JH IM Board Review - Acute and Chronic Liver Disease I Flashcards
Evaluation of elevated liver tests - When to fully evaluate?
Persistently or markedly (more than 10 times normal for aminotransferases or more than 4 times normal for alkaline phosphatase [AP]) elevated liver tests should ALWAYS BE FULLY EVALUATED.
AST and ALT values can guide us how?
Greater than 1000 IU/mL ==> Indicative of ACUTE viral, toxic, or ischemic hep.
==> Alcoholic hep almost NEVER raises aminotransferases above 400 IU/mL.
Which tests are the liver function tests and what do they reflect?
- Bilirubin.
- PT.
- Albumin.
==> REFLECT SYNTHETIC CAPACITY OF THE LIVER.
ALBUMIN HALF-LIFE:
3 WEEKS.
Contrary to the popular term “LFTs” …?
Aminotransferases and AP are NOT true liver function tests.
Dx - Investigating elevated liver enzymes - 1st step:
- Look at PATTERN of elevation ==> Dictates the evaluation process and diseases to be considered.
- A careful history and a review of patient’s medications, both prescribed + OTC, are CRITICAL.
Dx - Investigating elevated liver enzymes - Elevated aminotransferases should first be evaluated by …?
Serologic and biochemical tests.
Dx - Investigating elevated liver enzymes - Elevated bilirubin OR AP should be evaluated by an …?
US of the biliary tree + Anti-mt antibody.
Dx - Investigating elevated liver enzymes - If ascites is present …?
DOPPLER studies of hepatic veins to r/o outflow obstruction of the liver.
Dx - Investigating elevated liver enzymes - When to liver Bx?
Should be considered when diagnostic confirmation in required or if serologic and biochemical tests have NOT revealed the cause of the liver enzyme abnormality.
Elevated AP + GGT or 5-nucleotidase - What to do next?
- US (w/ Doppler if ASCITES present) + AMA.
- If AMA (+) or US normal ==> LIVER Bx.
- If AMA (-) or US shows dilated ducts ==> MRCP +/- ERCP.
Elevated AST and ALT - What to do next?
- Viral serologies, ANA, SMA, Iron studies, ceruloplasmin, AAT.
- Bx if above not helpful or to stage disease.
Summary of common liver disorders - Autoimmune hep:
- Elevated AST, ALT.
- Dx ==> ANA, SMA, Igs.
- Give prednisone + aza, transplant.
Summary of common liver disorders - PBC:
- Elevated AP.
- AMA.
- UDCA, transplant.
Summary of common liver disorders - PSC:
- Elevated AP.
- ERCP, MRCP, pANCA.
- Stenting of strictures, transplant.
Acute liver failure (ALF) is defined as …?
An onset of coagulopathy (ie INR >1.5) and encephalopathy within 26 WEEKS of disease presentation + WITHOUT Hx of liver disease.
==> Jaundice is often present as well.
MCC of ALF in the USA and Worldwide?
USA ==> Acetaminophen (35-40%).
Worldwide ==> Viral hep.
No specific cause of ALF is identified in approx. …% of cases.
20%.
ALF presentation - Pts may present with encephalopathy, the severity of which is related to …?
THE PRESENCE OF CEREBRAL EDEMA.
==> Cerebral edema can result in BRAINSTEM HERNIATION ==> LEADING CAUSE OF DEATH IN ALF.
ALF presentation - Patients who present with jaundice and then develop encephalopathy after several days have …?
WORSE PROGNOSIS.
ALF Presentation - Other important key points:
- Often complicated by SEPSIS, MULTI-ORGAN FAILURE (renal failure, pancreatitis), GI BLEEDING, COAGULOPATHY ==> Spontaneous hemorrhage.
- Widespread hepatocyte necrosis leads to loss of glycogen stores and impaired gluconeogenesis, causing HYPOGLYCEMIA.
ALF - Prognosis can be made using which criteria?
- King’s college criteria.
2. Clichy criteria.
King’s college criteria - Indicators of poor prognosis in ALF - Acetaminophen toxicity:
Arterial pH <7.3 after adequate fluid resuscitation OR all of the following within a 24h period:
- PT >100 (INR >6.5).
- Serum Cr >3.4mg/dL.
- Grade 3 to 4 HE.
King’s college criteria - Indicators of poor prognosis in ALF - NON-acetaminophen causes of ALF:
PT >100sec (INR >6.5) and HE (irrespective of grade). OR ANY 3 of the following:
- Wilson, idiosyncratic drug reaction, seronegative, or indeterminate hepatitis.
- Jaundice >7days before HE.
- Age <10 OR >40.
- PT >50 (INR >3.5).
- Bilirubin >17mg/dL.
ALF - Tx - Monitor which parameters?
- PT.
- pH.
- Glucose.
- Liver enzymes.
- Cultures.
- Fluid and electrolytes balance + CVP.
ALF - Tx - What to give?
- Enteral feeding, dextrose infusion, thiamine.
- PPI or H2 antagonists.
- N-acetylcysteine for ALL causes.
ALF - Tx - Mechanical ventilation?
To protect airways in pts with delirium.
ALF - Tx - Other important actions to take?
- Elevate head of bed.
- Hyperventilate initially.
- Induce hypothermia.
- Administer mannitol if serum osmolarity is less than 320 mOsm to keep ICP low; avoid procedures that may elevate the ICP.
- ICP monitor, when available, should be used to monitor perfusion pressures and ICP.
- Continuous venovenous hemofiltration for renal failure.
ALF - Tx - Clotting factors:
Incl. recombinant VII ==> ONLY FOR ACTIVE BLEEDING or before invasive procedures.
ALF - Tx - Disease-specific Tx?
- Penicillin G and silibinin for Amanita poisoning.
- Acyclovir for herpes hep.
==> There is some evidence that supports empiric use of acyclovir in idiopathic cases.
ALF - Tx - Transplantation:
Early transfer to liver transplantation center results in improved survival.
Drug-induced liver injury (DILI):
- MCC of ALF (>50%) in the USA.
- 6% of all adverse reactions involve the liver.
- DILI is the MC REASON for postmarketing withdrawal of medications.
- Reactions can be dose-dependent OR idiosyncratic.
DILI - Symptoms:
Range from ASYMPTOMATIC to nonspecific complaints, such as fatigue, nausea, vomiting, and/or mild RUQ pain.
DILI - Can follow several patterns of injury:
- Hepatitis.
- Cholestasis.
- Mixed cholestatic hep.
- Progressive bile duct injury ==> VANISHING BILE DUCT SYNDROME.
==> Injury pattern can give clue to offending agent.
Hepatic injury caused by various medications - Nonspecific or viral-like hep?
- Aspirin.
- Amiodarone.
- Diclofenac.
- INH.
- Methyldopa.
- Nitrofurantoin.
- Phenytoin.
- PTU.
- Sulfonamides.
Hepatic injury caused by various medications - Cholestasis:
- Carbamazepine.
- Chlorpromazine.
- Cotrimoxazole.
- Haloperidol.
- TCAs.
- Estrogens.
- 17-alpha steroids.
Hepatic injury caused by various medications - Steatosis:
- Alcohol.
- Prednisone.
- Tetracycline.
- Valproic acid.
- Amiodarone.
- Zidovudine.
Hepatic injury caused by various medications - Granulomatous hepatitis:
- Allopurinol.
- Quinidine.
- Sulfonamides.
- Sulfonylureas.
Hepatic injury caused by various medications - Veno-occlusive disease:
- Antineoplastics.
- Azathioprine.
- Pyrrolizidine alkaloids.
Hepatic injury caused by various medications - Adenomas and HCC:
Estrogens and anabolic steroids.
DILI - Other key features to keep in mind:
- Some cases can be immune-mediated, and HYPEREOSINOPHILIA is present (both in serum and on liver biopsy).
- Most biochem parameters return to normal after eliminating the offending agent.
DILI - Dx:
- Dx OF EXCLUSION: First exclude other more common causes of liver disease.
- Rechallenging with the suspected drug is NOT recommended.
==> If the liver injury is immune-mediated, 2nd exposure may be more severe than the initial episode.
Liver monitoring schedule for hepatotoxic medications - Every month?
- Azathioprine.
- All azoles (eg fluconazole).
- Protease inhibitors.