Differential disruption of blood-brain barrier in severe traumatic brain injury.
BACKGROUND
Traumatic brain injury (TBI) is a significant cause of death and disability in young adults, but not much is known about the incidence and characteristics of blood-brain barrier (BBB) dysfunction in this group. In this proof of concept study, we sought to quantify the incidence of BBB dysfunction (defined as a cerebrospinal fluid (CSF)-plasma albumin quotient of ≥0.007) and examine the relationship between plasma and CSF levels of proteins and electrolytes, in patients with severe TBI.


METHODS
We recruited 30 patients, all of whom were receiving hypertonic 20 % saline infusion for intracranial hypertension and had external ventricular drains in situ. Simultaneous CSF and blood samples were obtained. Biochemical testing was performed for sodium, osmolality, potassium, glucose, albumin, immunoglobulin-G, and total protein.


RESULTS
Eleven patients (37 %) showed evidence of impairment of passive BBB function, with a CSF-plasma albumin quotient of ≥0.007. There were strong positive correlations seen among CSF-plasma albumin quotient and CSF-plasma immunoglobulin-G quotient and CSF-plasma total protein quotient (r = 0.967, P < 0.001 and r = 0.995, P < 0.001, respectively). We also found a higher maximum intracranial pressure (24 vs. 21 mmHg, P = 0.029) and a trend toward increased mortality (27 vs. 11 %, P = 0.33) in patients with BBB disruption.


CONCLUSIONS
In summary, passive BBB dysfunction is common in patients with severe TBI, and may have important implications for effectiveness of osmotherapy and long-term outcomes. Also, our results suggest that the CSF-plasma total protein quotient, a measurement which is readily available, can be used instead of the CSF-plasma albumin quotient for evaluating BBB dysfunction.
Intensive Care Unit, Fremantle Hospital, PO Box 480, Fremantle, WA, 6959, Australia, melanie.saw@health.wa.gov.au.
Melanie M
MM
Saw
Jenny
J
Chamberlain
Michelle
M
Barr
Matt P G
MP
Morgan
John R
JR
Burnett
Kwok M
KM
Ho
D000328:Adult; D000418:Albumins / Q000032:analysis / Q000134:cerebrospinal fluid; D015415:Biomarkers / Q000097:blood / Q000134:cerebrospinal fluid; D001798:Blood Proteins / Q000032:analysis*; D001812:Blood-Brain Barrier / Q000503:physiopathology*; D001930:Brain Injuries / Q000097:blood / Q000134:cerebrospinal fluid / Q000150:complications; D002556:Cerebrospinal Fluid Proteins / Q000032:analysis*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D019586:Intracranial Hypertension / Q000188:drug therapy / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012709:Serum Albumin / Q000032:analysis; D012720:Severity of Illness Index; D012965:Sodium Chloride / Q000008:administration & dosage; D055815:Young Adult
D000418:Albumins; D015415:Biomarkers; D001798:Blood Proteins; D002556:Cerebrospinal Fluid Proteins; D012709:Serum Albumin; D012965:Sodium Chloride