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Liver Failure/Cirrhosis/Portal Hypertension
Article first published online: 7 JAN 2013
Copyright © 2012 American Association for the Study of Liver Diseases
Volume 57, Issue 1, pages 258–265, January 2013
How to Cite
Dam, G., Keiding, S., Munk, O. L., Ott, P., Vilstrup, H., Bak, L. K., Waagepetersen, H. S., Schousboe, A. and Sørensen, M. (2013), Hepatic encephalopathy is associated with decreased cerebral oxygen metabolism and blood flow, not increased ammonia uptake. Hepatology, 57: 258–265. doi: 10.1002/hep.25995
Potential conflict of interest: Nothing to report.
Supported by the Danish Council for Independent Research, Medical Sciences (09-073658 and 09-065565), the Aase and Ejnar Danielsen's Foundation, and the A. P. Møller Foundation for the Advancement of Medical Science.
- Issue published online: 7 JAN 2013
- Article first published online: 7 JAN 2013
- Accepted manuscript online: 10 AUG 2012 04:42AM EST
- Manuscript Accepted: 11 JUL 2012
- Manuscript Revised: 15 DEC 2011
Studies have shown decreased cerebral oxygen metabolism (CMRO2) and blood flow (CBF) in patients with cirrhosis with hepatic encephalopathy (HE). It remains unclear, however, whether these disturbances are associated with HE or with cirrhosis itself and how they may relate to arterial blood ammonia concentration and cerebral metabolic rate of blood ammonia (CMRA). We addressed these questions in a paired study design by investigating patients with cirrhosis during and after recovery from an acute episode of HE type C. CMRO2, CBF, and CMRA were measured by dynamic positron emission tomography (PET)/computed tomography (CT). Ten patients with cirrhosis were studied during an acute episode of HE; nine were reexamined after recovery. Nine patients with cirrhosis with no history of HE served as controls. Mean CMRO2 increased from 0.73 μmol oxygen/mL brain tissue/min during HE to 0.91 μmol oxygen/mL brain tissue/min after recovery (paired t test; P < 0.05). Mean CBF increased from 0.28 mL blood/mL brain tissue/min during HE to 0.38 mL blood/mL brain tissue/min after recovery (P < 0.05). After recovery from HE, CMRO2 and CBF were not significantly different from values in the control patients. Arterial blood ammonia concentration decreased 20% after recovery (P < 0.05) and CMRA was unchanged (P > 0.30); both values were higher than in the control patients (both P < 0.05). Conclusion: The low values of CMRO2 and CBF observed during HE increased after recovery from HE and were thus associated with HE rather than the liver disease as such. The changes in CMRO2 and CBF could not be linked to blood ammonia concentration or CMRA. (HEPATOLOGY 2013)