The edematous hand.

The purpose of this article is to increase the therapist's awareness of the effects of edema on the band and the need for early treatment. The physiology of tissue fluid production and the two basic types of edema are discussed. The use of elevation compression, and active exercise are the primary methods of controlling edema In the band Various modalities and commercial compression dressings are helpful for intractable edema; however, early intervention and treatment of y the edematous  band can prevent subsequent band dysfunction and sequelae. [Sorenson MK The edmutous band Phys Ther 69:1059-1064, 1989] Key Words: Edema; Hand; Hand injuries; Upper extremity, hand and wrist. Uncontrolled edema in the hand can lead to a devastating loss of function if allowed to continue. The therapist's role in the management of hand edema requires an understanding of the fluid forces creating the edema and of the mechanical forces altering the full function of the hand. Elevation and compression are important, but if edema persists and joint stiffness ensues, physical therapists must add other available treatment techniques to their armamentarium. physiology of Tissue Fluid In the healthy state, a delicate balance is maintained between the vascular and lymphatic systems. According to overman and Barion,

The capillary, being the only permeable

part of the vascular system, is in

this way the most important structural

part of that system, the principal function

of which is to transport materials

from place to place. The fluid in the tissue spaces surrounding the capillaries is called interstitial or extracellular fluid. Extracellular fluid is similar in makeup to blood plasma except that it contains no red blood corpuscles and the amount of protein is quite small (0.3% in tissue fluid of limbs vs 6.8% in plasma).2 The exchange of fluid between the capillaries and the tissue spaces is called transudation or diffusion. The fluid actually passes through the intercellular clefts between the endothelial cells that form the capillary wall. Several factors affect the amount of fluid in the extracellular spaces. One factor is the selective permeability of the capillary wall, which therefore acts as a filter. The capillary wall is freely permeable to water and solutes with a small molecular weight, but it is impermeable to the large protein molecules found in plasma (plasma proteins).' A second factor influencing extracellular fluid formation is the hydrostatic pressure in the capillary (capillary blood pressure). Under normal conditions, the pressure at the middle of a capillary is about 25 mm Hg. The pressure at the arteriolar end of the capillary is slightly higher, and it is lower at the venous end. The hydrostatic pressure outside the capillary varies but is normally only a few millimeters of mercury.2 An increase in blood pressure within the capillary walls forces more of the water and solutes into the tissue spaces by a process called filtration. Thus, the greater the capillary blood pressure, the greater the rate of filitration; hence, more fluid is accumulated in the extracellular space. A third factor is a restraining force that prevents all the water and solutes from leaving the capillaries.2 According to Tuttle and Schottelius,

As the plasma proteins pass with great

difficulty and only to a very limited

extent through the capillary wall, by

their water-drawing power they

oppose the blood pressure and thus

prevent the unrestrained filtration of

the plasma into the tissue spaces. This water-drawing power is due to the osmotic pressure exerted by these colloids called colloidal osmotic pressure (COP). A higher concentration of proteins in the plasma than in the extracellular space will increase the COP and fluid flow into the capillary. When the capillary blood pressure is greater than the COP, filtration takes place through the capillary wall. With the increased rate of filtration, fluid is lost in the capillary and the concentration of plasma proteins will increase. The COP is raised to a level higher than the capillary blood pressure, and absorption of fluid into the capillary then takes place. Tuttle and Schottelius's equation for this process of filtration versus absorption is

filtration pressure =

capillary blood pressure - COP Unless some pathological condition or trauma exists, this balance of fluid filtration and absorption maintains the interstitial fluid at a proper level, along with the help of the lymphatic system. Another means of maintaining proper tissue fluid levels is through the lymphatic system. According to Bower, the lymphatic system plays a role in normal tissue fluid and electrolyte balance in two distinct ways:

First, the lymphatic system returns to

the blood stream interstitial [extracellular)

fluid which accumulates locally as

the result of a positive net filtration

balance in a given area. Second, the

lymphatic system returns to the intravascular 

compartment those components

of tissue fluid which do not diffuse

freely back through the capillary

membrane; this includes primarily the

various protein fractions of the plasma

which are found in the interstitial

space. The term lymph is defined as the interstitial fluid that enters the lymph vesselS.4 The lymph capillaries are delicate one-layered cell vessels lying within the tissue spaces. These capillaries freely connect with each other and form larger vessels as they move lymph toward the axilla and eventually drain into the right and left subclavian veins.2 The rate of flow of lymph is very slow compared with the rate of blood flow. On the average, lymph flow is only 4 mm/sec versus 300 mm/sec of blood flow in the aorta.2 The volume of lymph discharged in a day (1,200-2,280 mL/day) also is very low compared with the volume of blood carried by the aorta (5,000 mL/min). The valves of the large lymph vessels are similar to those of the venous system, but lymph vessels have no special pumping mechanism to move lymph and are dependent on external forces.4 According to Bower,

The tissue fibrils surrounding

lymphatic vessels are attached to the

walls of the vessels in such a way that

distention of the tissue spaces with

fluid results in tension on the walls of

the lymphatic vessels, with resulting

passive dilation of these vessels. It has been observed that in the presence of chronic edema, the lymph vessels are dilated and the flow of lymph is small or absent. Whatever forces aid in venous drainage will also help lymphatic drainage. Lymph will not move in a resting limb, but rhythmic muscular contractions or passive massage will raise the tissue pressure enough to increase the flow of lymph. Two Types of EdemaTransudate and Exudate When excessive tissue fluid accumulates in a body part, the condition is called edema. One type of edema is caused by an accumulation of water rich tissue fluid called transudate. In the healthy state, the plasma protein molecules in the extracellular fluid are continuously absorbed by the lymphatic system and are eventually returned to the blood stream. When there is lymphatic obstruction or destruction, the proteins are not as readily absorbed and returned to the blood stream. Therefore, the protein concentration in the extracellular space is greater than in the capillaries. This concentration of protein results in a shift in the filtration equation, causing more filtration than absorption by the capillary. This transudate is rarely the cause of adhesions in the affected area.6 The second type of edema is created when the capillaries and lymphatics are injured as a result of trauma or surgery. initially, there is vasodilation in the traumatized area, thrombosis of the damaged vessels, and contraction of the muscular vessels. In the area immediately surrounding the lesion or wound, a protein-rich fluid called exudate will leak out of the injured capillaries. This outpouring of fibrin rich fluid and albumin (a protein found in blood) from the injured vessels results in the fluid shift that renders the injured area edematous and creates a condition of vascular insufficiency in the wound. With the reduction of albumin within the capillary, there is also a reduction of the COP, thus decreasing the absorption of fluids throughout the length of the capillary. in the presence of this excess interstitial fluid, there is a delay in the exchange of nutrients and metabolites into the extracellular spaces, which alters and slows down the healing process. The local lymphatic system is occluded by fibrin plugs formed from escaping plasma proteins.6,7 Although edema is a pathological condition of tissue fluid, it is a normal response to trauma. Madden states that

the key to normal hand function is the

ability of strong dense connective tissue 

structures to glide relative to one

another. Any alteration in macroscopic 

anatomy that changes the physical characteristics

or anatomic arrangement of

tissue prevents relative gliding and

reduces hand function significantly. When exudate remains in the hand, the protein-rich fluid causes fibrosis and thickening of the tissues, which leads to joint stiffness, contractures, pain, and dysfunction.9-11 Excessive swelling causes changes in the transverse and longitudinal arches of the hand. The dorsal skin on the hand is loose and pliable under normal circumstances, but when filled with excessive fluid, the arches of the hand are flattened and the thumb is pulled into adduction.9,10 Brand states that simple edema (a collection of water and electrolytes) restricts movement

by serving as a cushion o f passive

material that takes energy to move. It

also limits the longitudinal movement

of fibers by a reorientation in a transverse

direction.... Edema also has

direct effects on joint motion by changing

the moment arms of skin (on the

extensor side) and by direct obstruction

(on the flexor side). An example Brand gives to illustrate the effects of edema on joint motion is at the proximal interphalangeal (PIP) joint of a digit. To flex the PIP joint to 90 degrees, the dorsal skin normally must lengthen 12 mm. With 5 mm of edema thickness added to that PIP joint, the dorsal skin would need to lengthen 19 mm to flex the PIP joint to 90 degrees.12 Slowly applied torque will move the edema away from the joint and will redistribute it, allowing the skin to cross closer to the joint axis of rotation and thus require less stretch to flex the joint to 90 degrees. 12 Both inflammatory edema (exudate) and simple edema (transudate) have the same effect on tissue fiber reorientation and movement, but exudate has a higher viscosity and is therefore more difficult to redistribute than transudate.12 The fibrinogen in the exudate organizes and becomes fibrin. Fibrin then forms fibrous tissue, which is designed for repair, not motion.12 The loss of motion and function in the hand attributable to this process of fibrous tissue formation is what early edema management is meant to prevent. Assessment of Edema It is important to continually measure changes in the amount of edema present in the hand because of the potential harmful effects of either kind of edema. By continually recording the measurements of change in the amount of edema present, the patient can be alerted to be more vigilant in his or her home program, and these measurements can help assess the effectiveness of the treatment given to control the edema. A quick, simple way to measure edema is to use a Volumeters,' which measures the amount of water displaced by the hand and wrist (Fig. 1).9,12,13 Volumetric measurements taken before and after treatment can show a dramatic change, which in turn can influence the patient's compliance with a program of elevation and active exercise. in cases where Volumeters readings are not appropriate (eg, open wounds, casting), another method is circumferential measurement of each digit with a circumferential gauge or flexible tape measure (Fig. 2).9,13 These measurements are taken at the same place on each digit (ie, proximal phalanx, PIP joint, distal palmar crease, wrist crease) and by the same therapist to ensure consistency in the placement and tension applied to the tape. ideally, the measurements of volume and circumference should be taken at the same time each day because edema can vary from morning to evening, regardless of treatment.13 Qualitatively, edema should be described as either simple edema or inflammatory edema.12 Brand uses a torque angle curve to distinguish between joint stiffness attributable to structural changes versus edema. For example, he places a 500-mg weight on the next distal joint crease and leaves it on for one minute, taking joint-angle measurements every 15 seconds. A joint with structural stiffiness will demonstrate little change after the first 15 seconds. The angle of an edematous joint may change throughout the full minute. The change will be faster for simple edema and slower for protein-rich inflammatory exudate. Because of the constraints placed on a joint when edema is present, the need to reduce the edema and increase the range of motion to prevent joint stiffness becomes obvious. Position and Exercise The primary method of treating hand edema is with elevation and early active motion of all unaffected jointS.13-18 Affected joints or digits may also be exercised if there are no contraindications to early motion such as in tendon repairs, unstable fractures, or nerve repairs performed under tension. In these cases, the joints should be protected from unwanted motion, so the unaffected joints can be mobilized. Elevation with the hand above the elbow and die elbow above the shoulder must be maintained as long as the swelling continues. Slings or circumferential dressings to maintain elevation should be avoided because they may slip or tighten and block drainage, thus making the edema worse. When the patient is ambulatory, he or she can rest the edematous hand on top of the head. To maximize passive drainage while sitting, the entire arm should be above the level of the right atrium," making sure it is supported in such a way as to not cause compression of the ulnar nerve. Active exercises are extremely important to aid in lymph and venous drainage as well as to maintain joint ROM.6,9,13-15,19-21 Wiggling of the fingers does little to help reduce edema or increase tendon excursion and joint motion. Exercises emphasizing strong muscular contractions accelerate drainage, and with forceful flexion-extension of the digits, the fluid is forced out of the hand by squeezing it between the dorsal skin and the metacarpals. A home program of active exercises, performed while the arm is elevated, should include four basic tendon gliding exercises: 1. The "hook" exercise is flexion of

the PIP and distal interphalangeal

(DIP) joints while maintaining the

metacarpophalangeal (MP) joints at

0 degrees of extension. 2. The flat-fist" exercise is full

flexion of the MP and PIP joints

while maintaining the DIP joints at

0 degrees of extension. 3. The "full-fist" exercise is full

flexion of all three joints bringing

the fingertips into the distal palmar

crease. 4. The "straight-position" exercise is

extension of all three joints to 0

degrees of extension. These four exercises permit maximum tendon excursion, allowing the flexor digitorum sublimis and flexor digitorum profundus tendons to glide fully and freely, independent of one another.14,18 The thumb should also be exercised in all planes of motion.18 Although gentle passive ROM may be used to increase joint mobility, aggressive and forceful passive ROM is not an acceptable technique to gain joint motion and only causes pain and increased edema.11,14 Modalities Retrograde massage, which is performed in a distal-to-proximal direction, aids the venous and lymphatic systems in reducing edema.11,13,15,17,2-22 This massage should be administered firmly, yet gently, to the uninjured areas and can be carried out by the patient at home as well as by the therapist in the clinic. The arms should be elevated during retrograde massage to facilitate drainage. Pneumatic compression devices have been used to help "pump edema" out of the hand and wrist since the 1950s. Pneumatic compression has been the least effective technique for people with thick fibrotric tissue. When using the jobst Extremity Pumpo,* the force must be greater than 25 mm Hg but less than the diastolic blood pressure of the patient. The pressure levels should be started low and increased with patient tolerance. The Jobst Extremity Pumps should not be used when an infection is present, but it can be used in the presence of open wounds or internal fixation. Jobst Jet Air' splints can be worn for 20-minute intervals throughout the day as part of a home program.21 In 1977, Zelikovsky and Manoach developed a sequential pressure sleeve to be used with pneumatic compression.25 The sleeve has 9 to 12 compartments, which fill with air independently and compress or milk" the fluid in the extremity in a distal-to-proximal direction. An overlap in compartmental filling allows for a smooth outflow of fluid from the extremity. Sequential pneumatic compression also can use a higher peak pressure than nonsequential compression (100-110 mm Hg) because of the distal-to-proximal minding of the multiple compartments without any neurological or muscular complaints. The use of heat in the treatment of edema is controversial because it is thought to increase edema. Laseter believes whirlpool treatments only add to the problem of edema because they mix heat with placement of the hand in a dependent position." Mackin uses heat judiciously, lowering water temperature and ensuring the elbow is flexed and the patient is actively exercising throughout the treatment.14 Other heat modalities, such as paraffin wax or moist heat packs, can be useful in edema reduction. Used in conjunction with elevation, the heat can help reduce pain, which may improve ROM and thus increase muscle-pumping activities to aid in edema drainage. Compressive Dressings When there is a reduction in edema attributable to elevation, active exercises, or the addition of some modality, the effects may be temporary if those gains are not maintained with some kind of external compressive dressing. The first compressive dressing most patients will encounter is the postoperative dressing placed on them by their surgeon (Fig. 3). The surgical dressing consists of multiple gauze layers and plaster dressing preserving the transverse arch and the web space. This compressive dressing, coupled with ice and elevation for the first 48 hours following surgery, is effective in reducing edema and postsurgical pain. Several different types of commercial compressive dressings are available, depending on the area to be wrapped. Whatever dressing the therapist chooses, good circulation must not be compromised. This precaution is particularly important in cases involving recent surgery, vascular damage, skin grafts, or replantation. It should be noted that "the effects of elevation and compression are additive so that seemingly moderate amounts of each may significantly compromise cutaneous oxygen delivery when applied simultaneously. The patient must be instructed by the therapist or surgeon about not wrapping the extremity so tightly that circulation is impeded. A compressive stockinette is easy to apply and offers adequate pressure for reducing edema across the dorsum of the hand and up the arm (Fig. 4). Commercial custom-made sleeves provide pressures ranging from 3 to 25 mm Hg, and commercial gloves provide 30 mm Hg of pressure at the distal fingertips and 10 mm Hg at the wrist. jobst pressure-gradient dressings, isotoners gloves, or Tubigrip gloves are useful for long-term use in hands with chronic edema (Fig. 5). For individual digit compression, Coban is a useful elastic wrap that adheres to itself When wrapping individual fingers, the tip should be left open so that circulatory changes can be noted, The wrap should be applied at an angle with decreasing pressure distally to proximally to prevent compromising the circulation.21 For chronic edema in digits, a compression sleeve for individual digits is available Digi-sleeve*) (Fig. 5). The external compressive dressing should not restrict motion because ROM exercises should be performed regularly, even while the extremity is wrapped. if splinting is necessary to prevent joint contractures or to maintain proper joint position, neither the splint straps nor the splinting material should be restrictive so as to cause pressure areas or block the fluid flow out of the hand and into the arm. Precautions should be taken so that the application of the splint does not exacerbate the existing problem. Summary The mechanisms of fluid balance in the body are very complex and discussed only briefly in this article. When the vascular and lymphatic systems fail because of trauma, pathology, or surgery, the effects on the hand can be devastating unless they are treated correctly and quickly. Both types of edema-transudate and exudate can cause problems in the hand that can lead to joint stiffness. Exudate also can lead to fibrosis and joint contractions. Elevation and compression are the primary passive means of counteracting excessive tissue pooling. Strong rhythmic muscular contractions are the active external means of aiding venous and lymphatic drainage. Full joint motion and tendon gliding, achieved with active exercise, should be the goal early in the treatment of edema. If edema persists despite the standard treatment of elevation and active exercise, the utilization of modalities and compressive dressings is necessary to prevent the unfortunate outcome of an edematous hand left untreated.