Term
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Definition
· Occurs as result of scrape which causes epidermal cells to be torn off due to friction
· Dermis may be mostly spared and no perforation of skin may occur
2 types: friction blister & tennis heel |
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Term
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Definition
| layers of the epidermis are torn apart by friction, but the integrity of the surface is not breached. The area is RE-EPITHELIALIZED, either by proliferation of the epidermal cells below the level of the abrasion, or epidermal cells migrate upward from dermal adnexae to re-epitheliazed. |
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Term
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Definition
| Abrasion due to changing direction resulting in small skin hemorrhages resembling melanomas. |
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Term
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Definition
· Irregular tear of skin or deeper tissue produced by stretching
· May be linear due to force from 2 sides or radial with tears extending out from central point due to extreme pressure applied such that skin is stretched
· Typically have irregular, hemorrhagic border, and are traversed by strands of fibrous tissue and blood vessels seen deep within lesion
· Damage to deep tissues, organs may exist with little observable superficial injury
· Laceration of mesenchymal tissues (i.e. liver, kidney): patient may feel well but injury may lead to extensive internal hemorrhage and death
· Laceration of hollow viscera (i.e. intestines): pain due to distention which may result in rupture and subsequent peritonitis
· Incision |
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Term
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Definition
· Due to cutting into tissue by knife, scalpel, glass, shiv, etc.
· Edges are sharp with no bridging strands of connective tissue or blood vessels
· Any incision of abdominal wall requires exploratory laparotomy since visceral penetration is serious (can cause peritonitis or persistent hemorrhage) |
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Term
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Definition
· Caused by blunt force which injures blood vessels, leading to edema and hemorrhage within tissue
· Causes decreased tissue perfusion and results in necrosis with later scar formation
· May be recognized in superficial skin (i.e. black eye), but displays only swelling and tenderness in deeper tissue injury.
Examples includes: Caning and Crush Syndrome |
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Term
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Definition
| myoglobin is released by skeletal muscle (myoglobinemia) when injured by crushing injury and causes renal failure |
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Term
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Definition
· Include military guns, rifles, sporting rifles
· Bullets impart large amount of energy into tissues and are more damaging than low velocity weapons
· Injury to tissue extends several inches in any direction from path of bullet |
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Term
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Definition
· Includes most domestic handguns
· Standard caliber weapons: bullets proceed directly through tissues with little tendency to ricochet
· Small caliber weapons: bullets may cause barely noticeable entry wound but does extensive damage due to ricocheting into different body areas
· Area of injury limited to 2-3 inches of bullet trajectory within tissue |
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Term
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Definition
· As bullet hits skin, it first pulls skin with it and causes abrasion
· If bullet comes at angle, longest abrasion is toward origin of bullet
· Bullet penetrates dermis which contracts behind it such that entry wound is slightly smaller than diameter (caliber) of bullet |
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Term
| Effects of distance on GSWs: Muzzle of gun is few inches or less from skin |
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Definition
· Some expanding gases may enter tissue along with bullet
· This produces swelling and is apparent where bone is present under skin (i.e. head) in the form of STELLATE lacerations which form due to sudden extension of skin |
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Term
| Effects of distance on GSWs: Muzzle of gun is 1 foot or less from skin |
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Definition
· Gunpowder burns may exist around bullet hole
· Called “FOULING” |
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Term
| Effects of distance on GSWs: Muzzle of gun is 3 feet or less from skin |
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Definition
| · STIPPLING due to fragments of unburned gunpowder may be seen |
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Term
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Definition
· Usually larger and more irregular in shape than entry wound
· No fouling or unburned gunpowder deposits
· Higher bullet velocity = larger exit wound
· Wound may be surrounded by radiating lacerations |
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Term
| Injuries due to Physical Exhaustion |
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Definition
· Dehydration, electrolyte imbalance
· Hypokalemia is of concern for marathon runners since it can cause cardiac arrest
· Myogloblinemia is associated with physical exhaustion is and causes renal failure
· Can exacerbate thermal injuries (i.e. heat stroke) |
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Term
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Definition
· Increase in body heat generated as result of tissue damage due to infection or acute exacerbation of leukemia
· Lesser degrees of pyrexia seen in stroke, occult cancer
· Mechanism involves circulating IL1, TNFα affecting hypothalamus
· Temperature above 40° C requires treatment (i.e. ice water bath immersion) to prevent convulsions, brain damage |
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Term
| Hyperthermia: Exertional Heat Stroke |
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Definition
· Seen in active, usually healthy people (i.e. athletes, military recruits, laborers)
· Hot, humid weather is factor
· Electrolyte imbalance (especially if person doesn’t rehydrate) is often seen
· Vomiting occurs, furthering fluid and electrolyte imbalance
· Skin often ceases to produce sweat shortly before person becomes unconscious
· Lactic acidosis is present (although this occurs in all exertion)
· 1/3 develop rhabdomyolysis (skeletal muscle breakdown) and subsequent myoglobulinemia, myoglobinuria
· Severe cases progress to ATN (acute tubular necrosis) of kidney, DIC (disseminated intravascular coagulation) |
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Term
| Hyperthermia: Classic Heat Stroke |
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Definition
· Seen in very young, elderly, obese, chronically ill, debilitated
· Exertion is almost never present, but person has febrile illness
· Weather is often hot and humid
· Lack of sweat production by skin with flushing of skin blood vessels cause generalized erythema
· Increased respiratory rate causes metabolic alkalosis
· Lactic acidosis, ATN, DIC are rare
· Marked hypotension occurs which may cause coma due to brain hypoperfusion |
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Term
| Localized heat injury: Chronic |
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Definition
· Due to chronic heat exposure (i.e. sitting in front of heater)
· Produces combination of vascular changes and tissue damage
· Result is discolored lesion (erythema ab igne)
· Usually of little clinical significance, but may ulcerate and become infected or cancerous (esp. in elderly)
· More common in cold, damp climates (i.e. UK, Canada) |
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Term
| Localized heat injury: Cholinergic Urticaria |
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Definition
· Occurs when person is allergic to self-antigens that appear in tissue due to change in protein when temperature is increased
· Patient is allergic to altered protein and local urticaria (i.e. wheal) forms
· Form of type I hypersensitivity |
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Term
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Definition
· First degree: partial thickness burn
· Only epidermis affected
· Erythema, blistering occur rapidly
· Patient requires only bed rest, supportive care until epithelial cells regenerate via upward migration of cells from adnexae
· Healing occurs without scarring
· Second degree: partial thickness burn
· Affects epidermis, superficial dermis
· Deep dermis, epithelium of adnexal structures are intact
· Blisters occur rapidly, but no erythema
· Patient requires sterile environment, meticulous care but usually recovers
· Slight to moderate scarring of burned tissue occurs |
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Term
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Definition
· Third degree: full thickness burn
· Affects epidermis, entire dermis with adnexae
· Skin appears chalky-white
· Sterile needle can be passed through skin with no pain elicitation
· Healing is slow and severe scarring occurs |
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