Difference between revisions of "Asphyxial deaths"

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This article deals with '''asphyxial deaths''', where "asphyxia" is used in the conventional context, i.e. it is not used appropriately when considered from the perspective of its etymology (as pointed-out by Knight).<ref>{{Ref KFP|352}}</ref>
This article deals with '''asphyxial deaths''', where "asphyxia" is used in the conventional context, i.e. it is not used appropriately when considered from the perspective of its etymology (as pointed-out by Knight).<ref>{{Ref KFP|352}}</ref>


Asphyxia is, etymologically, ''lacking pulsation''; in common usage it is essentially ''hypoxia'' (blood lacking oxygen)<ref>URL: [http://dictionary.reference.com/browse/hypoxia http://dictionary.reference.com/browse/hypoxia]. Accessed on: 12 September 2010.</ref> and ''anoxia'' (tissues lacking oxygen).<ref>URL: [http://dictionary.reference.com/browse/anoxia http://dictionary.reference.com/browse/anoxia]. Access ed on: 12 September 2010.</ref>
Asphyxia is, etymologically, ''lacking pulsation''; in common usage it is essentially ''hypoxia'' (blood lacking oxygen)<ref>URL: [http://dictionary.reference.com/browse/hypoxia http://dictionary.reference.com/browse/hypoxia]. Accessed on: 12 September 2010.</ref><ref>{{Ref PCPBoD8|10}}</ref> and ''anoxia'' (tissues lacking oxygen).<ref>URL: [http://dictionary.reference.com/browse/anoxia http://dictionary.reference.com/browse/anoxia]. Access ed on: 12 September 2010.</ref>


An introduction to forensic pathology is in the ''[[forensic pathology]]'' article.
An introduction to forensic pathology is in the ''[[forensic pathology]]'' article.


==Overview==
=Overview=
==Classification==
===DiMaio classification<ref>{{Ref HoFP|155-64}}</ref>===
===DiMaio classification<ref>{{Ref HoFP|155-64}}</ref>===
{{familytree/start}}
{{familytree/start}}
Line 25: Line 26:
{{familytree | C01 | | C02 | | C03 | | | | C05 | | C07 | | | | | |C01=Hanging|C02=Ligature|C03=Manual|C05=Abnormal<br>skin colour|C07=No abnormality|}}
{{familytree | C01 | | C02 | | C03 | | | | C05 | | C07 | | | | | |C01=Hanging|C02=Ligature|C03=Manual|C05=Abnormal<br>skin colour|C07=No abnormality|}}
{{familytree/end}}
{{familytree/end}}
==Mechanism of death==
The mechanism of death in [[asphyxial death]]s seems to be an exam favourite.
===Short answer===
*Brain stem hypoxia due to ischemia caused by venous obstruction in the neck.<ref>URL: [http://www.forensicmed.co.uk/pathology/mechanisms-of-death/ http://www.forensicmed.co.uk/pathology/mechanisms-of-death/]. Accessed on: 1 May 2012.</ref><ref>URL: [http://www.forensicmed.co.uk/pathology/pressure-to-the-neck/ http://www.forensicmed.co.uk/pathology/pressure-to-the-neck/]. Accessed on: 1 May 2012.</ref><ref name=pmid20456578/>
===Long answer===
*It depends on who one asks.
*Other explanations include:<ref name=pmid20456578>{{Cite journal  | last1 = Clément | first1 = R. | last2 = Redpath | first2 = M. | last3 = Sauvageau | first3 = A. | title = Mechanism of death in hanging: a historical review of the evolution of pathophysiological hypotheses. | journal = J Forensic Sci | volume = 55 | issue = 5 | pages = 1268-71 | month = Sep | year = 2010 | doi = 10.1111/j.1556-4029.2010.01435.x | PMID = 20456578 }}</ref>
**"Cardiac inhibition secondary to nerve stimulation".
**"Respiratory asphyxia".


==The obsolete asphyxia quintet==
==The obsolete asphyxia quintet==
Components of quintet (memory device: ''FRCPC''):<ref name=pmid18665887>{{cite journal |author=Gilbert JD, Jensen L, Byard RW |title=Further observations on the speed of death in hanging |journal=J. Forensic Sci. |volume=53 |issue=5 |pages=1204–5 |year=2008 |month=September |pmid=18665887 |doi=10.1111/j.1556-4029.2008.00840.x |url=}}</ref>
Components of quintet (memory device: ''[[FRCPC]]''):<ref name=pmid18665887>{{cite journal |author=Gilbert JD, Jensen L, Byard RW |title=Further observations on the speed of death in hanging |journal=J. Forensic Sci. |volume=53 |issue=5 |pages=1204–5 |year=2008 |month=September |pmid=18665887 |doi=10.1111/j.1556-4029.2008.00840.x |url=}}</ref>
*Fluid blood.
*Fluid blood.
*Right heart engorgement.
*Right heart engorgement.
Line 39: Line 52:
*''Fluid blood'' is considered totally useless as a sign of anything.
*''Fluid blood'' is considered totally useless as a sign of anything.


=Specific types of asphyxial deaths=
==Hanging==
==Hanging==
===Gross (classic)===  
===General===
*Common way to suicide.
*May be accidental in the context of adolescents playing - see ''[[choking]]''.
 
===Gross===  
Classic findings:
*V-shaped furrow on the neck.
*V-shaped furrow on the neck.
*V "open" at the point of suspension.
**V "opens" at the point of suspension.
*+/-Tongue sticking-out.
 
Note:
*Hyoid bone fracture - uncommon in hanging.<ref name=pmid20206574>{{Cite journal  | last1 = Mukhopadhyay | first1 = PP. | title = Predictors of hyoid fracture in hanging: Discriminant function analysis of morphometric variables. | journal = Leg Med (Tokyo) | volume = 12 | issue = 3 | pages = 113-6 | month = May | year = 2010 | doi = 10.1016/j.legalmed.2010.01.002 | PMID = 20206574 }}</ref>


Documentation (The Rose method):<ref>TR. 28 September 2010.</ref>
Documentation (The Rose method):<ref>Rose, T. 28 September 2010.</ref>
*Anterior mid-line:
*Anterior mid-line:
**Measure distance from angle of neck to superior aspect of ligature mark.
**Measure distance from angle of neck to superior aspect of ligature mark.
Line 57: Line 80:
**Measure distance from C7 (???) to inferior aspect of ligature mark.
**Measure distance from C7 (???) to inferior aspect of ligature mark.
**Measure width of ligature mark.
**Measure width of ligature mark.
DDx:
*[[Ligature strangulation]].
==Choking==
===General===
*Typical accidental.
*May be part of game adolescents play known as the ''choking game''.<ref name=pmid19190276>{{Cite journal  | last1 = Macnab | first1 = AJ. | last2 = Deevska | first2 = M. | last3 = Gagnon | first3 = F. | last4 = Cannon | first4 = WG. | last5 = Andrew | first5 = T. | title = Asphyxial games or the choking game: a potentially fatal risk behaviour. | journal = Inj Prev | volume = 15 | issue = 1 | pages = 45-9 | month = Feb | year = 2009 | doi = 10.1136/ip.2008.018523 | PMID = 19190276 }}</ref>
**Known by many synonyms, e.g. ''asphyxial game'', ''fainting game'', ''black-out game''.
Associations:
*[[Ethanol]] intoxication.<ref name=pmid20666919>{{Cite journal  | last1 = Nikolić | first1 = S. | last2 = Zivković | first2 = V. | last3 = Dragan | first3 = B. | last4 = Juković | first4 = F. | title = Laryngeal choking on food and acute ethanol intoxication in adults--An autopsy study. | journal = J Forensic Sci | volume = 56 | issue = 1 | pages = 128-31 | month = Jan | year = 2011 | doi = 10.1111/j.1556-4029.2010.01510.x | PMID = 20666919 }}</ref>
*Neurologic disease.<ref name=pmid17209932>{{Cite journal  | last1 = Dolkas | first1 = L. | last2 = Stanley | first2 = C. | last3 = Smith | first3 = AM. | last4 = Vilke | first4 = GM. | title = Deaths associated with choking in San Diego county. | journal = J Forensic Sci | volume = 52 | issue = 1 | pages = 176-9 | month = Jan | year = 2007 | doi = 10.1111/j.1556-4029.2006.00297.x | PMID = 17209932 }}</ref>
Epidemiology:
*Extremes of age.<ref name=pmid17209932/>
**Old - often associated with neurologic disease or [[alcohol]].
**Young - may be foreign body ingestion.
===Gross===
Features:
*Foreign object that obstructs the airway.
**Usually a large laryngeal bolus of food - typically meat.<ref name=pmid17209932/>


==Drowning==
==Drowning==
===General===
===General===
Classic:
*Drowning is difficult to prove on autopsy.<ref name=pmid16378701>{{cite journal |author=Piette MH, De Letter EA |title=Drowning: still a difficult autopsy diagnosis |journal=Forensic Sci. Int. |volume=163 |issue=1-2 |pages=1–9 |year=2006 |month=November |pmid=16378701 |doi=10.1016/j.forsciint.2004.10.027 |url=}}</ref>  The diagnosis is often based on circumstance, i.e. the scene.
*Autopsy is often negative, i.e. there is no anatomical cause of death.
**The [[autopsy]] is often negative, i.e. there is [[negative autopsy|no anatomical cause of death]].


Drowning is difficult to prove on autopsy.<ref name=pmid16378701>{{cite journal |author=Piette MH, De Letter EA |title=Drowning: still a difficult autopsy diagnosis |journal=Forensic Sci. Int. |volume=163 |issue=1-2 |pages=1–9 |year=2006 |month=November |pmid=16378701 |doi=10.1016/j.forsciint.2004.10.027 |url=}}</ref>  The diagnosis is often based on circumstance, i.e. the scene.
====Laboratory====
There are a few tests of debated value:<ref name=pmid16378701/>
*Diffusion of particulates into the blood (left ventricle) from the water.
**Diatom test.
*Haemodilution.  
**Mostly useless - CPR interferes with it, not reliable if there putrefaction or autolysis.
*Transport of aveolar element into blood circulation.


===Macroscopic===
===Gross===
External:
====External findings====
*Plume of froth at the mouth/nostrils (fresh drowning only).<ref name=pmid16378701/><ref name=pmid12134758>{{cite journal |author=Bohnert M, Ropohl D, Pollak S |title=[Forensic medicine significance of the fluid content of the sphenoid sinuses] |language=German |journal=Arch Kriminol |volume=209 |issue=5-6 |pages=158–64 |year=2002 |pmid=12134758 |doi= |url=}}</ref>
*''[[Plume of froth]]'' ([[AKA]] ''cone of foam'') at the mouth/nostrils (fresh drowning only).<ref name=pmid16378701/><ref name=pmid12134758>{{cite journal |author=Bohnert M, Ropohl D, Pollak S |title=[Forensic medicine significance of the fluid content of the sphenoid sinuses] |language=German |journal=Arch Kriminol |volume=209 |issue=5-6 |pages=158–64 |year=2002 |pmid=12134758 |doi= |url=}}</ref>
**Classic DDx for this finding is: narcotics, congestive heart failure.
**Classic DDx for this finding is: narcotics, [[congestive heart failure]].
**Underlying etiology of this finding: pulmonary edema (as may be seen in a cerebral vascular malformation<ref name=pmid8454093>{{cite journal |author=Bilotti A |title=Noncardiogenic pulmonary edema: a certain etiology? |journal=Del Med J |volume=65 |issue=1 |pages=25–7 |year=1993 |month=January |pmid=8454093 |doi= |url=}}</ref>).
**Underlying etiology of this finding: pulmonary edema (as may be seen in a cerebral vascular malformation<ref name=pmid8454093>{{cite journal |author=Bilotti A |title=Noncardiogenic pulmonary edema: a certain etiology? |journal=Del Med J |volume=65 |issue=1 |pages=25–7 |year=1993 |month=January |pmid=8454093 |doi= |url=}}</ref>).
*Wrinkled skin ([[AKA]] ''washerwoman skin'' and ''hydration changes'') - changes due to water immersion; changes may be present in the context of immersion post-mortem.<ref name=pmid6741294>{{cite journal |author=Reh H |title=[Early postmortem course of washerwoman's skin of the fingers] |language=German |journal=Z. Rechtsmed. |volume=92 |issue=3 |pages=183–8 |year=1984 |pmid=6741294 |doi= |url=}}</ref>
*Wrinkled skin ([[AKA]] ''washerwoman skin'' and ''hydration changes'') - changes due to water immersion; changes may be present in the context of immersion post-mortem.<ref name=pmid6741294>{{cite journal |author=Reh H |title=[Early postmortem course of washerwoman's skin of the fingers] |language=German |journal=Z. Rechtsmed. |volume=92 |issue=3 |pages=183–8 |year=1984 |pmid=6741294 |doi= |url=}}</ref>


Internal:<ref name=pmid12134758>{{cite journal |author=Bohnert M, Ropohl D, Pollak S |title=[Forensic medicine significance of the fluid content of the sphenoid sinuses] |language=German |journal=Arch Kriminol |volume=209 |issue=5-6 |pages=158–64 |year=2002 |pmid=12134758 |doi= |url=}}</ref><ref>URL: [http://netk.net.au/Forensic/Drowning.pdf http://netk.net.au/Forensic/Drowning.pdf]. Accessed on: 20 September 2010.</ref>
====Internal findings====
Features:<ref name=pmid12134758>{{cite journal |author=Bohnert M, Ropohl D, Pollak S |title=[Forensic medicine significance of the fluid content of the sphenoid sinuses] |language=German |journal=Arch Kriminol |volume=209 |issue=5-6 |pages=158–64 |year=2002 |pmid=12134758 |doi= |url=}}</ref><ref>URL: [http://netk.net.au/Forensic/Drowning.pdf http://netk.net.au/Forensic/Drowning.pdf]. Accessed on: 20 September 2010.</ref>
*Lung emphysema; "kissing lungs" = lungs touch one another -- on opening the chest.  
*Lung emphysema; "kissing lungs" = lungs touch one another -- on opening the chest.  
*Froth in the trachea.
*Froth in the [[trachea]].
*Paltauf spots -- light-red washed-out appearing fingertip-sized spots.<ref>URL: [http://www.mijnwoordenboek.nl/EN/theme/ME/EN/DE/P/3 http://www.mijnwoordenboek.nl/EN/theme/ME/EN/DE/P/3]. Accessed on: 20 September 2010.</ref>
*Paltauf spots -- light-red washed-out appearing fingertip-sized spots.<ref>URL: [http://www.mijnwoordenboek.nl/EN/theme/ME/EN/DE/P/3 http://www.mijnwoordenboek.nl/EN/theme/ME/EN/DE/P/3]. Accessed on: 20 September 2010.</ref>
**Thought to arise from hemolysis + fluid decedent drown in.
**Thought to arise from hemolysis + fluid decedent drown in.
*Fluid in the paranasal sinuses.<ref name=pmid8643988>{{cite journal |author=Hottmar P |title=[The presence of fluid in the paranasal sinuses in comparison with other diagnostic signs of drowning] |language=Czech |journal=Soud Lek |volume=40 |issue=4 |pages=34–6 |year=1995 |month=December |pmid=8643988 |doi= |url=}}</ref>
*Fluid in the paranasal sinuses.<ref name=pmid8643988>{{cite journal |author=Hottmar P |title=[The presence of fluid in the paranasal sinuses in comparison with other diagnostic signs of drowning] |language=Czech |journal=Soud Lek |volume=40 |issue=4 |pages=34–6 |year=1995 |month=December |pmid=8643988 |doi= |url=}}</ref>


===Micro/Lab===
===Microscopic===
There are a few tests of debated value:<ref name=pmid16378701/>
*None that are specific.
*Diffusion of particulates into the blood (left ventricle) from the water.
**Diatom test.
*Haemodilution.
**Mostly useless - CPR interferes with it, not reliable if there putrefaction or autolysis.
*Transport of aveolar element into blood circulation.


==Carbon monoxide==
==Carbon monoxide toxicity==
*Abbreviated ''CO toxicity''.
===General===
===General===
*Carbon monoxide (CO) is a common way to commit suicide.
*Carbon monoxide (CO) is a common way to commit suicide.
Line 95: Line 144:
*CO binds to myoglobin.
*CO binds to myoglobin.


===Gross findings===
===Gross===
*External: salmon pink skin.
====External findings====  
*Internal: organs pink hue.
*Salmon pink skin.
 
 
DDx of pink skin includes:
*[[Hypothermia]].
*Cyanide poisoning.
*Fluoroacetate poisoning.
 
====Internal findings====
*General: organs pink hue.
*Brain: globus pallidus [[necrosis]] - bilateral.<ref name=pmid21150349>{{Cite journal  | last1 = Fielding | first1 = J. | last2 = Lang | first2 = W. | last3 = White | first3 = OB. | title = Carbon monoxide poisoning: impact on ocular motility. | journal = Cogn Behav Neurol | volume = 23 | issue = 4 | pages = 256-61 | month = Dec | year = 2010 | doi = 10.1097/WNN.0b013e3181c5e2c1 | PMID = 21150349 }}</ref>
 
Notes:
*Bilateral necrosis of the putamen is seen in [[methanol toxicity]].
 
Image:
*[http://i.dailymail.co.uk/i/pix/2011/02/14/article-1357042-0D0AEDBC000005DC-598_468x286.jpg CO toxicity of the brain (dailymail.co.uk)].


Note:
*The DDx of pink skin includes [[Forensic pathology#Hypothermia|hypothermia]].
===Microscopic===
===Microscopic===
*Non-specific.
Features:<ref>{{Ref PBoD8|1329}}</ref>
*Neuronal loss in the:
**Cerebral cortex layers III and V.
**Hippocampus CA1.
**Purkinje cells.


===Laboratory findings===
===Laboratory findings===
Line 121: Line 188:


==Fire deaths==
==Fire deaths==
===General===
Many artefactual findings:
*Postmortem [[epidural hematoma]].<ref name=pmid2309533>{{Cite journal  | last1 = Ritter | first1 = C. | title = [A heat gelatinized subdural hematoma in a burned cadaver as an indication of a vital accident]. | journal = Z Rechtsmed | volume = 103 | issue = 3 | pages = 227-30 | month =  | year = 1990 | doi =  | PMID = 2309533 }}</ref>
**[[Subdural hematoma]]s are ''not'' considered artefactual.
*Pugilistic attitude (boxer's position/stance).<ref>{{Cite journal  | last1 = Levy | first1 = AD. | last2 = Harcke | first2 = HT. | last3 = Getz | first3 = JM. | last4 = Mallak | first4 = CT. | title = Multidetector computed tomography findings in deaths with severe burns. | journal = Am J Forensic Med Pathol | volume = 30 | issue = 2 | pages = 137-41 | month = Jun | year = 2009 | doi = 10.1097/PAF.0b013e3181879cc9 | PMID = 19465802 }}</ref>
*Heat fractures.
**Base of skull seems to be an exception.<ref name=pmid9219359>{{Cite journal  | last1 = Bohnert | first1 = M. | last2 = Rost | first2 = T. | last3 = Faller-Marquardt | first3 = M. | last4 = Ropohl | first4 = D. | last5 = Pollak | first5 = S. | title = Fractures of the base of the skull in charred bodies--post-mortem heat injuries or signs of mechanical traumatisation? | journal = Forensic Sci Int | volume = 87 | issue = 1 | pages = 55-62 | month = May | year = 1997 | doi =  | PMID = 9219359 }}</ref>
===Gross===
===Gross===
Features:
Features:
*Soot in mucosa of respiratory tract.
*Soot in mucosa of respiratory tract - '''diagnostic'''.
 
===Microscopic===
Features:
*Black crap on the airway epithelium.


===Toxicology===
===Toxicology===
*Carboxyhemoglobin.<ref>{{Ref OPMfP|18}}</ref>
*Carboxyhemoglobin.<ref>{{Ref OPMfP|18}}</ref>
==Hydrogen sulfide toxicity==
===General===
*Fashionable for suicides; has high mortality and may be toxic to responders/death investors.<ref name=pmid20920221>{{cite journal |author=Morii D, Miyagatani Y, Nakamae N, Murao M, Taniyama K |title=Japanese experience of hydrogen sulfide: the suicide craze in 2008 |journal=J Occup Med Toxicol |volume=5 |issue= |pages=28 |year=2010 |pmid=20920221 |pmc=2954931 |doi=10.1186/1745-6673-5-28 |url=}}</ref>
**Can be generated by mixing a source of sulfide with an acid ''or'' ingesting the sulfide which will then react with stomach acid.
*Mechanism: bonds to mitochondrial cytochrome enzymes.<ref name=pmid18695173>{{cite journal |author=Truscott A |title=Suicide fad threatens neighbours, rescuers |journal=CMAJ |volume=179 |issue=4 |pages=312–3 |year=2008 |month=August |pmid=18695173 |pmc=2492967 |doi=10.1503/cmaj.080878 |url=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2492967/?tool=pubmed}}</ref>
===Toxicology===
*Classically has the smell of "rotten eggs".<ref name=pmid20920221>{{cite journal |author=Morii D, Miyagatani Y, Nakamae N, Murao M, Taniyama K |title=Japanese experience of hydrogen sulfide: the suicide craze in 2008 |journal=J Occup Med Toxicol |volume=5 |issue= |pages=28 |year=2010 |pmid=20920221 |pmc=2954931 |doi=10.1186/1745-6673-5-28 |url=}}</ref>
*Lab: ''thiosulfate''.
===Gross===
*Green discolourization of the skin.<ref name=Ref_Shkrum33>{{Ref Shkrum|33}}</ref>


==Manual strangulation==
==Manual strangulation==
Features:<ref name=Ref_HoFP>{{Ref HoFP|155}}</ref>
===General===
*Hands - from in front.
*Sleeper hold - from behind.
 
===Gross===
Features:<ref name=Ref_HoFP155>{{Ref HoFP|155}}</ref>
*Petechiac of sclerae (white part of eye) & conjunctivae (cover sclerae); present ~ 90% of the time.
*Petechiac of sclerae (white part of eye) & conjunctivae (cover sclerae); present ~ 90% of the time.
*Hyoid bone fracture.
*Hyoid bone fracture.
*Thyroid cartilage fracture.
*Thyroid cartilage fracture.
*Haemorrhage in strap muscles of the neck.
*Hemorrhage in strap muscles of the neck.
*Patterned ovoid contusions (from the fingers).
*+/-Defensive-type injuries.
 
====Image====
<gallery>
Image:Hofmann_Lehrbuch_suidide_hanging.jpg | Drawing of suicide by hanging. (WC/National Library of Medicine)
</gallery>
 
===Microscopic===
*Usually not contributory.
 
Features:
*+/-Siderophages.
*+/-Inflammation - esp. [[neutrophil]]s.


==See also==
==Ligature strangulation==
===General===
*May be suicide ''or'' homicide.
*In females may be associated with a sexual assault.<ref name=pmid10739219/>
*More likely to be a homicide than a [[hanging]].
 
===Gross===
Features:
*Horizontal furrow/depression on the neck - due to ligature.
*Petechiae - very common.<ref name=pmid10739219>{{Cite journal  | last1 = DiMaio | first1 = VJ. | title = Homicidal asphyxia. | journal = Am J Forensic Med Pathol | volume = 21 | issue = 1 | pages = 1-4 | month = Mar | year = 2000 | doi =  | PMID = 10739219 }}</ref>
*+/-Fractures of the hyoid, thyroid or cricoid cartilage - more common in males.<ref name=pmid10739219/>
 
DDx:
*[[Hanging]] - furrow/depression typically rises to a point of suspension.
 
=See also=
*[[Forensic pathology]].
*[[Forensic pathology]].


==References==
=References=
{{reflist|2}}
{{reflist|2}}
=External links=
*[http://failuremag.com/index.php/feature/article/the_game_that_makes_parents_gasp/ The choking game (failuremag.com)].


[[Category:Forensic pathology]]
[[Category:Forensic pathology]]

Latest revision as of 04:02, 6 January 2017

This article deals with asphyxial deaths, where "asphyxia" is used in the conventional context, i.e. it is not used appropriately when considered from the perspective of its etymology (as pointed-out by Knight).[1]

Asphyxia is, etymologically, lacking pulsation; in common usage it is essentially hypoxia (blood lacking oxygen)[2][3] and anoxia (tissues lacking oxygen).[4]

An introduction to forensic pathology is in the forensic pathology article.

Overview

Classification

DiMaio classification[5]

 
 
 
 
 
 
 
 
 
 
 
Asphyxia
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Strangulation
 
 
 
 
Chemical
 
 
 
 
 
 
Suffocation
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Hanging
 
Ligature
 
Manual
 
 
 
Mechanical
 
Environmental
 
Choking
 
Smothering
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Positional
 
 
 
Overlay
 
 
 
 
 
 
 
 
 
 

Practical classification

 
 
 
 
 
 
 
 
 
 
Suspected
asphyxia
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Signs of neck
compression
(Strangulation)
 
 
 
 
 
 
 
 
 
No signs of
neck compression
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Hanging
 
Ligature
 
Manual
 
 
 
Abnormal
skin colour
 
No abnormality
 
 
 
 
 

Mechanism of death

The mechanism of death in asphyxial deaths seems to be an exam favourite.

Short answer

  • Brain stem hypoxia due to ischemia caused by venous obstruction in the neck.[6][7][8]

Long answer

  • It depends on who one asks.
  • Other explanations include:[8]
    • "Cardiac inhibition secondary to nerve stimulation".
    • "Respiratory asphyxia".

The obsolete asphyxia quintet

Components of quintet (memory device: FRCPC):[9]

  • Fluid blood.
  • Right heart engorgement.
  • Cyanosis.
  • Petechiae.
  • Congestion, facial.

Notes:

  • The most useful are petechiae and facial congestion. Both are thought to result from an occlusion of the venous circulation without significant compromise of the arterial circulation, as may occur in partial suspension hangings.
    • The corollary to the above is that complete occlusion of the venous and arterial circulation (as may be seen in a complete suspension hanging) does not result in petechiae or facial congestion.
  • Fluid blood is considered totally useless as a sign of anything.

Specific types of asphyxial deaths

Hanging

General

  • Common way to suicide.
  • May be accidental in the context of adolescents playing - see choking.

Gross

Classic findings:

  • V-shaped furrow on the neck.
    • V "opens" at the point of suspension.
  • +/-Tongue sticking-out.

Note:

  • Hyoid bone fracture - uncommon in hanging.[10]

Documentation (The Rose method):[11]

  • Anterior mid-line:
    • Measure distance from angle of neck to superior aspect of ligature mark.
    • Measure width of ligature mark.
  • Left ear lobe-head junction:
    • Measure distance from ear lobe-head junction to superior aspect of ligature mark.
    • Measure width of ligature mark.
  • Right ear lobe-head junction:
    • Measure distance from ear lobe-head junction to superior aspect of ligature mark.
    • Measure width of ligature mark.
  • Posterior mid-line:
    • Measure distance from C7 (???) to inferior aspect of ligature mark.
    • Measure width of ligature mark.

DDx:

Choking

General

  • Typical accidental.
  • May be part of game adolescents play known as the choking game.[12]
    • Known by many synonyms, e.g. asphyxial game, fainting game, black-out game.

Associations:

Epidemiology:

  • Extremes of age.[14]
    • Old - often associated with neurologic disease or alcohol.
    • Young - may be foreign body ingestion.

Gross

Features:

  • Foreign object that obstructs the airway.
    • Usually a large laryngeal bolus of food - typically meat.[14]

Drowning

General

Laboratory

There are a few tests of debated value:[15]

  • Diffusion of particulates into the blood (left ventricle) from the water.
    • Diatom test.
  • Haemodilution.
    • Mostly useless - CPR interferes with it, not reliable if there putrefaction or autolysis.
  • Transport of aveolar element into blood circulation.

Gross

External findings

  • Plume of froth (AKA cone of foam) at the mouth/nostrils (fresh drowning only).[15][16]
    • Classic DDx for this finding is: narcotics, congestive heart failure.
    • Underlying etiology of this finding: pulmonary edema (as may be seen in a cerebral vascular malformation[17]).
  • Wrinkled skin (AKA washerwoman skin and hydration changes) - changes due to water immersion; changes may be present in the context of immersion post-mortem.[18]

Internal findings

Features:[16][19]

  • Lung emphysema; "kissing lungs" = lungs touch one another -- on opening the chest.
  • Froth in the trachea.
  • Paltauf spots -- light-red washed-out appearing fingertip-sized spots.[20]
    • Thought to arise from hemolysis + fluid decedent drown in.
  • Fluid in the paranasal sinuses.[21]

Microscopic

  • None that are specific.

Carbon monoxide toxicity

  • Abbreviated CO toxicity.

General

  • Carbon monoxide (CO) is a common way to commit suicide.

Pathophysiology:

  • CO binds to haemoglobin -- prevents oxygen from binding there.
  • CO binds to myoglobin.

Gross

External findings

  • Salmon pink skin.


DDx of pink skin includes:

  • Hypothermia.
  • Cyanide poisoning.
  • Fluoroacetate poisoning.

Internal findings

  • General: organs pink hue.
  • Brain: globus pallidus necrosis - bilateral.[22]

Notes:

Image:

Microscopic

Features:[23]

  • Neuronal loss in the:
    • Cerebral cortex layers III and V.
    • Hippocampus CA1.
    • Purkinje cells.

Laboratory findings

  • CO level (blood test) elevated.

COHb concentrations (by CO-oximetry):[24]

  • Smokers 10-15%.
  • Non-smokers <3%.
  • Fatal >50%.
    • Some say >35% % is fatal.[25]

Notes:

  • Two different methods:[26]
    1. Spectrophotometric methods - includes CO-oximeters.
    2. Gas chromatographic methods.
  • Spectrophotometric methods are considered good enough.
  • Gas chromatographic methods are considered the gold standard.

Fire deaths

General

Many artefactual findings:

Gross

Features:

  • Soot in mucosa of respiratory tract - diagnostic.

Microscopic

Features:

  • Black crap on the airway epithelium.

Toxicology

  • Carboxyhemoglobin.[30]

Hydrogen sulfide toxicity

General

  • Fashionable for suicides; has high mortality and may be toxic to responders/death investors.[31]
    • Can be generated by mixing a source of sulfide with an acid or ingesting the sulfide which will then react with stomach acid.
  • Mechanism: bonds to mitochondrial cytochrome enzymes.[32]

Toxicology

  • Classically has the smell of "rotten eggs".[31]
  • Lab: thiosulfate.

Gross

  • Green discolourization of the skin.[33]

Manual strangulation

General

  • Hands - from in front.
  • Sleeper hold - from behind.

Gross

Features:[34]

  • Petechiac of sclerae (white part of eye) & conjunctivae (cover sclerae); present ~ 90% of the time.
  • Hyoid bone fracture.
  • Thyroid cartilage fracture.
  • Hemorrhage in strap muscles of the neck.
  • Patterned ovoid contusions (from the fingers).
  • +/-Defensive-type injuries.

Image

Microscopic

  • Usually not contributory.

Features:

Ligature strangulation

General

  • May be suicide or homicide.
  • In females may be associated with a sexual assault.[35]
  • More likely to be a homicide than a hanging.

Gross

Features:

  • Horizontal furrow/depression on the neck - due to ligature.
  • Petechiae - very common.[35]
  • +/-Fractures of the hyoid, thyroid or cricoid cartilage - more common in males.[35]

DDx:

  • Hanging - furrow/depression typically rises to a point of suspension.

See also

References

  1. Saukko, Pekka; Knight, Bernard (2004). Knight's Forensic Pathology (3rd ed.). A Hodder Arnold Publication. pp. 352. ISBN 978-0340760444.
  2. URL: http://dictionary.reference.com/browse/hypoxia. Accessed on: 12 September 2010.
  3. Mitchell, Richard; Kumar, Vinay; Fausto, Nelson; Abbas, Abul K.; Aster, Jon (2011). Pocket Companion to Robbins & Cotran Pathologic Basis of Disease (8th ed.). Elsevier Saunders. pp. 10. ISBN 978-1416054542.
  4. URL: http://dictionary.reference.com/browse/anoxia. Access ed on: 12 September 2010.
  5. DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 155-64. ISBN 978-0849392870.
  6. URL: http://www.forensicmed.co.uk/pathology/mechanisms-of-death/. Accessed on: 1 May 2012.
  7. URL: http://www.forensicmed.co.uk/pathology/pressure-to-the-neck/. Accessed on: 1 May 2012.
  8. 8.0 8.1 Clément, R.; Redpath, M.; Sauvageau, A. (Sep 2010). "Mechanism of death in hanging: a historical review of the evolution of pathophysiological hypotheses.". J Forensic Sci 55 (5): 1268-71. doi:10.1111/j.1556-4029.2010.01435.x. PMID 20456578.
  9. Gilbert JD, Jensen L, Byard RW (September 2008). "Further observations on the speed of death in hanging". J. Forensic Sci. 53 (5): 1204–5. doi:10.1111/j.1556-4029.2008.00840.x. PMID 18665887.
  10. Mukhopadhyay, PP. (May 2010). "Predictors of hyoid fracture in hanging: Discriminant function analysis of morphometric variables.". Leg Med (Tokyo) 12 (3): 113-6. doi:10.1016/j.legalmed.2010.01.002. PMID 20206574.
  11. Rose, T. 28 September 2010.
  12. Macnab, AJ.; Deevska, M.; Gagnon, F.; Cannon, WG.; Andrew, T. (Feb 2009). "Asphyxial games or the choking game: a potentially fatal risk behaviour.". Inj Prev 15 (1): 45-9. doi:10.1136/ip.2008.018523. PMID 19190276.
  13. Nikolić, S.; Zivković, V.; Dragan, B.; Juković, F. (Jan 2011). "Laryngeal choking on food and acute ethanol intoxication in adults--An autopsy study.". J Forensic Sci 56 (1): 128-31. doi:10.1111/j.1556-4029.2010.01510.x. PMID 20666919.
  14. 14.0 14.1 14.2 Dolkas, L.; Stanley, C.; Smith, AM.; Vilke, GM. (Jan 2007). "Deaths associated with choking in San Diego county.". J Forensic Sci 52 (1): 176-9. doi:10.1111/j.1556-4029.2006.00297.x. PMID 17209932.
  15. 15.0 15.1 15.2 Piette MH, De Letter EA (November 2006). "Drowning: still a difficult autopsy diagnosis". Forensic Sci. Int. 163 (1-2): 1–9. doi:10.1016/j.forsciint.2004.10.027. PMID 16378701.
  16. 16.0 16.1 Bohnert M, Ropohl D, Pollak S (2002). "[Forensic medicine significance of the fluid content of the sphenoid sinuses]" (in German). Arch Kriminol 209 (5-6): 158–64. PMID 12134758.
  17. Bilotti A (January 1993). "Noncardiogenic pulmonary edema: a certain etiology?". Del Med J 65 (1): 25–7. PMID 8454093.
  18. Reh H (1984). "[Early postmortem course of washerwoman's skin of the fingers]" (in German). Z. Rechtsmed. 92 (3): 183–8. PMID 6741294.
  19. URL: http://netk.net.au/Forensic/Drowning.pdf. Accessed on: 20 September 2010.
  20. URL: http://www.mijnwoordenboek.nl/EN/theme/ME/EN/DE/P/3. Accessed on: 20 September 2010.
  21. Hottmar P (December 1995). "[The presence of fluid in the paranasal sinuses in comparison with other diagnostic signs of drowning]" (in Czech). Soud Lek 40 (4): 34–6. PMID 8643988.
  22. Fielding, J.; Lang, W.; White, OB. (Dec 2010). "Carbon monoxide poisoning: impact on ocular motility.". Cogn Behav Neurol 23 (4): 256-61. doi:10.1097/WNN.0b013e3181c5e2c1. PMID 21150349.
  23. Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1329. ISBN 978-1416031215.
  24. Olson KN, Hillyer MA, Kloss JS, Geiselhart RJ, Apple FS (April 2010). "Accident or arson: is CO-oximetry reliable for carboxyhemoglobin measurement postmortem?". Clin. Chem. 56 (4): 515–9. doi:10.1373/clinchem.2009.131334. PMID 20348410. http://www.clinchem.org/cgi/content/full/56/4/515.
  25. TR. 28 September 2010.
  26. Boumba VA, Vougiouklakis T (2005). "Evaluation of the methods used for carboxyhemoglobin analysis in postmortem blood". Int. J. Toxicol. 24 (4): 275–81. doi:10.1080/10915810591007256. PMID 16126621.
  27. Ritter, C. (1990). "[A heat gelatinized subdural hematoma in a burned cadaver as an indication of a vital accident].". Z Rechtsmed 103 (3): 227-30. PMID 2309533.
  28. Levy, AD.; Harcke, HT.; Getz, JM.; Mallak, CT. (Jun 2009). "Multidetector computed tomography findings in deaths with severe burns.". Am J Forensic Med Pathol 30 (2): 137-41. doi:10.1097/PAF.0b013e3181879cc9. PMID 19465802.
  29. Bohnert, M.; Rost, T.; Faller-Marquardt, M.; Ropohl, D.; Pollak, S. (May 1997). "Fractures of the base of the skull in charred bodies--post-mortem heat injuries or signs of mechanical traumatisation?". Forensic Sci Int 87 (1): 55-62. PMID 9219359.
  30. Ontario Forensic Pathology Service (2009). Ontario Forensic Pathology Service: Practice Manual for Pathologists (2nd ed.). Queen's Printer for Ontario. pp. 18.
  31. 31.0 31.1 Morii D, Miyagatani Y, Nakamae N, Murao M, Taniyama K (2010). "Japanese experience of hydrogen sulfide: the suicide craze in 2008". J Occup Med Toxicol 5: 28. doi:10.1186/1745-6673-5-28. PMC 2954931. PMID 20920221. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2954931/.
  32. Truscott A (August 2008). "Suicide fad threatens neighbours, rescuers". CMAJ 179 (4): 312–3. doi:10.1503/cmaj.080878. PMC 2492967. PMID 18695173. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2492967/?tool=pubmed.
  33. Shkrum, Michael J.; Ramsay, David A. (2006). Forensic Pathology of Trauma: Common Problems for the Pathologist (1st ed.). Humana Press. pp. 33. ISBN 978-1588294586.
  34. DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 155. ISBN 978-0849392870.
  35. 35.0 35.1 35.2 DiMaio, VJ. (Mar 2000). "Homicidal asphyxia.". Am J Forensic Med Pathol 21 (1): 1-4. PMID 10739219.

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