CLASP Alcohol Flashcards
Where may methanol be found sometimes
Home brew alcohol - it is toxic
What is methanol metabolised into
Formaldehyde (fixes tissue)
Then Formic acid (dissolves you)
Main symptom of methanol poisoning
Blindness
How is methanol poisoning treated
Ethanol +/- dialysis
Ethanol - competitive inhibitor
What enzyme metabolises both ethanol and methanol
Alcohol dehydrogenase
Why does drinking on a full stomach reduce alcohol absorption rate
Reduced gastric emptying - more metabolised in stomach instead of being absorbed into blood stream
Where is alcohol absorbed
Mainly small intestine, some in stomach
Which drugs increase gastric emptying therefore increase the rate of alcohol absorption into bloodstream
Antihistamines
Domperidone
Metoclopramide
Effect on absorption of drinking high conc alcohol
Reduced absorption - irritates gastric mucosa, delays emptying
Why do men have higher alcohol tolerance than women
Men are leaner - greater dilution volume
Women also have reduced alcohol dehydrogenase activity
Where is alcohol metabolised
Liver (mainly)
Pancreas
Brain
Where is alcohol excreted
Urine
Breath
Sweat
Stool
Rate of alcohol removal from body
15mg/100ml/hour = 1 unit/hour
When does alcohol concentration peak
1 hour after absorption
How does blood alcohol concentration decrease
Linearly
Which ethnic groups have reduced alcohol dehydrogenase
Aboriginis, eskimos
Why do some people flush and feel sick after alcohol
Low ALDEHYDE dehydrogenase enzyme - acetaldehyde builds up
Which drug can be used to manage chronic alcoholism
Aldehyde dehydrogenase inhibitor - disulfaram/anabutase - causes them to flush and be sick
Why do people who drink more have higher tolerance
Alcohol dehydrogenase upregulated
Which alternative pathway of alcohol metabolism is activated in chronic drinkers?
MEOS pathway - cytochrome P450 family of proteins
Which 3 biochemical processes are impaired in chronic alcoholism
Gluconeogenesis
Kerbs cycle
Fatty acid oxidation
Why may you be sore after a night of drinking
Krebs cycle inhibited - anaerobic metabolism - lactic acid builds up
What 2 processes start in the liver when blood glucose is low after a night of heavy drinking
Gluconeogenesis (using fat, proteins etc)
Glyocogenolysis
Why does alcohol make you gain weight
Impaired fatty acid oxidation
Excess lipid synthesis
plus calories in alcohol
How can DKA and alcoholic ketoacidosis be differentiated
DKA - massive hyperglycaemia
Alcoholic KA - little/no hyperglycaemia
The level of which neurotransmitter is increased by alcohol
GABA
How can you die from acute intoxication
Aspiration - unconscious, swallowing impaired, vomit and aspirate
Trauma - misadventures, falls, fights
Vomiting - metabolic alkalosis, mallory-weirs, boerhaave syndrome, acute pancreatitis
Release of what hormone is inhibited in alcohol
ADH
Why does alcohol give you a heavy heartbeat
-ve inotrope
therefore heart rate increases
What is holiday heart syndrome
Binge drinking causing spontaneous SVT
What contributes to a headache the day following
Congeners - substances used to make alcohol smell a certain way
Serotonin
Dehydration
Acetic acid
Why can alcohol cause heartburn the next morning
Smooth muscle relaxant - GORD
therefore also causes snoring/suppression of cough/gag
Brain injury caused by falling when drunk
Subdural haematoma
2 things that thiamine (B1) deficiency causes
Beri-beri
Wernicke-Korsikoff syndrome
Symptoms of wernicke korsakoff syndrome
Ataxia
Abnormal eye movements
Impaired consciousness/memory loss
Confabulation
Seen in Wernicke Korsakoff syndrome (or just korsakoff) - can’t make new memories so make up lies to disguise this
Why can you get neuropathy in alcoholism
Thiamine maintains peripheral nerves:
- Foot drop
- Wrist drop
- Pain
More rarely - arrhythmias/CCF from CNX involvement
Consequence of aspiration into lungs
Acute inflammation (pneumonitis) Later infection (pneumonia)
What heart disease is assoc with chronic alcoholism, and what dies this pose a risk of
Dilated cardiomyopathy (big, heavy heart with normal wall thickness)
Arrhythmias, CCF
Name of thiamine deficiency along with cardiac arrhythmias and CCF in alcoholics
Wet Beri Beri
Initial liver disease after 1-2 days of heavy drinking
Alcoholic fatty liver (aka steatosis)
Reason for increased intracellular fat seen in AFLD
- More fatty acids delivered to liver
- Alcohol converts NAD>NADH, stimulating lipid synthesis
- Fatty acid oxidation is reduced
- Reduced fat export by tubulins
Liver disease seen after 3-4 weeks of heavy drinking
Alcoholic steatohepatitis (fat accumulation + inflammation)
direct toxicity of alcohol causes inflammation
Symptoms of steatohepatitis
Fever
Jaundice
Tender liver
What are all of these things seen in alcoholic steatohepatitis:
- Acute inflammatory cells
- Ballooning
- Mallory bodies
- lymphocytes
- Fat inclusions in hepatocytes
- Damaged intermediate filaments (stain dark purple)
Which cells deposit scar tissue around hepatocytes in cirrhotic liver
Interstitial cells of Ito
Where specifically is collagen deposited by cells of Ito and what does this leave behind
Space of Disse
Islands of functioning hepatocytes surrounded by bands of scar tissue
Why do ‘islands of hepatocytes’ function poorly in cirrhosis
Reduced blood supply and capacity to metabolise it, so toxic waste build up
Where is blood directed through if poor cirrhotic flow
Splenic vein
Oesophageal veins
Anorectal veins
Superficial veins
How can hypoglycaemia be caused by alcohol
Reduced gluconeogenesis - dangerous in diabetics
Type of cancer caused by barret’s
Adenocarcinoma
What is a varied
Abnormally dilated vein
In pancreatitis the lipase enzyme is prematurely activated and digests pancreatic cells, what is this process called?
Fat necrosis
Normal intestinal epithelium?
Columnar epithelium with goblet cells
In pancreatitis, enzymes come into contact with fat and turn it into soap, what is this process called?
Saponification
Difference between Wernicke and Korsakoff syndrome
Wernicke - Walking - ataxia, abnormal eye movements (reversible)
Korsakoff - memory loss, confabulation (irreversible)
In alcoholism, MCV is increased/decreased
Increased
Why do triglyceride levels increase in excessive liver
Increased lipid synthesis in liver
Tests to see if a patient is a chronic drinker
Gamma GT (raised) MCV (raised) Triglycerides (raised)
What tests are done when a patient comes into hospital in a coma
Blood glucose (hypoglycaemia) Serum osmolality
Calculation for serum osmolality?
Roughly = 2 x Na conc
How is serum osmolality used to determine if a patient is in an alcoholic coma
Osmolal gap = serum osmolality - calculated osmolality
Big gap = ethanol contributing
tests if main complaint of patient is vomiting
U&E
LFT
Amylase
ABG
U&E of an alcoholic who is vomiting
Low potassium
Low sodium
High urea and creatinine (reduced GFR)
tests for a patient who presents with haematemesis
U&E
LFT
PTR
Lactate
Why is urea classically raised in haematemesis
You’re absorbing your own blood, which contains proteins
What poison is seen in antifreeze? Treatment
Polyethylene glycol (antifreeze)
Ethanol again
What is the meyer-overton rule
As the number of carbons in an alcohol increases, so too does its ability to act as a general anaesthetic
Cut off point for general anaesthetic effect of alcohol
hexanol-pentanol, then decreases
What neurotransmitters does alcohol effect
Glutamate (excitatory)
GABA, Glycine (inhibitory)
Ethanols effect on neurotransmitters causes what?
CNS depression
Drink drive limit
0.05mg/100ml
Definition of harmful alcohol use
Misuse for 1 month
Criteria of alcohol dependence syndrome
Strong compulsion to take alcohol Difficulties in controlling alcohol use Using alcohol despite evidence of harm Preoccupation with alcohol use Increased alcohol tolerance Physiological withdrawal
Screening tests to determine patient’s dependence on alcohol
FAST - before treatment
AUDIT Screen - after treatment
What drugs help alcohol withdrawal
Chlordiazepoxide/Diazepam
Oxazepam
What is Child Pugh score
Calculate prognosis in cirrhosis and assess suitability for drugs e.g. chlordiazepoxide
Supportive treatment given to alcoholics
Oral thiamine
IM/IV Pabrinex (multi vitamins)
What is thiamine used for in body
co-enzyme for krebs cycle
Next step if alcohol withdrawal patient is delirious
Admit to hospital
IV pabrinex
What happens 2-3 days into alcohol withdrawal
Delirium tremens
What causes wernicke encephalopathy
Lactic acid in brain
What causes korsakoff syndrome
Irreversible brain damage from lactic acid in brain
Apart from Disulfarim, what can be given in chronic alcoholism
Acamprosate - reduces cravings
What type of stroke commonly presents in drinkers
Haemorrhagic
What neuro disease is common in drinkers
Amnesia
Chronically, what arrhythmia might alcoholism lead to
Long QT syndrome
