Principles of thermal energy: Cryotherapy Flashcards
Cryotherapy outside rehab used for:
Destruction of malignant and non-malignant tissue growths
Cryotherapy during rehab used for:
- Control inflammation
- control pain
- control edema
- reduce spasticity
- control symptoms of MS
- facilitate movement
Cryotherapy effects the following body systems
- Hemodynamic (blood)
- neuromuscular
- metabolic
Cryotherapy hemodynamic direct effects
Cold applied to the skin will cause immediate constriction of cutaneous vessels and a reduction in blood flow
- stimulation of cutaneous cold sensors directly stimulates smooth muscle in vessel walls to contract causing constriction
- stimulation of cutaneous cold sensors directly decreases production and release of vasodilator mediators (histamine & prostaglandins)
cryotherapy hemodynamic indirect effects
Indirectly there is a reflex activation of sympathetic adernergic neurons resulting in vasoconstriction
- reduce blood flow by increasing viscosity
- helps keep core temp from falling
- results in greater local cooling
- vasoconstriction persists as long as application time is less than 15-20 mins
Cryotherapy hemodynamic effects: later increase in blood flow (CIVD)
- CIVD= cold induced vasodilation
- occurs when cold is applied for extended periods of time or if temp reaches less than 10 degree C (50 degree F)
- reflex hyperemia with removal of cold source due to vasodilation to rewarm tissue
Hunting response
Process of alternating vasoconstriction and vasodilation in extremities exposed to the cold
Cryotherapy hemodynamic effects: erytherma
Reddening of skin secondary to cold application
- due to increase in oxyhemoglobin concentration in blood
- decrease in oxygen-hemoglobin dissociation
Cryotherapy hemodynamic effects: oxygen-hemoglobin dissociation curve
- 43 degree C shifts curve right
- 20 degrees C shift curve left
Neuromuscular effects: four stages of Cold
CBAN
- cold (intense)
- burning
- Aching
- Numbness
Neuromuscular effects: decreased nerve conduction velocity (NCV)
- NCV decreases in proportion to the degree and duration of the temp change
- decreased NCV will occur with superficial cooling for 5 minutes
- recovery time for NCV depends upon cooling time
- 5 minutes cooling reverses in 15 minutes
- 20 minutes reverses in 30 mins or longer
- cold most inhibits myelinated, small diameter fibers (a-beta)
- cold least inhibits large, unmyelinated fibers
Neuromuscular effects: increased pain threshold
- Counter irritant via the gate control mechanism
- reduction of muscle spasm
- sensory NCV inhibition
- decreased rate of reactions associated with acute inflammation (reduce secondary injury)
Neuromuscular effects: altered muscle strength after 5 mins of cooling
- Isometric muscle strength increases directly after 5 minutes of cooling
- facilitate motor nerve excitability
- increase psychological motivation to move
Neuromuscular effects: altered muscle strength after 30 mins cooling
- Isometric strength decreases initially after 30 mins of cooling then increases one hour later to greater than precooling strength
- decreased blood flow to muscle
- slowed motor nerve conduction
- increased muscle viscosity
- increased joint and soft tissue stiffness
Neuromuscular effects: Decreased spasticity
- Decreased gamma motor neuron activity
- reflex action to the stimulation of cutaneous cold receptors
- decreased afferent spindle and GTO activity after 10-30 mins of cooling
Neuromuscular effects: facilitation of muscle contraction
- Brief application of cold (seconds) may stimulate alpha motor neurons in pts with upper motor neuron lesion
- response is short lived
Metabolic effects:
Decreased metabolic rate
- decreases metabolic reactions involved in the inflammatory processes
- Decreases activity of collagenage, elastase, hyaluronidase, and protease (cartilage degrading enzymes)
- reccomended for treating OA and RA
Cryotherapy: ice
Limits secondary injury
- decreased blood flow theory
- decreased secondary injury theory
- metabolic- O2 debt due to ischemia-ice decreases metabolism
- chemical- ice limits permeability thus leakage of protein rich fluid into tissue thus edema formation
Cryotherapy indications
- immediate care of musculoskeletal injuries
- edema control
- pain control
- modification of spasticity
- symptom management in MS
- emergency care for small burns
- limitations in ROM secondary to pain
Cryotherapy contraindications
- impaired circulation (PVD)
- cold hypersensitivity or cold-induced urticaria
- Raynaud’s disease or phenomenon
- hypertension
- over a regenerating peripheral nerve
- Paroxysmal cold hemoglobinuria
- cryoglobulinemia
- decreased cold sensitivity
- open wound after 40-72 hours
Cold/ice pack, ice massage, cold baths, and cryokinetics, and controlled cold compression classification
Infrared modality emitting electromagnetic radiation
-wavelength approx 111,000A
- Frequency approx 2.7 x 10^12 Hz
Thermal modality used to provide a superficial cooling of tissue
- maximum depth of penetration- 1cm
- cools via conduction
Cold/ice pack description
- Crushed ice pack in leak proof container generally near 30 degree F
- Commercial ice pack- filled with hydrated gel
- cooled in refrigerated unit to between 0-12 degree for at least 30 mins
- easily conform to body part and hold cold for extended periods of time
- not as effective as ice at lowering body temp
Ice massage description
- The application of cold by rubbing ice over a part of the body
- ice should be smooth with rounded edges
- may use frozen water in paper cup or cryocup
Cold Bath description
- can also be called ice immersion
- placing a body part to be treated in water ranging from cold to icy
- temps of water depends on the condition being treated
- can be easily done on extremities
Cold bath temperature ranges
- cool 67-80 degrees F (19-27 degree C)
- cold 55-67 degrees F ( 13-19 degree C)
- very cold 32-55 degree F (0-13 degree C)
Cryokinetics description
- The application of cryotherapy to a part so as to numb the part prior to exercise
- Patient must be able to differentiate between them
- pre-existing pain
- ice induced pain
- exercise induced pain
Controlled cold compression description
- A nylon sleeve that connects via a tube to a one gallon cooler/jug
- cool water flows from the cooler to a sleeve that is wrapped securely around a body part
- water temp generally between 50-77 degree F
- Will reduce swelling as well as control for secondary injury new swelling
