Stroke, Vol 23, 498-505, Copyright © 1992 by American Heart Association
LA Kearse Jr, EN Brown and K McPeck
BACKGROUND AND PURPOSE: The relation between electroencephalographic
pattern changes and cerebral ischemia during carotid endarterectomy under
general anesthesia is well established. Pattern changes seen on
somatosensory evoked potentials under the same conditions are reported to
be more sensitive indicators of cerebral ischemia. We estimated the
sensitivity and specificity of somatosensory evoked potentials relative to
electroencephalography for detecting cerebral ischemia during carotid
endarterectomy under general anesthesia. METHODS: We simultaneously
monitored electroencephalographs and somatosensory evoked potentials in 53
carotid endarterectomies performed on 51 patients under general anesthesia,
and we determined the extent to which somatosensory evoked potentials
detected cerebral ischemia defined by electroencephalographic pattern
changes at the time of carotid cross-clamp. RESULTS: Twenty-three of the 53
cases studied had electroencephalographic evidence of ischemia following
carotid cross- clamp. Ten of these 23 cases had an increased somatosensory
evoked potential latency of 0.1 msec or greater (sensitivity 0.43). One of
these 23 patients had a decrease in somatosensory evoked potential
amplitude of 50% or greater (sensitivity 0.04). Of the 30 subjects who had
no electroencephalographic evidence of ischemia, 13 had either no change or
a decrease in somatosensory evoked potential latency (specificity 0.45).
None of these 30 cases had a significant decrease in somatosensory evoked
potential amplitude (specificity 1.0). If somatosensory evoked potential
latencies were a sensitive method for detecting cerebral ischemia (true
sensitivity of 0.95 or higher), the probability of only 10 subjects having
somatosensory evoked potential latency increases would be less than 0.001.
Therefore, our observed sensitivity cannot be attributed to chance.
CONCLUSIONS: We conclude that measuring somatosensory evoked potentials is
not a sensitive method for detecting cerebral ischemia during carotid
endarterectomy.
ARTICLES
Somatosensory evoked potentials sensitivity relative to electroencephalography for cerebral ischemia during carotid endarterectomy
Department of Anesthesia, Massachusetts General Hospital, Boston 02114.
This article has been cited by other articles:
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S. J. Howell Carotid endarterectomy Br. J. Anaesth., July 1, 2007; 99(1): 119 - 131. [Abstract] [Full Text] [PDF] |
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