The effect of electroencephalogram-targeted high- and low-dose propofol infusion on histopathological damage after traumatic brain injury in the rat.
BACKGROUND
Propofol is commonly used to sedate patients after traumatic brain injury. However, the dose-dependent neuroprotective effects of propofol after head trauma are unknown. We compared histopathological damage after 6 h of electroencephalogram-targeted high- and low-dose propofol infusion in rats subjected to controlled cortical impact (CCI).


METHODS
Animals were randomly assigned to CCI/propofol with electroencephalogram burst-suppression-ratio 1%-5% (CCI/lowprop), CCI/propofol with burst-suppression-ratio 30%-40% (CCI/highprop), control group CCI/1.0 vol % halothane (CCI/halo), or sham group with halothane anesthesia (SHAM/halo). Brain slices were stained with kresyl violet (KV) and hematoxylin/eosin (HE) to evaluate lesion volume, number of eosinophilic cells, and activation of caspase-3 in the hippocampus.


RESULTS
Lesion volume (mm3) and number of eosinophilic cells in the hippocampus did not differ significantly [lesion volumes: CCI/lowprop 31.55 +/- 14.66 (KV) and 53.77 +/- 8.62 (HE); CCI/highprop 33.81 +/- 10.57 (KV) and 52.30 +/- 11.55 (HE); CCI/halo 36.42 +/- 17.06 (KV) and 57.95 +/- 8.49 (HE)]. Activation of caspase-3 occurred in the ipsilateral hippocampus in all CCI-groups.


CONCLUSIONS
Despite different levels of cortical neuronal function, there were no relevant differences in the short-term histopathological damage. These results challenge the view that the neuroprotective effect of propofol relates to the suppression of cerebral metabolic demand.
Eberspächer
Eva
E
Department of Surgical and Radiological Sciences, Veterinary Medical Teaching Hospital, University of California at Davis, One Shields Ave., Davis, CA, USA. eberspaecher@ucdavis.edu
Heimann
Kerstin
K
Hollweck
Regina
R
Werner
Christian
C
Schneider
Gerhard
G
Engelhard
Kristin
K
D000818:Animals; D001921:Brain / Q000473:pathology*; D001930:Brain Injuries / Q000473:pathology* / Q000503:physiopathology; D053148:Caspase 3 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography / Q000187:drug effects*; D004804:Eosinophils / Q000473:pathology; D006221:Halothane / Q000494:pharmacology; D007262:Infusions, Intravenous; D007958:Leukocyte Count; D008297:Male; D018696:Neuroprotective Agents / Q000494:pharmacology*; D015742:Propofol / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D018696:Neuroprotective Agents; D053148:Caspase 3; D006221:Halothane; D015742:Propofol