Asphyxial deaths
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] and anoxia (tissues lacking oxygen).[3]
An introduction to forensic pathology is in the forensic pathology article.
Overview
DiMaio classification[4]
| Asphyxia | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Strangulation | Chemical | Suffocation | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Hanging | Ligature | Manual | Mechanical | Choking | Smothering | Environmental | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 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):[5]
- Fluid blood.
- Right heart engorgement.
- Cyanosis.
- Petechiae.
- Congestion, facial.
Hanging
Classic:
- V-shaped furrow on the neck.
- V "open" at the point of suspension.
Drowning
Classic:
- Autopsy is often negative, i.e. there is no anatomical cause of death.
Drowning is difficult to prove on autopsy.[6] The diagnosis is often based on circumstance, i.e. the scene.
Macroscopic
External:
- Plume of froth at the mouth/nostrils (fresh drowning only).[6][7]
- Classic DDx for this finding: narcotics.
- Underlying etiology of this finding: pulmonary edema (e.g. cerebral vascular malformation[8]).
Internal:[7]
- Lung emphysema.
- Froth in the trachea.
- Paltauf spots -- ???
- Fluid in the paranasal sinuses.[9]
Micro/Lab
There are a few tests of debated value:[6]
- 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 (CO) is a common way to commit suicide.
Pathophysiology:
- CO binds to haemoglobin -- prevents oxygen from binding there.
Findings:
- Salmon pink skin.
- CO level (blood test) elevated (???).
Manual strangulation
Features:[10]
- 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.
See also
References
- ↑ Saukko, Pekka; Knight, Bernard (2004). Knight's Forensic Pathology (3rd ed.). A Hodder Arnold Publication. pp. 352. ISBN 978-0340760444.
- ↑ URL: http://dictionary.reference.com/browse/hypoxia. Accessed on: 12 September 2010.
- ↑ URL: http://dictionary.reference.com/browse/anoxia. Access ed on: 12 September 2010.
- ↑ DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 155-64. ISBN 978-0849392870.
- ↑ 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.
- ↑ 6.0 6.1 6.2 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.
- ↑ 7.0 7.1 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.
- ↑ Bilotti A (January 1993). "Noncardiogenic pulmonary edema: a certain etiology?". Del Med J 65 (1): 25–7. PMID 8454093.
- ↑ 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.
- ↑ DiMaio, Vincent J.M.; Dana, Suzanna E. (2006). Handbook of Forensic Pathology (2nd ed.). CRC Press. pp. 155. ISBN 978-0849392870.