Liver Failure Flashcards
Definition
AASLD: illness < 26 weeks, coagulopathy (INR >1.5) not corrected by vitamin K. Encephalopathy (any degree). Can include Wilson’s, Autoimmune hepatitis, or vertical Hep B even with cirrhosis if <26 weeks.
PALF: biochemical evidence of liver injury, no chronic liver disease. INR >1.5 with encephalopathy. INR >2 without encephalopathy.
Physiology of Liver failure
- Loss of synthetic function: coagulopathy, hypoalbuminemia
- Abnormal glucose homeostasis: hypoglycemia
- Inability to maintain acid-base: acidosis.
- Poor bile synthesis and excretion: cholestasis
- Decreased urea cycle function: hyperammonemia
- Decreased ability to clear toxins: encephalopathy.
Liver failure DDX
- Infectious
- Vascular/circulatory: Shock, Budd-chiari
- DILI: Tylenol, anticonvulsants, antibiotics, mushrooms
- Infiltrative (leukemia, lymphoma)
- Idiopathic
- Metabolic
- Inflammatory
Infectious Causes of liver failure
- Hep A, B, E
- HSV in infants
- HSV/VZV in immunosuppressed.
Most common cause of liver failure in ICU
- Shock liver, usually after an episode of compromised perfusion
DILI
- Tylenol MCC of Dili
- Valproate can uncover mitochondrial disease (POLG mutation)
- Abx: INH, Rifampin, Augmentin
Wilson’s disease presentation of ALF
- Low all phos, high bill, hemolysis, neuropsychological issues.
- Ratio of all phos to bile will be low.
Galactosemia cause of ALF
- Associated with Gram negative sepsis in infant.
Tyrosinemia
-Disproportionate coagulopathy in neonate
Urea cycle defect in ALF
OTC deficiency is most common
X-linked, think baby boy
Fructose intolerance in ALF
- exposure to sucrose
Mitochondrial disease
- multisystem disease
- high lactate
HLH
- fever, multisystem involvement, high triglycerides, high ferritin, cytopenias, HSM
GALD
- Apparent Fe overload, recurs in later pregnancies, high ferritin/AFP, low ALT, bad synthetic function
Acetaminophen induced liver failure
- Dose dependent
- Conversion of acetaminophen to NAPQ1 is a reactive intermediate that is hepatoxic.
- Rumack nomogram: used after a single point in time injury
- level at 4 hours s/p ingestion
- determines risk for injury, not prognosis
- usually very high transaminases, low bile, renal injury can also occur
AKI in ALF
AKI occurs in 10-20% of kids with ALF
- functional kidney failure: renal vasoconstriction causing decreased renal perfusion
- ATN/hypovolemia
- Nephrotoxic drugs
- Tylenol injury.
In most cases the AKI resolves with liver transplantation
Prognosis of ALF
- Good etiologies: Tylenol, Hep A, shock.
- High grade encephalopathy is worse
- Kings College Criteria: if acetaminophen over dose, acidosis is, grade 3/4 encephalopathy and INR >6.4 are all bad.
if non-acetaminophen: INR >6.5, encephalopathy, jaundice, very high bili, very young/very old
When to do wedge pressure
- when you need to prove portal HTN.
