Asphyxia, Drowning, Environmental Deaths, And Sexual Assault

Front 1

Asphyxia

Back 1

-Definition: Inadequate oxygenation of tissues
-Impedence to oxygenation is the primary pathological derangement
-Leads to cerebral hypoxia, unconsciousness, death within minutes if not remedied

Front 2

Mechanisms of Asphyxia

Back 2

-Suffocation
-Strangulation
-Chemical
-Drowning

Front 3

Suffocation

Back 3

-Interference with the entrance of oxygenated air into lungs
- 4 types: smothering, choking, mechanical/traumatic/positional, environmental

Front 4

Smothering

Back 4

-Obstruction of external airways (nose and mouth)

Front 5

Autopsy findings in a smothering

Back 5

-Possibly none
-Homicidal smothering look for teeth marks on inside of lips

Front 6

Manner of death in a smothering

Back 6

-Accident: buried in a cave, baby smothered by bedding, overlay while co-sleeping
-Homicide: pillow over face, gagging, covering nose and mouth with duct tape
-Suicide: plastic bag over head

Front 7

Choking

Back 7

Obstruction/compression of internal airways (larynx & trachea)

Front 8

Manner of death in a choking

Back 8

-Accident: food or foreign body lodged in posterior pharynx
-Homicide: gag stuffed in mouth

Front 9

Mechanical asphyxia

Back 9

Inability to expand chest

Front 10

Manner of death in a mechanical asphyxia

Back 10

-Accident: Car falls off jack onto chest, pinned by heavy object
-Homicide: burking (when someone sits on someone else's chest)

Front 11

Environmental suffocation

Back 11

-Inadequate oxygen in the atmosphere
-Depletion of oxygen (enclosed space)
-Naturally low oxygen concentration (cave)

Front 12

Autopsy findings in an environmental suffocation

Back 12

Possible none

Front 13

Manner of death in an environmental suffocation

Back 13

Usually accident, e.g., child locked inside refrigerator

Front 14

Strangulation

Back 14

-Occlusion of blood vessels in the neck by external pressure
-Interferes with circulation
-3 types: hanging, ligature strangulation, manual strangulation

Front 15

Mechanism of death in a strangulation

Back 15

-Cerebral hypoxia due lack of oxygenated blood to the brain
-11 lbs of force necessary to occlude carotid arteries
-Loss of consciousness in 10-15 seconds

Front 16

Autopsy findings in a strangulation

Back 16

-Petechiae (scleral, conjunctival, facial)

Front 17

Hanging

Back 17

-Neck vessels occluded by weight of body causing constriction of noose around neck
-Does not require complete suspension, weight of head (10-12 lbs)

Front 18

Autopsy findings in a hanging

Back 18

-Furrow
-Inverted V-configuration above larynx
-Patterned imprint
-Strap muscle hemorrhages
-Pooling of blood in lower extremities and forearms, Tardieu spots on legs
-Pale face

Front 19

Manner of death in a hanging

Back 19

-Suicide-vast majority
-Accident-occasional (“choking” game, autoerotic asphyxia)
-Homicide-rare

Front 20

Autoerotic asphyxia

Back 20

Controlled hanging of short duration to reduce blood flow to brain resulting in transient cerebral hypoxia in order to increase pleasure of masturbation

Front 21

Scene of an autoerotic asphyxia

Back 21

-Nude
-Padded ligature to prevent abrasion
-Escape mechanism
-Pornography
-Bondage material

Front 22

Manner of death of an autoerotic asphyxia

Back 22

Accident

Front 23

Ligature strangulation

Back 23

Ligature tightened by other than body weight

Front 24

Autopsy findings of a ligature strangulation

Back 24

-Ligature mark
-Overlies or below larynx
-Horizontal, since the body is not suspended and the noose will not be pulled up like in a hanging
-Fracture of hyoid bone and/or thyroid cartilage

Front 25

Manner of death in a ligature strangulation

Back 25

Most homicide, occasional accident, rare suicide

Front 26

Manual strangulation

Back 26

Pressure from hand, forearm, or other limb used to compress neck vessels

Front 27

Autopsy findings in a manual strangulation

Back 27

-Abrasions and contusions of skin of neck and undersurface of jaw
-Semicircular fingernail marks
-Hemorrhage in neck muscles
-Fracture of hyoid and/or thyroid cartilage with surrounding hemorrhage

Front 28

Manner of death in a manual strangulation

Back 28

Most are homicides, suicide not possible (when you apply enough pressure to make you pass out, you release your hands and circulation will resume)

Front 29

Choking game

Back 29

-Strangulation game played by youth to achieve a “high-like” sensation without taking drugs
-In contrast to autoerotic asphyxia, not done for sexual gratification
-Involves cutting off of circulation to carotid artery with a rope, belt, hands
-Occurs alone or in groups
-Accidental form of manual strangulation or hanging

Front 30

Physical signs of choking game

Back 30

-Bloodshot eyes
-Unexplained marks/bruises on the neck
-Small red dots around the face, eyelids, or the lining of the eyelids and eyes
-Frequent, severe headaches
-Disorientation after spending time alone

Front 31

Indications at a scene that choking game was cause of death

Back 31

Unexplained presence of dog leashes, choke collars, bungee cords, ropes, scarves or belts tied to bedroom furniture or doorknobs or found knotted on the floor

Front 32

Chemical asphyxia

Back 32

-Gasses prevent utilization of oxygen at cellular level
-Carbon monoxide (accident, suicide)
-Hydrogen cyanide (suicide)
-Hydrogen sulfide (accident)

Front 33

Drowning

Back 33

-Death from asphyxia within 24 hours of submersion in water/fluid
-Diagnosis of exclusion
-3 types: salt water, fresh water, icy water

Front 34

Near drowning

Back 34

-Survival of at least 24 hours after submersion in and aspiration of fluid
-Complications: pulmonary edema, cardiac arrhythmia, pneumonitis, sepsis, cerebral edema (edema occurs when an attempt is made to resuscitate you)

Front 35

Mechanism of death in a drowning

Back 35

Airway submerged in water results in aspiration of water/fluid when person attempts to breathe, leads to impaired gas exchange, decreased oxygenation, hypoxic brain injury

Front 36

Diagnosis of exclusion

Back 36

-Drowning
-Non-specific findings
-Need to rule out other causes of death by full autopsy and toxicology studies

Front 37

Manner of death in a drowning

Back 37

Accident, suicide, homicide

Front 38

Salt water drowning

Back 38

-Decreases blood volume
-Salt draws plasma into alveoli by osmosis
-Hemoconcentration, hypernatremia, pulmonary edema

Front 39

Fresh water drowning

Back 39

-Increases blood volume
-Loss of surfactant causes alveolar collapse, pulmonary edema, hemodilution, hemolysis, circulatory overload, hyponatremia

Front 40

Icy water drowning

Back 40

-Survival without neurological deficits possible after prolonged submersion
-Reflex bradycardia and vasoconstriction of all blood vessels except those supplying heart and brain

Front 41

Autopsy findings of a drowning

Back 41

-Edema, frothy fluid throughout airway
-Water in stomach
-Cerebral edema
-Washerwoman hands- skin on hands and feet pale and wrinkled (occurs regardless of whether individual was alive or dead at time of submersion)
-Diatoms (unicellular algae) in lungs or other organs, aspiration of fluid containing diatoms
-Postmortem artifacts- scrapes on body from rough surfaces, animal/fish feeding activity, barnacles
-Body decomposes twice as fast in water as in air
-Time to rise to surface depends on temperature of water, body fat composition
-Contributory factors: alcohol/drug intoxication

Front 42

Environmental deaths

Back 42

Two types: hyperthermia and hypothermia

Front 43

Hyperthermia

Back 43

-Elevated core body temperature ≥105°F
-Types
-Heat cramps
-Heat exhaustion
-Heat stroke

Front 44

Heat stroke

Back 44

-Body’s normal heat-dissipating mechanisms incapable of compensating for increased environmental heat
-Life-threatening
-Marked increase in core body temperature causes direct thermal tissue injury

Front 45

Risk factors for heat strokes

Back 45

-Alcoholism
-Cardiac disease
-TCA’s, MAOI
-Obesity
-Elderly, poor
-Exertional – long distance runners, laborers, military recruits, football players

Front 46

Symptoms of a heat stroke

Back 46

-Hyperthermia, hot dry skin, nausea, vomiting, muscle cramps, dyspnea, CNS dysfunction
-Vasodilation, circulatory collapse, cardiac failure
-Complications: pneumonia, ATN, DIC, MI
-Purkinje cell necrosis

Front 47

Autopsy findings of a heat stroke

Back 47

-Non-specific
-Diagnosis based on antemortem history
-Core body temperature
-Environmental conditions

Front 48

Manner of death in a heat stroke

Back 48

Accident

Front 49

Hypothermia

Back 49

-Core body temperature below 95°F
-Shivering, vasoconstriction, increased metabolism by brown fat (infants)
-Causes paradoxical undressing: terminal hallucinations and feelings of warmth, so take off all clothes

Front 50

Risk factors for hypothermia

Back 50

-Infant greater ratio of BSA to body mass, underdeveloped reflex centers
-Cold water immersion causes more rapid loss of heat that dry cold air because water dissipates heat from body much faster than air

Front 51

Effects of hypothermia

Back 51

-Loss of ability to shiver
-Impaired cerebral function (reflexes)
-Cold narcosis
-v-fib, bradycardia

Front 52

Autopsy findings in a hypothermia case

Back 52

-Cherry red lividity due to accumulation of oxyhemoglobin in tissues from underutilization (also seen carbon monoxide intoxication, cyanide poisoning, and refrigerated bodies)
-Hemorrhagic pancreatitis, focal ulcers of the gastrointestinal mucosa (Wischnevsky spots - picture)
-Pneumonia, ATN, myocardial necrosis

Front 53

Sexual assualt scene

Back 53

-Female
-Supine
-Exposed breasts
-Leg apart
-Naked below the waist

Front 54

Autopsy findings of a sexual assault

Back 54

-Bite marks on breasts
-Bruises on inner thighs
-Vaginal/anal trauma (lacerations, contusions)
-Semen deposits
-Evidence of blunt trauma, strangulation

Front 55

Evidence collection needed in a sexual assault

Back 55

-Swabs mouth, vagina, rectum
-Microscopic slides for sperm
-DNA analysis
-Acid phosphatase test for seminal fluid
-Panties/underwear
-Bite marks
-Double swab for saliva/DNA (wet swab, dry swab)
-Photograph