ACR Appropriateness Criteria for abnormal liver function tests
Ultrasound first-line
CT as second-line problem solving
Ultrasound
Right upper quadrant ultrasound with Doppler
First-line imaging
Exclude biliary obstruction
Assess hepatic vasculature for Budd-Chiari
Expected acute hepatitis findings
Hepatomegaly and periportal edema
Gallbladder wall thickening
Chronic disease features
Nodular contour
Splenomegaly and ascites
Performance and guidance
Sensitivity for biliary dilation
Operator dependent
Limited by body habitus and bowel gas
Elastography caution
Inflammation falsely elevates stiffness
Not useful in the acute setting
Disposition
Level of care selection
Admission indications
Coagulopathy or encephalopathy
INR above 1.5
Any encephalopathy even subtle
Inability to maintain oral intake
Intractable vomiting
Dehydration requiring IV fluids
Deep jaundice with worsening trajectory
Bilirubin above 171 umol/l and rising
Hypoglycemia or renal insufficiency
High-risk comorbidity
Pre-existing liver disease
Immunosuppression or pregnancy
Transfer and ICU criteria
Transfer to transplant center for ALF
Coagulopathy plus encephalopathy
Viral ALF spontaneous survival about 25 percent
ICU admission
Grade III to IV encephalopathy
Hemodynamic instability
Discharge criteria and follow up
Outpatient criteria
Synthetic function preserved
INR below 1.5
Normal mental status
Tolerating oral intake
Adequate hydration
No persistent vomiting
Reliable follow up and return precautions understood
Stable or improving transaminases
Caregiver support
Follow-up plan
Recheck liver enzymes and INR within 1 to 2 weeks
Repeat at 4 to 6 weeks to confirm resolution
Hepatology linkage
Virus-specific surveillance
HBsAg at 6 months to confirm clearance versus chronicity
HCV RNA at 12 to 16 weeks
Public health reporting
Acute hepatitis A, B, C reportable in all US states
Contact tracing
Treatment
Initial stabilization
Supportive measures
IV fluids for dehydration
Correct electrolyte abnormalities
Treat hypoglycemia with dextrose
Antiemetics for nausea and vomiting
Ondansetron 4 mg IV every 8 hours as needed
Avoid hepatotoxic alternatives
Avoid hepatotoxic medications
Hold or limit acetaminophen to under 2 g per day
Avoid NSAIDs and statins
Discontinue herbal and dietary supplements
Acute liver failure management
If ALF criteria met, intensive support
N-acetylcysteine
Improves transplant-free survival in early coma grades even in non-acetaminophen ALF
IV loading 150 mg/kg over 1 hour
Then 12.5 mg/kg/hour for 4 hours
Then 6.25 mg/kg/hour maintenance
ICU admission and transplant referral
Early transplant center contact
Intracranial pressure monitoring if grade III to IV
Glucose and coagulopathy support
Continuous dextrose for hypoglycemia
Vitamin K and reserve plasma for active bleeding
Virus-specific therapy
HAV and HEV
Supportive care only
Self-limited in over 99 percent of HAV
No specific antiviral therapy
Ribavirin for severe or chronic HEV
Immunocompromised host
Specialist guided
HBV
Supportive in most cases
Over 95 percent spontaneous recovery in adults
Interferon-alpha contraindicated in acute HBV
Nucleoside or nucleotide analogue if severe or protracted
Entecavir 0.5 mg PO daily
Tenofovir disoproxil fumarate 300 mg PO daily
Indicated for INR above 1.6, bilirubin above 171 umol/l, or encephalopathy
HCV and HDV
HCV direct-acting antivirals
Sofosbuvir-velpatasvir one tablet PO daily for 12 weeks
May defer 12 to 16 weeks for spontaneous clearance
HDV management
Treat underlying HBV
Bulevirtide for chronic HDV
Post-exposure prophylaxis
HAV prophylaxis
Vaccine for healthy contacts
Within 2 weeks of exposure
Single antigen HAV vaccine
Immune globulin
Add for age over 40, immunocompromised, chronic liver disease
0.1 mL/kg IM
HBV prophylaxis
Unvaccinated exposed contacts
Hepatitis B immune globulin 0.06 mL/kg IM
Plus HBV vaccine series
Neonates of HBsAg-positive mothers
HBIG plus vaccine within 12 hours of birth
Complete vaccine series
Special Populations
Pregnancy
Pregnancy considerations
HEV severity in pregnancy
Up to 25 percent mortality in third trimester
Aggressive monitoring and transfer
Vertical transmission risk
HBV perinatal transmission high without prophylaxis
Neonatal HBIG plus vaccine
Antiviral safety
Tenofovir preferred antiviral in pregnancy for HBV
Avoid ribavirin due to teratogenicity
Maternal monitoring
Serial INR and mental status
Obstetric and hepatology co-management
Geriatric
Older adult features
Higher severe disease risk
Age over 40 increases HAV severity
Pre-existing liver disease prevalence
Atypical presentation
Delirium as encephalopathy
Blunted febrile response
Medication and comorbidity
Polypharmacy with hepatotoxins
Dose adjustment for renal function
Disposition bias toward admission
Limited physiologic reserve
Dehydration risk
Pediatrics
Pediatric differences
Milder typical course
HAV often anicteric in young children
HBV chronicity higher in perinatal infection
Acute hepatitis of unknown cause
Adenovirus association investigated
Exclude metabolic disease
Weight-based supportive dosing
Ondansetron 0.15 mg/kg IV per dose
Maintenance dextrose-containing fluids for hypoglycemia
Vaccination and prophylaxis
Routine HAV and HBV immunization
Birth-dose HBV vaccine
Background
Epidemiology
Burden and distribution
Etiology varies by region and risk
HAV and HEV fecal-oral
HBV, HCV, HDV parenteral and sexual
Outbreak patterns
HAV foodborne and community outbreaks
Person-to-person spread in unvaccinated populations
Chronicity rates
HBV about 5 percent chronicity in adults
HCV about 55 to 85 percent chronicity
Severity epidemiology
ALF incidence
Under 1 percent in HAV
0.1 to 0.5 percent in HBV
Spontaneous clearance
About 25 percent in acute HCV
Over 95 percent recovery in acute HBV adults
Pathophysiology
Mechanisms of injury
Immune-mediated hepatocyte injury
Cytotoxic T-cell response
Necroinflammation
Cholestatic component
Canalicular dysfunction
Pruritus and acholic stools
Synthetic failure in severe disease
Coagulopathy from reduced clotting factor synthesis
Hypoglycemia from impaired gluconeogenesis
Clinical course phases
Prodromal to icteric to convalescent
Prodrome 1 to 2 weeks
Convalescence weeks to months
Atypical courses
Cholestatic prolonged jaundice in HAV
Relapsing in 10 to 15 percent of HAV
Biphasic with HDV coinfection
Therapeutic Considerations
Treatment principles
Supportive care is the foundation
Hydration and antiemetics
Avoidance of hepatotoxins
Antiviral reserved by virus
HBV antivirals for severe or protracted course
HCV DAAs with possible deferral for spontaneous clearance
N-acetylcysteine in early ALF
Benefit greatest at low coma grades
Bridge to recovery or transplant
Prevention as therapy
Vaccination
HAV and HBV vaccines
Post-exposure prophylaxis programs
Transmission counseling
Hand hygiene for HAV and HEV
Barrier protection and no needle sharing
Patient Discharge Instructions
copy discharge instructions
Home care
Rest and stay well hydrated
Eat small frequent meals if nauseated
Avoid alcohol completely until full recovery
Avoid acetaminophen and other liver-stressing medicines and supplements
Return to ER immediately for
Confusion, excessive drowsiness, or personality change
Worsening yellow skin or eyes, very dark urine, or pale stools
Inability to keep fluids down
Easy bruising or bleeding
Abdominal swelling
Preventing spread
Wash hands well after using the toilet
Do not share needles, razors, or toothbrushes
Use barrier protection during sex until cleared
Hepatitis A is generally noninfectious about 1 week after jaundice starts
Follow up
Repeat blood tests within 1 to 2 weeks
See liver specialist as arranged
Most hepatitis A recovers within 2 months
Some people have prolonged symptoms up to 6 months
References
Guidelines and key sources
Guideline sources
AASLD acute liver failure guidelines
AASLD hepatitis B guidance
ACG evaluation of abnormal liver chemistries
ACOG viral hepatitis in pregnancy clinical practice guideline
Evidence summaries
Reviews on hepatitis A and E treatment options
Cochrane review of pharmacologic interventions for acute hepatitis B
ACR Appropriateness Criteria for abnormal liver function tests
Coding standards
ICD-10 B15 to B17 acute viral hepatitis codes
SNOMED CT acute viral hepatitis concept
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.