Bodies from Fire and Asphyxia

Question 1

What is the incipient phase of fire dynamics?

Answer 1

Fuel supply heated and ready to burn

Question 2

What happens in the emergent smouldering phase of fire dynamics?

Answer 2

Inefficient combustion-smoke

Question 3

What happens in growth flaming phase of fire dynamics?

Answer 3

Efficient burning

Intensity doubles for each 10 degrees rise in temperature

Question 4

What happens in the oxygen regulated smouldering phase of fire dynamics?

Answer 4

Free burning depletes available oxygen
Glowing combustion
Superheated gases and smoke

Question 5

What are the 4 phases of fire dynamics?

Answer 5

1. Incipient
2. Emergent smouldering
3. Growth flaming
4. Oxygen-related smouldering

Question 6

What is the term for when a fire produces radiant heat and hot gases which brings nearby combustible objects to ignition temperature, then to ignite?

Answer 6

Flashover

Question 7

`What temperatures can flashovers produce?

Answer 7

500-600

Question 8

What is the term for if the fires oxygen supply is depleted, flames die out, residual heat, gases and smouldering remains so reintroduction of oxygen to fire causes explosive ignition?

Answer 8

Backdraft

Question 9

Name three primary identifiers for victims in fire?

Answer 9

Fingerprinty comparison
Dental comparison
DNA- need comparison sample

Question 10

Name three secondary identigiers for victims of fire?

Answer 10

Medical records
Radiological records
Medical devices and implants

Question 11

Name some tertiary identifiers for victims of fire?

Answer 11

Circumstances, personal items, blood group and type

Question 12

If victim was alive during fire what might be found on autopsy?

Answer 12

Soot creases around eyes
Soot around nostrils, mouth, airways
tehrmal injury to laryngeak mucosa
congestion of lungs

(CO and cyanide levels)

Question 13

What czuses laryngeal injury?

Answer 13

Dry air bigger than 150 degrees. More common with steam inhalation (x4000 heat capacity of dry air)

Question 14

What causes cardiac arrest with thermal airway injury?

Answer 14

Reflex vagal inhibition

Question 15

What can cause tracheobronchial necrosis?

Answer 15

Thermal airway injury

Question 16

What are normal levels of CO?

Answer 16

less than 1ppm- present in smokers and city dwellers

Question 17

If CO bigger than 50% whast happens?

Answer 17

Fatalities- can be low as 30 in severe natural disease/children/elderly

Question 18

What colour is carboxyhaemoglobin lividity?

Answer 18

Cherry red

Question 19

Where will a 1-3 nm superheated soot particle reach?

Answer 19

Alveoli. Seen on histology.

Question 20

What does cellulose, polyurethanes and acrylonitrile release?

Answer 20

Nitrogen dioxide

Question 21

What does PVC release?

Answer 21

Hydrogen chloride

Question 22

What does burning wool, silk, nylons and polyurethanes release?

Answer 22

Hydrogen cyanide

Question 23

What does burning wool, cotton, paper, plasters, wood, nylon and polyester resin release?

Answer 23

Aldehydes

Question 24

What does burning petrol, plastics and polystyrene release?

Answer 24

Benzene

Question 25

What does burning melamine and nylon release?

Answer 25

Ammonia

Question 26

Give an example of a radiany burn?

Answer 26

Sunburn- no direct contact

Question 27

Describe a flash burn?

Answer 27

Uniform burning of exposed areas

Question 28

What type of burn causes damage in less thsan one second for temperatures above 70?

Answer 28

Contact burn

Question 29

What causes a scald?

Answer 29

Hot liquid or vapour

Question 30

Wht degree of burns are superficial?

Answer 30

First - heals without scarring

Question 31

What degree of burns are full thickness?

Answer 31

Third- epidermis, dermis and subcut tissue

Question 32

Ard third degree burns sore?

Answer 32

Painless, dry and white and leathery with black/brown eschar

Question 33

What type of burns do scalds gibe?

Answer 33

First or second. Well demarcated.

Question 34

What colour does hair go after mild fire?

Answer 34

Ginger

Question 35

In fire what mimics an extradural haematoma?

Answer 35

Heat haematoma. Blood extruded from venous sinuses. Altered blood colour and texture.

Question 36

For electrical injuries where are burns seen?

Answer 36

At entry and exit points

Question 37

What burn is described with: collapsed blister surrounding zone of erythema peripheral zone of pallor metallisation of skin

Answer 37

Firm/direct contact electircal burn

Question 38

How far can 100 000v leap?

Answer 38

35 cm

Question 39

What melts epidermal keratin which then cools to form a hard brown noduel?

Answer 39

Arcing of electricity

Question 40

What produceds crocodile skin?

Answer 40

High voltage producing multiple sparks from loose contact

Question 41

What are litchtenberg figures from?

Answer 41

Lightening

Question 42

What do acid burns cause?

Answer 42

Coagulative necrosis- denaturation of proteins and enzymes

Question 43

What penetrates deeper acid or alkali?

Answer 43

Alkali- cement, drain cleaner, ammonium hydroxide cleaner

Question 44

What causes liquefactive necrosis?

Answer 44

Alkali- grey/white mucoid burns

Question 45

Define asphyxia?

Answer 45

Interference with oxygenation

Question 46

Give an example of impaired peripheral utilisation of oxygen?

Answer 46

Cyanide poisoning

Question 47

Severe hypoxia levels?

Answer 47

Less than 40mmHg

Question 48

Can you diagnose hypoxia PM?

Answer 48

No because blood gas levels change within minutes of death

Question 49

What does arterial occlusion to brain cause?

Answer 49

Cerebral hypoxia

Question 50

What does venous occlusion to brain cause?

Answer 50

Circulatory stagnation

Question 51

What are 5 stages of asphyxiation?

Answer 51

1. Struggle 2. Quiescence 3. Convulsions 4. Apnoea 5. Anoxia and death

Question 52

What happens to heart in asphyxia?

Answer 52

Engorgement of right heart chambers

Question 53

Where is congestion and oedema seen?

Answer 53

Upstream of obstruction

Question 54

What is cyanosis obscured by?

Answer 54

Development of hypostasis

Question 55

When can inhalation asphyxia occur surprisingly?

Answer 55

Vomitus- occurs agonally, PM

Question 56

What is circmoral and circumnasal pallor seen in?

Answer 56

Asphyxia

Question 57

Where are petechial haemorrhages seen in asphyxia?

Answer 57

Eyelids, tarsal plates, lips and gums, behind ears, heart, lungs

Question 58

Other than asphyxia what else can you see petechial haemorrhages in?

Answer 58

Coughing Vomiting Crush/entrapment Cardiopulmonary resuscitation

Question 59

Pressure on baroreceptors leads to increase in sinus BP, decreased HR, vascular dilatation and decreased BP

Answer 59

Vagal inhibition