IBCC Acute liver failure

Question 1

What is the definition of acute liver failure?

Answer 1

1) synthetic liver dysfunction (INR > 1.5) with encephalopathy, 2) no underlying cirrhosis 3) hepatic encephalopathy beginning w/in < 12 weeks.

Question 2

what are the grades of hepatic encephalopathy?

Answer 2

grade 1 - altered behavior w/ normal consciousness/reduced attention span, grade 2 - altered behavior w/ disorientation/drowsiness, grade 3 - confused, incoherent, somnolent but arousable, grade 4 - comatose and unresponsive

Question 3

what are the neuroimaging findings in acute hyperammonemic encephalopathy?

Answer 3

MRI - T2/flair hyperintensity of insular gyri and cingulate gyri. May also involve the thalami, posterior limb of the internal capsule, dorsal brainstem, and sometimes periventricular white matter

Question 4

what are the etiologies to consider for acute liver failure

Answer 4

tylenol, drugs (anti-microbials, chemo, statins, NSAIDS, phenytoin, carbamazepine), substance use (cocaine, MDMA), mushrooms/supplements, viral hepatitis (HAV, HBV > HEV, HCV), HSV, EBV, CMV, VZV, auto immune

less common - wilsons, budd-chiari, pregnancy (HELPP, pre-eclampsia), ischemic, hyperthermia, malignant, VOD s/p BMT, HLH, reyes syndrome

Question 5

What is the major cardiovascular consequence of acute liver failure and what are the major considerations.

Answer 5

Hypotension as a result of a vasodilatory state (ie distributive picture).

Apart from evaluating for concurrent infection, major considerations are 1) use levophed for MAP goal 75 (to protect cerebral perfusion pressure and kidneys), 2) use 5% albumin for fluid resuscitation PRN, 3) consider SDS given higher prevalence of AI in liver patients

Question 6

What are the GI considerations for acute liver failure?.

Answer 6

stress ulcer ppx. hold nutrition if ammonia is >150.

Question 7

what is the justification for early RRT in acute liver failure?

Answer 7

for clearance of ammonia (?target <100), which is a risk factor for elevated ICP and herniation

Question 8

what are the management considerations for ICP elevation?

Answer 8

low-normal pCO2, high-normal Na, avoid fever, avoid hypoglycemia, EEG/propofol usage, maintain CCP >60, RRT for elevated ammonia

Question 9

what treatment should be given regardless of the etiology of the liver failure? What are other considerations (ie other treatment options for other etiologies?)

Answer 9

NAC

Others include - acyclovir for HSV (or other anti-viral therapies), steroids for alcohol (controversial) or auto-immune