infrared agents Flashcards
Where does infrared lay on the light spectrum?
in between visible light and microwave diathermy
Do infrared agents penetrate a lot?
No, wavelength is too short
What is the heat range wavelength?
1-2 mm
What is the cold range wavelength?
1 cm
When are infrared agents the most effective?
when their energy is absorbed and used to provide analgesia as an adjunct to therapuetic exercise
How does cold work?
the body’s deeper layers lose heat to the more superficial tissues causing cooling effects in deeper tissues
How deep can cooling be measured?
3 cm
What are the responses to cold?
decreased temp, metabolism, pain, muscle spasm, elasticity, local neural activity
increased tissue stiffness, vasoconstriction
What breaks temperature zones?
agitation
Do tissues cool right away?
No, they gradually start after several minutes and plateau after a subtle change
Can the body dissipate cooling effects?
yes, with circulation
What is a good insulator?
fat
What is latent fusion of heat?
the amount of energy needed to convert a solid to a liquid without changing temp
What is the cold treatment time for a small area?
10-15 minutes
What is the cold treatment time for a small joint/muscle?
15-20 minutes
What is the cold treatment time for a large joints/muscles?
20-30 minutes
What does activity do to rewarming time?
decrease it
What sensations are felt during cold?
cold deep aching pain pain plateaus or decreases pins and needles numbness bouts of pain at intervals
How does cold decrease hemorrhaging?
causes vascular spasm (constriction)
causes adhesiveness in endothelial cells in blood vessel
increase viscosity of blood making it flow slower
How does compression effect cold?
it helps decrease temperature by decreasing circulation and increasing interface
How does cold decrease edema?
decreases tissues debris which decreases ancotic pressure and vessel wall permeability
How does cold help against secondary hypoxic injury?
cold=decreased metabolism=less need for oxygen=less hypoxic damage
Is cold good for wound healing?
no, it decreases circulation and metabolism
is cold good for infection?
yes it limits spread and slows growth
How does cold create analgesia?
cold numbess occurs when superficial nerves are cooled causing decreased conduction velocity and an increase in transmission time. Nerve membrane current is decreased which increases refractory period.
What are contraindications for cold?
impaired circulation PVD CAD cold allergy hypertension skin anesthesia open wounds Raynaud's disorder over a regenerating peripheral nerve cryoglobulinemia
What is pallor?
lack of color that occurs with numbness from frostbite indicating vasoconstriction has prevented blood flow to tissues
What are the temperatures used for a cold whirlpool?
extremity: 50-60 degrees
whole body: 65-80 degrees
How long should you do a cold whirlpool?
15-20 minutes
