A different view of lactate in trauma patients: protecting the injured brain.
BACKGROUND
The relationship between lactate and head injury is controversial. We sought to determine the relationship between initial serum lactate, severity of head injury, and outcome. We hypothesized that lactate is elevated in head injured patients, and that initial serum lactate increases as the severity of head injury increases. Furthermore, lactate may be neuroprotective and improve neurologic outcomes.


METHODS
We identified normotensive adult patients over a 6-y period at our university-based urban trauma center with isolated blunt head injury. We performed univariate and multivariate analysis to examine the relationship between lactate and Glasgow coma scale (GCS). The correlation of admission lactate with survival and neurologic function was also examined.


RESULTS
There were 555 patients who met study criteria. While controlling for injury severity score and age, increased lactate was associated with more severe head injury (P<0.0001). The admission lactate was 2.2+/-0.07, 3.7+/-0.7, and 4.7+/-0.8 mmol/L in patients with mild, moderate, and severe head injury respectively (P<0.01). Patients with moderate or severe head injury and an admission lactate>5 were more likely to have a normal mental status on discharge (P<0.0001).


CONCLUSIONS
In normotensive isolated head injured patients, there was an increase in serum lactate as head injuries became more severe. Since lactate is a readily available fuel source of the injured brain, this may be a mechanism by which brain function is preserved in trauma patients. Elevations in lactate due to anaerobic metabolism in trauma patients may have beneficial effects by protecting the brain during injury.
Cureton
Elizabeth L
EL
Department of Surgery, University of California San Francisco-East Bay, Alameda County Medical Center, Oakland, California 94602, USA.
Kwan
Rita O
RO
Dozier
Kristopher C
KC
Sadjadi
Javid
J
Pal
Jay D
JD
Victorino
Gregory P
GP
D000328:Adult; D006259:Craniocerebral Trauma / Q000097:blood*; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
D019344:Lactic Acid