[Changes in the electroretinogram during enflurane anesthesia].

We have investigated a method of intraoperative monitoring of anesthetic depth using the electroretinogram (ERG). The effects of enflurane on ERG were studied in 12 patients undergoing surgical procedures. Recordings were made at 0%, 0.8%, 1.7% end-tidal enflurane concentrations. There were statistically significant increases in the latencies of the a-waves, b-waves and oscillatory potentials (OP) with increasing concentrations of enflurane. The amplitudes of the a-waves were reduced with increasing concentrations of enflurane, but the amplitudes of the b-waves did not change. The latencies of OP were thought to be the most sensitive indicator of the anesthetic depth among these parameters. To apply this technique to clinical practice, there were many problems to be solved. However, this may be one of useful monitors of anesthetic depth in future.