Biochemistry of Alcohol Flashcards
What are the biomarkers of chronic alcohol abuse?
- Gamma GT: upregulated by ethanol
- Triacylglyceride: increased synthesis in liver
- raised MCV (mean corpuscular volume)
What bloods must be done on patients with suspected alcohol-induced coma?
- glucose: are they hyperglycaemic?
- serum osmolality:
What is the main contributing electrolyte to serum osmolality? What is the reference interval?
Na, Sodium
275-295 mmol/kg
What is the osmolal gap?
The difference between the measured osmolality and the calculated osmolality
How is osmolality calculated?
2([Na] + [K]) + [urea] + [glucose]
simplified
What is a possible contributor to the osmolal gap in comatose patient?
alcohol
List the LFTs:
ALT Bilirubin ALP Albumin GGT PTR (prothrombin ratio)
ALT is a marker of liver function
False
Marker of hepatocyte damage
Sources of ALP?
liver
bone
kidneys
small intestine
Where is Gamma GT found?
Liver, kidneys, pancreas, prostate
What is the half life of albumin?
3 weeks
During systemic inflammatory response levels of albumin rise
False
albumin levels fall
Prothrombin ratio is a good marker of current liver synthetic function (T/F)
True
What is the prothrombin half-life (T/F)
3-4 days
What biochemical tests are run on a patient presenting with vomiting?
U&E
ABG
LFT
Amylase
What is the differential diagnosis of vomiting in an alcoholic patient?
- acute gastritis
- oeseophageal stricture
- pyloric stenosis
Vomiting causes metabolic acidosis (T/F).
Explain why.
False
- metabolic alkalosis
- loss of H+ drives the release of bicarbonate into blood
Why is metabolic alkalosis aggravated in vomiting patients with pyloric stenosis?
Normally, loss of acid from stomach is ‘compensated’ by loss of alkali (bicarbonate) from duodenum.
In pyloric stenosis, mostly acidic stomach contents are lost
High bicarbonate and low H+ indicate…
If CO2 was high, this would indicate…
metabolic alkalosis
-that it’s compensated metabolic alkalosis (via decreased breathing rate)
What biomarkers are relevant in a haematemesis patient?
U&E
LFT
PTR
Lactatic acid
Very high Urea is seen in haematemesis patients (T/F)
Explain
True
proteins from the blood are metabolised
What hormones are released in response to low blood volume?
Aldosterone - promotes Na and water retention
ADH - promotes water retention
In alcoholic patients, what can be a cause of low blood volume?
Hypoalbuminaemia - failure of synthesis by cirrhotic liver
Extremely low bicarbonate may be a sign of what?
Ingestion of methanol
Why is lactate high in a haematemesis patient?
Loss of blood decreases perfusion of peripheral tissues. They therefore go into anaerobic metabolism, producing lactic acid.
