Hepatic Encephalopathy Flashcards
Hepatic encephalopathy
Neuropsychiatric syndrome caused by lack of function of the liver and diversion of portal blood to systemic circulation bypassing the liver
Liver functions
Blood glucose regulation
Bile drainage
Blood circulation and filtration
Detoxification
Synthesis and storage of aa, proteins, vitamins and fats
Acute hepatic failure
Failure of hepatic detoxification
Caused by toxins, medications and xenobiotics, heavy metals and infectious agents
Hepatic fibrosis/ cirrhosis (chronic)
Failure of detoxification
Caused by idiopathic, hereditary and congenital
Circulatory failure of hepatic detoxification
Portosystemic shunt
Portal atresia
Hepatic arteriovenous (AV) fistula
Pathophysiology of hepatic encephalopathy
Loss of hepatic detoxification
Systemic accumulation of toxins
Toxins affect CNS
Toxins gut derived from break down of protein and short chain fatty acids
Ammonia (toxic outcomes)
Alterations of BBB
Cerebral edema
Changes in brain energy metabolism (brain glucose)
Changes in cerebral neurotransmission (toxic outcomes)
Benzodiazepines-like substances
Enhancement of gamma butyric acid (GABA) activity
Inhibition of glutamine
Causes of Hepatic encephalopathy in young animals
Congenital (portosystemic shunt)
Toxins and biologicals
Causes of Hepatic encephalopathy in middle-aged animals
Familial/ hereditary (chronic fibirosis)
Toxins, medication and biologicals
Causes of Hepatic encephalopathy in older animals
Neoplasia
Familial/ hereditary (chronic fibirosis)
Toxins, medication and biologicals
Causes of Hepatic encephalopathy in cats
Cholangitis/ cholangiohepatitis
Hepatic lipidosis
Medications
CS of Hepatic encephalopathy: altered consciousness
Stupor/ Coma**
Depressed behavior
Anorexia/ lethargy
Difficulty housetraining
Ptyalism
CS of Hepatic encephalopathy: personality changes
Vocalizing
Aggression/ submissive behavior
Dementia and disorientation (compulsive walking, head pressing, pacing)
CS of Hepatic encephalopathy: motor dysfunction
Ataxia, wide base stance, tremors and circling
CS of Hepatic encephalopathy: neurological
Sudden blindness (amaurosis)
Seizures (not as common)
Accompanying signs of hepatic encephalopathy includes …..
Liver failure
Dx testing
Neurological exam
ECG
Thoracic and abdominal rads
CBC, serum chemistry, electrolyte panel
Liver panel (bile acid assay, blood amonia)
Urinalysis
Shunt hunt (ultrasound, fluoroscopy, tomography)
Diagnostic abnormalities
↑ ALP, ALT, AST, CK
↓ BUN bc liver not functioning → concentrates in the urine and USG will ↓
↑ blood ammonia and abnorm BA assay (↑)
Abdominal rads
Non-specific findings
Shift gastric axis cranially
Microhepatica **
Poor serosal detail
Surgery
Intraoperative fluoroscopy
Single extrahepatic portoazygous shunt near splenic vein
Surgical treatment ameroid constrictor occlusion
Liver biopsy/ histopatholgy findings
Hepatocellular atrophy and periportal fibrosis
