The Infratrochlear Nerve Block Reduces the Incidence of Postoperative Nausea Vomiting in Pediatric Patients Undergoing Strabismus Surgery-A Retrospective Study.

Background/Objectives: Strabismus surgery in pediatric patients is associated with a high incidence of postoperative nausea and vomiting (PONV). Patients showing pain are more prone to develop PONV. As the infratrochlear nerve (ITN) block can ameliorate perioperative pain following strabismus surgery, we hypothesized that ITN block may influence PONV in pediatric patients undergoing strabismus surgery. Methods: The medical charts of pediatric patients older than 2 years with exotropia who underwent strabismus surgery under general anesthesia, with or without ITN block, were reviewed retrospectively. The incidence of PONV, intraoperative surgical pleth index (SPI), state entropy (SE), response entropy (RE), the changes in hemodynamics, and perioperative use of metoclopramide and ketoprofen were investigated. Results: The study population comprised 116 patients (58 for the No-block group vs. 58 for the ITN group). The incidence of PONV was significantly lower in the ITN block group compared to the No-block group (5.2% vs. 22.4%, respectively; p = 0.015). The SPI at conjunctiva incision, muscle dissection and traction were significantly lower in the ITN block group than in the No-block group. SE was comparable between the two groups, but RE at muscle dissection and traction was significantly lower in the ITN block group than in the No-block group. The use of metoclopramide and ketoprofen was also lower in the ITN block group than in the No-block group. Conclusions: ITN block reduced PONV as well as perioperative pain in pediatric patients undergoing strabismus surgery.