Merged forensics

physical agents that can cause forensic injuries

high temp (burn, hyperthermia)

low temp (hypothermia, frostbite)

electricity (electrocution, atmospheric electric current)

changes in atmospheric p (submersion, hyperbaric narcosis, caisson disease)

radiation

etiologies of burns: heat emitted by _____ - – burns with limited area but deep that take the shape of the body that produced them

incandescent solid objects

etiologies of burns: heat emitted by _____ - skin contact with hot liquids, the burns have increased stretch and limited depth.

hot liquid (scalding)

severity of scalding lesions is given by

temp of l

duration of action

interposition of clothes

etiologies of burns: heat emitted by _____ - ascending character, associate clothes and hair burns, soot deposits

flame

etiologies of burns: heat emitted by _____ -extensive, superficial lesions usually affecting children and the elderly

hot vapors/gases

etiologies of burns: heat emitted by _________- direct contact of the electric flame emitted by the voltaic arc and excessive heating of the tissues affected by the transition of electric current through the organ

electricity

1st dg burns (erythematous) lesions description

diffuse skin erythema, edema, pain, healing w/o sequelae, death if >75% of body surface

1st dg burns occur at which temp

>50dg

2nd dg burn (blistering) lesion description

erythematous, moist skin w/ blisters, death if >50% of body surface

types 2nd dg burn (blistering)

• superficial - destruction stratum corneum and granulosum

• profound - basal layer affected, leaves scars

3rd dg burn (necrotic) lesion description

destruction skin appendages (sweat glands, hair root), no blisters, death if >30% body surface

4th dg burn (carbonization) lesion description

all layers (including one), mummified, blackish, charred w/ dry gangrene smell, healing w/ keloid and anesthesia, death

quantitative quantification of burns

estimating the body’s burnt surface: rule of 9 (X1 head, upper limbs, X2 anterior and posterior torso, lower limbs, 1% neck + genital area)

aspects of charred corpses

• body in flexion (pugilistic attitude)

• fx of skullcap and limb bones, bones crumbly, white-gray

• skin cracks/detachments

steps of death by burns (tanatognesis)

1. immediately - CO poisoning, asphyxia, acute resp dailure

2. hrs/days - postcombusional shock (primary/algic or secondary/hypovolemic), acute resp failure

3. delayed, over 2-3d - sepsis, febrile cachexia

caloric syncope

sudden and short-term loss of consciousness, associat ed with interruption of respiratory and cardiovascular activity after heat exposure

what is painful tetanus-like muscle contractions, of the extremi ties and abdominal wall, occurring during or at the end of a strenuous physical activity performed in a warm environment

caloric cramp

what is: exposure of >5m at a temp >40˚C, linked with an erythematous, itchy rash on an edematous background

heat hives

what is caused by prolonged exposure of the cranial region to heat. Mild forms: fever, headache, vomiting. Șevere forms: meningeal ir ritation, coma, death.

heliosis (insolation)

what is prolonged exposure to dry and hot environments. Body temperature is slightly ele vated or normal with sweat production predominantly on the head and neck, headache, asthenia, tremors, anorexia

thermogenic anhydrosis

heat stroke / hyperthermic shock

hyperthermia, dry and hot skin, impaired sensory function, hypotension tachycardia and tachypnea → death by arrythemias w/ resp failure at >43dg

predisposing factors heat stroke

alcohol consumption, obesity, extreme age, use of diuretics, tricy clic antidepressants

what occurs when administering general anesthetics to ppl with a genetic predisposition, caused by increased intracellular calcium levels with the onset of muscle stiffness and accelerated endogenous thermogenesis

malignant hyperthermia

degrees of frostbites

1. erythematous - painful, edematous, healing w/o sequelae

2. blistering - serous/sup. or hemorrhagic/deep

3. necrotic - all skin layers, dry, blackish, detach leaving atonic ulcer

4. gangrenous - necrosis of entire segment (including bone), mummified, blackish, dry gangrene smell

Hypothermia occurs if the general body temperature drops below

35

pathophysio mechanism (phases) hypothermia

reaction phase - per vasoconstriction, m contractions

actual hypothermic phase

hypothermic coma phase (irreversible), death

hypothermia phase at 32dg (mild)

analgesia, disturbances of consciousness, drowsiness, hallucinations, slowing of reflexes, tachycardia, hypertension and later bradycardia with hypotension

hypothermic phase at 28dg (mod)

gradual abolition of reflexes, numbness, bradycardia, hypotension, the pulmonary functional vascularization decreases by decreasing the pump function of the right ventricle

hypothermic phase at 25dg (severe)

functions decrease, the difference between the external and the internal compartment exceeds 10 degrees, phrenic nerve paralysis appears with increasing of the respiratory dead space up to 50%, hypotension and severe bradycardia

cold syncope (hydrocution)

exaggerated response to cold stimulus → death by heart smapsm and retrograde esophafgeal dilatation, bradycardia

by cold drink, cold water immersion

electrocution can occur by

• direct unipolar

• direct bipolar/biphasic (touching 2+ parts of body)

• indirect (conductive liquid or air)

severity of electrocution injuries given by

amperage, voltage, type current (continuous/alternating), frequency, contact duration, crossing direction

morpho aspects electrocution lesions

• 1-4 burn injuries, spark lesions (embossed brown nodule)

• electric mark - at entry/exit site of current, hard, dry, bloodless, surrounded by pale area

• metallization (particles conductive metal, skin hard, dry, rough, brown (Fe), yellow (Cu), silver (Ag)

• electrogenic edema - biochem effect from plasma extravasation

• m, organ rupture, bone fx,

electrocution death occurs by (immediate vs delayed)

• immediate - acute central or periph resp failure

  • delayed - cell electrolyte dissociations, acute renal failure, burn injury complications

types of atmospheric electricity/lightning strike injuries

• cloud - ground

• cloud - cloud

thermic consequences of injuries by lightning

severe burns

lichtenberg figures (fir branches)

ignation clothes

mechanical consequences lightning burns

• deep, penetrating crateriform wound

• severe m tear, visceral tear, disarticulation, fx

types of consequences of lightning injuries

• thermal

• mechanical

• biochem (electrogenic edema)

• electromagnetic

survivors of lightning strikes have what long term effects

cataract, hearing loss, mental sequelae

lesions caused by submersion - classification by time of occurrence

• while descending - nitrogen narcosis (martini effect), barotrauma

• while surfacing - caisson disease

nitrogen narcosis (martini effect)

with increasing pressure the nitrogen will pass into the liquid phase, initially manifested by agitation, restlessness and later with decreased respiratory and heart rate, drowsiness, lipothymia

barotrauma (submersion lesion)

• otic (→ deaf)

• sinusal - orbit pain, epistaxis

• pul - alveolar rupture w/ hemoptysis

caisson disease (ascension air embolism, decompression sickness)

liquid nitrogen turns again into gaseous form, causing an air embolism

acute/mod exposure to high atmospheric p leads to which pathos

• mountain sickness (ascents >2500m) - dizzy, drowsy, dyspnea, lipothymia

• altitude sickness (@ 6000m), in mountain climbers, aeronautical staff

mod/chronic exposure to high atmospheric p - 2 types pathos

• altitude polyglobulia - htn, risk ischemic stroke

• Monge’s disease (chronic mountain sickness) - residents at high altitudes, extertional dyspnea, fatigue, eye and hearing disorders

what kind of radiation ionizes the matter through which they pass, with the displacement of the atom’s electrons on which they act

ionizing radiation

which radiation has high penetration capacity, low ionization

electromagnetic (xray, gamma)

which radiation has low penetration capacity, high ionization;

corpuscular (alpha, beta)

acute radiation sd

Caused by irradiation of the whole organism, potentially lethal; days - weeks, depending on the absorbed dose

3 clinical types of acute radiation sd

• neurovasc sd - >4000 rad, fatal in a few d

• GI sd - lower doses (1000-4000rad), fatal

• hematopoeietic sd - 150-1000rad, possibility of healing

acute radiation sd - phases

• initial non-specific - in few hrs post, malaise, anorexia, vomit, diarrhea

• latency - few hrs-d

  • neurovasc sd (cerebral edema, neuro disorders, death in 48h)

  • GI sd (lower doses, loss fluid and electtolytes, severe hemorrhagic diarrhea, death in 10d)

  • hematopoietic sd (hemorrhagic sd, anemia, infections, death in 1m)

delayed effects radiation

BM, kidney, lung lesions

malignant in exposed doses >100rad

non-ionizing radiation - microwaves lesions at high doses

burns, cataracts, cns lesions, temp sterility

non-ionizing radiation - UV radiation lesions

• actinic edema

• photodermatitis

• actinic urticaria

• premature photoinduced skin aging

• neoplasia

• opthalmic burns

main causal factors vehicle accidents

• men - psychosomatic health, recklnessness, selfishness

secondary causal factors of vehicle accidents

• technical faults

  • road conditions

favourable causal factors vehicle accidents

• weather condition

• sdegree illumination

• high speed

• altered consciousness

effects on pedestrians hit by vehicles w/ tires depend on

• speed

• type vehicle

• side of vehicle w which impact occurs and anatomical area hit

mechanisms of pedestrian hit by vehicle w/ tire

simple - hit, fall, projecting, compressing, dragging, ironing

associated - groups 2 simple ones

complex - 3+ simple ones, fatal, OA injuries, mulitpolar

particularities of train pedestrian hit

• polytrauma, rapid death, traces oil, fragments scattered over long distance

effects of pedestrian-train accidents

• sectioned body segments

• complex mechanisms impact

• compression band parchment-like skin at amputation site

effects suicidal pedestrian-train hit

decapitation/hemicorporectomy

signs murder pedestrian-train hit

hands and feet tied, other signs violence

concealing a crime in pedestrian-train hit - key sign

total lack of vital response to train injuries

mechanisms motorcyclist

• frontal/lat collisions w/ obstacle - localized injuries to legs

• skidding/rolling

• lat collisions

  • sudden braking - projection

injuries motorcyclist

• lesions following projections most severe

• head trauma - fx falling into vertex, penetration spine into foramen magnum, compression bulb

• long bones, antero-lat pelvis, rib fx

• sliding - outer and inner pelvic limb injuries

• int organ lesion

steering wheel sd (if driver is unrestricted)

• hitting with steering wheel

• semicirc ecchymosis in thorax

• rib/sternal fx

  • abd visceral injuries, hand injuries

dashboard sd (if driver unrestricted)

• knee injury, patella fx, calf bone fx

• femoral neck fx

  • pelvic fx

windshield sd (if driver unrestricted)

• head impact, viscerocranium level

  • visceral and neurocranial fx

seat belt sd (restricted driver)

• ecchymosis - diagonally from upper l → r hemithorax, transversally in lower 1/3 of abd

• excoriated areas

  • rib fx

airbag sd

generated by viscerocranium impact w/ airbag

excoriations, ecchymosis

nasal pyramid fx, sup burns, hearing disorders

pedal sd

• leg + feet injuries from braking

• penetration femoral head to acetabular cavity

In the case of a passenger that is unrestricted with seat belt, he will be projected :

forward and upwards, with traumatic injuries located mainly on the right sid

Mechanical asphyxia is defined as:

pathophysiological processes that associate the decrease or lack of circulating oxygen, respectively hypoxia or anoxia

classification asphyxia

• by production circumstances - violent or patho

• by respiratory process stages - hypoxic, transport, alteration @ alveolo-cap membrane, from O2 deficiency @ tissues, anoxic

classification mechanical hypoxic asphyxia

• obstruction - suffocation, w/ foreign body or aspiration

• compression - on thorax-abd, on cervical region (hanging, strangulation, choking)

macro external exam asphyxia

• cyanosis - face, extremities, patchy, uneven, intensity depends on anoxic state duration

• cadaveric lividities - prematurely developed, blue-purple, on large surfaces

• asphyxiated hemorrhagic petechiae - purple, black hemorrhagic spots, on lividities, subconjunctiva, lips

• sphincteric incontinence

• mydriasis

• prolabatic tongue bw dental arches

internal macro exam asphyxia

• marked, generalized visceral blood stasis

• asphyxiated petechiae - in serosa, meninges, cerebral white matter, pleural (‘Tardieu’)

• blood is liquid, dark in colour, increased CO2 and catecholamines

micro aspects asphyxia (Spielmayer and Kernbach anoxic imprint)

• organ stasis and edema

• endotheliosis

• rupture cap. and interalveolar septa

• hydropicnovacuolar dystrophy

• fragmentation myocardial fibers

tanatochemical

In mechanical asphyxiation, death can occur through the following mechanisms:

• acute anoxia (lack O2)

• hemodynamic mechanism (compression vasc structures in cervical region)

• reflex mechanism (compression carotid sinus)

• fx cervcal spine (only in hanging)

classification hanging

• according to node position - typical (post cervical node, nape of neck), atypical (node anywhere else)

• according to corpse position - complete (w/o support points, totally suspended), incomplete (body has support point around it)

ligature mark findings hanging

• parchment like skin depression, yellow-brown, uneven depth

• upper 1/3 of neck, submandibular

• circular, circular, interrupted next to node

• oblique trajectory, towards node

• excoriated edges, ecchymosis

• hemorrhagic infiltration in subcutaneous tissue, muscles

• putrefaction-resistant lesion

3 noose categories

• soft - superficial ditches

• semi-hard (electric cable, rope)

• hard (wire, chain) - deep ditthces

2 node categories in asphyxia

fixed

sliding

int exam asphyxia

• hemorrhagic infiltration in soft tissues of neck

• rare hyoid bone fx/laryngeal thyroid cartilage

• carotid lesions - longitudinal hemorrhagic infiltration in outer tunic, hemorrhagic suffusions in intima, transverse bursts in intima (Amussat’s sign)

• rare axis fx - by hyperextension cervical spine

strangulation

Form of mechanical asphyxia caused by external compression of the neck with a cord that forms at this level a circular shape, which is actively tightened, being controlled by an external force

ext ema strangulation

• strangulation mark - parchmentlike skin depression in middle 1/3 of neck, horizontal trajectory, complete ciruclar appearance

• yellow-brown, uniform

• ± ecchymosis/excoriations in vicinity (victims attempt to free themselves)

• ext stigmas, signs violence

int exam strangulation

hemorrhagic infiltration into soft tissues of neck

fx thyroid cartilage/hyoid bone

choking vs strangulation- legal issues

choking is exclusively homicide

strangulation can be suicide (rare)

ex exam choking

oval ecchymosis (fingers), crescent excoriations (nails)

• if one-handed - one side of the neck there is an oval ecchymosis flanked by a crescent excoriation, other side of the neck four ecchymosis flanked by crescent excoriations

int exam strangulation

• hemorrhagic infiltration neck muscles

• fx laryngeal cartilage, hyoid bone

thoraco-abd compression

Form of mechanical asphyxia, caused by exerting a high pressure on the thorax and/or upper abdomen with the blockage, by the pressure exerted, of the diaphragmatic excursion (the main respiratory muscle) and the blockage of the pulmonary compliance

legal issues thoraco-abd compression

• accidental

• criminal

ext exam thoraco-abd compression

signs intense asphyxia (intense cyanosis face, petechiae)

int exam thoraco-abd compression

sternal fx, bilat rib fx

lungs - carmine edema lungs

thoracic/abd organs injuries (contusions, pul abd and cardiac rupture)

in what asphyxia method do we have discordance between reduced skin lesions and severe internal lesions!

thoraco-abd compression

suffocation

Mechanical asphyxia achieved by concomitant coverage of the external respiratory orifices (nostrils, oral cavity) making it impossible for air to enter the airways into the lungs

methods suffocation

by hand, pushing face into soft objects

damp cloth to resp tract, wrapping head w/ sheet

fixing adhesive tapes on resp orifices

inserting head into plastic bag