Thermal

Question 1

What is internal kinetic energy or thermal energy

Answer 1

Molecules in continuous motion

Question 2

Temperature

Answer 2

a measure of the average internal kinetic energy of all the atoms of an object.

The only way to change the temperature of an object is to add or remove energy.

Question 3

Heat

Answer 3

thermal energy transfer from one body to another due to a difference in temperature.

The direction of the energy flow will be from the higher temperature body to the lower temperature body.

Question 4

What are the physical changes when you add or remove heat

Answer 4

Temperature

Chemical reactions- accelerated by a rise in temp

Viscosity of fluids- adding heat makes increases viscosity

State- changed by adding heat when ice goes to water latent energy is released (high to low kinetic energy)

Question 5

What are the transfer of heat energy in therapeutic applications

Answer 5

conduction

evaporation

radiation

Question 6

Conduction

Answer 6

Conduction is a mechanism of heat transfer in solids

Direct contact between the two objects of different temperatures

Heat flows from high to low hotter faster molecules bang the not the slower colder molecules

Question 7

The rate of heat transfer depends on the……

Answer 7

♦ difference in temperature between the regions in contact.

♦ surface area of contact at the boundary.

♦ thermal conductivity of the materials in contact.

Question 8

Radiation

Answer 8

is the transfer of heat from one place to another by means of electromagnetic waves

The waves travel through space until they meet an interface with an object.

Radiation is partly reflected, absorbed and partly transmitted

The absorbed part raises the temperature of the object. Therapeutically, infra-red lamps can be used to raise local temperature.

Question 9

Evaporation

Answer 9

involves the application of a chemical of low boiling point to the body surface, heat being taken from the skin during this process.II

Question 10

Structure of the skin

Answer 10

X2 layers

> epidermis is superficial and avascular and made of stratified epithelium.

> dermis is deeper layer of the skin and is made up of dense connective tissue.

contains blood vessels, lymphatic vessels, sensory endings. sebaceous glands and sweat glands.

Question 11

What are the blood vessels of the dermis divided into

Answer 11

1) superficial vascular plexus

2) deep vascular plexus.

Question 12

Superficial vascular plexus

Answer 12

comprises arteries that feed a network of capillaries loops to bring the blood closer to the skin surface. These drain into small veins via venules.

Question 13

Deep vascular plexus

Answer 13

comprises arteries connected with larger deep venous plexuses via arteriovenous anastomoses.

Question 14

What affects how the blood flows

Answer 14

depends on the body’s need to retain or lose heat

Regulated by SNS which controls the blood flow through the arteries and anastomoses

Question 15

Skin in cold conditions

Answer 15

skin flow will be reduced to retain heat by constricting the vessels so that little blood flows into the venous plexus

Question 16

Skin in warm conditions

Answer 16

the blood flow will be increased by dilation of the vessels so that more blood fills the venous plexus, warms the skin and allows heat loss to the environment.

Question 17

What is the skin

Answer 17

An organ

Question 18

How many and what are the sensory nerve endings in the skin

Answer 18

6

exteroceptive sensations of touch,

pressure

heat

cold

pain

Question 19

Physiological effects of thermal agents

Answer 19

changes are mainly confined to the local level of the application

some general or remote effects can be produced.

nature and extent of the changes produced depend on:

> area being treated (size of the area and the thermal conductivity of the tissue)

> method of application and the duration of application.

Question 20

Physiological effects of thermal agents

See tables

Answer 20

See tables

Question 21

What are the Therapeutic Conductive Heating (Thermotherapy)

Answer 21

Conductive heating is the transfer of heat by contact.

PARAFFIN WAX BATHS
HOT PACKS
HOT WATER BOTTLES
ELECTRIC HEATING PADS

Question 22

What must be tested for thermal agents to be used

Answer 22

thermal sensitivity

state of the circulation to the part must be assessed.

Warning to the patient must be given and recorded.

Question 23

When are Paraffin Wax Baths used

Describe the wax

Answer 23

Used less frequently

Used in specialist hand and rheumatology clinics

Wax for therapeutic use is solid at room temperature, melts at 540C but will remain liquid at temperatures of between 45 and 52 0C with the addition of mineral oil (liquid paraffin).

The wax is contained in a bath, which is electrically heated. A thermostat keeps a constant temperature.

Question 24

Hot parrifin wax for home use

Procedure

Answer 24

the wax can be heated in a container immersed in hot water or microwave

The patient must be warned that wax is inflammable and must not be heated directly over a naked flame.

Wax is usually applied to the hand/wrist and feet/ankle. The most commonly use method of application is ‘dip and wrap’. The part should be:

♦ inspected for open wound and/or skin lesions
♦ washed and dried
♦ free of jewellery
♦ immersed in the wax for a few seconds
♦ lifted out and allowed to cool for 2-3 seconds
♦ reimmersed.

repeated 6-12 times to produce a solid ‘glove’ around the part. The part should then be wrapped in a plastic bag or paper cover and wrapped in a small blanket or towel to help retain the heat.
Latent heat is given off as the wax solidifies.

When applying to the hands it is advisable to spread the fingers apart slightly before immersing in the wax.

The glove is usually left in place for 15-20 minutes. The wax is easily removed after treatment when it is cleaned in a purifier and re-used. It makes a good medium to exercise with because as it cools, it becomes more resistant to distortion.

Question 25

Hot parrifin wax for home use What do you do if oedema is present

Answer 25

If oedema of the part is present it is advisable to elevate the limb during treatment.

Question 26

Dangers and precautions of hot parrifin wax

Answer 26

1. Wax is inflammable if it becomes overheated so a fire blanket and CO2 or foam fire extinguisher must be available 2. Wipe up any spillages of wax promptly as it will make the floor slippery and dangerous

Question 27

Hot packs what is it how is it stored

Answer 27

This method of heating provides superficial moist heat. A pack consists of a canvas case filled with a hydrophilic substance such as bentonite or silicate gel. Available in a number of sizes and shapes. The pack is stored in a water filled cabinet thermostatically controlled at a temperature of 700C. Between treatments the packs should be immersed in water in the heating unit. Reheating usually takes approx. 30 minutes. Commercial hot packs can be heated in microwaves.

Question 28

Hot pack application

Answer 28

For application the pack is: ♦ wrapped in 6-8 layers of towelling before being placed on the part to be treated ♦ moulded to the contours of the part, making sure that it covers all the intended areas ♦ secured in place by a towel wrapped round the part. Five minutes after initiating treatment, the pack should be removed and the patient’s skin checked for any signs of excess heating i.e. mottled erythema. If the heat is too intense additional towelling may be used. The pack should be reapplied and the normal treatment time is 20-30 minutes.

Question 29

Dangers and precautions Hot packs

Answer 29

Avoid the patient lying on top of the hot pack as body weight squeezes out the water and accelerates the rate of heat transfer. Local circulation can be reduced in this situation and prevent the heat being carried away from the part resulting in a burn.

Question 30

Hot water bottles

Answer 30

A hot water bottle is a cheap and simple method of applying conductive heat. It is easily prepared and ideal for home use, however, it cools fairly rapidly and must be refilled regularly. It should be wrapped in a towel before being placed on the part to avoid the skin overheating.

Question 31

Electric heat pads

Answer 31

Electric pads=useful source of conductive heating for home use. Vary in size from small pads to larger electric blankets. Each pad should have a control unit so that it can be operated at different temperatures. The patient must be warned of the danger of burns and cautioned about falling asleep on a pad set at high temperature.

Question 32

Cold therapy Cryotherapy

Answer 32

Cold may be used: i. as a first aid measure immediately following trauma ii. as a treatment modality in the management of musculo-skeletal and neuromuscular problems

Question 33

Cryrotheraphy What cooling agents are available

Answer 33

LOCAL IMMERSION ​​ COLD PACKS CRYOCUFF​​​​ICE TOWELS ICE MASSAGE ​​​SPRAYS

Question 34

How do cooling agents work

Answer 34

All methods have the common goal of reducing the body tissue temperature. Some agents are more effective at achieving this goal than others. Tissue fluCirculation

Question 35

All cooling agents achieve their effects by either:

Answer 35

♦ evaporating a chemical of low boiling point on the body surface ♦ direct contact with the skin that results in conducting heat energy away from the skin and underling tissues.

Question 36

Explain the use of ice

Answer 36

Ice is more effective than cold water a due to the greater amount of heat transfer needed to change the solid state of ice to the liquid state of water (latent heat).

Question 37

Why would you use flaked ice

Answer 37

Flaked ice is used as it can conveniently be applied to any region of the body and is more efficient than cubed ice as it provides a larger surface area over which the ice can melt.

Question 38

Local Immersion

Answer 38

This method involves the use of a mixture of cold water and flaked ice in a container.

Question 39

When would you use local immersion

Answer 39

This method can be used for treatments involving the hands, forearm, foot and leg.

Question 40

Local immerson explain the ratio of water to ice and temperature

Answer 40

The ratio of ice to water can be varied to vary the temperature. At a temperature of 16-180C continuous immersion can be tolerated for 15-20 minutes. At a lower temperature of 100C, created by using a larger proportion of ice, the part can only be immersed for a few minutes at a time. Intermittent immersion over 5 –10 minutes is used.

Question 41

Ice packs

Answer 41

Flaked ice is placed in a damp towelling bag and applied directly to the skin. The bag is held in place by plastic sheeting and towels to decrease the heat gained from the environment and minimise the seepage of the melting ice. The pack can be moulded to fit the region being treated. This method is tolerated for 20-25 minutes.

Question 42

ice packs for home use

Answer 42

Flaked ice, in a plastic bag, can be stored in a freezer for home use. Bags of frozen peas can also be used in this way (but must not be used for consumption). Patients should be advised to wrap home ice packs in a damp towel to separate it from the skin.

Question 43

Commercial ice packs

Answer 43

These are vinyl bags usually filled with silica gel. The pack remains flexible when frozen and can be molded to the part. Stored in a freezer, the packs are often at a temperature between –5 to 120C. The average length of cooling time is 20 minutes.

Question 44

Ice towels

Answer 44

A terry-towel is soaked in a mixture of flaked ice and water and then wrung out. This leaves chipped ice adherent to the cloth. This is placed over the surface to be cooled. If the towel is changed every 2 to 3 minutes over a period of 15 to 20 minutes adequate cooling will occur. This technique is most effective over muscle and allows movement and/or exercise during the ice application.

Question 45

Cryocuff

Answer 45

This is often used post-operatively following orthopaedic surgery and combines compression with continuous cold delivered by ice water circulation. Frequency and duration varies for type of surgery and also between post-operative protocols.

Question 46

Ice massage

Answer 46

Massage can be given using a block of ice made from flaked ice wrapped in paper or cloth. The block is moved over the part in a slow circular motion for 5 to 10 minutes, if the application is for pain relief. Alternatively, the block is brushed briefly (5 seconds) over the skin dermatome using short strokes, if the treatment is being used to facilitate muscle contraction.

Question 47

Sprays

Answer 47

Spraying a rapidly evaporating liquid onto the skin is often used as an immediate first aid measure following trauma.

Question 48

Describe a volitile liquid

Answer 48

A volatile liquid is bottled under pressure and is emitted as a fine spray when the nozzle of the container is depressed

Question 49

Describe what happens to the skin when the spray hits

Answer 49

As the spray hits the skin over the injured part, it begins to evaporate by using the heat energy from the skin thus producing cooling. The skin temperature can fall quickly to approx. 150C but with no change in subcutaneous and muscle tissue temperature. This cooling agent, therefore, has limited use as a first aid measure and commercial cold packs are more effective.