Interpreting bloods Flashcards

1
Q

LFTs

Why might we order LFTs?

4

A
  • investigate patients for liver disease
  • monitor patients confirmed liver disease
  • monitor the effects of medications
  • baseline’ screening panel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

LFTs

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

LFTs

ALT

A

Alanine aminotransferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

LFTs

AST

A

aspartate aminotransferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

LFTs

What are ALT and AST?

What do raised levels indicate?

A
  • enzymes found within liver cells at high concentrations
  • liver cell (hepatocyte) inflammation or damage.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

LFTs

What can we assess using the ratio between AST and ALT?

A

The AST:ALT ratio can help determine the aetiology of hepatocellular injury, with a >2:1 ratio classical of alcoholic liver disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

LFTs

What are some common causes of hepatocellular injury?

A
  • Hepatitis (viral, alcoholic, ischaemic)
  • Liver cirrhosis
  • Drug / toxin-induced liver injury (e.g. paracetamol overdose)
  • Malignancy (hepatocellular carcinoma)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

LFTs

ALP

A

alkaline phosphatase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

LFTs

GGT

A

Gamma-glutamyltransferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

LFTs

Where is ALP derived from?

What do raised levels indicate?

A

biliary epithelial cells

cholestasis or bone disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

LFTs

Where is GGT found?

How do we interpret its levels?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

LFTs

How do we interpret ALP and GGT together?

3

A
  • high ALP + normal GGT => bone disease
  • high ALP rise + high GGT => cholestasis
  • normal ALP + high GGT => alcohol excess
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

LFTs

Bilirubin is a waste product of ____

A

haemoglobin breakdown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

LFTs

Raised levels of bilirubin in the blood will lead to ____

A

jaundice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

LFTs

Jaundice is usually absent until the bilirubin level exceeds ____ micromol/L.

A

50 micromol/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

LFTs

Describe the bilirubin metabolism/excretion pathway.

A
  • RBC breakdown -> unconjugated bilirubin -> binds to albumin in the bloodstream
  • Hepatocytes take up unconjugated bilirubin -> conjugated bilirubin
  • conjugated bilirubin -> biliary tract -> bowel lumen (bile)
  • Gut bacteria + bile -> urobilinogen -> stercobilinogen (stool)

A small amount of urobilinogen is reabsorbed from the intestine into the portal venous system, and as urobilinogen is water-soluble, the kidney is able to excrete some of this into the urine.

17
Q

LFTs

In pre-hepatic jaundice, patients are often anaemic due to excess red blood cell breakdown. The diagnosis may be ____ if no anaemia is present.

A

Gilbert’s syndrome

18
Q

LFTs

Causes of predominantly unconjugated hyperbilirubinaemia:

2

A
  • Pre-hepatic jaundice (e.g. haemolysis)
  • Gilbert syndrome
19
Q

LFTs

Causes of predominantly conjugated hyperbilirubinaemia:

2

A
  • Cholestasis
  • Hepatocellular jaundice (!)

! Hepatocellular jaundice can initially cause a mixed conjugated/unconjugated jaundice, but at its most severe, unconjugated hyperbilirubinaemia is seen.

20
Q

LFTs

What is the role of albumin?

A

helps to bind water, cations, fatty acids and bilirubin. It also plays a crucial role in maintaining the oncotic pressure of blood

21
Q

LFTs

How is albumin used to assess the liver?

A

as a non-specific marker of the synthetic function of the liver.

22
Q

LFTs

Albumin levels can fall due to:

2

A
  • Decreased albumin production: malnutrition, severe liver disease
  • Increased albumin loss: protein-losing enteropathies, nephrotic syndrome
23
Q

LFTs

A decrease in the synthetic function of the liver indicates ____.

A

severe liver disease

24
Q

LFTs

Severe liver disease leads to decreased production of clotting factors and an increased____ / ____ in the absence of other causes of coagulopathy.

A

prothrombin time (PT) / INR

25
Q

LFTs

A greater than 10-fold increase in ALT and a less than 3-fold increase in ALP suggests a predominantly ____

A

hepatocellular injury

26
Q

LFTs

A less than 10-fold increase in ALT and a more than 3-fold increase in ALP suggests ____

A

cholestasis

27
Q

LFTs

An isolated ALP rise without a GGT rise should raise your suspicion of ____.

A

bony pathology

28
Q

LFTs

An isolated bilirubin rise without further LFT derangement suggests ____ or ____ .

A

pre-hepatic jaundice or Gilbert’s disease

29
Q

LFTs

How might LFTs appear in chronic hepatocellular pathology?

A

the ALT / AST may return to within the normal range, however synthetic function of the liver can be markedly impaired.

30
Q

LFTs

A