Effect of fentanyl on the electrophysiological recovery following incomplete global cerebral ischemia

Abstract

The effects of two commonly used doses of the opioid fentanyl (50 and 100 Fglkg) on the electrophysiological outcome following global cerebral ischemia were studied in rats. The somatosensory evoked responses (SSER) and EEG activity were utilized to assess neurophysiological outcome. Prior to ischemia, there was no difference in the latency of the cortical peak of the SSER between groups. During the ischemic period, SSER and EEG activity were abolished in both groups. During the reperfusion period, however, the cortical peak of the SSER returned within 30 min in the animals anesthetized with 50 pglkg of fentanyl, whereas in the animals anesthetized with 100 pgikg fentanyl the cortical peak did not return by 60 min. This suggests that the animals anesthetized with a high dose of fentanyl are more susceptible to ischemic damage and that a high dose of fentanyl may exacerbate neurological damage following an ischemic insult to the brain.