Asphyxia - pathophysiology, autopsy findings & medicolegal importance

Undergraduate Medical topic

1. Asphyxia Dr. Chandan Bandyopadhyay

2. CBME Competency FM 2.20 Mechanical Asphyxia define, classify and describe asphyxia and medicolegal interpretation of post-mortem findings in asphyxia death

3. Asphyxia Definition It is a condition caused by interference with respiration, or due to lack of oxygen in respired air, due to which the organs and tissues are deprived of oxygen together with failure to eliminate carbon di oxide, causing unconsciousness or death.

4. T he term asphyxia indicates the mode of death, rather than the cause of death

5. Asphyxia TYPES Mechanical Pathological Toxic Environmental Traumatic Postural/positional iatrogenic

6. Asphyxia TYPES Mechanical – in which there is mechanical obstruction to breathing or air passages are blocked mechanically Pathological – in which the entry of oxygen as well the exit of carbon di oxide from lungs are prevented due diseases of the upper or lower respiratory tracts Toxic – in which the physiological process of respiration is deranged due to the toxic effect of some substance.

7. Asphyxia TYPES Environmental – in which there is insufficiency of oxygen in the inspired air or irrespirable gases are present in the atmosphere. Traumatic – this results when there is Pulmonary embolism resulting from injury or traumatic impairment of respiratory excursions. Postural/positional – respiratory excursions are hampered due to abnormal or unusual posture. Iatrogenic – physician/therapy induced, usually refers to that associated with anaesthesia.

8. Asphyxia pathophysiology

9. Asphyxia stigmata Cyanosis Petechiae – facial, palpebral, bulbar, subpleural, subepicardial Visceral congestion

10. Asphyxia symptoms Stage of dyspnoea Stage of convulsion Stage of exhaustion

11. Asphyxia post-mortem findings External W ell developed hypostasis Cyanosis Petechial haemorrhages Prominent eyes, conjunctival congestion, dilatation of pupils, protruded tongue, discharge of blood stained froth through mouth and nostrils Face may be pale/dusky with distortion

12. Asphyxia post-mortem findings Internal B lood is fluid and dark Mucous membranes are congested Lungs are dark, congested and oedematous Tardieu spots are present All the abdominal viscera are congested

13. Asphyxia-2 Dr. Chandan Bandyopadhyay

14. CBME Competency FM 2.21 Mechanical Asphyxia Mechanical asphyxia: Describe and discuss different types of hanging and strangulation including clinical findings, causes of death, post-mortem findings and medico-legal aspects of death due to hanging and strangulation including examination, preservation and dispatch of ligature material

15. hanging H anging or self suspension is that form of mechanical (violent) asphyxia, which is caused by suspension of the body by a ligature which encircles the neck, the constricting force being the weight of the body, partly or wholly.

16. Hanging types D epending upon degree of suspension Complete and partial D epending upon position of the knot typical and atypical

17. Hanging types

18. Hanging types

19. Hanging Ligature mark I t is oblique, non-continuous, high up around the neck . T he skin under the ligature mark is brownish, perchmentised and furrowed at places . T he subcutaneous tissue under the ligature is hardened, condensed, whitened and glistening.

20. Hanging Ligature mark

21. Hanging Symptoms L oss of power and subjective sensations Loss of consciousness Convulsion Respiration stops before the heart

22. Hanging causes of death ( immediate ) Asphyxia Venous congestion Combined asphyxia and venous congestion Cerebral anaemia Reflex vagal inhibition Fracture/dislocation of cervical vertebra Fatal period is usually 3-5 minutes

23. Hanging causes of death ( delayed ) Aspiration pneumonia Oedema of larynx/lungs Hypoxic encephalopathy Infarction of brain Brain abscess

24. Hanging Postmortem findings The ligature mark Cyanosis, petechial haemorrhages Dried mark of dribbling of saliva from the mouth Visceral congestion and subserosal petechial haemorrhagic spots

25. Hanging medicolegal questions Antemortem hanging or Postmortem hanging Suicidal/accidental/homicidal hanging Judicial hanging Lynching

26. Judicial hanging

27. lynching

28. strangulation S trangulation is that form of asphyxia which is caused from constriction of the air passage at the level of neck by a ligature or any other means without suspending the body .

29. Strangulation types S trangulation by ligature M anual s trangulation / t hrottling P almar s trangulation M ugging G arrotting b ansdola

30. strangulation causes of death ( immediate ) Asphyxia Cerebral anoxia or Venous congestion Combined asphyxia and venous congestion Reflex vagal inhibition Fracture/dislocation of cervical vertebra

31. Strangulation Ligature mark W ell defined, completely encircles the neck transversely about the middle or below the thyroid cartilage . T here is a wide area of bruising at the site of the knot. Petechial haemorrhages are usually found immediately adjacent to the ligature mark.

32. Strangulation Ligature mark

33. strangulation Postmortem findings The ligature mark Asphyxial signs are more prominent Extensive bruising of the deeper tissues of the neck Fracture of thyroid cartilage is more common, at one or both superior horns

34. strangulation Postmortem findings

35. strangulation medicolegal questions Hanging or Strangulation Suicidal/accidental/homicidal strangulation

36. Manual strangulation or throttling A sphyxia caused by compression of the neck by human hands is called throttling. Death occurs due to occlusion of carotid arteries . O cclusion of airways play a minor role .

37. Manual strangulation or throttling

38. Manual strangulation or throttling

39. Palmar Strangulation I t is a type of strangulation where one palm is placed horizontally across the mouth and nostrils, and the other palm is placed perpendicular across the first hand in such a way that the heel of the second hand presses upon the front of the neck .

40. mugging I t is a type of strangulation caused by holding the neck of the victim in the bend of the elbow .

41. mugging

42. garrotting G arrotting is a method of killing by asphyxia, where the victim is attacked from the behind without warning and his throat is constricted, by hand or other means.

43. garrotting

44. bansdola B ansdola (doing away with bamboos) is a form of homicidal strangulation where the compression of the neck is achieved by bamboos.

45. Hyoid bone fractures I nward (lateral) compression fracture O utward (anteroposterior) compression fracture A vulsion/Tug/Traction fracture

46. preservation and dispatch of ligature material T he knot should never be opened for removing the ligature material. the first step is to take photograph before removal of the ligature material. T he ligature is now cut opposite the knot and the two cut ends are secured with a string after noting measurements. T he ligature material is then air dried, packed in paper envelope, labelled, sealed, signed and handed over to the escorting police personnel.

47. preservation and dispatch of ligature material

48. Asphyxia-3 Dr. Chandan Bandyopadhyay

49. CBME Competency FM 2.22 Mechanical Asphyxia Mechanical asphyxia: Describe and discuss pathophysiology, clinical features, post-mortem findings and medico-legal aspects of traumatic asphyxia, obstruction of nose & mouth, suffocation and sexual asphyxia.

50. Sexual hanging / Autoerotic asphyxia / asphyxophilia / sexual asphyxia I t is accidental death caused by a self induced decrease in oxygenation of blood (hypoxia) produced most commonly by partial hanging

51. Autoerotic asphyxia features Cerebral disturbances caused by partial asphyxia may lead to hallucinations of an erotic nature in some men. Death is not intended….occurs accidentally, Victims are usually males Associated with some form of abnormal sexual behaviour

52. Autoerotic asphyxia features Hanging is usually the most preferred form of asphyxia. The neck is usually protected by a padding. Bizarre POA/Scene is the key to diagnosis

53. Autoerotic asphyxia features

54. suffocation S uffocation is a general term to indicate that form of asphyxia, which is caused by deprivation of Oxygen, either due to lack of Oxygen in the environment or from obstruction of the air passages at the level of nose and mouth.

55. Suffocation ( alternate definition ) S uffocation is a form of Mechanical (Violent) Asphyxia in which death occurs due to prevention of entry of air in the lungs by any means other than constriction of neck or drowning.

56. Suffocation - types D ue to insufficient oxygen concentration in atmosphere or presence of irrespirable gases -e nvironmental S uffocation. Due to closure of mouth and nostrils- Smothering . Due to pressure over chest and/or abdomen- Traumatic Asphyxia, Overlaying. Due to obstruction within the mouth or windpipe- Choking, Gagging Burking , Postural or Positional Asphyxia

57. Environmental Suffocation Death from Hypoxic Hypoxia Deaths are almost always accidental An Oxygen conc. of 16% or less is dangerous and with 5% conc. consciousness is lost rapidly and death occurs within few minutes.

58. smothering T his is a form of asphyxia which is caused by closing the external respiratory orifices (nostrils and mouth) by the hand or by other means like cloth, pillow etc .

59. gagging T his is a form of asphyxia which results from forcing a cloth into the mouth, or the closure of the mouth and nose by a cloth or similar material, which is tied around the head.

60. overlaying O verlaying is accidental death by smothering caused by a larger individual sleeping on top of a smaller individual, usually an infant.

61. Traumatic asphyxia Traumatic Asphyxia results from respiratory arrest due to mechanical fixation of the chest, so that the normal movements of the chest wall are prevented.

62. burking Burking is a method of homicidal asphyxia, where two asphyxia methods- smothering and traumatic asphyxia- are simultaneously used.

63. choking C hoking is a form of asphyxia caused by an obstruction within the air passages (at a level below that of vocal cord). I t is almost always accidental . Special type: Cafe Coronary

64. Postural/positional asphyxia I t is a type of asphyxia caused by abnormal position of the body i.e.   which occurs when someone's position prevents him from breathing adequately.

65. Asphyxia-4 Dr. Chandan Bandyopadhyay

66. CBME Competency FM 2.23 Mechanical Asphyxia Describe and discuss types, patho -physiology , clinical features , postmortem findings and medico-legal aspects of drowning , diatom test and, gettler test

67. drowning D rowning is a form of asphyxia due to aspiration of fluid into air-passages, caused by submersion in water or other fluid . C omplete submersion is not necessary, for submersion of mouth and nose for a sufficient period of time can cause death by drowning .

68. Drowning - types W et d rowning /p rimary d rowning D ry d rowning S econdary d rowning /n ear d rowning /p ost immersion s yndrome I mmersion s yndrome / h ydrocution /s ubmersion i nhibition

69. Drowning - mechanism

70. Drowning - pathophysiology

71. Drowning - causes of death Asphyxia Ventricular fibrillation Laryngeal spasm Vagal inhibition Injuries Death usually occurs in 4-8 minutes of complete submersion

72. Drowning - Postmortem findings Clothing is wet with cold, wet and pale skin Light pink hypostasis Typical froth of drowning Lung are voluminous, heavy. Paltauf’s haemorrhage may be present Mud and sand beyond the bifurcation of trachea is the surest sign

73. Drowning - Postmortem findings

74. Drowning - Postmortem findings

75. Drowning - Postmortem findings

76. Drowning - Postmortem findings

77. Drowning - Postmortem findings

78. Emphysema aquosum Condition of victim when went in water --------live and conscious Efforts to breathe--- intense, violent Churning of water within air passages and creation of foam Passive entry of water in lungs-- not excessive, because of constant coughing, spasms of air passages Appearance of lungs-- foamy. contains excessive froth, but relatively less water Alveolar walls-- ruptured due to violent efforts at breathing Edema aquosum Live and unconscious No efforts No such Excessive because of absent cough reflex. copious water enters with each inspiration Watery. contains excessive water, but relatively less, or virtually no froth Intact

79. Drowning - laboratory tests Gettler test Diatom test Biochemical tests

80. Drowning - laboratory tests

81. Drowning - medicolegal questions Antemortem OR post-mortem drowning Suicidal , accidental or homicidal drowning Probable duration of submersion

82. Thank you