Thermal Agents: Heat

Heat modalities: Superficial Heat Skin temperature rises but subQ tissue increase is minimal 1cm penetration depth of penetration is related amount of fat in area HP Whirlpools Paraffin Baths Infrared Lamp

Heat Modalities: Deep Heat Ultrasound and diathermies Transmits well through superficial tissue layers 3-5cm penetration

Factors effecting tissue temperature rise: temperature gradient/rate: high or low Vs time volume of tissue: if treatment area is great there may be a decrease in BP from hypothalamus (vasodilatation) Duration of treatment 100-113ÞF is needed to get an effect

Factors effecting tissue temperature rise: Beyond 113 ÞF protein denaturization and tissue burning may occur Heat is dissipated faster because of increased blood flow Best general tissue temperature and blood flow increase is via exercise

Physiological effect of superficial heat: Metabolic Increase metabolic rate Increase oxygen demand Therefore the is increased cell death with swelling

Physiological effect of superficial heat: Hemodynamic Depth of effects are not as great as with cold Vascular changes are confined to skin (1cm) So Why use it?

Physiological effect of superficial heat: Hemodynamic Capillary dilation is the main effect from: axon reflex (non-synaptic) release of substance from axon causing arterioles to relax Chemical mediators released causing mild inflammatory reaction Spinal cord reflex: A-delta fibers carry temperature to spinal cord to inhibit sympathetic activity causing vasodilatation

Physiological effect of superficial heat: Neuromuscular Increase sensory nerve conduction Temperature is carried on A-delta fiber Analgesic effects both distal and proximal to area treated This is why non-acute back patients use heat instead of ice

Physiological effect of superficial heat: Neuromuscular Firing of II fibers results in a decrease in muscle firing, reducing muscle spasm Increased golgi tendon organ firing which inhibits muscle contraction

Physiological effect of sup. heat: Connective tissue “plastic” or viscous properties permit residual elongation after stretch is applied and released (plastic deformation) elastic properties result in recoverable deformation Heat aid elongation (heat with stretch works best)

Indications for the use of superficial heat Muscle spasm Subacute inflammation Trigger points Thromboflabitis Local inflammation (caution!)

Contraindications for the use of superficial heat Acute inflammation Decrease sensation in area Impaired circulation (unable to dissipate heat) Malignancies: increased metabolic rate Pregnancies

Superficial Heating Modalities Moist Heat Pack Infrared Heat Lamp Whirlpool Paraffin Bath Slides in Packet for specific review of each Clinical Application

Transitions from cold to heat: No signs of increased inflammation; decreased swelling No increase in tissue temperature If decreased range from pain- stay with cold Change to heat when effect from ice applications plateaus If decrease range from stiffness then use heat

Contrast Treatments: used as a transition between cold and heat allows type of vascular pumping via cold/hot/cold treatment ? may use water or ice packs/hot packs etc.. May vary the length of time in cold vs.. heat depending on effects desired Ending of treatment should reflect effect you want to end with Latest research says ineffective

Contrast Bath Set Up Two tubs placed as close together as possible Fill one tub in the range from 105 F- 110 F and the other 50 F - 60 F Position pattern on chair or bench between two tubs Heat Tx given 1st Contrast bath 20 -30 minutes at 3-5 minute intervals or a combination (3 min hot 5 min cold etc.)

Contrast Bath Precautions Indications Contraindications Same as with all whirlpools Indications Ecchymosis removal Edema removal Subacute or Chronic Inflammation Impaired circulation Pain Reduction Contraindications Acute injuries Hypersensitivity to cold Contraindication relative to whirlpool use Contraindications relative to cold application Contraindications relative to heat application

Moist Heat Packs Canvas Pouch with Silica Gel Pack is kept in a water-filled heating unit maintained between 160º F -170 º F Pack maintain temperature for 30-45 minutes Packs transfer heat by conduction Main benefit is superficial heat to 1cm

Moist Heat Packs Set-up Cover pack with t6erry cloth covering Place pack on patient in comfortable manner Check patient within 56 minutes for comfort Allow pack to reheat for a minimum of 30 minutes before reuse

Moist Heat Pack Precaution Contraindications Indications Subacute or chronic inflammatory conditions Reduction of subacute or chronic pain Subacute or chronic muscle spasm Decreased ROM Hematoma resolution Reduction of joint contractures Infection Precaution infected areas must be covered with gauze Contraindications Acute conditions Peripheral vascular disease Impaired circulation Poor thermal regulation

Paraffin Bath A mixture of wax an mineral oil in a ration of 7 parts wax to 1 mart oil Temperature of 118º F to 126 ºF for upper extremity tx. Temperatures of 113 º F to 121 º F for lower extremity (circulation is less efficient) Paraffin can provide approx.. 6x the amount of heat as water due to low specific heat (.5 to .65)

Paraffin Bath Used to deliver heat to small irregularly shaped areas (hands, fingers, wrist and foot) Increases intrarticular heat 6.3 ºF

Paraffin Bath Set Up Immersion Bath Clean body part Dip both part an allow coat to dry Dip the extremity 6-12 more times Then place extremity back in paraffin for duration of tx (10-15 min) DO NOT touch sides or bottom of bath (burns) After tx scrape of was and replace in bath Pack (Glove) Method Clean extremity Immerse extremity in bath and allow wax to dry - repeat 7-12 more times After final withdrawal from wax, cover extremity with plastic bag, aluminum foil, or wax paper. Then wrap in terry cloth towel If indicated elevate body part Following tx remove wax and return to bath

Paraffin Bath Precautions Contraindications Indications Sensation is different from specific heat and thermal capacity - may cause burns Avoid using with athlete who are required to catch or throw a ball - skin becomes slippery Contraindications Open wounds Skin infections Sensory loss Peripheral vascular disease Indications Subacute and chronic inflammation limitation on ROM after immobilization

Infrared Lamp Radiant energy 2 types luminous (infrared) and nonlumious (far infrared) Luminous produces some visible light (as opposed to nonluminous), nonlumious is less penetrating than luminous

Infrared Lamp Set-up Warm lamp if necessary Clean area for any sweat, dirt, or oils and remove jewelry Position patient in a comfortable manner Place lamp so that the source of heat is approx 24 inches away from patient To prevent burns, instruct patient not to move Check patient periodically Duration 20-30 minutes

Infrared Lamp Indications Contraindications Subacute or chronic inflammatory conditions Skin infections Peripheral nerve injuries before electrical stimulation Contraindications Acute conditions Peripheral vascular disease Areas with sensory loss or scarring Sunburns

Whirlpools Tx temperature is between 105º-110º F the larger the area the less the temperature down to 100º F for whole body Tx times begin with 5-10 minutes and may be increased to 20-30 minutes once or twice daily

Warm Whirlpool Precautions must be connected to ground-fault indicator Instruct patient not to turn whirlpool motor on or off while in whirlpool Patient should be continually monitored Do not run while turbine is dry Flowing water may nauseate some patients Patients under the influence of drugs

Warm Whirlpool Indications Contraindications Decreased ROM Subacute or chronic inflammatory conditions Peripheral vascular disease Peripheral nerve injuries irregular shaped areas Contraindications Acute conditions where water turbulence would further irritate injured area Fever Patients requiring postural support Skin conditions