Acute Liver Failure

Question 1

How is it defined?

Answer 1

• Definition: onset of liver symptoms (usually jaundice) at least 8 wks b/f altered mental status and sig coagulopathy w/o pre-existing liver disease
  
  • Hyper-acute: < 7 days
  • Acute: 8-28 days
  • Subacute: 29-72 days

Question 2

7 Common Causes

Answer 2

• Acetaminophen (50% of cases)
• Viral Hep (Hep A, B, D, E and EBV not Hep C)
• Hypoperfusion / shock liver from CHF
• Wilson’s Disease
• Autoimmune Hep
• Pregnancy (HELLP - acute fatty liver of pregnancy)
• Idiosyncratic drug reactions or toxins

Question 3

Outcomes

Answer 3

• 2/3 survive w/ supportive care alone (no transplant)
• Cerebral edema = #1 cause of death
• Worse outcomes post-transplant than those w/ chronic liver disease
• Age does NOT affect outcome

Question 4

King’s Criteria for Prediction of Non-survival

Answer 4

• If acetaminophen … arterial pH OR serum creatinine, INR and hep encephalopathy
• If not acetaminophen … INR OR young/old age, certain etiology (Hep C, Hep D, Hep E, halothane, drugs), progress form jaundice to encephalopathy in < 7 dys, INR still high and high bilirubin

Question 5

Management

Answer 5

NEED TRANSPLANT
- MELD score does not apply; status 1 for transplant

• ICU w/ multi-disciplinary team (manage mult complications)
• Short window of hrs to days

Question 6

Renal Complications

Answer 6

• Why? -B/c less renal blood flow, acetaminophen kidney toxicity and rhabdomyolysis
• acidosis, hypophosphate, hyper or hypokalemia, resp alk, hyper or hyponatremia, hypocalcemia + low urine vol, low urine sodium, RAAS
• Cont veno-venous hemodialysis to remove excess fluids and toxins

Question 7

Neuro Complications

Answer 7

• cerebral hyper or hypo perfusion, clinical or subclinical seizures, intracranial HTN –> compression and death, intracerebral hemorrhage, encephalopathy (so must protect airway)
• Monitor cerebral pressure (bolt placed) and manipulate (30 deg head elevation, BP control, avoid suction, mannitol, hypothermia, barb coma to dec EEG bursts, hyperventilation)

Question 8

3 Drugs for Encephalopathy

Answer 8

• Lactulose- to remove NH3 by ion trapping (NH3 –> NH4+) so not absorbed in colon and inhibit urea splitting bacteria in colon
• Neomycin - non-absorbable abx that inhibits urea-splitting bacteria
• Flumazenil - antagonizes false neurotransmitters (may cause seizures)

Question 9

Heme Complications

Answer 9

• dec clotting factors (I, II, V, VII, IX, X) and clotting factor consumption (DIC), thromboytopenia
• Can lead to spont hemorrhage in procedures

Question 10

3 Other Complications

Answer 10

Shock, ARDS, hypoglycemia