A rare case of a somatosensory evoked potentials recording during cardiopulmonary resuscitation

Background: Neuronal damage is a possible complication of cardiac surgery. To reduce the potential risk of postoperative neurological deficit, the functional state of affectedcentral nervous system pathways is monitored intraoperatively by recording evoked potentials (EPs). Apart from animal research, there is little clinical evidence of EPs recordingduring cardiac arrest and cardio-pulmonary resuscitation (CPR). Methods: Both scalp (SCEPs) and spinal (SSEPs) short-latency somatosensory EPs were recorded as the response to theelectrical stimulation of the right median nerve during mitral valve replacement surgery. Evoked potentials were recorded before, during, and after sudden ventricular fibrillationfollowed by CPR. Results: Preoperative control recordings of both SCEPs and SSEPs were in the normal ranges. During the first 4 min of cardiac arrest and resuscitation, all SCEPs waves disappeared, while the spinal component of the SSEPs was still recognizable. After CPR, all waves of both EPs recordings recovered completely. The patient woke from anesthesia without neurological deficits. Conclusions: As expected, scalp-recorded EPs are more sensitive to the cardiac arrest than spinal EPs. Rapid and almost complete recovery of postoperative EPs, namely SCEPs, correlated well with normal neurological recovery.