Medic-legal aspects of alcohol intoxication

Question 1

Law associated with alcohol

Answer 1

The National Road Traffic Act No. 93 of 1996

Question 2

Blood alcohol limit

Answer 2

0.05 grams per 100ml

Question 3

Breath alcohol limit

Answer 3

0.24 mg per 1000ml

Question 4

Offences created in Section 65

Answer 4

• driving on a public road while under the influence

- occupying the driver’s seat of a motor vehicle with the engine running on a public road

Question 5

Sentences for National Road traffic act

Answer 5

• fine or imprisonment for <6 years

Question 6

Law relating to taking blood samples for alcohol

Answer 6

Criminal Procedure Act No 51 of 1977

Question 7

Formula used to calculate the probably amount of alcohol in tissue at time of blood taking

Answer 7

Widmark formula
A = p x c x r
A = total body alcohol
p = body mass
c = blood alcohol conc
r = factors

Question 8

Stages of alcohol intoxication

Answer 8

• slight effect
• under the influence
• drunk
• very drunk

Question 9

Psychoactive ingredient in alcohol

Answer 9

Ethyl alcohol

Question 10

Where is alcohol absorbed?

Answer 10

• 20% from stomach

- 80% from small bowel

Question 11

Route of elimination of alcohol

Answer 11

• 90% metabolised in liver, initiated by ADH
• 5% by breath
• 5% by urine

Question 12

Contents of a container used to take BAC

Answer 12

• potassium oxalate (anti-coagulant)

- sodium fluoride (enzyme inhibitor)

Question 13

Lab method used to analyse BAC

Answer 13

Gas chromatography

Question 14

10 main clinical findings in alcohol intoxication

Answer 14

• gait
• Rhomberg’s sign
• incoordination
• speech
• pupils and nystagmus
• behaviour
• orientation to time and place
• concentration
• content of speech
• memory

Question 15

Things that make a person sensitive to effects of alcohol

Answer 15

• extreme cold or fatigue
• pre-existing post concusisonal states
• chronic cerebro-vascular states
• cerebral depression by drugs
• neurological conditions
• psychological disorders

Question 16

Differential diagnoses for alcohol intoxication

Answer 16

• acute anxiety
• traumatic chock
• head injuries
• acute stroke
• subarachnoid haemorrhage
• epilepsy
• acute febrile illness
• hypoglycaemia
• hyperglycaemia
• narcotic poisoning
• environmental intoxicants
• hyperthyroidism
• disseminated sclerosis
• intracranial tumours
• Parkinson’s disease
• acute aural vertigo
• metabolic disorders
• mental disorders

Question 17

Differentials of alcoholic coma

Answer 17

• acute head injury
• diabetes
• uraemia
• narcotic poisoning
• epilepsy

Question 18

Factors affecting alcohol absorption

Answer 18

• rate of passage into small intestine
• concentration of alcohol
• carbonated drinks
• drugs, physiological and genetic factors

Question 19

Explain “R” in Widmark formula

Answer 19

Ratio between total body alcohol and blood alcohol conc

• high in people with low body fat
• low in people with high body fat

Question 20

Law around blood alcohol levels in drivers

Answer 20

• if a specimen is taken within 2 hours of the alleged offence and is above he legal limit, it is presumed to have not been less at the time of the offence

Question 21

Which other act is involved in taking blood for alcohol levels?

Answer 21

• criminal procedures act (act 51 of 1977)