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1

Cortical Contusions

 Coup contusion

at site of impact)

1

Fall vs. Assault

2

Acute Liver Pathology Fatty Liver mech

– Increased catabolism peripheral fat

– Increased NADH stimulates lipid synthesis

– Decreased fatty acid oxidation

– Decreased transport lipoproteins from liver (acetaldehyde induced microtubule dysfunction)

2

Contrecoup contusion

(opposite site of impact)

2

Death by Neck Compression

• Airway occlusion

• Arrest of arterial supply to brain

• Obstruction of venous return from brain

• Cardiac arrhythmia via stimulation of carotid baroreceptors (carotid sinus reflex)

• Spinal cord/brainstem disruption

2

Postural (Positional) Asphyxia

• At risk

– Intoxicated individuals

– Seizure disorders

– Rollover motor vehicle accidents

3

Entrance vs. Exit wounds

3

Manual strangulation

• Petechiae

• Fingertip bruises

• Fingernail marks

• Chin abrasion

• Tongue injury

• Strap muscle injury

• Laryngeal fractures (70%)

• Defense wounds

• Sphincter incontinence

4

Range of Fire

6

Common STD in rape victims

– Common - Neisseria gonorrhoea, Chlamydia trachomatis, Trichomonas vaginalis, bacterial vaginosis

– Rare - syphilis, HIV

– Others – HSV, HPV, hepatitis

7

Hazerdous lead levels 

800 microg lead/ft2 hazardous)

8

Abrasions (scratch, scrape)

– Scraping or stamping of outer layers of skin

8

Side Impact Collisions

• Injuries from intrusion

• Injuries from lateral flexion of neck

• Seatbelts less protective

8

Perpetrators SBS

• Biological father 37%

• Boyfriend 20.5%

• Female sitter 17.3%

• Mother 12.6%

• Male sitter 3.9%

• Stepfather 3.1%

 

 

8

Hydrogen Sulfide

• Sources

– Fermentation of organic matter (“rotten eggs”) – Sewer gas (with CO2 and methane)

– Oil and chemical industry

9

Major Abdominal & Pelvic Injuries

• Liver lacerations

• Spleen lacerations

• Mesenteric lacerations

• Pelvic fractures

9

Ligature strangulation

• Petechiae with tide mark • Horizontal ligature mark

• Chin abrasion

• Tongue injury

• Strap muscle injury

• Laryngeal fractures (12%)

• Defense wounds

• Sphincter incontinence

11

Stages of Ethylene Glycol Poisoning

• Neurologic (0.5 – 12 hrs) – Nausea/vomiting

– Inebriation/euphoria

– CNS depression, seizures

• Cardiopulmonary (12 – 24 hrs)

– Compensatory hyperventilation, heart failure

• Renal (24 - 72 hrs)

– Acute tubular necrosis

12

Contusions (bruise, hematoma)

Disruption of subcutaneous blood vessels

13

Whiplash Shaken Infant Syndrome

INjries

• Acceleration and deceleration forces

– Intracranial injuries (shearing with SDH)

– Retinal hemorrhages

– Long bone (metaphyseal)

fractures

– Posterior rib fractures

14

Toxic Effects of Cocaine

 

• Pulmonarydysfunction • Pregnancy

– Abruption, premature labor, IUGR, teratogenesis • Other

– Rhabdomyolysis, perforated septum, infection

• CNS

– Hyperpyrexia, seizure, cerebral infarct, intracerebral hemorrhage, agitated delirium

• Cardiovascularsystem

– Increased blood pressure and heart rate, arrhythmia, MI,

aortic dissection

• Pulmonarydysfunction • Pregnancy

– Abruption, premature labor, IUGR, teratogenesis • Other

– Rhabdomyolysis, perforated septum, infection

14

Self-inflicted v Homicide

16

Ethylene Glycol fatal dose 

 Fatal dose =100 – 200 mL

17

Abusive Head Trauma

• Shaken baby syndrome

• Shaken impact syndrome

• Non-accidental head trauma

• Homicidal craniocerebral trauma

18

Lacerations (tear, split, “cut”)

– Tearing or rupture of skin

19

High Voltage Electrocution

• Third degree electrical burns

• Second degree contact burns (eg watch)

• Arcing “splash” electrical burns

• Skeletal fractures (tetany or blunt impact)

• Asphyxia (brain stem hyperthermia)

• Vascular thromboses

• Myocardial injury (both UE and LE entrance/exit)

20

Pedestrian injuries 

21

When Do Petechiae Occur?

• Violent sneezing or coughing

• Straining (e.g. at stool, childbirth, trumpet playing)

• Compression of the neck with incomplete occlusion of carotid arteries

• Fixation of the chest

21

Electricution Mechanism of Death

• Directelectricaleffects

– Vfib

– Asphyxia (paralysis of respiratory muscles)

– Direct disruption of brain stem • Thermalburns

– Heat, ignition of clothing • Bluntforceinjuries

– Falls, blast effect

22

Features of Asphyxial Game Playing

 

• Headaches

• Unexplained bruising around neck

• Blood shot eyes

• Facial petechiae

• Disorientation after being alone

• Ligatures tied in strange knots or unusual places

• Wear marks on furniture

23

Lacerated Aorta Mechanisms

• Deceleration injury

– Heavy heart keeps moving while tethered to vertebrae at distal arch

– May see ladder tears with possible local dissection • Crush injury (osseous pinch)

• Hyperextension

24

Rollover Accidents injuries

• Unrestrained passengers commonly ejected (partial or total)

– Amputations

– Patterned injuries

• Mechanical asphyxia

24

Langer’s Lines

26

Findings in Non-abused Children

Normal variants

– Midlinewedge-shaped smooth areas (diastasis ani) 

– Midlineanalskintags,folds

– Failureofmidlinefusion

27

Sexual Assault physical

Genital (esp. posterior fourchette, fossa navicularis, labia minora)

– Non-genital (esp. arms, thighs for restraint marks, bite marks)

27

H2S in Inspired Air

29

Cocaine mech

– Blocks reuptake DA, E, NE (sympathomimetic)

29

Epidural vs. Subdural Hemorrhage

30

Toluidine Blue Dye

Normalskinsurfacehas anucleated cells

• Traumaexposesdeeper nucleated cells

• Dye applied, allowed to dry and removed

• Retained stain in areas of trauma

32

Traumatic Brain Injury

Diffuse

– Concussion

– Diffuse axonal injury

34

Severe Diffuse TBI

• Widespread structural damage to axons (DAI)

• Initial LOC followed by coma, PVS or death

• Associated with brain swelling and secondary ischemic injury

35

Ethanol Metabolism

– 9 gm/hr

– 90% metabolized to acetaldehyde and acetic acid in gastric mucosa and liver

35

Rear Impact Collisions injuries

• More neck injury at lower speed – Cervical strain at 4-5 mph

– Critical/fatal at 20 mph

• Hyperflexion/extension of neck with cervical spine fractures (usually C5, C6)

• Risk of gas line explosion (1/2 of 1% of MVA and 1 to 1.5% of fatalities)

37

Methanol (wood alcohol) fatal dose 

15–500mL

38

Carboxyhemoglobin deadly at what HbCO %

• >50%

39

Heroin (diacetylmorphine)Toxic Effects

 

• Sudden death

– Profound respiratory depression, arrhythmia, pulmonary edema

– Due to variable drug purity and loss of tolerance

– Hypersensitivity rxn?

• Pulmonary

– Edema, septic emboli, abcess, infection, foreign body granulomas

• Skin

– Abcess, cellulitis, ulceration, scarring, hyperpigmentation, vein

thrombosis • Infection

– Endocarditis,hepatitis,AIDS

41

CNS Depressant Effects of Ethanol

Bac and effect

400 + 

Death

43

Head-on Collisions injuries

44

Where Are Petechiae Found?

• Periorbital skin • Conjunctivae

• Face and neck • Oral mucosa

46

Majority of car accidents is on what side

Frontal

48

affinity for hemoglobin as oxygen

CO has 230 to 300 times

49

Subdural Hemorrhage

• Hemorrhage between dura and arachnoid – Fromtornbridgingveins

– Withorwithoutfracture

– Samesideofimpact,oppositeorbilateral

• Cause

– Rapid acceleration/deceleration or rotational forces (e.g. fall, MVA,

assault) or

– Simple fall in at risk patient (elderly, alcoholic, dementia)

• Presentation

– –

May 2014

Immediate unconsciousness and rapid death or

Headache with gradual onset decreased responsiveness to coma to death

50

High vs. Low Voltage Electrocution

51

Biochemical Effects of Lead

• Inhibits iron incorporation into heme

• Competes with calcium

• Inhibits membrane associated enzymes

• Impairs production of active vitamin D

51

Cocaine Excited Delirium

Fatal arrhythmia precipitated by ischemia

– Increased MVO2 from elevated catecholamines – Decreased O2 supply from vasconstriction

– Accelerated atherosclerosis and thrombosis

52

Stages of Methanol Poisoning

• Early

– Transient euphoria, inebriation, drowsy

• Latent (6 - 30 hrs)

– Blurred vision, abdominal pain, vomiting – Metabolized to formic acid, formaldehyde

• Delayed

– Systemic effects of acidosis (high anion gap)

53

Cardiovascular System ethanol

• Toxic effects

– Hypertension (catecholamine release) – Dilated cardiomyopathy (direct toxicity)

• Protective effects

– Increased HDL

– Decreased platelet aggregation

54

Hydrogen Sulfide mech

– Inhibits cytochrome oxidase

– Reduction of oxyhemoglobin to methemoglobin

56

Traumatic Brain Injury

• Focal

– Cortical contusions

– Cerebral lacerations

58

Cocaine Effects

• Fast-acting stimulant of short duration • Rush

– Pleasure, power, strength and excitement

– (Not achieved by snorting) • High

– Increased alertness, confidence, disinhibition, well-being

– Followed by anxiety, apathy, insomnia (cocaine crash) • Sideeffects

– Weight loss, insomnia, fatigue, H/A, paranoia, “coke bugs”

59

Pathologic Features of SBS

• Externalinjury(85%)

• Fractureofskulland/orlongbones(25%)

• Subduralhemorrhage

• Contusiontears

• Tears of corpus callosum &/or rostral brainstem

• Diffuseaxonalinjury&/orhypoxic/ischemicinjury

• Cerebraledemawithorwithoutherniation

• Ocular findings

• Rarelycervicalinjury

61

Signs of Basal Skull Fractures

 

• Raccoon eyes (periorbital contusions)

• Battle sign (hemorrhage in mastoid process)

• Blood or CSF rhinorrhea or otorrhea

62

Oxygen in Inspired Air percentage and effects 

64

Temporary vs. Permanent Cavity

• Permanent cavity

– Actual track of crush injury caused by bullet

• Temporary cavity

– Shearing, compression and stretching of adjacent

tissue as energy is lost from bullet

65

Asphyxial Signs

66

Ethylene Glycol Diagnosis

 severe metabolic acidosis, seizures to ARF to death

High anion gap (above 18)

Urine microscopy

– Sodium fluorescein (additive)

– Calcium oxalate crystals (“sheafs of wheat”)

67

Epidural Hemorrhage

• Hemorrhage between skull and dura

• Cause (most)

– Blow to side of head with

– Temporal bone skull fracture and

– Laceration of middle meningeal artery

• Presentation

– Initial lucid interval (up to several hours) – Lethargy

– Death

68

Wound Path

69

Heroin psychological effects

euphoria,hallucinations,sedation