MECHANICAL ANOXIA (ASPHYXIA)

1. MECHANICAL ANOXIA (ASPHYXIA)

2. Anoxia/ Asphyxia→ troubles of the gaseous metabolism - brutal lack of oxygen and increased amount of CO2 (acute anoxia). • Asphyxia → absence of the pulse • Classification ofasphyxia: • contribution (prevention of the entrance of oxygen in the lungs); • transportation (transport of oxygen from the lungs to the tissues is blocked); • utilization (the use of oxygen in the tissues is blocked).

3. Classification of contribution anoxia: • Pathological- tumors of larynx, pneumonia etc; 2. Violent-mechanical anoxia • Reduced concentration of oxygen in the air • Compression of the neck- hanging, strangulation by hand or ligature • Suffocation- obstruction of mouth and nose, superior respiratory airways- smothering (blockage of the mouth/nose); gagging (fabric/ adhesive tap oclude the mouth to prevent speaking/shouting) • Thoracic- abdominal compression • Blockage of the pulmonary alveoli- drowning

5. General signs of anoxia External examination: • Cianosis of the face and extremities; • Hemorrhagic petechias on the conjunctival membrane, skin, lividity; • Loss of urine, feces and sperm; • Cadaveric lividity- bluish, covers large surface of the skin Internal examination • Right heart - dilated and filled with blood (increased pressure in the pulmonary circulation); • Liquid, bluish blood; • Generalized stasis; • Pulmonary emphysema, acute pulmonary edema; • Petechial hemorrages on visceral pleura (Tardieu), epicardium , internal side of the scalp

6. Hemorrhagic petechias

7. Hanging • Compression of the neck with a traumatic loop under the weight of the body • Complete/incomplete • Tipical/atipical

8. Hanging External examination • Cadaveric lividity in the inferior parts of the body; • Hanging mark - upper part of the neck - yellowish-brownish, dehydrated (abrasion) - oblique, the upper point at the level of the knot - maximum depth - opposite to the knot; - the shape and the dimensions according- type of loop; - may be interrupted at the level of the knot - - very resistant to putrefaction • On the neck- bruieses and abrasions • Injuries on the body- convulsions- crime scene investigation

9. Hanging Internal examination • Hemorrhagic infiltration in the muscle of the neck; • Fractures of the hyoid bone and tyroid cartilage; • Horizontal fissures of intimae of the carotid arteries; • Fractures of the cervical spine- hanging with a chain ( hard loop) or when the body falls very rapidly in gap (executions).

12. Incomplete, tipical hanging

13. Incomplete, atipical hanging

15. Direction of the hanging mark

17. Mechanisms of death • Anoxic 2. Vascular • Blue hanging 3. Inhibition • white hanging • 4. Fracture of the upper cervical spine

18. Type of death • Violent death • a) suicide- the most frequent in men; • b) accident – in small children falling from bed - in the mountaineers • c) murder - very rare , in persons who cannot protect themselves • d) dissimulation of a murder

20. Strangulation by ligature External examination • Ligature mark - Middle part of the neck - Horizontal; - Complete, circular; - Uniform depth on the hole circumference ; - Abrasions , bruises on the neck , aroundthe ligature mark , produced by the victim's fingers and nails 2. Intense general signs of asphyxia Internal examination • Similar to hanging Ştrangulare cu laţul şi tentativa victimei de a se elibera prin introducerea mâinilor sub laţ.

21. Strangulation by ligature • Violent death • Mechanism of death anoxic vascular • Crime- most frequent • Suicide- rare, but not impossibile • Accident

24. Strangulation by hand External examination • Intense cianosis - progressive compression of the neck; • On the neck – ovalar bruises (finger pads) and curved abrasions (nails) ↓ - Position of the victim and aggressor - If the victim was killed with one or both hands/with the right or left hand Injuries in other regions of the body Internal examination • Similar to hanging Violent death- 100% murder! Excoriaţii şi echimoze produse prin sugrumare

25. Infiltrat hemoragic şi fracturi

26. Thoraco-abdominal compression Compression of the thorax and abdomen- prevents the respiratory movements. External examination • Various injuries; • Subcutaneous emphysema; • Intense general signs of apshyxia Internal examination • Rib fractures, fracture of sternum • Injuries of thoracic organs +/- abdominal organs ! Characteristic→ minimal/reduced lesions of the skin vs. severe internal lesions.

27. Thoraco-abdominal compression Violent death Mechanism - anoxia Juridical perspective Crime Accident

29. Leziuni pe faţa internă a buzelor, prin sufocare Suffocation by blockage of external air passages (nose and mouth) • Hand - bruises and abrasions on the cheeks , around the nose and mouth , due to the finger pads and nails • Soft object ( pillow ) - no injuries on the face. • Internal side of the lips- hemorrhagic infiltration- prints of the teeth • Plastic strip, plastic bag- general signs of asphyxia Violent death Mechanism- anoxia

31. Suffocation due to the blockage of the superior airways • Various objects and materials- soil , sand , vegetable materials , coins , food etc. External examination • Intense general signs of asphyxia ; • Injuries around of the lips, • Injuries located in other regions of the body- fight between the victim and the assaulter ; Internal examination • Injuries of the teeth, pharynx; • The foreing object or material blocking the superior airways- hemorrhagic infiltration of the mucosal surface

35. Suffocation due to the blockage of the upper airways Violent death Mechanisms anoxic inhibitory reflexes Juridical perspective • Crime- injuries of the lips, teeth, pharynx • Accident- especially in children • Suicide- extremely rare

36. Drowning Replacement of the alveolar air with a liquid (water , wine , oil etc) Clinical features • Voluntary apneea – 30-60 sec.- increase of CO2 concentration • Inspiratory dispneea- 1 min- inhalation and swallowing of water • Reflex expiratory dispneea • Convulsions • Lack of respiration • Terminal respiration, failure of vital functions

37. Drowning I Signs of immersion - produced by the water ; • Visible on each body who lays in water, no matter the cause of death; • They may help to estimate for how long the body was immersed- maceration of the skin - first on the hands and feet; - the skin becomes white on the palms and plants in 3-6 hours ; - in 3-5 days- the " laundress glove" ( the wrinkling of the skin of the finger pads ) ; - detachement of the skin of the hands and feet- 10-15 days ; • “Goose flesh“- due to contraction of the erector pilae muscles (attached to each hair follicles) due to the contact with the cold water. • - presence of mud , oil , silt , on the body, hair , mouth and nostrils.;

38. Drowning laundress glove

39. Drowning II. Injuries produced by animals : • aquatic animals may destroy parts of the corpse (fingers, nose, ears)- no hemorrhagic infiltration. III. Injuries produced by the contact with stones , bridges , propellers of the ships : • may be serious , e.g. fragmentation of the body by the propeller of a ship ; • injuries due to dragging of the body on the bottom of the water (especially in running waters); IV. Injuries due to the jump in the water - cervical spine, internal organs ( due to the contact with the surface or the bottom of the water ).

40. V. Drowning injuries: • due to entrance of the water or other liquid in the organism-vital drowning ; • fluid blood in the left heart and sometimes , liquid in the pleural cavities (due to absorbtion of the breathed water ); • "drowning mushroom" - white foam around the mouth and nostils , due to the mixture between the breathed water , air and mucus in the superior airways; • the lungs overinflated , diminished elasticity, dry aspect - acute pulmonary emphysema due to the rupture of the alveoli walls; • Paltauf spots - on the serosal surfaces, especially on the pleura- bluish, diffuse margins • water in the stomach and intestines; • soily mug, algae in the respiratory ways. VI. General signs of asphyxia

41. Drowning Examination of diatoms : • Diatoms- microscopic algae with a silicaceous exoskeleton • The types of diatoms varies in different waters→the examination of diatoms shows if the person drowned in the same water where the body was found. • The diatoms also prove drowning during the life- the diatoms are in the organs with terminal circulation (e.g. spleen).