1. Wounds Dr. Raid Jastania

2. Wound and Injury Injuries results from the damage caused by energy (Force) Weapons transmit energy Relation between injury and weapon Terms: Blunt force, Sharp force, Penetrating injury Entry wound, Exit wound, track of weapon Physical properties of weapon, structure of tissue, position of body, Angle, Energy, type

3. Wounds Blunt force trauma Sharp force trauma

7. Blunt Force Trauma Abrasions: –Scratches and removal of superficial epidermis –Usually do not bleed

9. Blunt Force Trauma Contusions: –Bruises –Blunt trauma with rupture of blood vessels with leakage of blood into surrounding tissue –Color: blue/dark blue/purple/green/yellow –In adults, usually resolve by 1 week –If yellow >18 hours

13. Blunt Force Trauma Laceration: –Splitting of skin due to overstretching blunt force, usually with full thickness tear –Bleed –Bridging fibers –Ragged edges

16. Sharp Force Wounds Incised wounds (cut): –Sharp cut longer than its depth –Sharp edges –No bridging fibers –Rarely life threatening

19. Sharp Force Wounds Stab wounds –Cut deeper than its length –Often fatal –Common in homicide –Weapon shape and size Knives with one sharp edge and one blunt edge Depth of injury can be longer than the weapon May be surrounded by bruising and abrasions

20. Pattern of Injury Punching: –Blow by clenched fist –Usually in skin close to bone –Resulting in bruises, abrasions –Laceration of skin edge eg. Eyebrow, cheek, lips –Bruises of face, periorbital hematoma “black eyes”

21. Pattern of Injury Kicking: –By foot –Resulting in bruises, abrasions, lacerations –Common in head, chest, abdomen –Rib fractures

23. Pattern of Injury Bite marks –Bruises and laceration –Seen in sexual assault: neck, breast, shoulder –Seen in child abuse: arms, buttocks –Pair of curved lines of bruises

28. Pattern of Injury Defense injury: –Defense against blunt weapon attack: Bruises of forearm (ulnar side) –Defense against sharp weapon attack: Incised wounds on palm, and forearm

30. Pattern of Injury Self-inflicted injury –Bites: on medial aspect of arm –Incised wounds “elective sites”: front of wrist, and neck –Stab wounds Abdomen –Hesitation injury –Sites not injured: eyes, lips, nipples, genitalia

31. Head Injuries Components: –Scalp –Skull –Brain

32. Head Injury Scalp: layers: –Vascular and hair-bearing skin –Thick fibrous membrane (Galea Aponeurotica) –Connective tissue –Blood vessles –Periosteum

33. Head Injury Scalp: Injuries Common by blunt trauma Profuse bleeding Bleeding continues after death

34. Scalp: Injuries Bruises: Difficult to see, Easier to palpate, prominent edema, shaving Laceration: seen as cut, bleed profusely Tear of flaps of scalp: major trauma

35. Skull Injury Components: –Mandible, –Facial bones, –skull bone plates Different thickness of bone Fracture at the point of maximum stress May bend Indicates major trauma Brain injury may occur in the absence of skull fracture

36. Skull Injury Depressed fracture: –Blunt trauma –Part of the bone plat is pushed inward –Eg. Hammer Blow to the top of the head –Long linear fracture pass down the parietal plates and may pass across the floor of the skull –May join the two sides at the pituitary fossa

38. Skull Injury Fall from height: –On feet or the top of head –Ring fracture at the base of the skull around foramen magnum Direct blow to the bone plate: –Spider web fracture Orbital plate: –Fracture in the upper surface of orbit

41. Intracranial Hemorrhage Types: –Epidural (Extra dural) –Subdural –Subarachnoid Space occupying lesion Increased intracranial pressue Decreased blood flow Brain ischemia Herniation through tentorium cerebelli

42. Epidural Hemorrhage Fracture of skull plates Meningeal arteries run in grooves in the inner side of bone plates Common injury of middle meningeal arteries at the temporal bone Bleeding in extradural space Displacement of brain Rarely due to venous injury

44. Subdural Hemorrhage Rotational or shearing force Injury of venous sinuses Common in the very young and the very old May be present without skull fracture May organize

46. Subarachnoid Hemorrhage Very common Usually small and not fatal Associated with brain contusion and laceration May be fatal if large –Most common non-traumatic is due to rupture berry aneurysm in the circle of Willis

48. Brain Injury Sometimes in the abscess of hemorrhage Results in cerebral edema Swelling of brain Increased intracranial pressure Herniation: tentorium cerebelli and foramen magnum Findings: heavy brain, flat surface, hemorrhage and necrosis, compression of ventricles

49. Brain Injury Bruises and lacerations –Fracture –Penetrating injury –Hemorrhage Rotational injury Acceleration/Deceleration injury –Shearing between different layers of brain –Laceration deep in the brain –Common at region of corpus callosum –Diffuse axonal injury

50. Brain Injury Coup and contra Coup injury: –Coup injury occurs when a static head is stuck Injury of scalp will overly injury to brain –Contra Coup injury: Skull and brain are moving and suddenly arrested Injury of brain is opposite to scalp or skull injury

51. Neck Injury –Contains vital structures –Asphyxia Spine: –Very common –Can be subtle –Atlanto occipital joint –Damage of spinal cord –Damage to disc –Hyper extension > hyper flexion

52. Chest Blunt and Penetrating injury External pressure Positional asphyxia

55. Chest Blunt and Penetrating injury –Fracture of ribs: few or many –Flial chest –Pneumothorax, hemothorax –In children: sign of abuse –CPR injury: symmetrical and parasternal –Internal organ injury

56. Abdomen Bruises, laceration, rupture of organs Liver, pancreas, duodenum Severe force in major trauma Kidney and spleen: rotational injury Aorta, vena cava Ruptured bowel Internal bleeding: eg. spleen

58. Firearm Injury Two main types: –Smooth Barrel: fire group of pellets –Rifled Barrel (Grooved): fire single bullet

60. Shotguns Sporting weapons Fire large number of lead pellets Barrel about 66-70 cm Smooth internal surface One or two barrels Used up to 30-50 m range Size be “gauge” or bore diameter, eg. 12 gauge

61. Handguns 3 types: –Revolvers –Pistols –Rifles

65. Rifled Weapon One bullet Barrel has spiral grooves 4-6

68. Wounds due firearm weapon Cartridge: cap, case, wad, bullet or pellets, powder Velocity: 100 m/sec – 1000 m/sec Energy: ½ MV 2 Injury due to: Bullet or pellets Smoke and flame, and gases Powder Muzzle Range of distance Entry, Exit wound

72. Smooth Barrel Guns Pellets spread in cone shape pattern Entry wound: –Contact wound: Circular, wound edge is clean cut and regular No individual pellets No smoke Muzzle mark Split (laceration) if against bony parts Track is black, burned surrounded by pinker tissue Wads inside the track

76. Smooth Barrel Guns Entry wound: –Close range shot: Few centimeters No muzzle mark More smoke and burning of skin Powder tattooing of skin Wads inside the track

78. Smooth Barrel Guns Entry wound: –Intermediate range: 20 cm – 1 meter No muzzle mark, no smoke or burning Possible powder tattooing Irregular rim of wound Separate wad injury

80. Smooth Barrel Guns Entry wound: –>1 meter range: –No smoke or tattooing –Spread of shot –Satellite pellet holes around the main wound

81. Smooth Barrel Guns Entry wound: –Long range: 20-50 meters Uniform peppering Rarely fatal

82. Smooth Barrel Guns Exit wound: –May or may not be there –Single pellet exit or huge wound

83. Rifled weapon wounds Usually entry and exit Entry: –Contact wound: Circular, skin split (laceration) if over bony part Muzzle mark Bruising around wound Slight smoke burn

84. Rifled weapon wounds Entry: –Close range 20 cm More smoke marks Powder marks Inverted skin edges The defect is smaller than the bullet Abrasion around the wound

85. Rifled weapon wounds Entry: –Over 1 meter range: No smoke No powder –Long range Entry with collar of abrasion Margins may be irregular

86. Exit Wounds Everted skin Split flaps Stellate appearance No burning, no smoke No powder May be large, huge May be multiple exit wound If skin is supported by pressure (eg. Belt, or against the wall) it can be similar to entry wound

88. Internal injury Depends on the energy Usually much more than what appears Cavity formation inside internal organs

89. Suicidal Shots Contact or close range Weapon at scene Site: below chin, neck, forehead, temporal area, chest Side of dominant hand Never in eyes, abdomen, or inaccessible site Rare in women Consider accidental and homicial

91. Drowning

92. Body Recovered from Water Died naturally before water Died naturally in water Died from hypothermia Died from injury before water Died from injury in water Died from submersion Died from true drowning

93. Signs of immersion in water Skin is opaque and wrinkled, palm and sole Maceration of skin 1-2 weeks: peeling of hands and feets Cutis anserina due to contraction of errector pili muscle Decomposition of body

94. Rate of decomposition is ½ of speed in air –1 week: body bloated: face, abdomen, genetalia –2 weeks: skin becomes loose –Float on surface –Obese and women may float –Effect of animals and fish

95. Drowning Not simple hypoxia Entry of water into lungs Fresh water is hypotonic –Enters lungs – water diffuse to vascular space – by osmosis – increase in blood volume upto 50% in one minute + hemolysis of blood – severe hyperkalemia – heart failure Seawater is hypertonic –Enters lungs – fluid is shifted from vessels to alveolar space – longer survival

96. Lack of oxygen Hypothermia >40 minutes recovery Death by submersion in water: –Cold water in airways – vagal stimulation – cardiac arrest

97. Drowning Post mortem findings: –Frothy fluid in nose and mouth, trachea and lungs –Lungs sink in water –“dry lung drowning” –Finding of Diatom in lungs, and distal organs, brain, kidneys…

99. Injury Due to Heat

100. Injury due to heat Depends on temperature, length, exposure As low as 40 degrees (long exposure) If dry: results in burning If wet: results in scalding

101. Burning Classified according severity and extent: –First degree: erythema and blistering –Second degree: burning of whole thickness of epidermis and exposed dermis –Third degree: destruction of subdermal tissue and muscle, bone Size: Rule of Nine’s If more than 50%: poor prognosis But elderly may die of only 20% burn

103. Scalding Similar to burn Charring of skin by extremely hot liquid metal Immersion into liquid or splash

104. Fire Death may not be due to burn Inhalation of CO, Cyanide Difficult to determine ante-mortem from post-mortem Erythema and blistering in ante-mortem (not accurate) Position of body found in fire: corners, near exist

105. Fire Cherry pink skin in CO ( and internal organs) Soot in larynx, trachea and bronchi Absence of soot is not useful

106. Fire Cause of death: complex –Direct heat –Asphyxia –Carbon monoxide poisoning –Cyanide poisoning –Plasma loss, dehydration –Infection

107. Injuries on burned body Difficult X-ray Look for signs of strangulation, and shooting Heat hematoma in the epidural space with carboxy-hemoglobin blood

108. Hypothermia Common in elderly and infants Due to immersion – vagal stimulation Or true hypothermia –Core body temperature 35: minor clinical effect –Below 32: shivering ceases –Below 28: almost certain to die

109. Hypothermia Pink erythema around large joints Stomach shows numerous brown-black acute erosions Hyperviscosity, micro-infarctions Hemorrhagic pancreatitis “Reciprocal undressing” “hide-and-die” syndrome Frost bite

110. Electrical Injury In industry Current in amperes Voltage and resistance in Ohm’s Rare to result is death if voltage less than 100 v Entry point: usually hand Exit point: usually the other had or feet Current will cross the chest: cardiac arrest and respiratory paralysis

111. Electrical Injury Burn marks might be seen at entry point: blister May not be seen at all

112. Electrical Injury 10 mA current: pain and muscle twitching >30 mA current: muscle spasm “Hold on” grip >50 mA curent: across the chest will result in ventricular fibrillation AC is worse than DC Tissue resistance fall in wet conditions

113. Effect of Injury Internal Hemorrhage and Shock Infections Embolism: Fat, Air, Thrombo, Foreign Body embolism, Amniotic fluid embolism Disseminated intravascular coaguation ARDS