Chronic Liver Disease

Definition And Pathophysiology

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.