Brain lactate by magnetic resonance spectroscopy during fulminant hepatic failure in the dog.
A noninvasive test is needed to assess the severity of encephalopathy during fulminant hepatic failure. This feasibility study was designed to compare a noninvasive test, brain lactate measurement by magnetic resonance spectroscopy, with intracranial pressure monitoring in a large animal model of fulminant hepatic failure. Five dogs received an intraventricular catheter for intracranial pressure measurement. Liver injury was induced by intravenous bolus of D-galactosamine. Brain lactate concentrations were determined by magnetic resonance spectroscopy for up to 48 hours after D-galactosamine administration (t = 0 hour). A dose of D-galactosamine exceeding 1.5 g/kg resulted in fulminant hepatic failure. Brain lactate levels increased to > 10 mmol/L in the two dogs that developed severe intracranial hypertension of > 50 mm Hg and sustained cerebral perfusion pressures of < 40 mm Hg. Both dogs experienced brain death, 42 and 48 hours after the administration of D-galactosamine. Brain lactate concentrations determined by magnetic resonance spectroscopy were in agreement with brain tissue concentrations of lactate determined by high-performance liquid chromatography at necropsy. Plasma lactate concentrations were only mildly elevated (3.2 and 4.2 mmol/L) at the time of brain death. Elevated levels of brain lactate are associated with intracranial hypertension and poor neurological outcome during fulminant hepatic failure.
Nyberg
S L
SL
Department of Surgery, Mayo Medical Center, Rochester, MN 55905, USA.
Cerra
F B
FB
Gruetter
R
R
D000818:Animals; D015415:Biomarkers / Q000032:analysis; D001921:Brain / Q000378:metabolism*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005240:Feasibility Studies; D005688:Galactosamine / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006501:Hepatic Encephalopathy / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D019586:Intracranial Hypertension / Q000503:physiopathology*; D019344:Lactic Acid / Q000097:blood / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013997:Time Factors
D015415:Biomarkers; D005973:Glutamine; D019344:Lactic Acid; D018698:Glutamic Acid; D005688:Galactosamine