Intermittent Compression Devices Jennifer Doherty-Restrepo, ATC, LAT Entry-Level Athletic Training Education Program PET 4995: Therapeutic Modalities

Definitions Edema  Abnormal amounts of fluid in extracellular tissue spaces Joint swelling  Blood and/or fluid accumulation  Appears and feels like a water balloon Lymphedema  Accumulation of lymph in subcutaneous tissues  Occurs over several hours following injury

The Lymphatic System Pick up plasma and plasma proteins that escape from small blood vessels and return them to blood circulation Acts as a safety valve for fluid overload  Prevents edema formation Maintains homeostasis of extracellular environment  Removes excess protein molecules and waste from the interstitial fluid Cleanses interstitial fluid  Blocks thes spread of infection or malignant cells

The Lymphatic System Closed vascular system Parallels arterial system Lymphatic capillaries made of single layered endothelial cells

The Lymphatic System Lymphatic capillaries are surrounded by interstitial fluid Terminal lymphatics provide entry way into lymphatic system for excess interstitial fluid and plasma proteins

The Lymphatic System Lymphatic capillaries form a network of lymphatic vessels Lead to larger Collecting Vessels in extremities Collecting vessels connect with thoracic duct or right lymphatic duct, which join the venous system

The Lymphatic System Fluid moving into interstitial spaces pushes or pulls on fibrils  Fibrils = connective tissue fibers supporting lymphatic capillaries Endothelial cell junctions in lymphatic capillary wall open Allows entry of interstitial fluid, cellular waste, large protein molecules, plasma proteins, extracellular particles, and cells into terminal lymphatics

The Lymphatic System Once in the terminal lymphatics, the interstitial fluid, cellular waste, large protein molecules, plasma proteins, extracellular particles, and cells become lymph Endothelial cell junctions in lymphatic capillaries remain closed when there is …  No increase in interstitial volume  No tissue activity Movement of lymph is accomplished via muscle activity, active and passive motion, elevation, respiration, and blood vessel contraction

Injury Edema: Pitting Edema Local edema Formed by plasma, plasma proteins, and cellular debris moving into interstitial spaces Hormones released by injured cells stimulate small anterioles, capillaries and venules to vasodialate separating endothelial cells in vessel wall  Increases permeability

Injury Edema: Pitting Edema Increased permeability allows more plasma, plasma proteins, and cellular debris to escape into local area Results in gel-like fluid that is trapped by collagen fibers Gel-like fluid referred to as pitting edema

Injury Edema: Lymphedema Accumulation of edema causing overdistention of lymph capillaries  Entry pores become ineffective and interstitial fluid increases Lymphedema results Constriction of lymph capillaries due to increased pressure will also discourage lymph flow and cause lymphedema formation

Negative Effects of Edema Edema compounds injury by causing secondary hypoxic cellular death in surrounding tissues Other negative effects include:  Physical separation of torn tissue ends  Pain  Restricted joint range of motion  Prolonged recovery times  Interstitial fibrosis  Reflex sympathetic dystrophy

Treatment of Edema P.R.I.C.E.  Minimize edema formation E-stim or AROM exercises  Retard edema accumulation Any treatment that assists lymph flow will decrease plasma protein content in interstitial spaces and decrease edema

Treatment of Edema: Elevation Gravity used to assist lymph flow The higher the elevation, the greater the effect on the lymph flow

Treatment of Edema: Compression Muscle contractions provide rhythmic internal compression of lymph vessels to assist lymph flow  Isometrics, AROM exercise, or E-stim External compression assists lymph flow  Massage, elastic compression, or intermittent pressure devices External compression spread interstitial edema over a larger area, enabling more lymph capillaries to become involved in removing plasma proteins

Treatment of Edema: WeightBearing Exercise Treatment of Edema: Weight-Bearing Exercise Activates a venous pump  Not related to muscle activity Mediated by release of an endothelial- derived relaxing factor (EDRF)  EDRF is liberated by sudden pressure changes and it diffuses locally  Functions to relax smooth muscle and stimulate blood flow in the veins

Treatment of Edema: Cryotherapy Cryotherapy used in conjunction with intermittent compression has shown the best results in the reduction of post-acute injury edema

Intermittent Compression Treatment Parameters Inflation Pressure On/Off Time Sequence Total Treatment Time

Inflation Pressure Loosely correlated with BP Most treatment protocols utilize a pressure approximating diastolic BP

Inflation Pressure Arterial capillary pressures ~ 30 mmHg Any pressure that exceeds this should encourage  Edema absorption, and  Lymph flow

Inflation Pressure Maximum pressure should correspond to diastolic BP More pressure is not necessarily better Enough pressure is needed to squeeze lymphatic vessels and encourage lymph flow

On/Off Time Sequence On/Off time sequences are variable Patient comfort should be a primary deciding factor 30s on, 30s off is effective and comfortable Lymphatic massage  Shorter on/off time sequences may have an advantage

Total Treatment Time Clinical studies show significant limb volume reduction after 30 minutes of compression A treatment of minutes may be adequate unless edema is overwhelming in volume or is resistant to treatment Multiple treatment times per day may also be an advantage in controlling and reducing edema

Equipment Setup and Instructions Compression sleeves  Half-leg, full-leg, half-arm, or full-arm Connect compression sleeve (deflated) to unit via a rubber hose and connecting valve

Equipment Setup and Instructions Assess BP and set inflation pressure Set On-time (between 30 to 120 seconds) Off-time is left at 0 until the compression sleeve is inflated and treatment pressure is reached  Then adjust off-time between 0 and 120 seconds During the off-time, instruct patient to move extremity Treatment should last between minutes

Cold and Compression Combination Combination of cold and compression is effective in treating edema Cold/compression unit  Temperature adjustment ranges between o C  Cooling accomplished by circulating cold water through compression sleeve

Compression and Electrical Stimulating Currents Combination of compression and e-stim induced muscle pumping is effective in treating edema Facilitates reabsorption of injury byproducts by lymphatic system

Sequential Compression Pumps Sequentially inflate compression sleeves with multiple compartments Massage effect Applies pressure from distal to proximal Gradual decrease in pressure gradient

Sequential Compression Pumps Highest pressure in distal compartment sleeve  Determined by mean value of systolic to diastolic BP Middle compartment is set at 20 mm lower than the distal cell Proximal compartment pressure is reduced an additional 20 mm

Sequential Compression Pumps Each pressure cycle is 120s Distal compartment is pressurized initially and continues pressurization for 90s 20s later, the middle compartment inflates After another 20s, the proximal compartment inflates A final 30s period allows pressure in all three compartments to return to 0 Entire cycle is then repeated

Indications Lymphedema Traumatic edema Chronic edema Stasis ulcers Intermittent claudications Postoperatively to reduce the possibility of developing a deep vein thrombosis Facilitate wound healing following surgery

Contraindications Deep vein thrombosis Local superficial infection Congestive heart failure Acute pulmonary edema Displaced fractures Cancer