Liver Function Tests:- Part 1 – Bilirubin Normal values, Jaundice Classification
Liver Function Tests
- The venous blood is needed to prepare the serum.
For the complete evaluation of liver functions, the following tests are recommended.
- Total Bilirubin.
- Direct bilirubin.
- Indirect bilirubin.
- Alkaline phosphatase.
- Gamma-glutamyltransferase (γ-GT).
- Total protein.
- A / G ratio.
- Prothrombin time (PT).
- Ultrasound of the abdomen to evaluate the liver or any other mass in the abdomen.
- Viral markers.
- Total Bilirubin.
|Total bilirubin||o.3 to 1.0 mg/dL|
|Conjugated bilirubin||0.1 to 0.3 mg/dL|
|Unconjugated bilirubin||0.1 to 0.8 mg/dL|
|Newborn total bilirubin||1.0 to 12.0 mg/dL.|
Adult = 30 to 120 units/L
Child <2 years = 85 to 235 units/L
2 to 8 years = 65 to 210 units/L
9 to 15 years = 60 to 300 units/L
16 to 21 years = 30 to 200 units/L
Adult = 0 to 35 units
Elderly = values slightly higher than adult
Newborn and infants = 15 to 60 units/L
Adult and child = 4 to 40 units/L
Infants may be twice high as the adult value
Adult = 3.5 to 5 g/dL
Premature infants = 3 to 4.2 g/dL
Newborn = 3.5 to 5.5 g/dL
Infant = 4.4 to 5.4 g/dL
Child = 4 to 5.9 g/dL
|Total protein||6.4 to 8.3 g/dL|
|A/G ratio||0.8 to 2.0|
>45 years = 8 to 38 units/L
Female <45 years = 5 to 27 units/L
Childlike adult level
Newborn = 5 times higher than the adult level
|Prothrombin time (PT)||
11 to 12.5 seconds
Anticoagulant therapy = 1.5 to 2 times control
Phases of the Jaundice:
- Preicteric phase.
- Icteric phase.
- Nonicteric phase.
- Preicteric phase:
- In this phase urine, bilirubin is usually positive 1 to 6 days before the onset of clinical jaundice.
- Urinary urobilinogen is usually increased.
- BSP test is usually the first test to become positive in this phase.
- Thymol flocculation, turbidity tests, and cephalin flocculation tests are positive in the late phase of jaundice.
- Icteric phase:
- Direct bilirubin is increased.
- Urinary urobilinogen is increased, and bile is present in the urine.
- Alkaline phosphatase is may or may not be elevated.
- Thymol turbidity and flocculation test and cephalin-flocculation test are positive.
- The Bromsulphalein test is not helpful.
- Nonicteric phase:
- Urinary urobilinogen is increased.
- Thymol-flocculation and turbidity and cephalin flocculation tests are usually positive.
- The Albumin-globulin ratio shows high globulin and low serum albumin.
- Alkaline phosphatase and cholesterol ester may or may not be helpful.
Classification of jaundice:
The major causes of jaundice are:
- Pre hepatic jaundice where there is hemolysis.
- Hepatic jaundice where there is intrahepatic biliary tract obstruction.
- Post hepatic jaundice where there is extrahepatic biliary tract obstruction.
- Please see more details in the LFT part.