Cryotherapy Flashcards
Methods of energy transfer
Conduction Convection Conversion Radiation Evaporation
Conduction
Transfer of heat by direct interaction of molecules
Factors affecting conduction
Temperature gradient
Type of tissue
Length of exposure
Tissue depth
Examples of conduction
Cold pack
Ice bag
Convection
Energy transfer by direct contact between the skin and moving fluid particles
Heat abstraction is faster with convection or conduction?
Convection
What is convection practical for?
Distal extremities only
Conversion
Change from one form of energy to another
Nonthermal form of energy converted into heat
Examples of conversion
Ultrasound
Radiation
Transfer of electromagnetic waves
Factors that influence rate of temperature increase via radiation
Intensity
Size
Distance/angle
Evaporation
Release of energy upon conversion from liquid to gas/vapor
Evaporation has negligible effects on…
deeper tissues
Uses of cryotherapy
Control inflammation, pain, and edema
Reduce spasticity
Facilitate movement
Hemodynamic effects #1
Thermoreceptors are activated by cold. As cooling progresses, production and release of histamine and prostaglandin decreases, which leads to vasoconstriction
Hemodynamic effects #2
When skin temperature decreases, free nerve endings in the skin are stimulated, causing a reflex excitation of sympathetic adrenergic fibers, also leading to vasoconstriction
Hemodynamic effects #3
Increased viscosity decreases blood flow
Hemodynamic effects #4
Body reduces blood flow to protect other areas of excessive decrease in temperature and stabilize core body temp.
Prolonged exposure to tissue temperatures <10 deg C leads to
Cold induced vasodilation (increase in blood flow)
Cold-induced vasodilation (CIVD) is a response to
Axon reflex due to pain of very low temps
OR
Inhibition of smooth muscles in blood vessel walls due to extreme cold
Cause of skin redness from cold exposure
Increase in oxyhemoglobin concentration of blood
Neuromuscular effects of prolonged cold exposure
Decreased nerve conduction velocity Increased pain threshold Decreased spasticity Facilitation of muscle contraction Altered muscle strength
Cold application for spasticity
Cold application for at least 30 minutes can help decrease spasticity for 1-1.5 hours
Stage 1 of sensation (feeling)
Cold
Stage 2 of sensation (feeling)
Burning
Stage 3 of sensation (feeling)
Aching
Stage 4 of sensation (feeling)
Numbness
Stage 1 of sensation (time)
1-3 mins
Stage 2 of sensation (time)
3-5 mins
Stage 3 of sensation (time)
5-7 mins
Stage 4 of sensation (time)
7+ mins
