Objective: To assess the validity of early sensory evoked potential (SEP) r
ecording for reliable outcome prediction in comatose cardiac arrest survivo
rs within 48 h after restoration of spontaneous circulation (ROSC).
Design and setting: Prospective cohort study in a medical intensive care un
it of a university hospital.
Patients: Twenty-five comatose, mechanically ventilated patients following
cardiopulmonary resuscitation
Measurements and results: Median nerve short- and long-latency SEP were rec
orded 4, 12, 24, and 48 h after ROSC. Cortical N20 peak latency and cervico
medullary conduction time decreased (improved) significantly between 4, 12,
and 24 h after resuscitation in 22 of the enrolled patients. There was no
further change in short-latency SEP at 48 h. The cortical N70 peak was init
ially detectable in seven patients. The number of patients with increased N
70 peak increased to 11 at 12 h and 14 at 24 h; there was no further change
at 48 h. Specificity of the N70 peak latency (critical cutoff 130 ms) incr
eased from 0.43 at 4 h to 1.0 at 24 h after ROSC. Sensitivity decreased fro
m 1.0 at 4 h to 0.83 at 24 h after ROSC.
Conclusion: Within 24 h after ROSC there was a significant improvement in S
EP. Therefore we recommend allowing a period of at least 24 h after cardiop
ulmonary resuscitation for obtaining a reliable prognosis based on SEP.