CH 20: Compression

Question 1

What is an inward-directed mechanical force that increases external pressure on the body or body part?

Answer 1

Compression

Question 2

What are the instances when compression is used?

Answer 2

Improve fluid balance and circulation

Modify the formation of scar tissue

Question 3

Explain how compression improves fluid balance

Answer 3

Increasing the hydrostatic pressure in the interstitial space so that the pressure becomes greater in the interstitial spaces than in the vessels thus limiting or reversing outflow of fluid from blood vessels and lymphatics; keeping fluid in or returning to vessels allow fluid to circulate rather than accumulate

Question 4

What type of compression exerts a constant force?

Answer 4

Static Compression

Question 5

What type of compression exerts a force varying over time?

Answer 5

Intermittent Compression

Question 6

How does intermittent compression work?

Answer 6

Pressure may be applied to the entire limb at the same time, or it may be applied sequentially starting distally and progressing proximally

Question 7

What is the primary clinical application for compression?

Answer 7

To control peripheral edema caused by vascular or lymphatic dysfunction

Question 8

What are other instances in which compression may be applied?

Answer 8

• Help prevent formation of DVT
• Facilitate residual limb shaping after amputation
• Facilitate healing of venous ulcers

Question 9

What are the effects of external compression?

Answer 9

• Improves venous and lymphatic circulation
• Limits shape and size of tissue
• Increases tissue temp

Question 10

How do static and intermittent compression devices increase circulation?

Answer 10

Increase hydrostatic pressure in interstitial space outside the blood and lymphatic vessels and can limit the outflow of fluid from vessels into interstital space (where it pools), keeping fluid in circulatory system (to circulate)

Question 11

What occurs when venous and lymphatic vessels are compressed?

Answer 11

Fluid within them is pushed proximally

Question 12

What occurs when compression on venous and lymphatic vessels are reduced?

Answer 12

Vessels open and refill with new fluid from interstitial space

Question 13

How is Sequential Multichamber Compression more effective in milking compared to a single-chamber, intermittent compression?

Answer 13

It can cause a wave of vessel constriction moving in a proximal direction ensuring fluid is pushed along vessels toward the heart rather than distal direction

Question 14

What are some benefits for improving circulation?

Answer 14

• Decreasing edema
• Preventing DVT
• Facilitate healing of ulcers caused by venous stasis

Question 15

What type of compression garment acts as having an elastic compression element or being less extensible than natural skin, limiting the size and shape or new tissue growth?

Answer 15

Static Compression Garments

Question 16

How is limiting size and shape of tissue or new tissue growth exploited with compression garments?

Answer 16

When applied over residual limbs after amputation, over skin damaged by burns (to reduce scarring), and to edematous limbs

Question 17

What can most compression devices do but is not considered a direct effect of compressive forces?

Answer 17

Increase the temperature of superficial tissues because devices insulate area to which they are applied

Question 18

How does compression garments increase tissue temp?

Answer 18

The warmth increases activity of temperature-sensitive enzymes (collagenase which breaks down collagen) to control scar formation