Thermal Agents Heat Heat modalities Superficial Heat Skin

Thermal Agents: Heat

Heat modalities: Superficial Heat • Skin temperature rises but sub. Q tissue increase is minimal • 1 cm 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 -5 cm 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 (1 cm) • 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 1 st • Contrast bath 20 -30 minutes at 3 -5 minute intervals or a combination (3 min hot 5 min cold etc. )

Contrast Bath • Precautions – 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 1 cm

Moist Heat Packs • Set-up – Cover pack with t 6 erry 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 – infected areas must be covered with gauze • Contraindications – Acute conditions – Peripheral vascular disease – Impaired circulation – Poor thermal regulation • 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

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. . 6 x 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 (1015 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 – 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 – 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 – 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