Definition And Pathophysiology
Core Definition
- Spectrum of disorders characterized by ongoing chronic liver damage and potential to progress to cirrhosis or end-stage liver disease.
- 6-month duration cut-off used for defining chronicity in hepatitis B and C.
- Cut-off does not apply to other etiologies; irreversible chronic liver damage may occur before symptoms are recognized.
Cirrhosis
- Histopathological diagnosis representing diffuse liver process.
- Characterized by fibrosis in response to inflammation/injury and nodular regeneration.
- Progressive fibrosis distorts blood vessels and bile ducts, increasing resistance to blood flow (portal hypertension) and causing tissue hypoxia.
- Compensated Cirrhosis: Normal synthetic function without ascites or encephalopathy.
- Decompensated Cirrhosis: Development of coagulopathy, jaundice, ascites, and/or hepatic encephalopathy.
Etiological Classification
| Category | Specific Disorders |
|---|---|
| Metabolic | Alpha-1-antitrypsin deficiency, Wilson disease, progressive familial intrahepatic cholestasis, glycogen storage diseases (types IV, VI, IX, X), lipid abnormalities (Gaucher), peroxisomal disorders, tyrosinemia, cystic fibrosis. |
| Developmental/Genetic | Biliary atresia, congenital hepatic fibrosis, Alagille syndrome. |
| Infectious | Viral (chronic hepatitis B or C), parasitic (echinococcosis). |
| Immune-Related | Autoimmune hepatitis, sclerosing cholangitis. |
| Vascular | Budd-Chiari syndrome, hepatic veno-occlusive disease, portal vein thrombosis. |
| Miscellaneous | Nonalcoholic steatohepatitis (NASH), drugs, cryptogenic. |
Clinical Features
| System | Manifestations |
|---|---|
| General/Nutritional | Insidious onset with failure to thrive, anorexia, muscle weakness, severe growth retardation, delayed puberty. |
| Hepatic | Firm to hard, nodular liver with irregular margins. Differential left lobe enlargement. Small, non-palpable shrunken liver indicates post-necrotic cirrhosis. |
| Stigmata Of Chronic Liver Disease | Spider angiomata, palmar erythema, clubbing, leukonychia, muscle wasting, gynecomastia. |
| Portal Hypertension | Splenomegaly, ascites, caput medusae (tortuous veins over abdominal wall with flow away from umbilicus), esophageal or gastric varices, massive gastrointestinal bleed. |
| Neurological | Altered sensorium, hepatic encephalopathy, asterixis, constructional apraxia. |
Diagnostic Evaluation
Laboratory Investigations
- Synthetic Function: Low serum albumin and prolonged prothrombin time (PT/INR) unresponsive to vitamin K indicate poor synthetic function.
- Hepatic Injury: Transaminases mildly or moderately elevated.
- Cholestasis: Elevated alkaline phosphatase and gamma-glutamyl transpeptidase (GGT).
- Metabolic Derangement: Elevated serum ammonia correlates with significant liver dysfunction and portosystemic shunting.
Imaging And Histology
- Abdominal Ultrasonography: Assesses liver size, echotexture, nodularity, biliary dilatation, ascites, and splenomegaly. Doppler study evaluates portal, splenic, or hepatic vein block and portosystemic shunts.
- Transient Elastography (FibroScan): Noninvasive measurement of liver stiffness; assesses moderate to higher grades of fibrosis; replaces need for serial liver biopsies.
- Liver Biopsy: Gold standard for histological diagnosis, assessment of fibrosis, metal quantification (copper), and enzyme activity. Scoring systems include Metavir (stages I-IV) and Ishak score (stages I-V).
Severity Scoring
- Child score and Pediatric End-Stage Liver Disease (PELD) score assess degree of liver dysfunction and predict mortality.
- PELD calculates risk using bilirubin, albumin, INR, growth failure, and age.
Major Complications
| Complication | Pathophysiology And Features |
|---|---|
| Portal Hypertension | Increased intrahepatic resistance leading to variceal bleeding, splenomegaly (hypersplenism with cytopenia). |
| Hepatic Encephalopathy | Neuropsychiatric abnormalities resulting from liver dysfunction; graded via specific criteria. |
| Ascites And Peritonitis | Fluid accumulation due to portal hypertension and hypoalbuminemia; increased risk for spontaneous bacterial peritonitis. |
| Hepatorenal Syndrome | Functional, reversible renal impairment defined as severe acute kidney injury without other known causes. |
| Hepatopulmonary Syndrome | Triad of chronic liver disease, intrapulmonary vascular dilations, and hypoxemia; causes dyspnea, cyanosis, and clubbing. |
| Hepatocellular Carcinoma | Increased risk in cirrhotic livers; requires surveillance. |
Management Protocol
Nutritional Rehabilitation
- Provide adequate caloric intake targeting 125% of recommended daily allowances based on ideal body weight.
- Supply protein at 2-3 g/kg/day in infants and 1-2 g/kg/day in older children.
- Strictly avoid protein restriction in encephalopathic patients.
- Utilize medium-chain triglycerides for fat calories.
- Supplement aqueous fat-soluble vitamins (A, D, E, K) and monitor serum levels.
- Evaluate triene-to-tetraene ratio (<0.3) for essential fatty acid deficiency.
Medical And Supportive Therapy
- Ascites: Sodium restriction, diuretic therapy (spironolactone); therapeutic paracentesis for tense ascites causing respiratory compromise.
- Pruritus: Ursodeoxycholic acid, rifampicin, phenobarbitone, cholestyramine, or naltrexone.
- Variceal Bleed Prophylaxis: Nonselective beta-blockers, endoscopic variceal band ligation.
- Immunizations: Ensure complete childhood vaccination schedule, specifically hepatitis A and B vaccines.
- Surveillance: Perform abdominal ultrasound and serum alpha-fetoprotein screening every 6 months to detect hepatocellular carcinoma.
Definitive Surgical Therapy
- Liver Transplantation: Only definitive therapy for end-stage liver disease, decompensated cirrhosis, refractory portal hypertension, severe growth failure, or hepatopulmonary syndrome.
- Allocate organs utilizing PELD/MELD scoring systems prioritizing severity of decompensation.