Management of Elevated Total Bilirubin

Initial Diagnostic Evaluation

• The American College of Gastroenterology recommends determining whether the hyperbilirubinemia is predominantly conjugated or unconjugated by obtaining fractionated bilirubin levels, and ordering complete liver function tests including ALT, AST, ALP, GGT, and albumin to assess for liver injury and synthetic function 1, 2
• Measurement of prothrombin time (PT) and INR is recommended to evaluate liver synthetic capacity, and a complete blood count with peripheral smear should be checked to assess for hemolysis if unconjugated hyperbilirubinemia is suspected 1

Diagnostic Pathway Based on Bilirubin Type

• If predominantly unconjugated hyperbilirubinemia, consider Gilbert's syndrome, and evaluate for hemolysis with reticulocyte count, haptoglobin, and LDH, as recommended by the American College of Gastroenterology 1, 2
• If predominantly conjugated hyperbilirubinemia, ultrasound of the abdomen should be performed as the initial imaging study to evaluate for biliary obstruction, with specificities ranging from 71% to 97% for detecting obstruction, as per the American College of Radiology 3

Management Considerations

• For biliary obstruction, preoperative biliary drainage (PBD) should be considered if the total bilirubin is >218.75 μmol/L (approximately 12.8 mg/dL), especially if major hepatic resection is planned, according to the International Journal of Surgery 4
• For patients with hilar cholangiocarcinoma, PBD may reduce postoperative complications when bilirubin levels are significantly elevated, as recommended by the International Journal of Surgery 4

Special Populations

• In neonates with total bilirubin >25 mg/dL, immediate admission for intensive phototherapy is required, and exchange transfusion should be performed only by trained personnel in a neonatal intensive care unit, as per the American Academy of Pediatrics 5
• For infants with conjugated bilirubin >25 μmol/L, urgent referral to a pediatrician for assessment of possible liver disease is essential, as recommended by the American College of Gastroenterology 2

Pitfalls to Avoid

• The American Academy of Pediatrics advises against subtracting direct (conjugated) bilirubin from total bilirubin when making treatment decisions, and against overinterpreting albumin concentrations as a marker of liver disease severity 5, 1
• The American College of Radiology recommends avoiding delay in appropriate imaging in patients with conjugated hyperbilirubinemia, as early identification of biliary obstruction is critical for timely intervention 3

Management of Elevated Total Bilirubin

Diagnostic Pathway Based on Bilirubin Type

• In neonates, assess for risk factors of severe hyperbilirubinemia, including G6PD deficiency, which may cause sudden increases in total serum bilirubin (TSB) 6
• If direct bilirubin is 50% or more of the total bilirubin, consultation with an expert in the field is recommended due to limited guidance for therapy 7
• Evaluate for dominant stricture with magnetic resonance cholangiography or endoscopic retrograde cholangiography if abrupt elevations in liver tests occur in patients with PSC 8

Management Considerations

For Neonates

• If TSB is at a level at which exchange transfusion is recommended or if TSB level is 25 mg/dL or higher at any time, it is a medical emergency requiring immediate admission for intensive phototherapy 7, 9
• Exchange transfusions should be performed only by trained personnel in a neonatal intensive care unit with full monitoring and resuscitation capabilities 7
• In isoimmune hemolytic disease, administration of intravenous immunoglobulin (0.5-1 g/kg over 2 hours) is recommended if the TSB is rising despite intensive phototherapy 7
• For all newborns, treatment is recommended at lower TSB levels at younger ages to prevent additional increases in the TSB level 6

Laboratory Tests for Neonatal Hyperbilirubinemia

• The American Academy of Pediatrics recommends measuring TSB and direct bilirubin levels, blood type (ABO, Rh) and direct antibody test (Coombs'), serum albumin, complete blood cell count with differential and smear for red cell morphology, reticulocyte count, and G6PD if suggested by ethnic or geographic origin or if poor response to phototherapy 10

Pitfalls to Avoid

• The American Academy of Pediatrics advises against subtracting direct (conjugated) bilirubin from total bilirubin when making treatment decisions 7
• Be aware that standard laboratory tests for hemolysis have poor specificity and sensitivity 9
• Remember that in the presence of hemolysis, G6PD levels can be elevated, which may obscure the diagnosis in the newborn period 6

Special Considerations

• The bilirubin/albumin (B/A) ratio can be used as an additional factor in determining the need for exchange transfusion in neonates, but should not be used in lieu of the TSB level 11
• Tin-mesoporphyrin, a drug that inhibits the production of heme oxygenase, could be considered for preventing the need for exchange transfusion in infants not responding to phototherapy, though it is not yet FDA approved 9

Management of Elevated Bilirubin

Initial Diagnostic Evaluation

• The American Academy of Pediatrics recommends using the bilirubin/albumin (B/A) ratio as an additional factor in determining the need for exchange transfusion in neonates, but not in lieu of the total serum bilirubin (TSB) level 12
• Measure prothrombin time (PT) and INR to evaluate liver synthetic capacity, as recommended by the European Association for the Study of the Liver 13

Special Populations

Neonates

• The American Academy of Pediatrics suggests screening for G6PD deficiency in infants with significant hyperbilirubinemia, as they may develop sudden increases in TSB 14

Adults

• No specific guideline society recommendations are provided for adults in the given text, however, it is implied that evaluation for underlying causes of jaundice is necessary, including viral hepatitis, alcoholic liver disease, medication effects, and biliary obstruction, although no specific citation is provided for this statement, a related fact is that albumin concentrations should not be overinterpreted as a marker of liver disease severity 13

Pitfalls to Avoid

• The European Association for the Study of the Liver advises against overinterpreting albumin concentrations as a marker of liver disease severity, as albumin can be reduced in many clinical situations including sepsis and malnutrition 13
• The American Academy of Pediatrics notes that in the presence of hemolysis, G6PD levels can be elevated, which may obscure the diagnosis in the newborn period 14

Red Flags Requiring Urgent Attention

• The American Academy of Pediatrics recommends urgent attention for failure of bilirubin to decrease during phototherapy, suggesting hemolysis 12
• The European Association for the Study of the Liver advises urgent attention for signs of acute liver failure (encephalopathy, coagulopathy) accompanying hyperbilirubinemia 13