Somatosensory evoked potential amplitude measurements are used to determine spinal cord function during surgery to correct idiopathic scoliosis, as well as other surgry around the spinal cord. A significant decrease in amplitude of the corticol response may indicate that neural conduction in the spinothalamic tracts is compromised. However, if the amplitude decrease is caused by anesthesia, it represents an innocuous event. Nitrous oxide is known to significantly reduce the corticol somatosensory evoked potential amplitude in adults, but little is known regarding its effect on children. This study evaluates the effect of nitrous oxide combined with propofol on the amplitude of the corticol response in children. The hypothesis is that the corticol amplitude would decrease 50% when nitrous oxide is combined with propofol compared with propofol alone.
