Biochemistry of Alcohol

Question 1

What are the biomarkers of chronic alcohol abuse?

Answer 1

• Gamma GT: upregulated by ethanol
• Triacylglyceride: increased synthesis in liver
• raised MCV (mean corpuscular volume)

Question 2

What bloods must be done on patients with suspected alcohol-induced coma?

Answer 2

• glucose: are they hyperglycaemic?

- serum osmolality:

Question 3

What is the main contributing electrolyte to serum osmolality? What is the reference interval?

Answer 3

Na, Sodium

275-295 mmol/kg

Question 4

What is the osmolal gap?

Answer 4

The difference between the measured osmolality and the calculated osmolality

Question 5

How is osmolality calculated?

Answer 5

2([Na] + [K]) + [urea] + [glucose]

simplified

Question 6

What is a possible contributor to the osmolal gap in comatose patient?

Answer 6

alcohol

Question 7

List the LFTs:

Answer 7

ALT
Bilirubin
ALP
Albumin
GGT
PTR (prothrombin ratio)

Question 8

ALT is a marker of liver function

Answer 8

False

Marker of hepatocyte damage

Question 9

Sources of ALP?

Answer 9

liver
bone
kidneys
small intestine

Question 10

Where is Gamma GT found?

Answer 10

Liver, kidneys, pancreas, prostate

Question 11

What is the half life of albumin?

Answer 11

3 weeks

Question 12

During systemic inflammatory response levels of albumin rise

Answer 12

False

albumin levels fall

Question 13

Prothrombin ratio is a good marker of current liver synthetic function (T/F)

Answer 13

True

Question 14

What is the prothrombin half-life (T/F)

Answer 14

3-4 days

Question 15

What biochemical tests are run on a patient presenting with vomiting?

Answer 15

U&E
ABG
LFT
Amylase

Question 16

What is the differential diagnosis of vomiting in an alcoholic patient?

Answer 16

1. acute gastritis
2. oeseophageal stricture
3. pyloric stenosis

Question 17

Vomiting causes metabolic acidosis (T/F).

Explain why.

Answer 17

False

• metabolic alkalosis
• loss of H+ drives the release of bicarbonate into blood

Question 18

Why is metabolic alkalosis aggravated in vomiting patients with pyloric stenosis?

Answer 18

Normally, loss of acid from stomach is ‘compensated’ by loss of alkali (bicarbonate) from duodenum.
In pyloric stenosis, mostly acidic stomach contents are lost

Question 19

High bicarbonate and low H+ indicate…

If CO2 was high, this would indicate…

Answer 19

metabolic alkalosis

-that it’s compensated metabolic alkalosis (via decreased breathing rate)

Question 20

What biomarkers are relevant in a haematemesis patient?

Answer 20

U&E
LFT
PTR
Lactatic acid

Question 21

Very high Urea is seen in haematemesis patients (T/F)

Explain

Answer 21

True

proteins from the blood are metabolised

Question 22

What hormones are released in response to low blood volume?

Answer 22

Aldosterone - promotes Na and water retention

ADH - promotes water retention

Question 23

In alcoholic patients, what can be a cause of low blood volume?

Answer 23

Hypoalbuminaemia - failure of synthesis by cirrhotic liver

Question 24

Extremely low bicarbonate may be a sign of what?

Answer 24

Ingestion of methanol

Question 25

Why is lactate high in a haematemesis patient?

Answer 25

Loss of blood decreases perfusion of peripheral tissues. They therefore go into anaerobic metabolism, producing lactic acid.