Bodies From Water Flashcards
Definition of drowning
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
Possible manners of death in bodies from water
Accident
Suicide
Homicide
Natural
Causes of accidental drowning
Alcohol use Head injury Toddlers falling in Children playing in rivers Diving in shallow water Snorkelling and SCUBA diving Boating accidents Fishing
Causes of suicidal drowning
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
Causes of homicidal drowning
Rare as an actual method
Immersion is a common method of disposal of body or concealment of homicide
Causes of natural drowning
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
How to tell if alive or dead at time of entry to water
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
How to estimate duration of immersion
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
Features of decomposition in water
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
Features of duration of immersion
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
Features of body floating position
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
Features that affect sinking and refloating of body
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
Features of Artefacts of Immersion
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
Identification of bodies in water
Circumstances Personal effects Fingerprints DNA Dental X-rays Surgical operations
Causes of death in immersion in cold water
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
Features of hypothermia in water
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
Process of drowning
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
Stages of drowning
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
Mechanism of death by drowning
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
Mechanism that occurs in aspiration of water
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
Death by drowning
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
Suggested mechanisms for instantaneous death in drowning
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
Pathological features of drowning
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
Lab tests for drowning
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
Complications of near drowning
Acidosis and electrolyte disturbances Pulmonary oedema Haemolysis, Hb-uria, acute renal failure Pneumonitis and ARDS Bronchopneumonia
Causes of death in bathrooms
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
