Week 9 Compression Flashcards
what is compression?
a mechanical force that increases external pressure on the body or a body part
what is compression used for?
to improve fluid imbalance and circulation or modify scar tissue formation
what are the two type of compression?
static: constant force like compression garment
intermittent: varying force over time
what are the effect of external compression?
-improves venous and lymphatic circulation
-limits the shape and size of tissue
-increases tissue temperature
-edema reduction (improves healing environment, reduces neuromuscular inhibition, improves ROM, and decreases pain)
-prevention of DVT (increases flow in venous system to prevent clotting)
how does compression improve venous and lymphatic circulation?
-increases external hydrostatic pressure
-intermittent compression may be more effective than static by milking fluids from proximal to distal vessels
when is compression used to limit shape and size of tissue?
after amputation or burns
how does compression increase tissue temperature?
may increase activity of temperature-sensitive collagenases to control scar formation
what are the clinical indications for the use of external compression?
-EDEMA CONTROL
-prevention of DVT
-venous stasis ulcers
-residual limb shaping after amputation
-control of hypertrophic scarring (after burns)
what are the causes of edema?
-imbalance between hydrostatic and osmotic pressure inside and outside of vessels
-venous or lymphatic obstruction or insufficiency
-increased capillary permeability
-immobility
-pregnancy
-systemic diseases (do not treat with compression)
how does the lymphatic system work?
-help prevent the accumulation of fluid.
-it is a large system of vessels and nodes that act as an accessory channel that returns lymph fluid to the blood circulation via emptying into the subclavian vein.
-the fluid in the blood is then excreted through kidney functions.
-lymph flows due to higher concentration of proteins within the lymphatic vessels compared to the interstitial space.
what can cause reduced lymphatic flow and result in lymphedema?
-decreased levels of plasma proteins such as albumin
-mechanical obstruction of the lymphatics
-abnormal distribution of lymphatics or nodes
-reduced activity
what can result from prolonged edema?
-decreased ROM
-function impairments
-pain
-disfiguration
-infection
-ulceration
-amputation
-itching
-brown skin pigmentation
how does compression reduce edema?
-increases extravascular hydrostatic pressure = circulation promotion
-may move fluid proximally through the vessels
how can compression aid in the prevention of DVT?
-can increase circulation and reduce DVT formation
-effect is greatest when used in combination with other DVT prophylaxis
-DVT increases with reduced local circulation
how does compression aid with venous stasis ulcers?
-improves venous circulation
-improves rate of healing of venous stasis ulcers
-multilayered compression more effective than single layer
-high pressure more effective than lower pressure
what is the cornerstone of venous ulcer treatment?
compression therapy
what is the main contraindication for compression therapy?
-Ankle brachial index must be done to rule out arterial insufficiency
-ABI must be >0.8mmHg
what are the contraindications for intermittent or sequential compression pumps?
-heart failure or pulmonary edema (due to risk of system overload)
-recent or acute DVT thrombophlebitis or PE (can dislodge and cause HA or PE)
-obstructed lymphatic or venous return (can be helpful after obstruction is removed)
-severe PAD (can further impair circulation)
-acute local skin infection (increases temperature and moisture to the area)
-significant hypoproteinemia (can further decrease protein concentration which can cause cardiac or immune disfunction)
-arterial revascularization
what are the precautions of compression therapy?
-impaired sensation or mentation
-uncontrolled hypertension
-cancer
-stroke/significant cerebrovascular insufficiency
-superficial peripheral nerves
what are the adverse effects of compression therapy?
-aggravate condition causing edema
-impairing circulation with excessive pressure
(shortness of breath can occur which indicates overload in the lungs or PE)
what mmHg should compression be for DVT prevention?
16-19 mmHg
worn 24hrs/day
what mmHg should compression be for scar tissue control?
20-30 mmHg
what mmHg should compression be for edema control?
30-40 mmHg
what are the disadvantages of intermittent pneumatic compression pump?
-only used for limited times
-cant be used for scar formation
-requires static compression to be used between treatments
-expensive
-patient cannot move during treatment
-can aggravate acute conditions
