Bodies From Water Flashcards

1
Q

Definition of drowning

A

Aphyxia (suffocation) due to immersion of nostrils and mouth in a liquid
Suffocation (asphyxia) caused by liquid entering the lungs and preventing the absorption of oxygen leading to cerebral hypoxia and cardiac arrest
Death due to submersion in liquid

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2
Q

Possible manners of death in bodies from water

A

Accident
Suicide
Homicide
Natural

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3
Q

Causes of accidental drowning

A
Alcohol use
Head injury
Toddlers falling in 
Children playing in rivers
Diving in shallow water
Snorkelling and SCUBA diving
Boating accidents
Fishing
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4
Q

Causes of suicidal drowning

A
Often associated with alcohol and drugs
Circumstances offer best clues
Clothes may be left
Ligatures and weights
Suitable typical locations - bridges
Injuries from impact with water
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5
Q

Causes of homicidal drowning

A

Rare as an actual method

Immersion is a common method of disposal of body or concealment of homicide

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6
Q

Causes of natural drowning

A
Range from natural (died before in water) , mixture, drowning ( die whatever natural diseases present)
Collapse and fall into water
Hot bath
Exertion of swimming 
Underlying medical conditions
- heart disease
- epilepsy
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7
Q

How to tell if alive or dead at time of entry to water

A
Artefacts of immersion occur whether alive or dead
- injuries
- gooseflesh
- washerwomen change
Vital phenomena means was alive in water
- foam in airways
- emphysema aquosum
- foreign material inhaled/swallowed
- shoulder muscle bruising
- middle ear haemorrhage
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8
Q

How to estimate duration of immersion

A

Estimation based on presence of PM changes
Body temperature
- dependent on water temperature
- naked body cools 2x faster in water than air
- accelerated by moving water/currents
- retarded by clothing
Rigor mortis
Hypostasis
- may never set in if body buffeted in turbulent sea
Decomposition

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9
Q

Features of decomposition in water

A
At similar average temperatures corresponding degrees of putrefaction 
- in open air for 1 week
- immersed for 2 weeks
- buried for 8 weeks
Approx. 50% slower than air
Delayed by
- cold water temperature
- moving water currents
Accelerated by
- warm water temperature
- water pollution
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10
Q

Features of duration of immersion

A

Over-ridding factor is water temperature
< few hours = no wrinkling of finger pads
12-30 hours = wrinkled fingers, palms and feet
4-10 days = early decomposition in dependent head, neck and abdomen and thighs
2-4 weeks = bloating of face and abdomen, venous marbling and peeling of epidermis on hands and feet, scalp slippage
1-2 months = gross skin shedding, muscle loss and exposure of skeleton

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11
Q

Features of body floating position

A
Face down
Chest and abdomen most buoyant
Head dangles downwards
- lividity and injuries to prominences of face due to impact on rocks when washed along shallows
Arms and legs dangle down
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12
Q

Features that affect sinking and refloating of body

A

Specific gravity of body is similar to water
- air trapped in clothes increases
- air in lungs displaced by water decreasing buoyancy
- heavy items in pockets decreases buoyancy
Putrefactive gases with refloat a sunken body
- time depends on water temperature
- average 1-2 weeks
- exposed body undergoes accelerated decomposition

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13
Q

Features of Artefacts of Immersion

A

Occur irrespective of death
Injuries
- entry impact - from height into water
- fractured ribs and humerus
- rocks and river/sea bed - flowing/tidal water
- abrasions to prominent features
- fish and crab activity
- above trouser line, prominent features, eye balls
- eat in circular motion
- hard to latch onto smooth surfaces
Gooseflesh - cutis anserina
- pilor rectus muscles contract pulling hair follicle and hair erect, pulls skin down giving bump
Washerwoman change - maceration
- keratin starts to wrinkle
- skin whitens
- as becomes more advanced get loosening of skin and loss of top layer
Undressing by water movement
- movement of clothing rubs away epidermis
Chromogenic bacteria cause skin pigmentation
- algae growth browns exposed skin
- able to be wiped off
Adipocere
- tissues replaced by waxy, fatty, white substance

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14
Q

Identification of bodies in water

A
Circumstances
Personal effects
Fingerprints
DNA
Dental 
X-rays
Surgical operations
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15
Q

Causes of death in immersion in cold water

A

Diving response - immersion of face in cold water
- apnoea
- peripheral vasoconstriction
- bradycardia
Cold shock response - sudden immersion in cold water
- sudden cooling of skin
- reflex gasp
- hyperventilation - feeling breathless makes swimming more difficult
- breath holding time reduced to 20 seconds
- increased HR and BP - may induce arrhythmia
2 responses may compete and induce cardia arrhythmias

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16
Q

Features of hypothermia in water

A

Average adult wearing outdoor clothing cools to 35°C
- 1 hour if temp 5°C
- 2-3 hours if temp 10°C
- 3-6 hours if temp 15°C
Deep body temp < 34°C causes reduced conscious level -> aspiration of water
Body temp < 28°C -> ventricular fibrillation
Body temp < 24°C -> asystole

17
Q

Process of drowning

A

Struggle subsides with exhaustion
Breath held but rising CO2 stimulates inhalation
Gulping, coughing, vomiting and unconsciousness
Convulsions and involuntary respiratory movements
Death within few minutes

18
Q

Stages of drowning

A

Brouardel’s experiments 1897
1. surprise/panic - 5-10 seconds
2. 1st stage respiratory arrest - 1 minute
3. deep respiratory efforts - 1 minute
4. 2nd stage respiratory arrest - 1 minute
5. Terminal gasping
Death

19
Q

Mechanism of death by drowning

A

Obstruction of airways by inhaled water
Fresh water absorbed into pulmonary circulation
Sea water absorbs fluid from pulmonary circulation
Vagal inhibition - reflex cardiac arrest
Laryngeal spasm
Hypothermia and exhaustion

20
Q

Mechanism that occurs in aspiration of water

A

Fresh water
- inhaled hypotonic water in alveoli is absorbed into pulmonary capillaries
- Na passes from blood into alveoli -> hyponatraemia
- haemodilution - HYPERVOLAEMIA
- haemolysis
- HYPERKALAEMIA
- fatal arrythmias - VENTRICULAR FIBRILLATION
Salt water
- inhaled hypertonic water in alveoli draws water from pulmonary capillaries
- haemoconcentration - HYPOVOLAEMIA
- Na and Cl absorbed
- HYPERNATRAMIA
Loss of surfactant and heart failure due to PULMONARY OEDEMA

21
Q

Death by drowning

A

Fresh water - 4-5 minutes
- fresh water inhaled into alveoli absorbed into pulmonary circulation
- haemodilution - fluid overload
- haemolysis and hyperkalaemia
Sea water - 8-10 minutes
- sea water inhaled into alveoli absorbs fluid from pulmonary circulation
- haemoconcentration
- absorption of Na,Cl into circulation
Prolonged resuscitation is often successful - body metabolism and O2 use diminished

22
Q

Suggested mechanisms for instantaneous death in drowning

A

Fatal form of cold water shock response
Sudden unexpected immersion in cold water
Feet first - effect of water shooting up nose
Hypersensitivity due to alcohol
Very rapid death with no struggle - may be witnessed
Reflex cardiac arrest mediated by vagal inhibition
Usual signs of drowning absent

23
Q

Pathological features of drowning

A

Foam in airways
- fine white froth externally at nostrils and mouth
- more exudes on compressing chest
- also internally with trachea and bronchi
- mixture of water, air, mucus and surfactant whipped up by respiratory efforts
- non-specific - head injury, epilepsy, overdose, LVF
Emphysema aquosum
- lungs voluminous and ballooned, overlapping
- peripheral air trapping
- pleural surfaces have marbled appearance
- doughy texture, pitting on fingertip pressure
- due to active inspiration of water
- histological distension of alveoli
Foreign material in airways and stomach
- sand, silt, weed in airways, lungs and stomach
- presence suggests submersion in life
- absence suggest rapid death or already dead
- debris can reach pharynx, trachea/bronchi and oesophagus in dead victim
Middle ear haemorrhage
- blue discolouration in bony roof of middle ear
- due to pressure changes or irritation via Eustachian tubes
- also occurs in HI, asphyxia and electrocution
Others
- venous congestion - absorption of fresh water by pulmonary circulation
- foreign material in hands - cadaveric spasm
- shoulder girdle bruising - violent struggle tears pectoral and scalene muscles
- pleural effusion - seems to depend on period of immersion

24
Q

Lab tests for drowning

A
Diatoms
- class of unicellular algae
- differences in different bodies of water
- demonstrate in bone marrow, liver and brain if blood was circulating at death
- contamination can occur
- should compare with drowning medium
Specific gravity of blood in LV
Plasma chloride
Plasma magnesium
25
Q

Complications of near drowning

A
Acidosis and electrolyte disturbances
Pulmonary oedema
Haemolysis, Hb-uria, acute renal failure
Pneumonitis and ARDS
Bronchopneumonia
26
Q

Causes of death in bathrooms

A

Natural disease whilst in bath
Falls - wet floor, heard surfaces
Drowning - drugs, epilepsy, natural disease
CO from faulty heater
Electrocution
Drug addicts places in bath after overdose
Suicidal incisions often performed in bath