Changes in the Somatosensory Cortical Evoked Potential Produced by Hypovolemic Shock 1

Summary

Cortical and cuneate evoked responses and the EEG were studied during the various stages of hypovolemic shock. In 16 out of 18 animals, a decrease in amplitude of the cortical evoked response preceded or was concomitant with the period of spontaneous uptake of blood. Changes in amplitude and frequency of the EEG paralleled the changes noted in the cortical response but were much more variable. There was no correlation between changes in systemic blood gas levels or pH and the disappearance of the electrical responses. The fall in evoked cortical potential appears to provide a good indication of impending failure to maintain systemic arterial pressure.