1. Outline the principles of pre-hospital care of a seriously ill patient
  2. Explain the ‘ABCDE’ system of primary survey.
  3. Outline the anatomy of the airway, and label the sagittal section provided.
  4. Describe the normal reflexes which keep the airway clear, and discuss the problems of airway obstruction by the tongue or aspiration of stomach contents in the unconscious.
  5. Discuss the influence of alcohol.

Initial action

  • Potential problems at scene of accident
    • Hostility of environment
    • Lack of familiarity with surroundings
    • Intrusive onlookers
  • Assess safety of yourself and any casualties
  • Make the accident site as safe as possible before assessing any casualties
  • Determine the nature of accident and likely mechanism of injuries
  • At road traffic accidents
    • Determine number, direction and types of vehicles involved
    • Degree of intrusion of damages vehicles
    • Whether occupants were wearing seatbelts

Indications of potential significant trauma

  • Penetrating injury to chest and abdomen
  • Two or more proximal long bone fractures
  • Burns involving more than 15% of body surface area
  • Burns to face and airway
  • Evdience of high-energy impact
    • Fall more than 6m
    • Crash speed greater than 20 mph
    • Inward deformity of car of more than 0.6 m
    • Rearward displacement of front axle
    • Ejection of passenger from vehicle
    • Rollover of vehicle
    • Death of another car occupant
    • Pedestrian hit at great than 20 mph
    • Abnormal physiological variables

external image accident_scene2.jpg
Picture provided by Joanne Rubin, Santa Clara County, California, USA

Prehospital resuscitation

  • Should follow same principles as that in hospital
  • Will need to be adapted to circumstances
  • Airway management can be difficult
  • Can often be maintained with basic measures
  • Intubation without anaesthesia and rapid sequence induction is ill advised
  • Can induce vomiting and raised intracranial pressure
  • The cervical spine should be immobilized with a hard collar
  • Oxygen should be given
  • Haemorrhage should be controlled with direct pressure
  • If casualty is entrapped ensure good venous access before releasing from vehicle
  • Fluid resuscitation should be give to a systolic blood pressure of 90 mmHg
  • If venous access difficult consider 'scoop and run' rather than delay transfer
  • Analgesia can be achieved with Entonox or ketamine
  • Entonox is contraindicated if possibility of:
    • Pneumothorax
    • Basal skull fracture
  • Extrication requires close co-ordination between medical and fire services
  • Casualty should be 'packaged for transport'
  • This will require hard collar, head blocks, limb splints, scoop stretcher or vacuum mattress

Influence of Alcohol

Ethanol acts as a central nervous system depressant. In small amounts, ethanol causes a mild euphoria and removes inhibitions, and in large doses it causes drunkenness, generally at a blood ethanol content of about 200mg/100ml. At higher concentrations, alcohol causes intoxication, coma and death. A blood ethanol content above 400mg/100ml can be fatal, although regular heavy drinkers can tolerate somewhat higher levels than non-drinkers.

A unit of alcohol is 8g of pure ethanol


Action on the brain

Ethanol is quickly absorbed into the bloodstream and reaches the brain. As a small molecule, it is able to cross the blood-brain barrier. For reasons that are still being studied, it then triggers the release of dopamine and endorphins into the bloodstream, which cause euphoria.
Alcohol initiall causes depression of the Central Nervous System (CNS.) The CNS depressant effect is likely is due to ethanol's acting on
potassium channels in the brain. Ethanol increases the activity of these channels, which are known to reduce activity of neurons. It is also known that alcohol acts on GABA - an inhibitory neurotransmitter- which slows down nerve impulses.

Ethanol also interferes with synaptic firing and causes the death of brain cells. ?243?


Alcohol lipid soluble - starts absorption in stomach - approx 20% occurs here, 80% in the small intestine.The concentration of alcohol in blood is usaually given by BAC.

Alcohol water soluble so is diluted in the blood stream. More water is stored in muscle than adipose tissue - men can have up to 10% more water in their bodies than women. As men have greater muscle mass than women, Blood Alcohol Concentration (BAC) is more dilute in a man compared to a woman of the same weight/leanness.

The Brain, Liver, Kidneys, Heart are all affected by alcohol within minutes of entering the blood stream.


Alcohol disrupts the way that blood is regulated by the liver. Hypoglycemia ( low blood sugar)

The enzyme alcohol dehydrogenase is found in the liver. It is the action of this enzyme which breaks ethanol down to acetaldehyde, which is converted to acetic acid by acetaldehyde dehydrogenase.

The alcohol dehydrogenase of women is less effective than that of men. Combined with the lower amount of water in women's bodies, this means that women typically become drunk earlier than men.
Some people, especially those of East Asian descent, have a genetic mutation in their acetaldehyde dehydrogenase gene, resulting incetaldehyde dehydrogenase. This leads to a buildup of acetaldehyde after alcohol consumption, causing hangover-like symptoms such as flushing, nausea, and dizziness. These people are unable to drink much alcohol before feeling sick, and are therefore less susceptible to alcoholism.

Factors Affecting Alcohol Absortion

Alcohol is faster aborbed in the small intestine, thus having just eaten keeps alcohol absorbed in food in the stomach, limiting a blood alcohol increase.

Experience/Tolerance to alcohol affects the effects of BAC.
The higher the concentration, the faster alcohol is absorbed.
Carbonated drinks enter the bloodstream faster than non-carbonated.
Congeners found in "dark" drinks such as port, brandy slow the progress of alcohol through the stomach.
Body Mass/Fat

How much alcohol can I drink and still be safe to drive?

You must not drive with
  • breath alcohol level higher than 35 mg / 100 millilitres
  • blood alcohol level of more than 80 mg / 100 millilitres
  • urine alcohol level of more than 107 mg / 100 millilitres.