Asphyxia and Wounds

8/20/2019 Asphyxia and Wounds

1/42

ASPHYXIA ANDWOUNDS

In Forensic Pathology

By

Dr C A Okolo MBBS FMCPath!


2/42

As"hy#ia $ S%&&ocation'ntra"(ent)'n*iron(ental s%&&ocationS(otheringChokingMechanical As"hy#ia

S%&&ocating +asesStrang%lation ,igat%re Strang%lation

Man%al Strang%lationChe(ical As"y#iantsSe#%al As"hy#ia -A%toerotic As"hy#ia)Death.


3/42

Wo%n/s $ Bl%nt 0o%n/s $ A1rasions $ Dating o& A1rasions $ Cont%sions $ Dating o& Cont%sions $ Post$(orte( Br%ising $ 2he 'yes an/ 'yeli/s $ Deco("ose/ Bo/ies $ ,acerations $ De&ense 0o%n/s /%e

to Bl%nt &orce $ Deter(ination o& 0hether a 0o%n/ is Ante$ or Post$(orte( $ Fract%res Wo%n/s ca%se/ 1y "ointe/ or shar"s $ Sta1 0o%n/s $ Incise/ sta1 0o%n/s $ Incise neck 0o%n/s $ Cho" 0o%n/s $ 2hera"e%tic or Diagnostic 0o%n/s


4/42

As"hy#ial /eaths are ca%se/ 1y the &ail%re o&

cells to recei*e or %tili3e 45! 2he /e"ri*ation

o& o#ygen can 1e "artial -hy"o#ia. or total-ano#ia.!

2he classical signs o& as"hy#ia are *isceral

congestion "etechiae cyanosis an/ &l%i/ityo& 1loo/! 2hese are non$s"eci&ic an/ can

occ%r in /eaths &ro( other ca%ses!


5/42

Petechiae are "in"oint hae(orrhages

"ro/%ce/ 1y r%"t%re o& s(all *essels

"re/o(inantly s(all *en%les! 6%"t%re a""ears

to 1y (echanical in etiology an/ is ca%se/ 1ys%//en o*er /istension an/ r%"t%re o& the

*essels &ollo0ing a1r%"t increases in

intra*asc%lar "ress%re! 2hese are (ostco((on in *isceral "le%ral an/ e"icar/i%(

-Tardieu spots.!


6/42

In as"hy#ial /eaths &ro( strang%lation

"etechiae are classically seen in thecon7%ncti*ae an/ sclerae!

Cyanosis is non$s"eci&ic an/ ca%se/ 1y an

increase in the a(o%nt o& re/%ce/

hae(oglo1in! It /oes not 1eco(e o1ser*a1le

%ntil at least 8g o& re/%ce/ hae(oglo1in is

"resent!


7/42

Postmortem fluidity o& 1loo/ is the res%lt o&

a high rate o& &i1rinolysis that occ%rs in ra"i/

/eaths "ossi1ly 1y high agonal le*els o&

catechola(ines!


8/42

Asphyxial deaths can be loosely

grouped into three categories:

Suffocation $ 2his re&ers to /eaths ca%se/ 1y re/%ction o& 45in the res"ire/ at(os"here! 2here is &ail%re o& 45 to reach the1loo/! It can 1e 1y the &ollo0ing9

$ Entrapment/Environmental suffocation : Chinese s%ici/ein cars!

$ Smothering : (echanical o1str%ction o& e#ternal air0ay-nose (o%th. "lastic 1ag!

$ Choking : (echanical o1str%ction 0ithin the air "assages! $ echanical asphyxia : 6iot$cr%sh sta("e/e snake

"ython!

$ Mechanical as"hy#ia co(1ine/ 0ith s(othering! $ Suffocating gases : Dis"lace(ent o& O5! '!g! C45 an/

(ethane!


9/42

Environmental suffocation : /%e to re/%ce/

en*iron(ental o#ygen!

Nor(al at(os"heric 45 : 54!;8<

At O5 Conc o& =4 : =8< $ I("air(ent in

7%/ge(ent > coor/ination!

At O5 Conc o& ? : =4< $ ,oss o&

conscio%sness

At O5 Conc o& @ ?< $ Death!

At O5 Conc o& : < $ ,OC 0ithin 4 sec an/

/eath 0ithin &e0 (in%tes!


10/42

Strang%lation:

2his is characterise/ 1y clos%re o& the 1loo/

*essels an/ air "assages o& the neck as a

res%lt o& e#ternal "ress%re on the neck!

2here are three &or(s :

!anging : Us%ally s%ici/e '#ce"t in %/icial

Hanging : /islocation o& C5 C *eter1rae!

"igature strangulation $ Us%ally ho(ici/e

anual strangulation $ Us%ally ho(ici/e!


11/42

Cause of death instrangulation $ Cere1ral hy"o#ia secon/aryto co("ression an/ there1y occl%sion o& the *essels s%""lying

1loo/ to the 1rain!

Arterial supply to the brain $ internal caroti/s $ 2he *erte1rates $ 2he s(all s"inal arteries

$ Anasto(osis o& 1ranches o& e#ternal caroti/ an/ s%1cla*ianarteries

#enous drainage : (ainly 7%g%lar *eins an/ cer*icalis "ro&%n/a*eins!

$irect pressure to the front of the neck : co("ression o&caroti/s!

"ateral flexion or rotation of the neck : co("ression o&*erte1ral arteries e!g! in hanging!

Compression % &cclusion of carotids : ,OC in =4 sec I& "ress%re is release/ regain o& conscio%sness in : =4$=5 sec!


12/42

S(othering9

As"hy#ia 1y s(othering is ca%se/ 1y the

(echanical o1str%ction or occl%sion o& the

e#ternal air0ays i!e nose an/ (o%th!


13/42

Che(ical As"hy#iants

In che(ical as"hy#ia inhalation o& a gaseo%s

co("o%n/ "re*ents %tili3ation o& O5 at the cell%lar

le*el! Co((on che(ical as"hy#iants incl%/e

Carbon onoxide -CO. "oisoning $ Most co((on! !ydrogen cyanide : 1y ingestion ca%ses as"hy#ia

1y 1in/ing 0ith &erric iron ato( o& intracell%lar

cytochro(e o#i/ase!

!ydrogen Sulfide -H5S. &o%n/ in se0ers se0age"lant as 0ell as oil an/ che(ical in/%stries! Ca%ses

re/%ction o& O#yhae(oglo1in an/ the &or(ation o&

(ethe(oglo1in!


14/42

Se#%al As"hy#ia -A%toerotic

As"hy#ia.

Se#%al as"hy#ia is "rinci"ally ca%se/ 1y

hanging! Here transitory ano#ia is

intentionally in/%ce/ to enhance se#%al

aro%se(ent "ro/%ce/ 1y (ast%r1ation!

Death is %s%ally acci/ental an/ occ%rs (ost

co((only in (ales an/ is *ery rare!


15/42

Cr%ci&i#ion9

2he *icti( is naile/ to a cross han/s an/

&eet! Death is ca%se/ 1y shock 1oth

hy"o*olae(ic an/ secon/ary to "ain o&

nailing "l%s /ehy/ration an/ as"hy#ia!


16/42

Death By U"si/e Do0n

S%s"ension:

I& an in/i*i/%al is s%s"en/e/ %"si/e /o0n &or

long eno%gh "erio/ o& ti(e /eath can res%lt!

2he (echanis( o& /eath (ight 1e either

ac%te car/iac or res"iratory &ail%re on

co(1ination o& 1oth! 2he length o& ti(e it

takes &or /eath to occ%r /e"en/s on the

health o& the in/i*i/%al! It co%l/ range &ro( a&e0 ho%rs to a /ay or (ore


17/42

Deaths &ro( choke or Caroti/

Hol/s

Neck hol/s are %se/ 1y la0 en&orce(ent

agencies to s%1/%e *iolent in/i*i/%als!

6arely one 0ill enco%nter a /eath allege/ to

ha*e occ%rre/ /%e to a""lication o& either a

choke hol/ or a caroti/ slee"er hol/!


18/42

Wo%n/s:

'lunt trauma (ounds! 2he se*erity e#tent an/ a""earance o& 1l%nt

tra%(a in7%ries /e"en/ on :

$ 2he a(o%nt o& &orce /eli*ere/ to the 1o/y! $ 2he ti(e o*er 0hich the &orce is /eli*ere/! $ 2he region str%ck! $ 2he e#tent o& 1o/y s%r&ace o*er 0hich the

&orce is /eli*ere/! $ 2he nat%re o& the 0ea"on!


19/42

Bl%nt &orce in7%ries &all into &o%r categories9

A1rasions

Cont%sion

,acerations

Fract%res o& the skeletal syste(!


20/42

A1rasion

This is an in7%ry to the skin in 0hich there is

re(o*al o& the s%"er&icial e"ithelial layer o&

the skin -e"i/er(is. 1y &riction against a

ro%gh s%r&ace or /estr%ction o& the s%"er&icial

layer 1y co("ression! Ante(orte(

a1rasions ha*e re//ish 1ro0n a""earance

an/ heal 0itho%t scaring! Post (orte(a1rasions are yello0 an/ transl%cent 0ith a

"arch(ent$like a""earance!


21/42

2here are ty"es o& a1rasion9 $ Scrape or brush abrasion : 1l%nt

o17ects scra"es o&& the s%"er&icial layers o&

the skin lea*ing /en%/e/ s%r&ace! $ )mpact abrasions : the 1l%nt &orce is

/irecte/ "er"en/ic%lar to the skin cr%shing it!

$ Patterned abrasion : i("rint o& either theo&&en/ing o17ect or inter(e/iary (aterial isi("rinte/ on the skin!


22/42

$ating of Abrasions -Histologic.! In the li*ing!

2here are &o%r stages in the healing o& a1rasions9

Sca1 &or(ation : $hrs : 5 hrs!

'"ithelial regeneration : 4$E5 hrs!

S%1e"ithelial gran%lation an/ e"ithelial hy"er"lasia

: 8$? /ays!

6egression o& e"itheli%( an/ gran%lation tiss%e :=5 /ays!


23/42


24/42

Dating o& Cont%sion

Consistent (icrosco"ic /ating o& cont%sions has

1een &o%n/ to 1e i("ossi1le! Colo%r change is the

(ost relia1le (etho/ o& /ating9$

$ 6e/$"%r"le colo%ration $ *isi1le soon a&ter 1r%ise! $ In*ol%tion o& the colo%r occ%rs as the 1r%ise ages

0ith /egra/ation o& hae(oglo1in! 6e/ iolet

green /ark yello0 "ale yello0

/isa""earing! NB 9 Cont%sion cannot 1e &or(e/ a&ter /eath!


25/42

The Eyes and Eyelids

S%rgical re(o*al o& corneas or the glo1es o&

the eyes shortly a&ter /eath can res%lt in

hae(orrhage into the eyeli/s

%n/isting%isha1le &ro( ante(orte( tra%(as!

Con&l%ent hae(orrhages in eyeli/s can occ%r

a&ter /eath in cases o& hea/ tra%(a 0ith&ract%re o& the or1ital "lates!


26/42

,acerations

2his is a tear in tiss%e ca%se/ 1y either a shearing

or a cr%shing &orce! ,aceration o& the skin ten/s to

1e irreg%lar 0ith a1rai/e/ cont%se/ (argins! 2hey

are ca%se/ 1y 1lo0s &ro( 1l%nt o17ects &alls ori("act or &ro( *ehicles! 2he a""earance o&

laceration (ay not acc%rately re&lect the instr%(ent

that "ro/%ce/ it! ,acerations occ%r (ost co((only

o*er 1ony "ro(inence e!g! hea/ 0here the skin is&i#e/ an/ can (ore easily 1e stretche/ an/ torn!


27/42

$etermination of (hether a (ound is

Antemortem or post*mortem

2his is /one 1y gross an/ (icrosco"ic

e#a(ination9

Hae(orrhage .

In&la((atory res"onse . Ante(orte(


28/42

+ractures

Co((only ca%se/ 1y assa%lts an/ (otor

*ehicle acci/ents! Can 1e &ro( /irect or

in/irect a""lication o& &orce!


29/42

Wo%n/s ca%se/ 1y Pointe/ or

Shar" O17ects

2hese 0o%n/s co%l/ &all into the &ollo0ing

categories9

Sta1 0o%n/s

Incise/ 0o%n/s

Cho" 0o%n/s

2hera"e%tic)Diagnostic 0o%n/s


30/42

Sta1 Wo%n/s

Sta1 0o%n/s are "ro/%ce/ 1y "ointe/

instr%(ents! Most are ho(ici/al! In sta1

0o%n/s the /e"th o& the 0o%n/ in the 1o/y

e#cee/s itGs length in the skin! 2he e/ges o&the 0o%n/ in the skin are ty"ically shar"

0itho%t a1rasion or cont%sion! 2he ter(

laceration is not a""ro"riate as a laceration isa tear in the skin ca%se/ 1y 1l%nt &orce!


31/42

2he (ost co((only %se/ 0ea"on to "ro/%ce a sta1

0o%n/ is a kni&e : %s%ally a &lat$1la/e/ single e/ge

kitchen "ocket or &ol/ing kni&e 0ith a to 8 inch

1la/e! Other /e*ices incl%/e ice picks, scissors,

scre( drivers, broken glass, forks, pens and

pencils-

2he &orce nee/e/ &or a kni&e to "er&orate the skin/e"en/s on the con&ig%ration an/ shar"ness o& the

ti" o& the kni&e! 2he shar"er (ore nee/le$like the ti"

the (ore rea/ily it 0ill "er&orate the skin! Once the

ti" has "er&orate/ the skin the rest o& the 1la/e 0illsli/e into the 1o/y 0ith ease e#ce"t i& it contacts

1one!


32/42

De"th o& Sta1 Wo%n/s

2he /e"th o& a sta1 0o%n/ can 1e e%al less

or greater than the 0i/th an/ length o& the

kni&e! 2he /e"th a sta1 0o%n/ nee/s to

achie*e to "ro/%ce li&e threatening or &atal0o%n/ /e"en/s on the area o& the 1o/y

sta11e/!


33/42

Appearance of Stab (ound in skin 2he si3e an/ sha"e o& a sta1 0o%n/ in the

skin /e"en/s on the &ollo0ing9 $ Nat%re o& 1la/e an/ kni&e -shar" or 1l%nt.! $ 2he /irection o& the thr%st! $ 2he (o*e(ent o& the 1la/e in the 0o%n/!

$ 2he (o*e(ent o& the in/i*i/%al sta11e/! $ 2he state o& rela#ation or tension o& the

skin!


34/42


35/42

Parts o& a single e/ge/ kni&e

Back

Point

'/geS"ine

6icasso

+%ar/+ri"

Han/le or Hilt


36/42

Stab .ounds from .eapons other than

knives

2he sta1 0o%n/s in s%ch cases ha*e a

characteristic a""earance that tallies 0ith the

sha"e length an/ 0i/th o& the sta11ing

o17ect! '/ge o& 1roken 1ottle scre0 /ri*er

&orks etc!


37/42

)dentifying the (eapon

2he /octor is o&ten aske/ to gi*e an o"inion

as to the characteristics o& the 0ea"on %se/

in a killing 0as it a kni&e 0as it single or

/o%1le e/ge/! What 0as the length o& the

1la/e the 0i/th etc! One sho%l/ 1e

e#tre(ely ca%tio%s in gi*ing ans0er to s%ch%estions


38/42

)ncised stab (ounds9 An incise/$sta1 0o%n/ is a sta1 0o%n/ that is

con*erte/ to an incise/ -slashing. 0o%n/!

2he 0o%n/s starts o%t as a sta1 0o%n/ 0iththe kni&e "l%nge/ into the 1o/y! 2he kni&einstea/ o& 1eing i((e/iately 0ith/ra0n is"%lle/ to0ar/ the assailant slicing thro%ghthe tiss%e e#ten/ing the length o& the 0o%n/in the skin s%ch that the 0o%n/ is no0 longerthan /ee"!


39/42

)ncised 0eck .ounds

Most co((only ho(ici/al 1%t occasionally

acci/ental an/ rarely s%ici/al! 2he 0o%n/s(ay 1e o& *arying /e"ths an/ se*erity!

Death &ro( incise/ 0o%n/s o& the neck (ay

1e /%e not only to e#sang%inations 1%t to(assi*e air e(1olis(!

2he length o& ti(e it takes to /ie &ollo0ing an

incise/ 0o%n/ o& the neck /e"en/s on

0hether the *eno%s or arterial syste(s are

se*ere/ an/ 0hether there is air e(1olis(!

Physical Activity +ollo(ing a +atal Stab


40/42

Physical Activity +ollo(ing a +atal Stab

.ound

2he %estion o& 0hether an in/i*i/%al is

ca"a1le o& "hysical acti*ity i!e a1le to 0alk orr%n a0ay &ro( the assailant a&ter recei*ing a

&atal sta1 0o%n/ /e"en/s on the organs

in7%re/ the e#tent o& in7%ry the a(o%nt o&1loo/ lost an/ the ra"i/ity 0ith 0hich the

1loo/ is lost! With "ro&%se 1lee/ing "hysical

acti*ity is li(ite/ or lost ra"i/ly 0ith slo0

1lee/ing the *icti( is ca"a1le o& 0alkinga0ay &ro( the assailant!


41/42

Chop .ounds

Cho" 0o%n/s are "ro/%ce/ 1y hea*y

instr%(ents 0ith a c%tting e/ge e!g axes,

machetes and meat cleavers- 2he

"resence o& an incise/ 0o%n/ o& the skin 0ithan %n/erlying co((%nite/ &ract%re or /ee"

groo*e in the 1one in/icates that one is

/ealing 0ith a cho""ing 0ea"on!


42/42

Therapeutic or $iagnostic .ounds 2hese are 0o%n/s "ro/%ce/ 1y (e/ical

"ersonnel /%ring the treat(ent o& a "atient!Co((on e#a("les are thoracoto(yincisions s%rgical sta1 0o%n/s o& the chestor a1/ &or insertion o& t%1es an/ /rainsla"aroto(y incision c%t /o0n o& the 0ristsetc! 2hese (%st 1e s%&&iciently /i&&erentiate/&ro( ho(ici/al an/ s%ici/al 0o%n/s!

Asphyxia and Wounds

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