Lecture: LFT and EUC Flashcards
Intracellular potassium concentration
high
Intracellular sodium concentration
low
Extracellular potassium concentration
low
Extracellular sodium concentration
high
Intracellular potassium concentration
high
Extracellular potassium concentration
low
Intracellular chloride concentration
low
Extracellular chloride concentration
high
What drives the majority of changes in concentration of sodium?
disturbances in water homeostasis
What does hypernatraemia usually indicate?
Dehydration
Cholestasis LFT?
ALP significantly elevated
ALT normal/mildly elevated
What are the four hepatic enzymes commonly measured?
AST ALT GGT Alk. phos. liver transaminases: aspartate transaminase (AST or SGOT) alanine transaminase (ALT or SGPT) are useful biomarkers of liver injury in a patient with some degree of intact liver function Some tests are associated with functionality (e.g., albumin), some with cellular integrity (e.g., transaminase), and some with conditions linked to the biliary tract (gamma-glutamyl transferase and alkaline phosphatase).
Name two liver synthetic function tests.
INR and albumin
Where can AST be found in the body?
liver, heart, muscles, kidney, RBC
Where can ALT be found in the body?
Predominantly the liver
When is ALT>AST and what condition does this indicate?
Most chronic liver disease not caused by alcohol
When is AST>ALT?
Cirrhosis of the liver. AST:ALT > 2 strongly suggests alcohol as the cause of cirrhosis.
AST:ALT > 5 strongly suggests what?
An extrahepatic cause of elevated AST such as rhabdomyolysis or MI
What is ALP (alkaline phosphatase) and where is it found?
Alkaline phosphatase (ALP) is an enzyme in the cells lining the biliary ducts of the liver. It can also be found on the mucosal epithelium of the small intestine, proximal convoluted tubule of the kidneys, bone, liver, and placenta.
What is GGT?
GGT is a microsomal enzyme found in hepatocytes, biliary epithelial cells, renal tubules, pancreas, and intestines. It helps in glutathione metabolism by transporting peptides across the cell membrane.
Diagnostic consideration:
Mild/Moderate Elevated ALP
Elevated GGT
Hepatic or biliary disease
Diagnostic consideration:
Severely Elevated ALP
Elevated GGT
Biliary disease only
Diagnostic consideration:
Elevated ALP
Normal GGT
Bone disease
Diagnostic consideration:
Normal ALP
Elevated GGT
Alcohol abuse
What does the INR measure?
The prothrombin time. Measures the extrinsic pathway of clotting. This is dependent on clotting factors produced by the liver.
Probable etiology of:
Elevated unconjugated bilirubin
Elevated conjugated bilirubin
Diffuse hepatocellular or biliary system process
Probable etiology of:
Isolated Elevated unconjugated bilirubin
Haemolysis
Genetic conditions: Gilbert’s or GN syndromes
Probable etiology of:
Isolated Elevated conjugated bilirubin
Early biliary disease
Genetic conditions
Common pattern of LFT abnormalities on hepatocellular injury?
*AST and ALT mild/severe elevated
*ALP and GGT normal/moderate elevated
Bilirubin normal/moderate elevated
Albumin normal/moderate decreased
INR normal/moderate increase
Common pattern of LFT abnormalities on cholestatic injury?
AST and ALT normal/mild elevated *ALP and GGT mild/severe elevated *Bilirubin mild/severe elevated Albumin normal unless severe INR normal unless severe
Common pattern of LFT abnormalities on isolated hyperbilirubinaemia injury?
AST and ALT normal ALP and GGT normal *Bilirubin mild/severe elevated Albumin normal INR normal
Common pattern of LFT abnormalities on isolated synthetic dysfunction injury?
AST and ALT normal ALP and GGT normal Bilirubin normal *Albumin mild/severe decrease *INR mild/severe elevation
Common pattern of LFT abnormalities on cirrhosis injury?
*AST and ALT mild/severe elevated ALP and GGT normal *Bilirubin mild/severe elevated *Albumin mild/severe decreased *INR mild/severe increase
Causes of ALT 500 IU/L
When ALT rises to more than 500 IU/L, causes are usually from the liver. It can be due to hepatitis, ischemic liver injury, and toxins that causes liver damage. Poisoning causes levels in the 1000s
