Modalities Ch. 6 Flashcards
orthopedic injury model
normal tissue
- cells
- two blood vessels
- nerve
immediate ultrastructural change
primary traumatic damage
damage to the nerve
breakdown of the injured cells
hemorrhage
few minutes only
clot forms, stopping hemorrhage
what happens of a clot forms
hematoma forms
how does a clot form
fibrins form a network
-platelets are caught and it created a plug
pain from damaged nerve
-results
muscle spasm and more pain
neural inhibition
-leads to decreases in strength and ROM
the damaged cells release…
chemical mediators as a signal to the body that an injury has taken place
result of broken blood vessels
extravascular swelling
chemical mediators released from dying cells cause…
hemodynamic changes permeability changes -histamine -kinins -serotonin leukocyte migration
what happens at this point?
secondary enzymatic injury
hemodynamic changes
blood flow slows down OR blood flow ceases result -tissue oxygen decreases --hypoxia --metabolic changes -secondary hypoxic injury soon seen
phagocytosis
as cells are broken down free proteins are released
free proteins signal edema
pressure on undamaged nearby pain fibers cause additional…
pain
muscle spasm and inhibition
immediate care
subset of acute care
first 12 hours
RICES
Rest Ice Compression Elevation Stabilization
why RICES?
protection from further damage decrease or minimize the development of -swelling -pain -muscle spasm -neural inhibition -secondary injury -total injury (because of decreased secondary injury)
time course of swelling
immediate swelling -comes from hemorrhaging edema -begins minutes to hours after injury -continues to develop over many hours
secondary injury and edema
secondary injury leads to edema
increased edema increases secondary injury
two mechanisms
-increased distance between blood vessel and tissue cells
-edema can compress the blood vessel
both decrease circulation
-decreased oxygen to tissues
rest: why?
limits injury aggravation
- should be total during immediate care
- transition to “relative” rest
- different from, but related to, stabilization
ice: why?
most think it’s to control swelling
-important but only part of immediate care
limiting secondary injury and neural inhibition are most important than controlling swelling
decreased blood flow theory
older, traditional theory
cold decreases blood flow
logic of theory
-cold causes vasoconstriction
-vasoconstriction decreases blood flow
decreasing blood flow decreases hemorrhaging
decreased hemorrhaging = swelling reduced
decreased blood flow theory flaw
clotting occurs before tissue is cooled enough to substantially decrease blood flow
decreased secondary injury theory
cold decreases cellular metabolism
- reduces oxygen demand (consumption)
- less secondary hypoxic injury
- less total injury
- less free protein generated by phagocytosis
- less edema
metabolism and cooling
direct relationship
-greater cooling = greater decrease in metabolism
cryotherapy and swelling
decreases edema, not hemorrhage
-most occurs hours after injury, as free protein accumulates from phagocytosis
cold reduces edema formation
-by preventing secondary injury and thus less free protein accumulation
compression: why?
controls edema beyond normal volume (i.e. after tissue spaces are filled)
slows swelling
apply constantly until swelling is over
compression during immediate care
-RICES added benefit
enhances cooling
elevation: why?
decreases capillary hydrostatic pressure
stabilization: why?
controls neural inhibition
-process in which neural pathway is blocked so impulses cannot pass
–intended function does not occur
-partial: function is diminished
-total: function is abolished temporarily
allows muscles to relax, thus
-decreases pain-spasm-pain cycle
-numerous braces and splints for stabilization
cryotherapy physics and physiology
cold = the absence of heat
conduction
-heat exchange until two substances have exchanged energy and meet in the middle
rate of conduction factors
temperature differential regeneration of body heat and modality cooling heat storage capacity size of the cold modality amount of tissue in contact with pack length of application individual variability
heat storage capacity principles
specific heat
latent heat of fusion
specific heat
amount of heat energy required to raise 1 kg of a substance 1 degree C
latent heat of fusion
amount of heat energy need to convert a substance from a solid state to a liquid state
-phase change
ice to water = 80 cal/kg
crushed ice pack vs. gel pack
crushed ice is better -gel pack approx. 22 kcal --water from -17 C to 5 C crushed ice pack approx. 86 kcal -phase change -from -1 C to 0 C
factors that affect tissue cooling
type of cold pack duration of application size of cold pack amount of tissue in contact with pack depth of target tissue method of application
factors affecting temperature changes after cold pack application
depth of tissue
amount of heat available to rewarm area
activity level before cryotherapy
amount of heat removed from body during application (magnitude and duration of cold application)
types of cold packs
four general types
- crushed ice
- gel
- artificial ice
- chemical
crushed ice
most effective because of heat of fusion
excellent for on-the-field use
should not be used if kept in a freezer (too cold)
gel pack
water, alcohol, and gel substance
cooled to 1 F
-dangerous
should only be applied with barrier between skin and pack
artificial ice
water in vinyl pouches, surrounded by nylon cover (Dura Kold)
better than gel because of heat of fusion
not as good as crushed ice because of insulation from nylon cover
good for home use
chemical: double bags, crushable
chemical reaction when inner bag is crushed and contents react with outer chemicals
least cooling
frozen peas
popular; cheap and convenient effects -better than nothing and gel packs -worse than crushed ice packs or ice water immersion -little phase chang with peas avoid if possible
cold application protocol
apply directly to skin, not over a towel or elastic wrap
- except for gel packs
- except for crushed ice from freezer
cold: length of application
intermittent
-30-60 minutes every two hours
depth of target tissue
adipose tissue - leave on longer
average ice times based on area
finger: 20 minutes
ankle or arm: 30 minutes
thigh: 45 minutes
+5 minutes for each millimeter of skin-fold >1 mm
