Path Lab Trauma Flashcards
Discuss the pathology and symptoms behind an abrasion (no…I’m actually not kidding)
patho: loss of the superficial (epidermis) surface by frictional forces when the skin is rubbed against a hard surface or by compressional forces.
sx: Superficial = minimal hemorrhage and readily form a thin scab; heal without significant scarring.
Under abrasions we have two specific fun categories of road rash and pattern abrasions. What do these dumb terms mean?
Pattern abrasions -skin imprints formed by offending objects (e.g., grid marks on the body of someone hit head-on by a Mack truck).
Road rash - large abrasion caused by contact with pavement.
Injuries to the body can lead to contusions, unlike injuries to the skin which lead to abrasions. What morphological symptoms do we see for contusions and what will it look like to us?
sx: rupture of blood vessels, causing extravasation of blood into surrounding tissue (e.g., skin, heart, liver, or brain), hematoma may form.
cause: soft tissue injury that doesn’t break the skin
Small or barely noticeable contusions on the skin may be the only clues signifying significant internal bleeding.
Large skin contusions may only affect the superficial levels of tissue (e.g., dermis or subcutaneous tissue).
Remember neuro injuries? Remind me the difference between coup and contrecoup injuries
Brain coup and contrecoup: injury to brain seen on side of impact and 180* opposite
Closed head injuries can be fatal in what circumstance?
“closed head” injury = results in diffuse axonal injury to the brain = can be fatal
What’s so special about the morphological change in blunt trauma compared to other things like contusions or abrasions?
Blunt trauma- leaves behind fibrous strands or “tissue bridges”(not sufficient to sever the blood vessels or nerves)
Definition for laceration. Also, discuss its specific morphology (for BKR, this is very important)
cause: Injuries that cause the tissue to tear apart when it is crushed, stretched, or avulsed
sx: ragged edges; can have abrasions and contusions along the edges of the laceration.
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When discussing an incision wound, there are three categories we use. Discuss what an incision wound is and what these three subtypes are
cause: sharp force injury produced by a sharp edge (e.g., knife, surgical scalpel)
sx: tears vessels/nerves (no tissue bridging)
sx: incision is longer, wider than it is deep; superficial in depth compared to puncture wounds; clean linear margins without tissue bridging
Discuss what hesitation marks are
A. HESITATION MARKS – Usually self-inflicted with non-fatal superficial wounds produced during the contemplation or successful attempt of suicide. It is common to see healed hesitation marks in same areas as fresh ones.
Occasionally, these hesitation marks can occur during homicidal acts when the victim is trying to escape from the assailant. Classically, multiple parallel incised wounds are adjacent to a deeper, fatal wound on the arm or neck.
Discuss defensive incised wounds
B. DEFENSIVE INCISED WOUNDS - An injury produced during the act of warding off an attack by an assailant. Characteristic locations include the palms or back of the hands, forearms and arms. Usually these injuries are non-fatal, unless vital organs (e.g., heart, lung) are punctured elsewhere.
What the fuck are chop wounds?
C. CHOP WOUNDS- Axes, cleavers, shovels, machetes and vehicle propellers are examples. These incised wounds are associated with a wedged cut into underlying bone. Dull weapons may produce a wound that is more consistent with a laceration than an incised wound.
Characterize puncture wounds and what the wound entails.
cause: Sharp force injury produced by an instrument with a point (e.g., ice pick or syringe).
sx: wound is deeper than it is wide. small pinpoint lesion on the skin
classified: perforating (entrance and exit wounds) or penetrating (entrance wound, but no exit).
When do we consider a wound “patterned”?
An injury that indicates the nature of the instrument that produced it (e.g., dinner fork)
Why do we go into shock with a thermal burn?
Shock: Shift of body fluids into interstitial compartment (due to systemic inflammatory response syndrome)
What type of infection do we see with thermal burns?
Infection→ most common organism=*Pseudomonas aeruginosa, MRSA, Candida. With compromised blood flow to burn site preventing proper immune response, infection is very common.
What happens to our metabolism with thermal injury?
Hypermetabolic state→ heat loss and need for nutritional support.
What happens to our vasculature integrity with a thermal injury?
Pulmonary and generalized edema→ Vascular leakiness
Airway after a thermal burn injury?
Airway and lung injury from inhalation → complete or partial airway obstruction
Severity of injury depends on: depth of burn, % of body affected, internal injuries from inhalation, effectiveness of tx
How do we characterize burns?
Classification: no longer using 1st-4th degree
1* Superficial: confined to epidermis,
2* Partial thickness burns: injury to top of dermis, wet and pink
Deep partial thickness: through all dermis, dry and red
3* Full-thickness: extension to subcutaneous tissue, white/brown and leathery, no pain
4* into muscle tissue or bone, black charred
What are some late complications of thermal burns?
Complications: shock, sepsis and respiratory insufficiency, pneumonia
Heat cramps vs heat exhaustion
Heat cramps: from loss of electrolytes from sweating. A/w vigorous exercise
Heat exhaustion: most common. From failure of cardiovascular system to compensate for hypovolemia caused by dehydration. Onset is sudden with prostration and collapse
Discuss what we see with heat stroke and who is at risk for this
Heat stroke: Body temp>40C→ multiorgan dysfunction.
Sustained contractions of skeletal muscle → muscle necrosis and rhabdo; Generalized vasodilation→ peripheral blood pooling and ineffective circulation; hyperkalemia, tachycardia, arrhythmias.
A/w high temp, high humidity and exertion.
At risk: older people, people undergoing physical stress, people with CV dz
Discuss heat stroke as it relates to RYR1 nitrosylation
RYR1 nitrosylation: responsible for regulating Ca2+ release in sarcoplasm in skeletal muscle.
Heat stroke causes RYR1 dysfunction allowing Ca2+ to leak into cytoplasm, stimulating muscle contraction.
What is malignant hyperthermia?
Malignant hyperthermia: Inherited mutation in RYR1. Rise in body temp in response to anesthetics
