Effects of ethanol on brain lactate in experimental traumatic brain injury with hemorrhagic shock.
OBJECTIVE
Previous studies of traumatic brain injury (TBI) and hemorrhagic shock (HS) models, have shown cardiorespiratory depression in ethanol-treated animals. This study investigated the effects of ethanol (ET) on brain lactate concentrations and acidosis in a TBI/HS model.


METHODS
Anesthetized swine were instrumented and subjected to injury (INJ) consisting of fluid percussion TBI of 3 atm with concurrent 30 ml/kg graded hemorrhage over 30 min. Three groups were studied: Sham, INJ and INJ/ET. ET was given preinjury as a 2-g/kg i.v. bolus over 30 min, and an infusion of 0.4 g kg(-1) h(-1). Cardiorespiratory and cerebral physiologic data were monitored continuously for 150 min postinjury. Cerebral and renal blood flow was measured with colored microspheres. Brains were frozen in situ with liquid nitrogen. Lactate was measured with an enzymatic method.


RESULTS
ET levels at injury were 219+/-24 mg/dl. The INJ/ET group had increased mortality, impaired ventilation, and reduced renal blood flow. Brain (cortical) lactate levels were significantly higher and cerebral venous lactate concentrations were increased in the INJ/ET group during the postinjury period. Cerebral venous glucose was significantly higher in the INJ/ET group, and cerebral venous pH was significantly lower.


CONCLUSIONS
In this TBI/HS model, ethanol-induced increases in lactate concentrations in brain tissue and cerebral venous blood are associated with respiratory depression and reduced organ blood flow.
Zink
B J
BJ
University of Michigan, Section of Emergency Medicine and the Emergency Medicine Research Laboratory, Ann Arbor, MI 48109-0303, USA. bzink@umich.edu
Schultz
C H
CH
Wang
X
X
Mertz
M
M
Stern
S A
SA
Betz
A L
AL
D000704:Analysis of Variance; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism*; D001930:Brain Injuries / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D002302:Cardiac Output / Q000187:drug effects; D002531:Cerebellum / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D007427:Intracranial Pressure / Q000187:drug effects; D007668:Kidney / Q000098:blood supply; D007773:Lactates / Q000378:metabolism*; D008526:Medulla Oblongata / Q000378:metabolism; D012016:Reference Values; D012039:Regional Blood Flow / Q000187:drug effects; D012771:Shock, Hemorrhagic / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D013552:Swine
D007773:Lactates; D000431:Ethanol