Physics behind Compression
- Application of a mechanical force externally for therapeutic purposes
- Generally use of a bandage, wrap, cuff, sleeve, or garment
- May be static or intermittent (IPC-Intermittent Permatic Compression)
- Static
- Ex: Garment
- Static
- May be sequential (distal to proximal)
- Graded pattern
- Higher forcer distal, decreasing moving proximal
Explain the Starling Diagram and Concepts
When fluid enters in gives more energy pushing out.
As fluid moves out of capillary along capillary bed, internal hydrostatic pressure drops to the point where it is not forcing anymore fluid out. At equilibrium, protein take over and so you soak in more fluid as you leave vessel.
More pressure inside capillary than outside. At beginning
Fluid movement out is always greater than what is soaked up.
Lymphatics also play a role in soaking up fluids so that why we don’t look like the michelin man.
Too much fluid back can be an issue
Physiology of Injury
- With injury, comes swelling
- Accumulation of blood, cell debris, chemical and electrical signals to trigger the inflammatory response
- Results in fluid accumulation
- Two types:
- Intra-articular edema (blood and fluid in the joint)
- Ex: Torn ACL, Torn Meniscus
- Lymphedema acute or chronic
- Intra-articular edema (blood and fluid in the joint)
- Two types:
Lymphedema
Build up of lots of fluid and little protein in subcutaneous tissues
Ex: Pitting
What happens when large amounts of proteins are outside? (Starling Diagram)
More fluid moving out as water will follow certain fluids
Don’t have driving force of protein suction inside leading to more fluid outside
Really tight fluid might push some fluid back in BUT in very elastic tissues we will see lots of fluid.
Physiology of Compression
- Increase the external hydrostatic pressure to facilitate absorption into the venous system (Starling)
- Mechanically stimulate the lymphatic system to better absorb protein, thereby decreasing interstitial osmotic pressure
- Thin vessel walls, walls can be mechanically stimulated with contraction and stretching
- Think rope, hold water well in stretch and relaxed lead to opening acting as a vacuum.
- Use machine or garment (they stay active during day to push fluid)
- Best way to stimulate lymphatic is exercise!
Indications for Compression
- Reduction of acute tissue edema post-injury or post-operatively
- Acute Injury
- Chronic lymphedema
- Chronic Edema due to Immobility
- Chronic edema due to renal insufficency
- Venous insufficency (stasis) Ulcers
- Residual limb shaping/reduction
- Arterial insufficency
- DVT and PE Prevention
- Control/Prevention of hypertrophy scarring
- Keloid Formation
Indication - Reduction of acute tissue edema post-injury or post-operatively
- Swelling may decrease ROM
- Swelling can interfere with nerve activity
- Swelling decreases the effectiveness of lymph drainage (increasing the likeihood of infection)
- Swelling may impede wound healing
Reduction of edema can improve all of these factors
Combination with cold has even better results
Can use IPC, static compression, or a wrap, in combination
Acute Injury
- Part of PRICE
- Protection, Relative Rest, Ice, Compression, Elevation
- No good evidence that advanced devices are better than basic ice + wrap (but patients like them better)
Chronic Lymphedema
Impairment of lymphatic flow through lymph vessels
Results in decreased oxygen to tissue and promotes infection
IPC is effective
Compression garments (stocking, gloves, sleeve), often custom, are also effective
Best practice is combination of IPC and garments
Ex: Breast Cancer
Chronic edema due to immobility
Ex: Nerve injury or disease causing paralysis
Multiple Sclerosis
Peripheral nerve injury
1-2mm growth per day
Lack of mobility = ineffective lymph drainage = chronic edema
Combo of IPC and garments
Passive ROM works to help in fluid stimulation of fluids!!!
Chronic edema due to renal insufficiency
Often have extremity edema due to compromised kidney function (more common in those on dialysis)
Typically compression garments are suitable – be cautious based on degree of kidney failure
Use garments back into system because it does it slowly. If we bring the system back to fast you can perpetuate the kidney failure.
As goes for heart
Venous insufficiency (stasis) Ulcers
These occur when there is impairment of venous circulation (static blood), resulting in chronic edema and “pooling” of fluid
Valves lose elasticity as we age, get more fluid can cause ulcers
Compression may improve venous circulation in the area, reduce edema allowing better oxygenation of the tissue
Combination of IPC and garments
Can use IPC for those w/o cardiac and kidney
Residual limb shaping/reduction
- Post amputation there is significant edema that can inhibit healing and delay fitting of a prosthesis
- IPC and compression wraps/garments are effective
- Wraps can be customized everyday to make them tighter as swelling reduces
Arterial Insufficiency
- PIC is thought to improve flow in arterioles by improving the arteriovenous pressure gradient thereby improving venous return
- May be useful for those inappropriate for surgery due to advanced disease, or those mildly involved with intermittent claudication (pain related to walking due to a lack of blood flow)
- Those that can’t do surgery
DVT and PE Prevention
VTE = Venous Thromboembolism (Venous Blood Clots)
DVT = Deep Vein Thrombosis
PE = Pulmonary Embolism
Sometimes a complication with immobilization
Blood flow is slowed, sluggish; increasing likelihood of clot formation
IPC improves venous flow to deeper veins
Use of IPC reduces occurrence of DVT post-op an din immbolized patients
IPC reduces risk of VTE by 60% after general surgery, neurosurgery, and orthopedic surgery
Use in combination with compression stockings
IF A DVT ALREADY PRESENT OR SUSPECTED, IPC IS CONTRAINDICATED
Control/prevention of hypertrophy scarring
This is widened or unslightly scar that does not go beyond the bounds of the wound
Ex: Large laceration scar
Thought due to elevated tension in the area of the wound
Typically treated with custom garments
Keloid Formation
An abnormal scar that grows beyond the boundaries of the original of the original wound site
Push scars back together
Often painful
Typically custom garments
Can both IPC and Garments be used with someone with blood clots?
No only garmets!
IPC Contraindications
- Acute pulmonary edema
- Congestive heart failure
- Presence of a known DVT
- Acute or unstable fracture
- Acute local superficial infections (including cellulitis)
IPC Treatment considerations
- Inflation pressure
- Not to exceed diastolic BP
- Guidelines:
- 30-60 mm Hg UE
- 40-80 mm Hg LE
- 30 mm Hg lowest limit
- On-off time sequence (4:1 to 1:2)
- Patient comfort is best determinant
- Shorter sequence promote lymph flow
- Longer sequences promote external hydrostatic effects
- Patient comfort is best determinant
- Total Treatment time
- As low as 10-30 minutes
- May use for hours
Encourage patient to exercise during the Off phase (muscle pumps, isometric contractions)
IPC treatment considerations
- Use stockinette under sleeve for hygiene purposes
- Compression sleeve
- Single chamber (blow up entire sleeve together)
- Multi chamber (blow up distal to proximal)
Adverse Effects - Compression
May aggravate:
Heart or other organ failure
Overload lymphatic system
Infection (systemic)
Too much pressure – tourniquet effect
Check BP and edema
Compression Bandages
- Resting vs working pressure
- Resting pressure: pressure exerted by elastic when put on stretch
- Working pressure: pressure produced by the muscle when active/pushing against an inelastic bandage
- Creates internal working pressure
- Want high working and low resting pressure
