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).[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.



DiMaio classification[5]


Practical classification

Signs of neck
No signs of
neck compression
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.


  • 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



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


Classic findings:

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


  • 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.




  • 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.



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



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




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.


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


  • 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]


  • None that are specific.

Carbon monoxide toxicity

  • Abbreviated CO toxicity.


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


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


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]





  • 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]


  • 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


Many artefactual findings:



  • Soot in mucosa of respiratory tract - diagnostic.



  • Black crap on the airway epithelium.


  • Carboxyhemoglobin.[30]

Hydrogen sulfide toxicity


  • 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]


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


  • Green discolourization of the skin.[33]

Manual strangulation


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



  • 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.



  • Usually not contributory.


Ligature strangulation


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



  • 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]


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

See also


  1. Saukko, Pekka; Knight, Bernard (2004). Knight's Forensic Pathology (3rd ed.). A Hodder Arnold Publication. pp. 352. ISBN 978-0340760444.
  2. URL: 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: 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: Accessed on: 1 May 2012.
  7. URL: 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: Accessed on: 20 September 2010.
  20. URL: 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.
  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.
  32. Truscott A (August 2008). "Suicide fad threatens neighbours, rescuers". CMAJ 179 (4): 312–3. doi:10.1503/cmaj.080878. PMC 2492967. PMID 18695173.
  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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