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.

Overview

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
 
 
 
 
 

The obsolete asphyxia quintet

Components of quintet (memory device: FRCPC):[6]

  • 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.

Hanging

General

  • Common way to suicide.

Gross (classic)

  • V-shaped furrow on the neck.
  • V "open" at the point of suspension.

Documentation (The Rose method):[7]

  • 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.

Drowning

General

Classic:

  • Autopsy is often negative, i.e. there is no anatomical cause of death.

Drowning is difficult to prove on autopsy.[8] The diagnosis is often based on circumstance, i.e. the scene.

Macroscopic

External:

  • Plume of froth (AKA cone of foam) at the mouth/nostrils (fresh drowning only).[8][9]
    • 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[10]).
  • Wrinkled skin (AKA washerwoman skin and hydration changes) - changes due to water immersion; changes may be present in the context of immersion post-mortem.[11]

Internal:[9][12]

  • 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.[13]
    • Thought to arise from hemolysis + fluid decedent drown in.
  • Fluid in the paranasal sinuses.[14]

Microscopic/Laboratory

There are a few tests of debated value:[8]

  • 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 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 findings

  • External: salmon pink skin.
  • Internal - general: organs pink hue.

Note:

Microscopic

Features:[16]

  • 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):[17]

  • Smokers 10-15%.
  • Non-smokers <3%.
  • Fatal >50%.
    • Some say >35% % is fatal.[18]

Notes:

  • Two different methods:[19]
    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.[23]

Hydrogen sulfide

General

  • Fashionable for suicides; has high mortality and may be toxic to responders/death investors.[24]
  • Lab: thiosulfate - not available in Canada as of 2010.
    • 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.[25]

Toxicology

  • Classically has the smell of "rotten eggs".[24]
  • Lab: thiosulfate - not available in Canada as of 2010.

Manual strangulation

General

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

Gross

Features:[26]

  • Petechiac of sclerae (white part of eye) & conjunctivae (cover sclerae); present ~ 90% of the time.
  • Hyoid bone fracture.
  • Thyroid cartilage fracture.
  • Haemorrhage in strap muscles of the neck.

Microscopic

  • Usually not contributory.

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. ↑ 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.
  7. ↑ TR. 28 September 2010.
  8. ↑ 8.0 8.1 8.2 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.
  9. ↑ 9.0 9.1 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.
  10. ↑ Bilotti A (January 1993). "Noncardiogenic pulmonary edema: a certain etiology?". Del Med J 65 (1): 25–7. PMID 8454093.
  11. ↑ Reh H (1984). "[Early postmortem course of washerwoman's skin of the fingers]" (in German). Z. Rechtsmed. 92 (3): 183–8. PMID 6741294.
  12. ↑ URL: http://netk.net.au/Forensic/Drowning.pdf. Accessed on: 20 September 2010.
  13. ↑ URL: http://www.mijnwoordenboek.nl/EN/theme/ME/EN/DE/P/3. Accessed on: 20 September 2010.
  14. ↑ 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.
  15. ↑ 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.
  16. ↑ 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.
  17. ↑ 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.
  18. ↑ TR. 28 September 2010.
  19. ↑ 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.
  20. ↑ 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.
  21. ↑ 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.
  22. ↑ 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.
  23. ↑ Ontario Forensic Pathology Service (2009). Ontario Forensic Pathology Service: Practice Manual for Pathologists (2nd ed.). Queen's Printer for Ontario. pp. 18.
  24. ↑ 24.0 24.1 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/.
  25. ↑ 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.
  26. ↑ DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 155. ISBN 978-0849392870.
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