Alcohol Flashcards
what is the recommended weekly intake of alcohol for men and for women?
for both men and women 2-3 units/day or 14 units/week is recommended
what is classed as heavy drinking in men and in women?
M: 7 or more units/day
F: 5 or more units/day
a dependent drinker typically drinks how many units a day?
> 8-10 units/day
safe alcohol consumption = ?
2-3units/day (M&F)
hazardous alcohol consumption = ?
> 14 units/week
dangerous alcohol consumption = ?
> 35 units/week
A person who drinks 3 units 4 days a week would be classed as a … drinker
a social drinker
drinks in moderation, within safe limits and the benefits probably outweigh the risks
A person that drinks 8 units/day regularly would be classed as a … drinker
a heavy drinker
drinks heavily and regularly, exceeds sensible limits (>8 units/day) - will cause problems if maintained
A person that drinkers 10 units on 3 or 4 nights a week, every week would be classed as a … drinker
a heavy drinker
drinking heavily and irregularly = binge drinking
A person that drinks regularly which causes problems with their personal life, yet continues to drink despite this would be classed as a … drinker
Problem drinker
Drinking causes problems in personal or social adjustment but continues to drink heavily despite this.
Problems can be overcome by stopping
A person that has a tolerance to the effects of alcohol and has a compulsion to drink (which they are aware of), who avoids the feeling they get when they haven’t had any alcohol, would be classed as a … drinker
someone with alcohol dependence (alcoholic)
aware of compulsion to drink and show prominent drink seeking behaviour
Which abnormal blood results would fit the criteria required for alcohol dependence?
raised gamma glutamyl transferase (GGT)
raised carbohydrate-deficient transferrin (CDT)
raised MCV
What is the criteria for alcohol dependence?
heavy drinking (>10u/d) tolerance withdrawal syndromes inability to stop drinking abnormal blood tests
what is % ABV
alcohol content is expressed as a % of alcohol by volume (% ABV)
4% v/v alcohol = ?
4ml alcohol per 100ml beer
4% w/w alcohol = ?
4g alcohol/100g beer
how much does 1ml of alcohol weigh?
1ml alcohol = 0.79g
How many ml is 1 pint?
1 pint = 568ml
How many ml of alcohol was consumed from 125ml of 12% wine?
ml = 125 x 0.12 = 15ml
How many grams of alcohol was consumed from 125ml of 12% wine?
g = 125 x 0.12 x 0.79 = 11.85g
10g = 1 UK unit of alcohol… true or false
false
1unit = 10ml or 8g pure alcohol
Give examples of 1 unit of alcohol in drinks
1/2 pint of weak (3.5%) beer
small (<100ml) glass of wine (12%)
small (28ml) measure of spirit (40%)
Where does absorption of alcohol occur?
20% from stomach, 80% from small intestine
Rate of alcohol absorption depends on rate of alcohol ingestion - true or false
false
rate of alcohol absorption depends on rate of gastric emptying - e.g. decreased if food in stomach
tolerance to alcohol increases the rate of its absorption - true or false
true
Rate of alcohol absorption increases proportionately with strength of drink (%ABV) - true or false
false
rate of alcohol absorption depends on type of drink (strength and congeners)
optimum strength is 10-20%
the bubbles in champagne increase its rate of absorption - true or false
TRUE
The bubbles attract blood to stomach capillaries which results in faster alcohol absorption
Why is beer absorbed slowly?
the congeners present in the drink slow rate of absorption
it is also a lower concentration of alcohol
Why are neat spirits absorbed slowly?
Neat spirits irritate the stomach lining and induce mucus secretion - delays absorption
absorption of alcohol is complete within …hrs?
1-3hrs
Re. kinetics of alcohol, how do you find C0?
C0 = [alcohol consumed (g) x 100] divided by [body weight (kg) x W.F.]
the units for blood alcohol concentration ?
BAC in mg/100ml
Re. alcohol kinetics, how do you calculate concentration a T hours?
C at T hrs = C0 - (beta x T)
beta = rate of elimination T = hours passed
Cmax of blood alcohol concentration is reached during which phase of alcohol kinetics?
distribution phase
What does BAC depend on?
how much EtOH was consumed (g)
the volume of distribution (place for EtOH to hide)
how much has been eliminated (beta x T)
What is the normal range for the rate of alcohol elimination?
10-20mg alcohol/100ml blood/hr
When is BAC > VHAC ?
during absorption BAC > VHAC
At equilibrium, BAC < VHAC but at what ratio?
ratio 0.8
BAC < VHAC
Can BAC be predicted from VHAC?
BAC cannot be reliably predicted from VHAC
VHAC corroborates PM BAC (should be similar)
Urinary alcohol concentration is the average of several hours’ excretion - true or false
true
urine collects in bladder over several hours and UAC is the average of the secretion of this
When is UAC < BAC?
during absorption phase UAC < BAC
When is UAC > BAC?
during elimination phase, UAC > BAC
Alcohol is distributed in the body via the bloodstream and is taken up by tissues in proportion to…?
Alcohol is taken up from blood by tissues in proportion to their water content.
bone and muscle are referred to as “hollow legs”, why?
more alcohol is removed from blood into water-rich bone & muscle - they are like a large reservoir for alcohol aka. “hollow legs”
Obese persons take up less alcohol into their tissues - true or false
true
less alcohol is removed from blood by fatty tissue - more remains in bloodstream, less in tissues
how do you find lean body mass?
weight x W.F
what is the widmark factor?
an expression of how much body water you have, e.g. a lean person has high water content (more muscle) and an obese person has lower water content (more fatty tissue)
what is the average male and female W.F value?
female = 0.55 male = 0.68
What is the legal BAC limit?
80mg/ml in RUK
50mg/ml in Scotland
BAC = BrAC x ?
BAC = BrAC x 2.3
BAC = UAC x ?
BAC = UAC x 0.75
BAC = VHAC x ?
BAC = VHAC x 0.8
What is the legal BrAC limit?
35mg alcohol/100ml breath (RUK)
22mg alcohol/100ml breath (Scotland)
90% of alcohol is eliminated via the liver, but where is the rest lost from?
breath, sweat and urine
2-5% each
What is the average rate of alcohol elimination?
15mg/100ml/hr (1 unit/hr)
Alcoholics can have a rate of elimination of up to ?
up to 40mg/100ml/hr in alcoholics
Describe the hepatic metabolism of alcohol.
EtOH > acetaldehyde > acetate > uric acid, ketones, triglycerides
alcohol dehydrogenase is essential enzyme involved in EtOH > acetaldehyde and acetaldehyde > acetate
What are the 3 stages of intoxication and at what BAC do they occur?
- excitement (BAC <100mg%)
- confusion (BAC 100-200mg%)
- stupor (BAC >200mg%)
how is the brain effected when BAC is 80mg/100ml?
depression of higher inhibitory cortical function
how is the brain effected when BAC is 150mg/100ml?
depression of limbic system (memory, orientation)
depression of cerebellum (coordination, speech)
decreased motor control
slight slurring of speech
blurred vision
how is the brain effected during when BAC is 230mg/100ml?
upper brainstem depressed (RAS-conscious level)
lower brainstem depressed (breathing & vasomotor centres)
anaesthetic and unfeeling
simulates head injury - may also coexist
What are some of the dangers of severe intoxication?
hypotension hypothermia inhalation of vomit (loss of gag reflex) haematemesis trauma death
List the effects of alcohol on driving performance.
Decreased muscular control and co-ordination. Increased reaction times. Impaired peripheral vision. Inability to judge speed and distance. Inability to deal with unexpected.
Falsely increased confidence.
What is the legal limit for BAC in Sweden, Estonia and Poland?
BAC 20mg/100ml
What is the legal limit for BAC in Czech Republic, Slovakia, and Hungary?
0
Police constable pulls over driver - on what grounds do they have to carry out a screening breath test?
If they suspect the person:
Of having been drinking
Of having committed a moving traffic offence, or
Of being intoxicated at the time of an accident.
In the context of a RTA, who can be arrested and taken to the station?
A person who is unfit through drink or drugs.
A person that has provided a +ve roadside test.
A person that has refused a roadside test.
What tests/samples are done at the police station once a person has been arrested at roadside?
2 evidential breath samples
or
blood specimen for analysis (Dr required)
Lower of 2 values used for breath sample.
If BrAC is > legal limit, the driver can replace the sample with blood or urine - true or false
True in England & Wales
Not an option in Scotland
Describe the process of obtaining a police sample for BAC.
Blood specimen taken by a forensic Dr with driver’s consent.
Part of sample offered to driver.
Lab analysis by gas chromatography
6mg% (or 6% if >100mg%) is deducted to allow for lab error
Describe the process of taking a urine sample for UAC.
Urine sample must be taken within 1hr of incident, but detainees must empty their bladder first.
The next smallest volume of urine is collected when naturally voided.
Part of sample offered to driver - gas chromatography
Failure to provide a roadside screening breath sample and 2 evidential breath samples or blood/urine when required constitutes an offence tantamount to D&D - true or false
true
What is the ‘hip flask’ defence?
aka. post-accident drink defence
If person can prove that they consumed alcohol after they ceased to drive and if they had not done so, then they would not exceed the legal limit.
Burden of proof is on defence.
Skin contamination via alcohol wipes is a possibly defence against a D&D charge - true or false
true
if enough doubt is sowed into the jury’s mind then the case might get thrown
What is the caveat to BAC back calculation?
It is possible to assume all alcohol is taken at once and reaches one large theoretical peak (C0).
Average rate of elimination is assumed
However, this only works provided BAC never reaches zero.
Police can demand a blood/urine sample if initial examination of person suggests influence of drugs - true or false?
false
police have no right to demand this however a Dr may advise it if their exam suggests drug impairment
A person with alcohol dependence is aware of their compulsion to drink - true or false
true
alcohol withdrawal is always associated with delirium tremens - true or false
false
alcohol withdrawal can be uncomplicated, associated with withdrawal fits, or delirium tremens
Describe uncomplicated alcohol withdrawal.
Onset 6-12hrs, peak 48hrs
Lasts for a few days
Features include: tremor, N&V, malaise, headache, insomnia, sweating, tachycardia, HTN, anxiety, depression, irritability, transient hallucinations
what drug can be given to ease alcohol withdrawal?
chlordiazepoxide (oral)
What is the maximum dose of the drug given in alcohol withdrawal in 24hrs?
max dose of chlordiazepoxide in 24hrs is 200mg
What are some GIT complications of alcohol dependence?
Oesophagitis, MW tears Gastritis, duodenitis, peptic ulcer malabsorption diarrhoea pancreatitis
What are some hepatic complications of alcohol dependence?
Fatty change alcoholic hepatitis cirrhosis portal HTN & oesophageal varices liver cancer
What are some cardiac complications of alcohol dependence?
arrhythmias + sudden death
alcoholic cardiomyopathy
wet beri-beri
hypertension
a heart that is globular looking in a known alcoholic = what complication of alcohol dependence?
alcoholic cardiomyopathy is rare but globular looking
thiamine deficiency is associated with which cardiovascular complication of alcohol dependence?
wet beri-beri
triad of Wernicke’ encephalopathy?
eye signs (nystagmus), ataxia and (global) confusion
A known alcoholic presents with gaze palsy, confusion and disturbed memory, he also appears to be having trouble walking… diagnosis?
Wernicke’s encephalopathy
ataxia of trunk and lower extremities
eyes signs can be nystagmus, gaze palsies or ophthalmoplegia
What develops if Wernicke’s is not reversed fast enough?
Korsakoff’s syndrome will develop after an acute episode of Wernicke’s encephalopathy if it is not reversed fast enough
Short term memory loss and confabulation = ?
Korsakoff’s syndrome
amnesia state with profound impairment of both retrograde & anterograde memory but relative preservation of other intellectual abilities in a setting of clear consciousness.
What is the pathological basis for ‘alcoholic dementia’?
cerebral atrophy
List some possible metabolic disturbances from alcohol dependence
Hypoglycaemia hyper-lipidaemia hyper-uricaemia K+, Mg2+, PO4- lactic acidosis
Obesity is often seen in the first stages of alcohol dependence - true or false
true
initial obesity due to additional calories -> malnutrition -> vitamin deficiencies
thiamine = vitamin ?
thiamine = B1
folate = vitamin ?
folate = vitamin B12
What is the typical fatal alcohol level in a non-tolerant person?
> 250mg/100ml
What is the average fatal alcohol level for those tolerant to it?
average = 450mg%
A person in a coma due to fatal alcohol intoxication will have BAC > UAC on PM toxicology - true or false
false
UAC > BAC if death follows prolonged coma
What 3 mechanisms contribute to death in fatal alcohol intoxication?
Brain stem depression
Positional asphyxia
Inhalation of vomit
Why do you need to be cautious when interpreting BAC from PM toxicology results?
BAC/VHAC/UAC levels can be used to corroborate concentrations seen in life, but artifactual elevation is common due to PM alcohol redistribution and microbial alcohol production.
Passive diffusion of unabsorbed alcohol from stomach or aspirated vomitus in airways = ?
PM alcohol redistribution
Which cases favour PM microbial alcohol production?
warmth, hyperglycaemia, septicaemia, abdominal trauma
How much alcohol can bacteria produce within a few days PM?
levels <70mg/100ml can occur within few days (<150 in some cases)
What is a common pathological sign of the stomach seen in alcoholics, especially those who die outdoors?
lines of ulcers in stomach lining which are arranged where the mucosa has been pushed together on emptying
when stomach is spread out on autopsy, it looks like lines following the stomach curves
What is a common pathological sign seen in the stomach in deaths due to hypothermia?
Wischnewski ulcers
gastric mucosa petechial haemorrhages
What might be seen at the scene and external examination of a person who has died from hypothermia?
outdoors - disturbed scene
indoors - “hide and die” syndrome
paradoxical undressing
pink discolouration of knees and elbows
Homeless person found dead under table in abandoned house, curled up in a ball with only a t-shirt and shorts on. PM toxicology of urine shows which abnormality?
urinary catecholamines (adrenaline, NA) in hypothermia
which arrhythmia is an obscure cause of death in an alcoholic?
prolonged QT
Catecholamine surge can be mechanism of death in which stage of alcohol intoxication?
Catecholamine surge in acute intoxication or withdrawal
What is an obscure electrolyte disturbance and CoD in someone with alcohol dependence?
magnesium deficiency (also alcoholic ketoacidosis or hypoglycaemia)
When analysing a blood sample for BAC, how much is deducted from the calculated value and why?
6mg/100ml or
6% if >100mg/100ml
deducted to allow for lab error
