explore the effect and feasibility of SNB with ropivacaine for postoperative analgesia in pediatric patients undergoing craniotomy. Further aims are to compare the effects of preoperative and postoperative SNB on postoperative analgesia in order to identify whether there is a preemptive analgesic effect and determine the better time to implement SNB in pediatric patients during craniotomy. TRIAL REGISTRATION Chinese Clinical Trial Registry ChiCTR1800017386. Registered on 27 July 2018.