Hepatic Encephalopathy Flashcards
1
Q
definition of HE
A
- vague, generally reversible, neuropsychiatric disorder which results when products that are usually metabolized by the liver escape into the systemic circulation
2
Q
pathophysiology of HE
A
- high ammonia levels
- up regulation of astrocytic peripheral benzodiazepine receptors
- neurosteroid production
- modulation of GABA-A receptor
- HE
3
Q
type A HE
A
- associated with acute liver failure
- rapid onset
- frequently fatal
- main cause is cerebral edema
- treatment is liver transplant
4
Q
type B HE
A
- associated with porto-systemic bypass without intrinsic hepatocellular disease
5
Q
type C HE
A
- associated with cirrhosis and porto-systemic shunting
- gradual onset
- rarely fatal
- main cause is shunting/toxin
- treatment is usually effective
6
Q
clinical signs of cerebral edema
A
- decebrate posture
- profuse sweating
- tachycardia
- cardiac arrythmias
- high fever
- hyperventilation
- tachypnea
- intermittent HTN
7
Q
Modified West Haven, grade 0
A
- no abnormality detected
8
Q
Modified West Haven, grade 1
A
- change in personality, trivial lack of awareness, shortened attention, arithmetic difficulty (cant count backwards by 7s from 100)
9
Q
Modified West Haven, grade 2
A
- lethargy, loss of orientation for time, monotone voice, inappropriate behavior, obvious personality change
10
Q
Modified West Haven, grade 3
A
- somnolent, responsive to stimuli, gross disorientation, severe confusion
11
Q
Modified West Haven, grade 4a
A
- coma, responsive only to major stimuli
12
Q
Modified West Haven, grade 4b
A
- coma, unresponsive to any stimuli
13
Q
precipitating factors of HE
A
- sepsis
- hypokalemia
- high protein diet
- dehydration
- sedative/analgesic drugs
- poor lactulose compliance
- TIPS
- GI bleeding
14
Q
minimal HE abnormalities
A
- attention and cognitive deficits
- visual-spacial perception impaired
- impaired driving ability
15
Q
HE vs alcohol withdrawal
A
- patients with HE do not have hallucinations or diaphoresis
16
Q
hallmark in the diagnosis of HE
A
- asterixis
17
Q
role of blood ammonia testing in HE
A
- arterial or arterialized blood sample optimal
- normal value does not rule out HE
- abnormal value does not prove HE is present
- main utility is in detecting cause of obscure encephalopathy
18
Q
correlation of ammonia levels and HE
A
- poor correlation of ammonia levels with presence or severity of HE
19
Q
treatment of HE
A
- lactulose (2-3 BMs per day)
- stop source of ammonia
- remove substrate from GI tract (catharsis, enemas)
- suppress intestinal bacterial flora
- stimulate ammonia fixation (lactulose)
- correct glucose, electrolytes, anemia, hypoxia
20
Q
therapies to increase nitrogen elimination
A
- lactulose (1st line): gut acidification to decrease ammonia absorption, titrate to 2-3 BMs per day
- rifaximin: goal is to decontaminate the bowel
21
Q
protein restrictions and HE
A
- only useful when there is excessive intake of protein
22
Q
MOA of lactulose
A
- induces osmotic diarrhea
- traps nitrogen in stool
- lowers pH and reduces ammonia absorption
