Medic-legal aspects of alcohol intoxication Flashcards
Law associated with alcohol
The National Road Traffic Act No. 93 of 1996
Blood alcohol limit
0.05 grams per 100ml
Breath alcohol limit
0.24 mg per 1000ml
Offences created in Section 65
- 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
Sentences for National Road traffic act
- fine or imprisonment for <6 years
Law relating to taking blood samples for alcohol
Criminal Procedure Act No 51 of 1977
Formula used to calculate the probably amount of alcohol in tissue at time of blood taking
Widmark formula A = p x c x r A = total body alcohol p = body mass c = blood alcohol conc r = factors
Stages of alcohol intoxication
- slight effect
- under the influence
- drunk
- very drunk
Psychoactive ingredient in alcohol
Ethyl alcohol
Where is alcohol absorbed?
- 20% from stomach
- 80% from small bowel
Route of elimination of alcohol
- 90% metabolised in liver, initiated by ADH
- 5% by breath
- 5% by urine
Contents of a container used to take BAC
- potassium oxalate (anti-coagulant)
- sodium fluoride (enzyme inhibitor)
Lab method used to analyse BAC
Gas chromatography
10 main clinical findings in alcohol intoxication
- gait
- Rhomberg’s sign
- incoordination
- speech
- pupils and nystagmus
- behaviour
- orientation to time and place
- concentration
- content of speech
- memory
Things that make a person sensitive to effects of alcohol
- extreme cold or fatigue
- pre-existing post concusisonal states
- chronic cerebro-vascular states
- cerebral depression by drugs
- neurological conditions
- psychological disorders
Differential diagnoses for alcohol intoxication
- 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
Differentials of alcoholic coma
- acute head injury
- diabetes
- uraemia
- narcotic poisoning
- epilepsy
Factors affecting alcohol absorption
- rate of passage into small intestine
- concentration of alcohol
- carbonated drinks
- drugs, physiological and genetic factors
Explain “R” in Widmark formula
Ratio between total body alcohol and blood alcohol conc
- high in people with low body fat
- low in people with high body fat
Law around blood alcohol levels in drivers
- 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
Which other act is involved in taking blood for alcohol levels?
- criminal procedures act (act 51 of 1977)
