Acute Liver Failure in Children

Definition

• INR >2.0 in the absence of encephalopathy, or
• INR >1.5 with hepatic encephalopathy present

Etiology — Pediatric-Specific

• Neonates/infants: HSV, galactosemia, tyrosinemia, neonatal hemochromatosis, mitochondrial disease, HLH
• Older children: Wilson disease, autoimmune hepatitis, acetaminophen toxicity, viral hepatitis
• Adolescents: Acetaminophen (often intentional overdose), Wilson disease, autoimmune hepatitis

• Alkaline phosphatase/bilirubin ratio <4 (sensitivity 92%, specificity 96%)
• AST/ALT ratio >2.2 — combined with above approaches 100% sensitivity/specificity
• Low ceruloplasmin (though unreliable — also low in 50% of non-Wilson ALF due to poor synthesis)
• Hemolytic anemia + renal failure + deep jaundice = pathognomonic triad

Clinical Presentation & History

• Neurologic status (encephalopathy grade)
• Hepatosplenomegaly, ascites
• Bruising/petechiae (coagulopathy)
• Slit-lamp exam (Kayser-Fleischer rings for Wilson disease)
• Signs of chronic liver disease (palmar erythema, clubbing, xanthomas, prominent abdominal vessels) — their presence suggests preexisting disease

Diagnostic Workup

Pathophysiology of Complications

1. Hepatic Encephalopathy & Cerebral Edema

• Grade 1: Mild confusion, altered sleep
• Grade 2: Lethargy, disorientation
• Grade 3: Marked confusion, stupor but arousable
• Grade 4: Coma

2. Coagulopathy

3. Acute Kidney Injury

4. Infection/Sepsis

5. Metabolic Disturbances

Management

ICU Admission — Mandatory

Specific Therapies

Management of Complications

• Head of bed elevated 30°
• Minimize stimulation; sedation/paralysis if needed
• ICP monitoring (in centers with experience) — guides osmotherapy
• Mannitol 0.5–1 g/kg IV bolus for ICP spikes
• Hypertonic saline to maintain serum sodium 145–155 mEq/L
• Avoid lactulose (no proven benefit in ALF)
• Head CT only modestly sensitive early; useful to rule out hemorrhage; if edema evident on CT → irreversible injury likely → transplant contraindicated

• Dextrose-containing IV fluids (prevent/treat hypoglycemia)
• Correct electrolytes, especially phosphorus and magnesium
• Avoid sedatives that worsen encephalopathy

• CRRT preferred; norepinephrine if MAP <50 mmHg (best cerebral perfusion, least hepatic flow compromise)

• Vitamin K IV (rule out deficiency)
• FFP/platelets only for active bleeding or procedural cover
• Avoid prophylactic correction — masks prognostic markers

Prognosis & Liver Transplantation

• Acetaminophen: pH <7.30 (after resuscitation), or PT >100 s + Cr >3.4 mg/dL + grade 3–4 encephalopathy
• Non-acetaminophen: INR >6.5, or ≥3 of: unfavorable etiology (drug/idiopathic/Wilson), age <10 or >40, jaundice-to-encephalopathy interval >7 days, INR >3.5, bilirubin >17.4 mg/dL

Indeterminate PALF

Clinical Analysis: 10-Year-Old with 3 Weeks Jaundice

Interpreting the Clinical Picture First

Critical point: This child meets ALF criteria (deranged LFTs + coagulopathy not correctable by Vit K + structural changes on imaging). With 3 weeks of jaundice and no encephalopathy yet, this is subacute liver failure — which carries a worse prognosis than acute if medical therapy fails, with less propensity for cerebral edema but much poorer spontaneous recovery.

Top Differential Diagnoses (Age 10, Subacute)

🔴 #1 Priority: Wilson Disease — Must Rule Out Urgently

• Age 10 + jaundice + coagulopathy + ascites
• Can mimic autoimmune hepatitis or viral hepatitis
• Fulminant Wilson occurs in up to 12% — manifests as acute icteric hepatitis → coagulopathy + extreme jaundice + ascites + renal failure
• Fatal without liver transplantation

• ALP/Bilirubin ratio: if <4 → highly specific for Wilson (sensitivity 92%, specificity 96%)
• AST/ALT ratio: if >2.2 → combined with above approaches 100% specificity
• Serum copper (elevated in fulminant Wilson due to massive hepatic release)
• Serum ceruloplasmin (unreliable — low in 50% of any ALF due to poor synthesis)
• Slit-lamp exam for Kayser-Fleischer rings (absent in up to 50% of fulminant cases — don't rely on it)
• Coombs-negative hemolytic anemia (very characteristic)
• Urine copper 24-hour

🟠 #2: Autoimmune Hepatitis (AIH)

• Can present identically — subacute jaundice + coagulopathy in a child
• Wilson disease and AIH are often indistinguishable clinically; Wilson can even have positive autoantibodies (ANA, ASMA) at low titers
• Send: ANA, anti-smooth muscle antibody (ASMA), anti-LKM1, IgG levels

🟡 #3: Viral Hepatitis (HBV, HAV, HEV)

• Check: HBsAg, anti-HBc IgM, anti-HAV IgM, anti-HEV IgM (especially if endemic region)
• HBV can cause subacute liver failure in children

🟡 #4: Drug-Induced / Herbal Toxicity

• Always ask about paracetamol (even accidental), antiepileptics, herbal/ayurvedic medicines
• Serum paracetamol level

🟢 #5: Metabolic / Mitochondrial (less likely at age 10 with 3-week history)

• Consider if standard workup negative

Immediate Workup to Order

Blood Tests (STAT)

• Serum copper + ceruloplasmin (Wilson screen)
• 24-hour urine copper (if feasible)
• ALP/Bilirubin ratio — calculate from current values
• AST/ALT ratio — calculate now
• AST, ALT, GGT, ALP, Total/Direct bilirubin (if not already detailed)
• CBC with peripheral smear — look for hemolytic anemia (Coombs-negative in Wilson)
• Direct Coombs test
• Reticulocyte count
• BMP (creatinine — renal function critical in Wilson)
• Ammonia
• ANA, ASMA, anti-LKM1, IgG (autoimmune panel)
• HBsAg, anti-HBc IgM, anti-HAV IgM, anti-HEV IgM
• Serum ferritin (HLH screen if other features present)
• Urine toxicology, serum paracetamol level
• Factor V, Factor VII (prognostic markers)
• Serum uric acid (low in Wilson due to renal tubular losses)

Imaging

• Repeat USG abdomen with Doppler (portal vein patency, hepatic veins — rule out Budd-Chiari)
• Head CT if encephalopathy develops

Other

• Slit-lamp examination (ophthalmologist)
• Liver biopsy (transjugular if INR too high) — once Wilson/AIH suspected, histology + hepatic copper quantification is gold standard

Current Status Assessment

Immediate Management

1. Admit to ICU / Hepatology ward with close monitoring

• Neurological status q4h (watch for early encephalopathy: irritability, sleep changes, behavioral change)
• Blood glucose monitoring (4-hourly — hypoglycemia is a risk)
• Strict fluid balance + urine output
• Daily INR, LFTs, ammonia, renal function

2. IV Vitamin K

• 1–5 mg IV (single dose) — to exclude Vitamin K deficiency as a cause of coagulopathy
• If INR does not correct → confirms true hepatic synthetic failure

3. Do NOT give FFP unless active bleeding or before invasive procedure

• INR is your prognostic marker — correcting it masks disease severity

4. Nutrition

• Adequate calories via NG if needed
• Do NOT restrict protein significantly in children

5. Treat the underlying cause once identified:

• Wilson ALF → urgent listing for liver transplant + consider plasmapheresis/CVVH as bridge (no D-penicillamine in fulminant — worsens outcomes)
• AIH → IV methylprednisolone 1–2 mg/kg/day (but avoid steroids if Wilson not excluded)
• HBV → Entecavir

6. Refer NOW to liver transplant center

• Do not wait for etiology confirmation if deteriorating
• Wilson disease causing ALF = fatal without transplant

Key Diagnostic Calculation (Do Right Now)

If ALP (IU/L) ÷ Total Bilirubin (mg/dL) < 4 → strongly suggests Wilson disease If AST ÷ ALT > 2.2 → combined sensitivity/specificity approaches 100% for Wilson-ALF

Bottom Line

1. It is universally fatal without liver transplantation
2. Standard chelation therapy (D-penicillamine) is contraindicated in fulminant Wilson
3. The window for transplant listing is narrow

Reassessment: Alert Child, No Encephalopathy

Strict Criteria Review

What the Absence of Encephalopathy Tells You

• Brain not yet affected → better prognosis if cause identified and treated promptly
• More time to establish etiology before emergency transplant listing
• Subacute presentation (3 weeks) with no encephalopathy → child may still recover spontaneously with the right treatment

• INR is rising (synthetic failure is real)
• Ascites is new — portal hypertension developing
• Bilirubin 20 with 3 weeks jaundice = significant hepatocellular dysfunction
• Wilson disease and AIH can deteriorate within hours to days
• Encephalopathy can appear suddenly as INR climbs further

Revised Priority Diagnosis

🔴 1. Wilson Disease

• Subacute presentation: jaundice + coagulopathy + ascites before encephalopathy fits perfectly
• Up to 30% of Wilson patients present as chronic hepatitis progressing subacutely with portal hypertension
• The ascites here suggests underlying cirrhosis (Wilson causes cirrhosis even in first presentation) — this is acute-on-chronic Wilson

🟠 2. Autoimmune Hepatitis (AIH)

• Very common at age 10, especially girls
• Subacute jaundice + moderate coagulopathy + ascites
• Treatable — steroids can achieve remission if Wilson excluded
• If this is AIH and you treat correctly → child can fully recover without transplant

Your Immediate Priority List

Step 1 — Calculate RIGHT NOW from available results

ALP ÷ 20 — if result <4, strongly suspect Wilson disease

Step 2 — Tests to send today

Step 3 — Imaging

• Doppler USG of hepatic and portal veins (Budd-Chiari, portal thrombosis)
• Look for echogenic liver, nodularity → chronic disease suggesting Wilson cirrhosis

Holding Management Right Now

Decision Tree Based on Results

ALP/Bilirubin <4 AND/OR Coombs-neg hemolysis
        ↓
  Wilson Disease → Urgent transplant center referral
  No D-penicillamine, consider plasmapheresis as bridge
  
ANA/ASMA positive + IgG elevated + Wilson excluded
        ↓
  Autoimmune Hepatitis → Liver biopsy → IV methylprednisolone
  1–2 mg/kg/day, add azathioprine once LFTs improve

All negative
        ↓
  Viral screen, drug history, metabolic screen
  Consider transjugular liver biopsy

When to Escalate to Transplant Listing

• INR rises to >2.0
• Any encephalopathy appears (even subtle — sleep inversion, mood change)
• Creatinine rises (hepatorenal syndrome)
• Bilirubin continues climbing despite treatment
• Factor V <20–25% of normal