Changes in Cerebral Oxygenation During Laparoscopic Pyloromyotomy

This prospective study will include 50 patients under the age of 18 years who are having laparoscopic pyloromyotomy. There will be no change in the anesthetic or perioperative care of these patients. Tissue and cerebral oxygenation will be monitored using near infrared spectroscopy (NIRS). Prior to anesthetic induction, the NIRS monitor will be placed on the forehead. The device is non-invasive like pulse oximetry using a non-painful adhesive sticker. The device can be applied to different sites on the body to measure cerebral, tissue or even organ oxygenation. For the purpose of the study, the investigators will place one monitor on the forehead to measure tissue oxygenation and a second over the lower back to measure tissue (muscle or renal) oxygenation. These devices are used routinely in the operating room and the cardiothoracic intensive care unit for cardiac patients. Although not used on every surgical procedure, NIRS monitoring can be used on all patients who are undergoing major surgical procedures. Tissue and cerebral oxygenation will be recorded continuously starting just prior to anesthetic induction until the completion of the procedure.