Cortical Contusions
Coup contusion
at site of impact)
Fall vs. Assault
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)
Contrecoup contusion
(opposite site of impact)
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
Postural (Positional) Asphyxia
• At risk
– Intoxicated individuals
– Seizure disorders
– Rollover motor vehicle accidents
Entrance vs. Exit wounds
Manual strangulation
• Petechiae
• Fingertip bruises
• Fingernail marks
• Chin abrasion
• Tongue injury
• Strap muscle injury
• Laryngeal fractures (70%)
• Defense wounds
• Sphincter incontinence
Range of Fire
Common STD in rape victims
– Common - Neisseria gonorrhoea, Chlamydia trachomatis, Trichomonas vaginalis, bacterial vaginosis
– Rare - syphilis, HIV
– Others – HSV, HPV, hepatitis
Hazerdous lead levels
800 microg lead/ft2 hazardous)
Abrasions (scratch, scrape)
– Scraping or stamping of outer layers of skin
Side Impact Collisions
• Injuries from intrusion
• Injuries from lateral flexion of neck
• Seatbelts less protective
Perpetrators SBS
• Biological father 37%
• Boyfriend 20.5%
• Female sitter 17.3%
• Mother 12.6%
• Male sitter 3.9%
• Stepfather 3.1%
Hydrogen Sulfide
• Sources
– Fermentation of organic matter (“rotten eggs”) – Sewer gas (with CO2 and methane)
– Oil and chemical industry
Major Abdominal & Pelvic Injuries
• Liver lacerations
• Spleen lacerations
• Mesenteric lacerations
• Pelvic fractures
Ligature strangulation
• Petechiae with tide mark • Horizontal ligature mark
• Chin abrasion
• Tongue injury
• Strap muscle injury
• Laryngeal fractures (12%)
• Defense wounds
• Sphincter incontinence
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
Contusions (bruise, hematoma)
Disruption of subcutaneous blood vessels
Whiplash Shaken Infant Syndrome
INjries
• Acceleration and deceleration forces
– Intracranial injuries (shearing with SDH)
– Retinal hemorrhages
– Long bone (metaphyseal)
fractures
– Posterior rib fractures
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
Self-inflicted v Homicide
Ethylene Glycol fatal dose
Fatal dose =100 – 200 mL
Abusive Head Trauma
• Shaken baby syndrome
• Shaken impact syndrome
• Non-accidental head trauma
• Homicidal craniocerebral trauma
Lacerations (tear, split, “cut”)
– Tearing or rupture of skin
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)
Pedestrian injuries
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
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
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
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
Rollover Accidents injuries
• Unrestrained passengers commonly ejected (partial or total)
– Amputations
– Patterned injuries
• Mechanical asphyxia
Langer’s Lines
Findings in Non-abused Children
Normal variants
– Midlinewedge-shaped smooth areas (diastasis ani)
– Midlineanalskintags,folds
– Failureofmidlinefusion
Sexual Assault physical
Genital (esp. posterior fourchette, fossa navicularis, labia minora)
– Non-genital (esp. arms, thighs for restraint marks, bite marks)
H2S in Inspired Air
Cocaine mech
– Blocks reuptake DA, E, NE (sympathomimetic)
Epidural vs. Subdural Hemorrhage
Toluidine Blue Dye
Normalskinsurfacehas anucleated cells
• Traumaexposesdeeper nucleated cells
• Dye applied, allowed to dry and removed
• Retained stain in areas of trauma
Traumatic Brain Injury
Diffuse
– Concussion
– Diffuse axonal injury
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
Ethanol Metabolism
– 9 gm/hr
– 90% metabolized to acetaldehyde and acetic acid in gastric mucosa and liver
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)
Methanol (wood alcohol) fatal dose
15–500mL
Carboxyhemoglobin deadly at what HbCO %
• >50%
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
CNS Depressant Effects of Ethanol
Bac and effect
400 +
Death
Head-on Collisions injuries
Where Are Petechiae Found?
• Periorbital skin • Conjunctivae
• Face and neck • Oral mucosa
Majority of car accidents is on what side
Frontal
affinity for hemoglobin as oxygen
CO has 230 to 300 times
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
High vs. Low Voltage Electrocution
Biochemical Effects of Lead
• Inhibits iron incorporation into heme
• Competes with calcium
• Inhibits membrane associated enzymes
• Impairs production of active vitamin D
Cocaine Excited Delirium
Fatal arrhythmia precipitated by ischemia
– Increased MVO2 from elevated catecholamines – Decreased O2 supply from vasconstriction
– Accelerated atherosclerosis and thrombosis
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)
Cardiovascular System ethanol
• Toxic effects
– Hypertension (catecholamine release) – Dilated cardiomyopathy (direct toxicity)
• Protective effects
– Increased HDL
– Decreased platelet aggregation
Hydrogen Sulfide mech
– Inhibits cytochrome oxidase
– Reduction of oxyhemoglobin to methemoglobin
Traumatic Brain Injury
• Focal
– Cortical contusions
– Cerebral lacerations
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”
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
Signs of Basal Skull Fractures
• Raccoon eyes (periorbital contusions)
• Battle sign (hemorrhage in mastoid process)
• Blood or CSF rhinorrhea or otorrhea
Oxygen in Inspired Air percentage and effects
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
Asphyxial Signs
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”)
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
Wound Path
Heroin psychological effects
euphoria,hallucinations,sedation
