Term
| What are the 3 types of thermal injury? |
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Definition
1) Thermal burns
2) hyperthermia
3) hypothermia |
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Term
| *Why are the number of thermal burn deaths decreasing? |
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Definition
| smoke detectors, hot water temp regulators, imoprovements in burn care, flame-retardent sleepwear |
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Term
| What can cause thermal burns? |
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Definition
1) flame/flash
2) scalding from hot liquids
3) contact with hot object (iron, cigarette)
4) steam/gas
5) electricity |
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Term
| What are the 3 classifications of thermal burns? |
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Definition
1) superficial
2) partial-thickness
3) full-thickness |
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Term
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Definition
| injury limited to epidermis (i.e. sunburn) |
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Term
def
partial-thickness burn |
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Definition
1) damage extends to the dermis (blisters frequent)
2) adnexal (appendage) structures injured, but can regrow |
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Term
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Definition
deeper injury with destruction of the epidermis, dermis, & subcutaneous tissue.
Can extend to tendons, skeletal muscle & bone |
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Term
| What type of necrosis affects thermal burns? |
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Definition
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Term
| What is the pathology of superficial & partial-thickness burns? |
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Definition
| typical acute inflammatory response (hyperemia, exudative edema, infiltration by neutrophils & macrophages, pain) |
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Term
| What is the pathology of full-thickness burns? |
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Definition
| extensive damage to superficial blood vessels, never endings & adnexal structures => white or black dry, lethery, insensate wounds |
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Term
| *does morbidity & mortality of thermal burns depend on? |
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Definition
| extent & depth of burns, inhalation &/or coexistent traumatic injuries, age, pre-existent medical conditions, & adequacy of Tx |
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Term
| What 6 complications can arise in thermal burns? |
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Definition
1) hypovolemic shock
2) hyperkalemia
3) sepsis
4) resp. failure
5) gastric ulcers
6) chronic complications |
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Term
| How is % of body covered in burns estimated clinically? |
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Definition
| Rule of 9's (don't need to know now) |
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Term
| When is hypovolemic shock a concern in burn victims? |
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Definition
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Term
| Why are fluids lost in thermal burns => hypovolemic shock? |
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Definition
1) increased vasular permeability => loss of fluid into interstitum
2) evaporation due to loss of skin |
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Term
| What causes hyperkalemia in thermal burns? |
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Definition
| cellular disruption from the heat |
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Term
| What causes spesis in thermal burns? |
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Definition
| loss of skin barrier & decreased inflammatory response => wound infections => bacteremia => septic shock with multisystem organ failure |
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Term
| What can cause resp. failure in thermal burns? |
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Definition
inhalation injury
pneumonia
diffuse alveolar damage |
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Term
| Why are gastric ulcers a concern in patients with thermal burns? |
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Definition
| can lead to upper GI bleeding |
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Term
| What 2 chronic complications can arise from thermal burns? |
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Definition
1) excessive scar formation
2) contractures (esp. in children) |
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Term
| What are the effects of hyperthermia dependent on? |
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Definition
| duration of exposure , humitidy of the air, adequacy of fluid/electrolyte replacement, age, level or exertion, current medical conditions |
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Term
| What are the 3 effects of hyperthermia? |
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Definition
1) Heat cramps
2) heat exhaustion
3) heat stroke |
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Term
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Definition
| intermittent, involuntary, painful muscle spasms during or after strenuous exercise - often in hot environments |
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Term
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Definition
| electrolyte abnormalities |
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Term
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Definition
relatively sudden onset of dizziness, neausea, headache, profuse sweating, & fatigue associated with hypotension, tachycardia & low-grade fever
skin usually pale, cool, & moist |
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Term
| What causes heat exhaustion? |
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Definition
| inadqeuate compensation for hypovolemia & elevated body temp |
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Term
| *What's the most severe form of hyperthermia? |
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Definition
| heat stroke - potentially like-threatening |
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Term
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Definition
extremely high core body temp associated with hot, dry, flushed skin
tachycardia
difficulty breathing
neurological Sx
may progress to multi-organ failure & rhabdomyolysis |
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Term
| What are the differences between heat stroke & heat exhaustion seen in a patient? |
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Definition
Heat stroke: dry, hot skin. high body temp
heat exhaustion: moist clammy skin, normal/subnormal temp |
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Term
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Definition
| inability for heat dissipation fast enough => markedly elevated body temp => denaturation of proteins/cell membranes, alteration in HSP (heat shock protein) expression, amplified acute phase response => thermoregulatory failure |
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Term
| What do the effects of hypothermia depend on? |
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Definition
| duration of exposure, wind, moisture, age, weight, current medical conditions |
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Term
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Definition
| shivering, loss of motor coordination, slurred speech, confusion, drowsiness, apathy, irrational behavior, progressive loss of consciousness, focal tissue injury => cardiorespiratory failure & death |
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Term
| *What 4 places on the body are likely to see focal tissue injury due to hypothermia? |
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Definition
1) ears
2) nose
3) fingers
4) toes |
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Term
| What is the pathogenesis of focal tissue injury in hypothermia? |
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Definition
| peripheral vasoconstriction, interstitial fluid crystalization w/ cellular dehydration & protein denaturation, increased vascular permiability, & thrombosis |
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Term
| What are the 4 consequences of focal tissue injury due to hypothermia? |
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Definition
1) frostbite => 2) gangrene
3) trench (immersion) foot
4) chilblains (perniosis) |
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Term
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Definition
initially affected areas appear pale & have associated burning & clear blisters.
increasing severity: leisons become discolored (red => purple => black), swollen, firm, & ulcerated with eventual loss of sensation |
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Term
| What causes trench (immersion) foot? |
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Definition
| prolonged exposure to cold, damp, unsanitary conditions with constrictive footware => vascular, soft tissue & nerve injury with secondary infections |
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Term
def
chilblains (perniosis) |
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Definition
| abnormal vascular reaction to cold |
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Term
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Definition
| small, prutitic, swollen, painful skin leisons (red => blue) that develop upon re-warming |
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Term
| What are the 3 ways radiation can be measured? |
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Definition
1) emitted radiation
2) absorbed radiation
3) biological effect of radiation (equivalent doses) |
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Term
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Definition
| decay of a radionuclide per second |
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Term
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Definition
| energy absorbed per tissue mass |
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Term
def
biological effect of radiation |
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Definition
| product of the absorbed dose & the Quality Factor (depends on the type of radiation) |
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Term
| What are the units of emitted radiation (conventional & SI)? |
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Definition
c: curie [Ci]
SI: becquerel [Bq] |
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Term
| What are the units of absorbed radiation (conventional & SI)? |
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Definition
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Term
| What are the units of biological effect of radiation (conventional & SI)? |
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Definition
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Term
| What are the 3 additional factors that determine radiation's biologic effects? |
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Definition
1) Rate of delivery
2) extent of exposure
3) tissue vulnerability |
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Term
| Why does rate of delivery of radiation affect the biological effect? |
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Definition
| there may be time for cellular dependent depending on how fractioned the doses are |
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Term
def
extent of radiation exposure |
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Definition
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Term
| What 3 factors affect tissue vulnerability to radiation? |
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Definition
1) rate of cellular proliferation
2) availability of oxygen
3) extent of vascular injury |
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Term
| Are tissues with high cellular turnover more or less susceptible to radiation damage? |
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Definition
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Term
Are well oxygenated tissues more or less vulnerable to radiation injury?
Why? |
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Definition
| more b/c oxygen-derived free radicals exert the greatest damage to DNA |
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Term
| Are acute or chronic effects of radition seen in vessels? |
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Definition
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Term
| What are the areas of the cell that are affected by radiation? |
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Definition
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Term
| What happens in the nucleus when exposed to ionizing ration & resultant free-radical formation? |
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Definition
DNA damage & attampted repair =>
1) DNA recovery
2) persistant DNA abnormalities => apoptosis or perpetual alterations |
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Term
| What happens in the cytoplasm when exposed to ionizing ration & resultant free-radical formation? |
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Definition
| cellular swelling, injury to plasma & organelle membranes |
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Term
| What is the pathology of early radiation complication? |
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Definition
1) reversible & irreversible parenchymal cell injury, particularly in susceptible tissues
2) endothelial damage => hyperemia, increased vascular permeability, hemmorhage & thrombosis |
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Term
| What is the pathology of late radiation complication? |
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Definition
1) vascular & intestinal fibrosis w/ associated tissue atrophy & telangiectasia => secondary complications
2) cataracts
3) malignancies
4) CV disease
5) teratogenic effects |
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Term
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Definition
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Term
| *What malignancies are seen due to radiation therapy? |
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Definition
| laukemias, breask carcinoma, papillary thyroid carcinoma (esp. exposed children) |
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Term
| What teratogenic effects can be seen in radiation injury? |
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Definition
| impaired physical & mental development |
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Term
| What is the pathology of early & late radiation complication? |
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Definition
radiation-induced cytologic atypia (inc. enlarged, hyperchromatic, pleomorphic nuclei)
abnormal mitotic figures
bizarre giant cells |
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