Alcohol

Question 1

What is alcohol

Answer 1

OH group attached to carbon chain

Ethanol in alcoholic drinks

Question 2

Spectrum of alcohol use

Answer 2

Teetotal = 10%
Sensible/social drinker
- 14units/week
Heavy drinker
- men > 7 , women > 5 units/day
Problem drinker
- continues drinking whilst having problems in their life
Dependent drinker
- > 8-10 units/day

Question 3

Levels of alcohol drunk

Answer 3

Sensible < 14 units/week
Hazardous > 14 units/week
Dangerous > 35 u/w

Question 4

Cost equation of alcohol in society

Answer 4

Debit - £2bn
- absenteeism
- unemployment
- offences
- RTA
- health
- premature death
Credit - £7bn
- excise duty
- exports
- jobs

Question 5

Alcohol as a factor in social harm

Answer 5

20% of RTAs
25% of drownings
30% of accidents
35% of divorces and child abuse
40% of domestic violence
50% of murders
60% of head injuries
70% of suicides
80% of fire deaths

Question 6

Features of alcohol dependence

Answer 6

Aware of compulsion to drink
Prominent drink seeking behaviour
Tolerance to its effects
Withdrawal syndromes on stopping
Avoidance of withdrawal 
Social psychological and physical problems
Criteria
- heavy drinking - > 10u/d
- tolerance
- withdrawal syndromes
- inability to stop drinking
- abnormal blood tests - GGT, CDT, MCV

Question 7

Average content of alcoholic beverages

Answer 7

Alcohol content expressed as % alcohol by volume
- 4% = 4ml/100ml beer
1ml alcohol weight 0.79g
Amount alcohol (ml) = volume consumed (ml) x % ABV
1 unit = 10ml or 8g or pure alcohol
1unit =
- half pint of weak beer (3.5%)
- small (<100ml) glass wine (12%)
- small (28ml) measure of sprits (40%)
1 unit = amount of alcohol (ml) x 0.79 / 10

Question 8

Factors affecting absorption of alcohol

Answer 8

Gastric emptying accelerated - increased absorption
- tolerance
- gastrectomy
Gastric emptying slowed - reduced absorption
- food in stomach
- drugs

Question 9

Absorption of alcohol

Answer 9

20% from stomach
80% from small intestine
Rate of alcohol absorption depends on rate of gastric emptying
Food reduced rate and extent of absorption - 2/3 fasting value
Depends on type of drink - strength, effect of congeners
- 10-20% optimal
- champagne absorbed quick - high conc and bubbled
- beer absorbed slow - low conc, congeners
- neat spirits irritate stomach - mucus delays absorption
Absorption complete within 1-3 hours

Question 10

Kinetics of alcohol

Answer 10

Absorption phase
Distribution phase
- peak = Cmax ( max concentration)
- 15mg/100mls from 1 unit on empty stomach
Elimination phase
- mostly by liver
Tmax = time at max concentration
C0 = hypothetical track back of max concentration if all absorbed instantly
= weight alcohol consumed x 100 / body weight x widmap factor
W.F = measure of body water
= 0.6 roughly

Question 11

Rate of elimination

Answer 11

= 10-20mg alcohol / 100ml blood / hour

About 1 unit per hour

Question 12

Calculate blood alcohol levels

Answer 12

C at T hours = C0 - (rate of elimination x number of hours)

Question 13

Breath alcohol

Answer 13

1-2 hours after drinking

BAC:BrAC = 2300:1

Question 14

Vitreous humour alcohol concentration

Answer 14

During absorption BAC > VHAC
At equilibrium BAC < VHAC (ration 0.8)
- due to higher water concentration in VH
- takes longer to get into VH
Cannot reliably predict BAC from VHAC
VHAC corroborates BAC conc

Question 15

Urine blood alcohol concentration

Answer 15

Urine collects in bladder over several hours

• UAC average of several hours of excretion
• UAC < BAC during absorption phase
• UAC > BAC during elimination phase

Question 16

Distribution of alcohol

Answer 16

Dissolves in water
Distributed by bloodstream
Taken up by tissues in proportion to water content
- more alcohol removed from blood into water rich bone and muscle
- less alcohol removed from blood by fatty tissue
- those more lean able to take up more alcohol for lower BAC

Question 17

Factors affecting blood alcohol concentration

Answer 17

Depends on
- how much alcohol consumed 
- volume of distribution
= mass consumed / volume of distribution
Lean body mass = Wt x WF

Question 18

What is Widmark Factor

Answer 18

Gives rough estimate of BAC after alcohol - assumes instantaneous 100% absorption
Factor is proportion of body water
- 0.68 for M and 0.55 for F
- calculate from online chart

Question 19

Calculate BAC (Co)

Answer 19

Weight alcohol consumed (g) x 100
/
Body weight (g) x W.F

C at T hours = C0 - ( elimination rate x T)

Question 20

Conversion factors for body fluids

Answer 20

BrAC = BAC / 2.3
UAC = BAC / 0.75
VHAC = BAC /0.8

Question 21

Legal limit for driving

Answer 21

35 (E) or 22(S) micrograms alcohol / 100ml breath

80 (E) or 50 (S) mg alcohol/ 100ml blood

Question 22

Elimination of alcohol

Answer 22

90% broken down in liver
Small amounts lost in 
- breath - 2-5%
- sweat - 2-5%
- urine - 2-5%
Rate of elimination (b) is 10-20mg per 100ml blood per hour
- average 15 mg/100ml/h = 1 unit/ hour
- up to 40 in alcoholics
Amount eliminated in T hours = (b x T)

Question 23

Alcohol metabolism

Answer 23

Ethanol -> acetaldehyde
- by alcohol dehydrogenase
Acetaldehyde -> acetate
- by aldehyde dehydrogenase
Releases CO2 and H2O
Forms uric acid, ketones and triglycerides

Question 24

Stages of intoxication

Answer 24

Excitement - BAC < 100mg%
- depression of higher inhibitory cortical function
Confusion - BAC 100-200mg%
- depression of limbic system - memory, orientation
- depression of cerebellum - coordination, speech
Stupor - BAC > 200mg
- depression of upper BS - RAS - conscious level
- depression of lower BS - breathing and vasomotive centres

Question 25

Acute intoxication may mimic

Answer 25

Head injury
Neurological disease
Diabetic hypoglycaemia
Epilepsy and related states
Drug intoxication

Question 26

Features of hangover

Answer 26

Toxic effects of alcohol metabolites and congeners on brain and GIT
Headache, malaise, nausea, tremor
Temporary and self-limiting
Dehydration and hypoglycaemia worsen

Question 27

Effect on alcohol on performance

Answer 27

Decreased muscular control and coordination
Increased reaction times
Impaired peripheral vision
Inability to judge speed and distance
Inability to deal with unexpected
Falsely increased confidence

Question 28

Features of alcohol dependence

Answer 28

Aware of compulsion to drink
Prominent drink seeking behaviour
Tolerance to its effects
Withdrawal syndromes on stopping
Avoidance of withdrawal
Social, psychological and physical problems

Question 29

Factors leading to alcoholism

Answer 29

Constitution
- low self-esteem
- habit
- boredom
- loneliness
- anxiety and depression
- ethnicity
Environment
- availability
- peer pressure
- occupation
- stress
- competitive lifestyle
- unemployment

Question 30

Features of alcohol withdrawal

Answer 30

Uncomplicated

• onset 6-12 hours
• peak 48 hours
• lasts few days
• features tremor, N+V, malaise, headache, insomnia, weakness, sweating, tachycardia, hypertension, anxiety, depression, irritability, transient hallucinations

Question 31

Causes of death in alcoholics

Answer 31

Acute alcohol intoxication
Trauma
Alcohol related disease
Incidental natural disease

Question 32

Physical complications of alcohol

Answer 32

GIT
- oesophagitis
- Mallory-Weiss tears
- gastritis
- duodenitis
- peptic ulcer
- malabsorption
- diarrhoea
- pancreatitis
Liver
- fatty change
- alcoholic hepatitis
- cirrhosis
- liver failure
- portal hypertension and oesophageal varices
- liver cancer
CVS
- arrhythmias - sudden death
- alcoholic cardiomyopathy
- hypertension
CNS
- Wernicke's encephalopathy
- Korsakoff's syndrome
- cerebellar degeneration
- cerebellar atrophy - alcoholic dementia
- alcoholic hallucinosis
- peripheral neuropathy
Nutrition
- early obesity
- later malnutrition
- vitamin deficiencies
Metabolic
- hypoglycaemia
- hyperlipidaemia
- hyperuricaemia
- lactic acidosis

Question 33

Fatal alcohol intoxication

Answer 33

Fatal level variable
> 250mg% in non-tolerant person
> 450 mg% in tolerant
Urinary alcohol conc > BAC if death follows prolonged coma
Mechanisms
- brain stem depression
- positional asphyxia
- inhalation of vomit

Question 34

Features of post-mortem alcohol resdistribution

Answer 34

Passive diffusion of unabsorbed alcohol from
- stomach
- aspirated vomit in airways
To central vessels
< 400% difference between central vessels and peripheral vein