Liver failure is a multisystem disorder with complex interactions among the liver, kidneys, vascular structures, gut, central nervous system (CNS), and immune function. Hepaticencephalopathy is characterized by varying degrees ofimpairment (Table 130-3). Respiratory compromise occursas severity of the failure increases and requires early institution of ventilatory support. Hypoglycemia resulting fromimpaired glycogenolysis and gluconeogenesis must be prevented. Renal function is impaired, and frank renal failure, or hepatorenal syndrome, may occur. This syndrome ischaracterized by low urine output, azotemia, and low urinesodium content. Ascites develops secondary to hypoalbuminemia and disordered regulation of fluid and electrolytehomeostasis. Increased risk of infection occurs and may cause death. Esophageal varices may cause significant hemorrhage, whereas hypersplenism from portal hypertensionmay produce thrombocytopenia.
Coagulation tests and serum albumin are used to followhepatic synthetic function. These tests are confounded byadministration of blood products and clotting factors. Vitamin K should be administered to maximize the liver’s abilityto synthesize factors II, VII, IX, and X. In addition to monitoring prothrombin time and partial thromboplastin time,many centers measure factor V serially as a sensitive index ofsynthetic function. Renal function tests, electrolytes, serum
Neonatal hemochromatosis Electron chain transport defects Disorders of fatty acid oxidation Galactosemia Tyrosinemia Hereditary fructose intolerance Bile acid synthesis disorders
Shock, hypotension Congestive heart failure
Hepatitis virus A, B Echovirus Coxsackievirus Adenovirus Parvovirus Cytomegalovirus Sepsis Herpes simplex ammonia, blood counts, and urinalysis also should be followed. In the setting of acute liver failure, liver biopsy maybe indicated to ascertain the nature and degree of injury andestimate the likelihood of recovery. In the presence of coagulopathy, biopsy must be done using a transjugular or surgicalapproach.
Because of the life-threatening and complex nature of this condition, management must be carried out in an intensive care unit at a liver transplant center. Treatment of acute liver failure is supportive; the definitive lifesaving therapy is liver transplantation. Supportive measures are listed in Table 130-4.
Alert and awake Agitated and distractible Infants and young children—irritable and fussy Normal reflexes Tremor, poor handwriting Obeys age-appropriate commands
Confused and lethargic Combative or inappropriate euphoria Hyperactive reflexes Asterixis present Purposeful movements, but may not obey commands
Stuporous but arousable Sleepy Incoherent speech Motor response to pain Hyperreflexic Hyperventilation Asterixis present
Unconscious, not arousable Unresponsive or responds nonpurposefully to pain Reflexes hyperactive Irregular respirations Pupil response sluggish
Efforts are made to treat metabolic derangements, avoid hypoglycemia, support respiration, minimize hepatic encephalopathy, and support renal function.
Chronic liver disease in childhood is characterized by thedevelopment of cirrhosis and its complications, and byprogressive hepatic failure. Causative conditions may becongenital or acquired. Major congenital disorders leading to chronic disease include biliary atresia, tyrosinemia,untreated galactosemia, and α1-antitrypsin deficiency. In older children, hepatitis B or C virus, autoimmune hepatitis, Wilson disease, primary sclerosing cholangitis, cystic encephalopathy Lactulose via nasogastric tube—start with 1-2 mL/kg/day, adjust dose to yield several loose stools per day Rifaximin or neomycin Enemas if constipated Mechanical ventilation if stage III or IV