INVESTIGATIONOf Jaundice

By Prabhat

Investigation• Depends on aetiology –that can be concluded by :-1.history, 2.C/F, 3.Clinical Ex.• Jaundice- cause by rise in blood plasma of bilirubin Normal= <1 mg/dL---------- 1. Unconjugated/Indirect= 0.2-0.7 mg/dL 2.Conjugated/Direct =0.1-0.4 mg/dLIf bilirubin value is– 1. >1mg/dL, -Hyperbilirubinemia 2. >2-2.5mg/dL, -Start diffusing into tissues 3. ~3mg/dL, -Clinically jaundice detectableThe typical investigation will include blood levels of enzymes found primarily from the liver, such as the aminotransferases (ALT, AST), and alkaline phosphatase (ALP); bilirubin (which causes the jaundice); and protein levels, specifically, total protein and albumin. Other primary lab tests for liver function include gamma glutamyl transpeptidase (GGT) and prothrombin time (PT)

Pre-hepatic Jaundice• Cause- Mainly by haemolysis of RBC• Detoxification Function Test – Serum:- Increase unconjugated bilirubin Urine:- Bilirubin= Absent (unconjugated bilirubin is not water soluble) Urobilinogen= Increases (Increase in 6x function of Normal liver to cope with load of unconjugated bilirubin) Stool:- Fecal Urobilinogen increases• Rest of parameter usually remains normal.

Hepatocellular Jaundice• Detoxification Function Test:- 1. Serum bilirubin- conjugated and unconjugated both increased2. Urine -Bilirubin – Present (Conjugated Bilirubin is water soluble) Urobilinogen- decreased 3. Fecal stercobilinogen/Fecal Urobilinogen- decreased• Enzymatic test:-1. AST,ALT – highly raised (due to lysis of liver parenchymatic cells)2. ALP, GGT – is slightly raised AST and ALT rise is significantly higher than the ALP and GGT rise

• Plasma albumin level is low but plasma globulins are raised due to an increased formation of antibodies

Disorders Bilirubin Aminotransferases Alkaline phospha. Albumin Prothrombin time

Post Hepatic/Obstructive Jaundice• Detoxification test 1. Serum bilirubin – Direct(conjugated)– increased 2. Urine – Bilirubin- Present - Urobilinogen – absent 3. fecal stercobilinogen- trace to absent• Enzymatic Test 1. AST,ALT – Slightly increase 2. ALP, GGT- Highly IncresedIf the ALP (10–45 IU/L) and GGT (18–85) levels rise proportionately about as high as the AST (12–38 IU/L) and ALT (10–45 IU/L) levels, this indicates a cholestatic problem

Disorder Bilirubin Aminotransferases Alkaline phosphatase Albumin Prothrombin Time

Radiological Investigation• Plain radiographs -are of limited utility as Frequently, calculi are not

visualized because few are radiopaque.• Ultrasonography (USG)- most sensitive technique for visualizing the

biliary system, particularly the gallbladder. Procedure of choice for the initial evaluation of cholestasis and for helping differentiate extrahepatic from intrahepatic causes of jaundice• CT Scan -helps visualize liver structures more consistently than USG. CT

scan has limited value in helping diagnose CBD stones because many of them are radiolucent and CT scan can only image calcified stones ( in such situation CT cholangiography by the helical CT technique is used)

Radiological Investigation-Continue

• MRI- MRCP (Magnetic resonance cholangiopancreatography) type is used to visualize the hepatobiliary tree.

It helps in detecting biliary and pancreatic duct stones, strictures, or dilatations within the biliary system. It is also sensitive for helping detect cancer. MRCP combined with conventional MR imaging of the abdomen can also provide information about the surrounding structures (eg, pseudocysts, masses).

Biopsy• Usually done at last in series of investigation to establish the cause of Jaundice.• In patients with apparent intrahepatic cholestasis, the diagnosis is often made by

serologic testing in combination with percutaneous liver biopsy. • to assess the condition of the liver tissue if it may have been damaged by a condition

such as cirrhosis or liver cancer.