Quick Answer
Acute liver failure (ALF) is a top NEET PG hepatology case — the definition, aetiology mix, NAC protocol, King's College Criteria and transplant threshold recur every year.
- Definition — jaundice + INR at least 1.5 + hepatic encephalopathy of any grade in a previously healthy liver, within 26 weeks.
- Classify — hyperacute (less than 7 days — paracetamol, hep A/E), acute (7-28 days — hep B, drug), subacute (28 days-26 weeks — drug, autoimmune, indeterminate).
- Indian aetiology mix — hepatitis E (pregnant women worst — up to 20 percent mortality), hepatitis A + B, drug-induced (ATT, ART, herbal), paracetamol overdose (rising), Wilson disease (young + KF ring), pregnancy (HELLP, AFLP).
- NAC — 150 mg/kg over 60 min → 50 mg/kg over 4 h → 100 mg/kg over 16 h; given in ANY ALF (not just paracetamol).
- Do NOT give prophylactic FFP — obscures INR (prognostic marker) and worsens cerebral oedema; reserve for bleeding or pre-procedure.
- King's College Criteria (paracetamol) — pH less than 7.30 OR (INR greater than 6.5 AND creatinine greater than 3.4 mg/dL AND Grade III/IV encephalopathy).
- King's College Criteria (non-paracetamol) — INR greater than 6.5 OR any 3 of (age less than 10 or greater than 40; non-A non-B or drug-induced; jaundice-to-encephalopathy interval greater than 7 days; INR greater than 3.5; bilirubin greater than 17 mg/dL).
- Cerebral oedema management — head up 30 degrees, target Na 145-150, lactulose + rifaximin, mannitol or 3 percent saline for ICP surges; refer for liver transplant at Grade II encephalopathy.
The case
A 32-year-old previously well woman, married and working as a call-centre operator in Chennai, is brought to the medicine emergency by her husband. Four days ago, after a distressing argument, she took an intentional overdose of paracetamol tablets — the packaging suggests approximately 25 grams consumed over roughly 3-4 hours. She initially had only mild nausea and did not seek care. Over the past 48 hours she has developed fatigue and abdominal discomfort in the right upper quadrant, and over the past 24 hours the family has noticed yellowing of the eyes, drowsiness, mood swings, poor concentration, occasional confusion and one episode of aggressive outburst.
Past medical history:
- Depression and anxiety (untreated; declined referral 1 year ago)
- No known chronic liver disease, no prior jaundice
- No known allergy
- No prescription medications
- Occasional social alcohol use
- No IV drug use, no tattoos, no unsafe sex, no blood transfusion
- Not pregnant (LMP 10 days ago; urine pregnancy test negative on triage)
- No traditional Ayurvedic or herbal medications
- No mushroom or wild-plant ingestion
Family history: no liver disease, no Wilson disease, no autoimmune disease.
On examination — ill-looking, jaundiced, restless, drowsy but rousable to voice, mildly agitated when questioned. Grade II hepatic encephalopathy (West Haven scale) — lethargy, mild disorientation to time, personality change, obvious asterixis on wrist extension. Fetor hepaticus noted on approach.
- BP 100/70 (baseline 118/76 per her records), HR 110 regular, RR 22, SpO2 96 percent on room air, T 37.5, capillary refill 2 seconds, warm peripheries
- Icterus — deep yellow sclera, jaundice on skin
- No stigmata of chronic liver disease — no spider naevi, no gynaecomastia, no palmar erythema, no Dupuytren, no caput medusae, no clubbing
- No Kayser-Fleischer ring on slit-lamp examination
- Abdomen — soft, mildly tender in the right hypochondrium, liver not palpable (a shrunken liver is a poor prognostic sign), no palpable spleen, no shifting dullness, bowel sounds normal
- Cardiovascular — mild tachycardia, no murmurs, JVP not raised
- Respiratory — clear vesicular breath sounds, no crackles
- CNS — GCS 13 (E3 V4 M6), disoriented to time (place preserved), asterixis positive, no meningism, no focal deficit, pupils equal 3 mm reactive, plantars downgoing, no clonus
The admitting resident recognises paracetamol-induced acute liver failure with Grade II hepatic encephalopathy and immediately starts IV N-acetylcysteine, IV dextrose for hypoglycaemia, sends urgent labs, contacts the hepatology and liver-transplant units for early transplant assessment.
Initial assessment and the time-critical principle
The single most important principle in this case is that the King's College Criteria trajectory can be met within hours in a hyperacute paracetamol ALF, and early referral for liver transplant listing is the single most important survival lever. Waiting for Grade III/IV encephalopathy or renal failure is waiting too long — many transplant units accept referrals at Grade II.
A — Airway: at risk with worsening encephalopathy; intubate at Grade III-IV.
B — Breathing: RR 22, SpO2 96 percent, no distress currently.
C — Circulation: mildly hypotensive relative to baseline, tachycardic, warm peripheries — early distributive pattern from cytokine release.
D — Disability: GCS 13, Grade II encephalopathy, hypoglycaemia already detected on triage.
E — Exposure: no rash, no needle marks, no signs of self-harm elsewhere.
Tier 1 investigations (immediate)
- AST 8,500 U/L, ALT 9,200 U/L — massive hepatocellular necrosis (values greater than 1,000 in paracetamol are classic)
- Bilirubin 12 mg/dL (mostly conjugated)
- Albumin 3.4 g/dL (mildly reduced)
- INR 4.5, PT 45 s, aPTT 55 s — severe coagulopathy
- Glucose 45 mg/dL — hypoglycaemia (critical) — start 10 percent dextrose infusion immediately
- Creatinine 2.2 mg/dL, urea 78 mg/dL — AKI from hepatorenal syndrome or ATN
- Sodium 135 mmol/L, potassium 4.5, phosphate 1.5 mg/dL, magnesium 1.4 mg/dL — repleted aggressively
- Lactate 5 mmol/L — poor prognostic marker (persistent lactate greater than 3.5 after resuscitation is a KCC-supporting criterion)
- ABG — pH 7.30, HCO3 15, pCO2 30 (metabolic acidosis with respiratory compensation)
- Arterial ammonia 180 micromol/L — very high; risk of cerebral oedema at greater than 150-200
- Paracetamol level 40 microgram/mL at ~100 hours post-ingestion — below the Rumack-Matthew treatment line at this time (nomogram valid only up to 24 hours; late presentation warrants treatment regardless of level)
- Hepatitis serology — HAV IgM negative, HBsAg negative, anti-HBc IgM negative, HCV Ab negative, HEV IgM negative
- Ceruloplasmin, 24-hour urinary copper — sent (Wilson screen); slit-lamp for KF ring negative
- ANA, anti-smooth muscle, anti-LKM, IgG — sent (autoimmune hepatitis screen)
- Pregnancy test — negative
- HIV test — negative
- USG abdomen with Doppler — small liver (approximately 9 cm span), no ascites, patent hepatic veins and portal vein, no biliary dilatation, no focal lesion
- CXR — clear
- CT head — no acute intracranial haemorrhage; no gross cerebral oedema on this scan (early stage)
Interpretation: paracetamol-induced hyperacute liver failure, day 4 post-ingestion, Grade II encephalopathy, INR 4.5, creatinine 2.2, lactate 5, arterial ammonia 180, hypoglycaemia. Currently NOT yet meeting full King's College Criteria for paracetamol ALF but rapid escalation likely; initiate NAC, correct hypoglycaemia, refer to liver transplant unit immediately.
The diagnostic and classification workflow
NEET PG tests the ALF definition, the temporal subclassification, aetiology, King's College Criteria and NAC dosing heavily.
O'Grady temporal classification
| Category | Jaundice-to-encephalopathy interval | Typical aetiology | Cerebral oedema risk | Transplant-free survival |
|---|
| Hyperacute | less than 7 days | Paracetamol, hepatitis A, hepatitis E | High | Best (30-40 percent) |
| Acute | 7-28 days | Hepatitis B, drug-induced | Intermediate | Intermediate |
| Subacute | 28 days to 26 weeks | Drug-induced, autoimmune, indeterminate | Low | Worst (less than 15 percent) |
Aetiology in the Indian context
| Cause | Notes |
|---|
| Hepatitis E | Pregnant women worst affected — up to 20 percent mortality; enteric transmission; outbreak-prone (Delhi 1955, Kanpur 1991, Ahmedabad 2004) |
| Hepatitis A | Increasing in adults as childhood exposure declines |
| Hepatitis B | Reactivation on chemotherapy or immunosuppression; seroconversion; acute fulminant |
| Paracetamol overdose | Rising in urban India; often intentional |
| Drug-induced (DILI) | ATT (INH + rifampicin + pyrazinamide — pyrazinamide and INH the main culprits), ART, phenytoin, valproate |
| Herbal / traditional medicine | Ayurvedic medicines with heavy metals or hepatotoxic plants (kombucha, kava, Chinese herbs); big Indian problem |
| Wilson disease | Young patient + KF ring + haemolysis + very high bilirubin/AP ratio + low ceruloplasmin + high urinary copper |
| Autoimmune hepatitis | Females, ANA/ASMA/anti-LKM positive, high IgG |
| Pregnancy-associated | HELLP syndrome, acute fatty liver of pregnancy, severe pre-eclampsia |
| Vascular | Budd-Chiari syndrome (thrombosis, myeloproliferative disorder, OCP use) |
| Toxin | Amanita phalloides mushroom (tribal areas), aflatoxin |
| Ischaemic hepatitis | Shock, cardiac failure |
Rumack-Matthew nomogram (paracetamol)
- Plots paracetamol serum level (Y axis) against time from ingestion (X axis) from 4 hours onwards
- The treatment line (starts at 150 microgram/mL at 4 hours, extrapolated exponentially) mandates NAC if the level plots above it
- Nomogram invalid at less than 4 hours (absorption incomplete) and at greater than 24 hours (level unreliable)
- Late presentation, staggered ingestion, unknown-time ingestion → treat empirically
King's College Criteria (KCC)
Paracetamol-induced ALF (meet ANY):
- Arterial pH less than 7.30 after adequate fluid resuscitation, OR
- ALL three of: INR greater than 6.5 (PT greater than 100 s) AND creatinine greater than 3.4 mg/dL (300 micromol/L) AND Grade III or IV encephalopathy
Non-paracetamol ALF (meet ANY):
- INR greater than 6.5 (PT greater than 100 s) alone, OR
- Any 3 of the following 5:
- Age less than 10 or greater than 40 years
- Non-A non-B hepatitis or drug-induced aetiology
- Jaundice-to-encephalopathy interval greater than 7 days
- INR greater than 3.5 (PT greater than 50 s)
- Bilirubin greater than 17 mg/dL (300 micromol/L)
Alternative prognostic scores
- MELD — commonly used for cirrhosis; in ALF a MELD greater than 30 correlates with poor spontaneous survival
- ALFED (Acute Liver Failure Early Dynamic score) — developed at ILBS Delhi; incorporates arterial ammonia, INR and encephalopathy at day 3 and day 5
- APACHE II and SOFA — general ICU scores
- Lactate greater than 3.5 mmol/L after resuscitation — additional adverse prognostic marker
West Haven encephalopathy grading
| Grade | Clinical features |
|---|
| Grade I | Mild — trivial lack of awareness, altered sleep, mood change |
| Grade II | Lethargy, obvious disorientation to time, obvious personality change, asterixis |
| Grade III | Somnolence but rousable, gross disorientation, bizarre behaviour |
| Grade IV | Coma, unresponsive to pain |
Diagnosis
Paracetamol-induced hyperacute liver failure (day 4 post-25 g intentional ingestion), Grade II hepatic encephalopathy, INR 4.5, creatinine 2.2 mg/dL, lactate 5 mmol/L, arterial ammonia 180 micromol/L, hypoglycaemia and metabolic acidosis — for immediate IV N-acetylcysteine (21-hour regimen), 10 percent dextrose infusion for hypoglycaemia, electrolyte replacement, urgent liver transplant unit referral, cerebral-oedema precautions, close ICU monitoring for progression to King's College Criteria or Grade III-IV encephalopathy.
Management — antidote, supportive care and transplant referral
Antidote — N-acetylcysteine
IV NAC 21-hour Prescott regimen:
- 150 mg/kg in 200 mL of 5 percent dextrose over 60 minutes (loading)
- 50 mg/kg in 500 mL of 5 percent dextrose over the next 4 hours
- 100 mg/kg in 1000 mL of 5 percent dextrose over the next 16 hours
Continue NAC beyond 21 hours in ongoing hepatotoxicity, ALF, or late presentation until clinical and biochemical improvement. Adverse reactions — anaphylactoid response with flushing, urticaria, bronchospasm — most common during the loading infusion; slow the rate, give antihistamines and continue NAC.
Indications for NAC:
- Paracetamol ingestion greater than 150 mg/kg (or 7.5 g total in an adult)
- Serum level above the Rumack-Matthew treatment line at 4 hours or later
- Late presentation (greater than 8 hours) regardless of level
- Unknown time or staggered ingestion
- Any acute liver failure of any cause (POST-CHILD-ALF trial benefit in Grade I-II non-paracetamol ALF)
Supportive management
- Hypoglycaemia — 10 percent dextrose infusion continuous with hourly glucose checks; correct with 50 percent dextrose bolus for severe episodes
- Electrolytes — replace phosphate, magnesium, potassium aggressively; target sodium 145-150 mmol/L to reduce cerebral oedema; avoid rapid sodium swings
- Coagulopathy — do NOT give prophylactic FFP; give one dose of vitamin K 10 mg IV; reserve FFP for active bleeding or high-risk procedures (ICP monitor, large-bore central line); tranexamic acid controversial
- Acid-base — bicarbonate infusion for severe acidosis (pH less than 7.15)
- AKI — early CRRT for uraemia, hyperkalaemia, refractory acidosis, fluid overload, or ammonia clearance in refractory encephalopathy
- Sepsis — low threshold for cultures and empirical broad-spectrum antibiotics (ALF patients are functionally immunosuppressed); consider empirical antifungal in intubated + AKI + prolonged ICU stay
- Nutrition — early enteral feeding; do not routinely restrict protein (only briefly in Grade III-IV)
- Stress ulcer prophylaxis — PPI
- VTE prophylaxis — mechanical only in coagulopathic patients
Cerebral oedema — the leading cause of death
- Head elevation 30 degrees, midline neck position
- Minimise stimulation, suctioning and endotracheal manipulation
- Sedate lightly — propofol preferred, avoid over-sedation (masks neurological changes)
- Correct hyponatraemia — target 145-150 mmol/L
- Ammonia reduction — lactulose 30 mL every 6 hours titrated to 2-3 soft stools per day; rifaximin 550 mg twice daily
- Consider ICP monitoring in select centres for Grade III-IV encephalopathy — surges above 25 mmHg trigger:
- Mannitol 0.5-1 g/kg IV bolus (renal function permitting)
- 3 percent hypertonic saline to target Na 145-150
- Brief hyperventilation to pCO2 30-35 mmHg (only for herniation-threatened patients)
- Mild therapeutic hypothermia (35-36 degrees C) in refractory cerebral oedema
- CRRT for ammonia clearance in refractory cases
- Airway protection — intubate at Grade III-IV encephalopathy
Liver transplantation
- Refer to a transplant centre when Grade II encephalopathy is reached — do not wait for KCC
- Contraindications — active uncontrolled sepsis, severe irreversible extrahepatic disease, active malignancy (except selected HCC), non-adherence risk from active untreated psychiatric illness in some centres
- Options — deceased donor (NOTTO registry priority; MELD-based allocation in India), or living donor liver transplant (LDLT) from a family member (approximately 80-90 percent of Indian liver transplants are LDLT)
- Cost in India — approximately 20-40 lakh INR at private centres; some state PMJAY schemes cover partial costs
- Post-transplant 1-year survival — 70-90 percent at experienced Indian centres
Indian transplant centres of note
- Institute of Liver and Biliary Sciences (ILBS), Delhi
- Global Hospitals, Chennai and Hyderabad
- Apollo Hospitals, Delhi and Chennai
- Medanta, Gurugram
- Fortis Escorts, Delhi
- CMC Vellore
- PGI Chandigarh
- Rela Institute, Chennai
Complications
Acute
- Cerebral oedema and brainstem herniation (leading cause of death)
- Multi-organ failure — cardiovascular collapse, ARDS, AKI, DIC
- Hypoglycaemia (loss of hepatic gluconeogenesis)
- Metabolic acidosis (lactate)
- Sepsis (functional immunosuppression, invasive lines)
- Hyperammonaemia and hepatic encephalopathy
- Bleeding — although prophylactic FFP is discouraged, spontaneous bleeding does occur
- Hepatorenal syndrome
- Pancreatitis (paracetamol overdose)
Sub-acute and long-term (survivors)
- Persistent cognitive deficits from cerebral oedema episodes
- Renal impairment
- Post-transplant — infection, rejection, biliary complications, immunosuppression-related malignancy and metabolic disease
India-specific considerations
- Hepatitis E in pregnancy — the single most important Indian cause of ALF in the obstetric population; mortality 20 percent; enteric transmission; no specific antiviral; supportive care and delivery timing
- Hepatitis B and D — always test HBV DNA and HDV in an HBsAg-positive ALF
- Anti-tubercular therapy DILI — pyrazinamide, INH and rifampicin (in descending order) most hepatotoxic; monitor LFT at baseline, 2 weeks, then monthly; stop all ATT if ALT greater than 5x ULN or symptomatic hepatitis; rechallenge sequentially
- Ayurvedic and herbal medicine hepatotoxicity — under-recognised; always ask about traditional medicines including "pain balms", supplements and pregnancy tonics
- Paracetamol pack size proposal — a Ministry of Health proposal to limit blister-pack size to reduce impulsive overdose (mirroring UK 1998 legislation)
- NOTTO registry — National Organ and Tissue Transplant Organisation; brain-dead donor allocation
- PMJAY coverage — liver transplantation is not universally covered; state-level Chief Minister schemes offer partial coverage
- Living donor dominance — approximately 80-90 percent of Indian liver transplants are LDLT (family donor) due to limited deceased-donor supply
- HAV and HEV vaccination — HAV vaccine widely available; HEV vaccine (Chinese Hecolin) not yet available in India but in trials
- Mushroom poisoning — Amanita phalloides in Himalayan and Northeastern tribal areas; peak monsoon; management with NAC, silibinin (silymarin), high-dose penicillin G and early transplant
How NEET PG tests acute liver failure
Eight recurring patterns.
Pattern 1 — The definition question: ALF requires jaundice + INR at least 1.5 + encephalopathy in a previously healthy liver within 26 weeks.
Pattern 2 — The temporal classification question: Hyperacute is jaundice-to-encephalopathy less than 7 days — best transplant-free survival; classic cause = paracetamol and hepatitis A/E.
Pattern 3 — The King's College paracetamol question: pH less than 7.30 OR (INR greater than 6.5 AND creatinine greater than 3.4 mg/dL AND Grade III/IV encephalopathy).
Pattern 4 — The King's College non-paracetamol question: INR greater than 6.5 alone OR any 3 of the 5 (age less than 10 or greater than 40, non-A non-B or DILI, jaundice-to-encephalopathy greater than 7 days, INR greater than 3.5, bilirubin greater than 17 mg/dL).
Pattern 5 — The NAC question: 21-hour Prescott regimen — 150 mg/kg over 1 h → 50 mg/kg over 4 h → 100 mg/kg over 16 h; NAC also given in any ALF, not just paracetamol.
Pattern 6 — The FFP question: Prophylactic FFP is NOT indicated in ALF — obscures INR, worsens cerebral oedema; give only for active bleeding or pre-procedure.
Pattern 7 — The cerebral oedema question: Target sodium 145-150, lactulose + rifaximin, mannitol or 3 percent saline for ICP surges; leading cause of death.
Pattern 8 — The India aetiology question: Hepatitis E is the commonest cause of ALF in Indian pregnant women, with mortality up to 20 percent.
High-yield one-liners:
- Jaundice + INR at least 1.5 + encephalopathy in a previously healthy liver = ALF
- Hyperacute (less than 7 days), acute (7-28 days), subacute (28 d-26 w)
- Paracetamol hepatotoxicity — glutathione depletion → NAPQI accumulation
- Rumack-Matthew nomogram valid 4-24 hours
- NAC 21-h regimen 150 → 50 → 100 mg/kg
- Give NAC in any ALF (POST-CHILD-ALF)
- Vitamin K trial once; FFP only if bleeding
- Target sodium 145-150 mmol/L to reduce cerebral oedema
- Refer to transplant unit at Grade II encephalopathy
- King's College Criteria trigger transplant listing
- ALFED (ILBS Delhi) is the Indian dynamic score
- Hep E is the top Indian pregnancy-related ALF cause
- Wilson — young + KF ring + high bilirubin/AP ratio + low ceruloplasmin
- LDLT dominates the Indian transplant landscape
Frequently Asked Questions
How is acute liver failure defined and classified by time from jaundice to encephalopathy?
Acute liver failure (ALF) is the abrupt loss of hepatic function in a patient without pre-existing chronic liver disease, defined by three simultaneous criteria — jaundice, coagulopathy (INR at least 1.5), and hepatic encephalopathy of any grade — arising within 26 weeks of the first symptom. The temporal subclassification by O'Grady uses the interval from jaundice to encephalopathy: hyperacute (less than 7 days, typically paracetamol overdose and hepatitis A/E, best transplant-free survival because of the massive regenerative response), acute (7-28 days, viral hepatitis B and drug-induced), and subacute (28 days to 26 weeks, drug-induced, autoimmune and indeterminate cases, worst transplant-free survival). This classification matters because it predicts the trajectory of cerebral oedema, the likelihood of spontaneous recovery, and the urgency of transplant listing — hyperacute patients often survive without transplant if they get through the first few days, while subacute patients rarely recover without transplantation.
How is N-acetylcysteine dosed in paracetamol overdose and why is it also given in non-paracetamol acute liver failure?
N-acetylcysteine (NAC) is the specific antidote for paracetamol hepatotoxicity because it replenishes hepatic glutathione, which detoxifies the toxic paracetamol metabolite NAPQI (N-acetyl-p-benzoquinone-imine). The standard IV protocol is a 21-hour regimen — a loading dose of 150 mg/kg in 200 mL of 5 percent dextrose over 60 minutes, followed by 50 mg/kg over 4 hours, then 100 mg/kg over the next 16 hours. Longer regimens are used if there is ongoing hepatotoxicity or delayed presentation. The Rumack-Matthew nomogram guides treatment for known-time single-dose ingestion — a paracetamol level plotted at 4 hours or later that falls above the treatment line mandates NAC. In late presentations, staggered ingestions or unknown-time ingestions, treat empirically. In acute liver failure of ANY cause (paracetamol or non-paracetamol), NAC is now standard of care because the ALFSG and POST-CHILD-ALF trials showed improved transplant-free survival in Grade I-II encephalopathy in non-paracetamol ALF; the mechanism is antioxidant, microcirculatory and cytokine-modulating rather than glutathione replacement.
What are the King's College Criteria and how do they guide liver transplant listing in acute liver failure?
The King's College Criteria (KCC) are the classic prognostic scoring system for identifying acute liver failure patients who will not survive without emergency liver transplantation. For paracetamol-induced ALF the criteria are — arterial pH less than 7.30 after adequate resuscitation, OR the combination of INR greater than 6.5 (or PT greater than 100 seconds) AND serum creatinine greater than 300 micromol/L (3.4 mg/dL) AND Grade III or IV hepatic encephalopathy. Meeting any of these criteria predicts a very poor spontaneous survival and mandates urgent transplant listing. For non-paracetamol ALF the criteria are — INR greater than 6.5 (PT greater than 100 seconds) alone, OR any three of the following five: age less than 10 or greater than 40 years, non-A non-B hepatitis or drug-induced aetiology, jaundice-to-encephalopathy interval greater than 7 days, INR greater than 3.5, and bilirubin greater than 300 micromol/L (17 mg/dL). MELD score and dynamic scoring systems like ALFED (developed at ILBS Delhi for the Indian context) supplement rather than replace the KCC in modern practice.
Why should prophylactic FFP be avoided in acute liver failure despite the very high INR?
The elevated INR in acute liver failure reflects impaired hepatic synthesis of clotting factors, but it does NOT translate into a clinical bleeding tendency in most patients because the parallel loss of anticoagulant proteins (protein C, protein S, antithrombin) and the rise in factor VIII from endothelial release restore a rebalanced haemostatic state. Modern thromboelastography studies confirm that most ALF patients are near-normal or even hypercoagulable rather than bleeding-prone. Prophylactic transfusion of fresh frozen plasma corrects the INR number without any clinical benefit and carries three harms — (1) it obscures the INR, which is the single most important prognostic marker used to trigger transplant listing under the King's College Criteria, (2) it delivers a large fluid load that worsens cerebral oedema and pulmonary oedema, and (3) it exposes the patient to transfusion reactions and TRALI. FFP is reserved for active bleeding or before high-risk invasive procedures (ICP monitor insertion, large-bore central line in a high-risk position, surgery). Vitamin K 10 mg IV is given as a trial once, but usually does not correct the INR because the defect is synthetic, not vitamin K deficiency.
How is Grade III-IV hepatic encephalopathy with cerebral oedema managed in acute liver failure?
High-grade hepatic encephalopathy in acute liver failure is driven by ammonia-mediated astrocyte swelling and cerebral oedema, which can progress to brainstem herniation — the leading cause of death in ALF. First-line general measures are head elevation 30 degrees, minimise stimulation and suctioning, avoid over-sedation (which masks neurological changes), correct hypoglycaemia and hyponatraemia (target sodium 145-150 mmol/L to reduce cerebral oedema), and maintain normothermia or mild hypothermia (35-36 degrees C in select refractory cases). Lactulose 30 mL every 6 hours titrated to 2-3 soft stools per day and rifaximin 550 mg twice daily reduce ammonia production. Protein restriction is temporary. For Grade III-IV encephalopathy consider intracranial pressure monitoring in select centres, and treat surges above 25 mmHg with mannitol 0.5-1 g/kg IV bolus (renal function permitting) or 3 percent hypertonic saline. Brief hyperventilation to target pCO2 30-35 mmHg reduces ICP acutely but should be reserved for herniation-threatened patients. Renal replacement therapy (CRRT) is used early for ammonia clearance in refractory cases. Definitive treatment is liver transplantation — refer immediately when Grade II encephalopathy is reached.
This content is for educational purposes for NEET PG exam preparation. It is not a substitute for professional medical advice, diagnosis, or treatment. Clinical information has been reviewed by qualified medical professionals.
Written by: NEETPGAI Editorial Team
Reviewed by: Pending SME Review
Last reviewed: July 2026
