Fulminant hepatic failure (FHF) is often complicated by high intracranial pressure (ICP) and fatal brain damage.
In this study, a team from the University Hospital of Copenhagen, Denmark, determined whether a rise in [glutamate]ec and [lactate]ec preceded surges of high ICP in patients with FHF.
They assessed this by inserting a microdialysis catheter into the brain-cortex, together with an ICP catheter.
The 10 patients in the study had a median age of 42, of these, 7 were women.
|An increase in [glutamate]ec did not precede high ICP in any of the cases.|
The team purfused the microdialysis catheter with artificial cerebrospinal-fluid at a rate of 0.3 µl per min.
In addition, they collected dialysate approximately every 30 minutes, or when ICP increased.
The research team collected a total of 352 microdialysis samples during a median of 3 days, and also allowed for ~1,760 bedside analyses of the collected dialysate.
They found that in 5 patients, who later developed surges of high ICP, the initial values of [glutamate]ec and [lactate]ec were 2 to 5 times higher, compared with patients with normal ICP.
However, [glutamate]ec then tended to vanish with time in both groups of patients.
The team did not find that an increase in [glutamate]ec preceded high ICP in any of the cases.
In contrast, [lactate]ec was high throughout the study in the high ICP group. This further increased before surges of high ICP.
Dr Flemming Tofteng's team conclude, "In patients with FHF, cerebral [glutamate]ec and [lactate]ec are elevated".
"However, the elevated [glutamate]ec is not correlated to high ICP".
"In contrast, elevations in [lactate]ec preceded surges of high ICP".
"Accelerated glycolysis with lactate accumulation is implicated in vasodilatation and high ICP in patients with FHF".
"The data suggest that bedside cerebral microdialysis is a valuable tool in monitoring patients with FHF and severe hyperammonemia".