Interpreting bloods Flashcards
LFTs
Why might we order LFTs?
4
- investigate patients for liver disease
- monitor patients confirmed liver disease
- monitor the effects of medications
- baseline’ screening panel
LFTs
LFTs
ALT
Alanine aminotransferase
LFTs
AST
aspartate aminotransferase
LFTs
What are ALT and AST?
What do raised levels indicate?
- enzymes found within liver cells at high concentrations
- liver cell (hepatocyte) inflammation or damage.
LFTs
What can we assess using the ratio between AST and ALT?
The AST:ALT ratio can help determine the aetiology of hepatocellular injury, with a >2:1 ratio classical of alcoholic liver disease.
LFTs
What are some common causes of hepatocellular injury?
- Hepatitis (viral, alcoholic, ischaemic)
- Liver cirrhosis
- Drug / toxin-induced liver injury (e.g. paracetamol overdose)
- Malignancy (hepatocellular carcinoma)
LFTs
ALP
alkaline phosphatase
LFTs
GGT
Gamma-glutamyltransferase
LFTs
Where is ALP derived from?
What do raised levels indicate?
biliary epithelial cells
cholestasis or bone disease
LFTs
Where is GGT found?
How do we interpret its levels?
hepatocytes and also biliary epithelial cells
It is a non-specific but highly sensitive marker of liver damage and cholestasis.
ALP and GGT are interpreted together to localise the source of raised ALP in the blood
LFTs
How do we interpret ALP and GGT together?
3
- high ALP + normal GGT => bone disease
- high ALP rise + high GGT => cholestasis
- normal ALP + high GGT => alcohol excess
LFTs
Bilirubin is a waste product of ____
haemoglobin breakdown
LFTs
Raised levels of bilirubin in the blood will lead to ____
jaundice
LFTs
Jaundice is usually absent until the bilirubin level exceeds ____ micromol/L.
50 micromol/L