Comparative Effects of Two Anesthetic Techniques on Auditory Brain Response in Children

The proposed study will be a single-center, prospective, crossover-controlled study of the two anesthetic techniques (propofol and sevoflurane). The investigators plan to enroll 80 patients who receive general anesthesia at Cincinnati Children's Hospital Medical Center Department of Radiology for ABR testing. A sample size recalculation will be performed during the study to determine the exact number of subjects necessary for sufficient power. As per standard anesthesia practice for this test in radiology department, all subjects will serve as their own control, receiving both anesthetic techniques within the same ABR testing session. The audiologist will employ broadband click stimulus testing after induction with Sevoflurane, after which the patient will be switched over to a propofol infusion and the sevoflurane stopped. After the completion of the remainder of the ABR (tone-burst testing), the audiologist will repeat the broadband click testing (now while under propofol anesthesia), and the results will be recorded. At this point, results will be de-identified, with the exception of which ear was tested and the intensity level, and these results will be reviewed by a panel of 5 audiologists. These audiologists will be blinded to the anesthetic technique and patient information. They will provide a judgment at each intensity level, for each ear whether or not a response is present (in a Yes/No format). A study coordinator blinded to the anesthetic technique will record the outcome data. The anesthesia providers and nursing team will not be blinded.

Inclusion criteria

• 0 - 18 years old
• ASA status I, II, or III
• Scheduled for ABR with general anesthesia

Exclusion criteria

• Contraindication to sevoflurane or propofol
• ASA >3