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NEONATAL CHOLESTATIC JAUNDICE
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Key clinical features of disorders causing prolonged neonatal cholestasis are (1) jaundice with elevated serum conjugated (or direct) bilirubin fraction (> 12 mg/dL and > 20% of total bilirubin), (2) variably acholic stools, (3) dark urine, and (4) hepatomegaly.
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Neonatal cholestasis (conditions with decreased bile flow) is caused by both intrahepatic and extrahepatic diseases. Specific clinical clues (Table 22–1) distinguish these two major categories of jaundice in 85% of cases. Patients with intrahepatic cholestasis frequently appear ill and are failing to thrive, whereas infants with extrahepatic cholestasis typically do not, have stools that are usually completely acholic, and have an enlarged, firm liver. Histologic examination of percutaneous liver biopsy specimens increases the accuracy of differentiation to 85%–95% (Table 22–2).
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INTRAHEPATIC CHOLESTASIS
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ESSENTIALS OF DIAGNOSIS & TYPICAL FEATURES
Elevated total and conjugated bilirubin.
Hepatomegaly and dark urine.
Patency of extrahepatic biliary tree.
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General Considerations
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Intrahepatic cholestasis is characterized by impaired hepatocyte secretion of bile and patency of the extrahepatic biliary system. A specific cause can be identified in about 60%–80% of cases. Patency of the extrahepatic biliary tract is suggested by pigmented stools and lack of bile duct proliferation and portal tract bile plugs on liver biopsy. Bile duct patency can be confirmed least invasively by hepatobiliary scintigraphy using technetium-99m (99mTc)-dimethyliminodiacetic acid (diethyl-IDA [DIDA]). Radioactivity in the bowel within 4–24 hours is evidence of bile duct patency, as is finding bilirubin in duodenal aspirates. However, these tests are rarely needed in the clinical setting. Patency can also be determined, when clinically indicated, by cholangiography carried out either intraoperatively, percutaneously by transhepatic cholecystography, or by endoscopic retrograde cholangiopancreatography (ERCP) using a pediatric-size side-viewing endoscope. Magnetic resonance cholangiopancreatography in infants is of limited use and highly dependent on the operator and equipment.
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1. Perinatal or Neonatal Hepatitis Resulting From Infection
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This diagnosis is considered in infants with jaundice, hepatomegaly, vomiting, lethargy, ...