Comparison of vascular access devices

Comparison of Vascular Access Devices Lynn C. Hadaway

Objective: To provide an overview of venous access device designs and methods of insertion and removal. Conclusions: Venous access devices are indicated for many patients who require reliable long-term venous access. Three types of venous access devices are available including nontunneled, tunneled, and implanted ports. Since their introduction into clinical practice, the widespread use of these devices has had an enormous impact on cancer treatment by decreasing the overuse of peripheral veins while allowing for more flexibility and choice of the type of device used. Although numerous devices are available, each offers unique designs and performance expectations. Each type of device has similar

features and can be used for intravenous drug and nutritional therapy, administration of blood products, and withdrawal of blood. Implications for nursing practice: Even if only a single device is used in a given setting, the nurse must have a basic understanding of all types of venous access devices. It is imperative that the nurse be fully cognizant of the anatomic position and structure of the major vessels associated with the central venous system, especially for the insertion of peripheral central catheters. Understanding the venous system and venous access design can assist in preventing or assessing potential complications.

N THE PAST DECADE, a rapid increase in the complexity of intravenous therapies as well as the variety of devices available has been seen. Historically, choices have included repeated peripheral venipunctures or the insertion of a subclavian or jugular catheter. Although these choices are still prevalent, they limit the type, duration, and frequency of therapies as well as the patient's environment during infusion. Alternatives include midline catheters, p e r i p h e r a l l y inserted central catheters (PICCs), tunneled catheters, implanted ports, and plasmapheresis catheters. The designs of catheters, the composition and characteristics of the materials used, and the methods of insertion vary greatly. A working knowledge of these devices by health care professionals will result in the use of a cost-effective device that will meet the patient's needs and preferences (Table 1).

chemical reaction within or on the body. 1 A vascular access device is one type of biomaterial device. Advances in polymer (plastic) technology and device engineering have diminished some of the early problems encountered with vascular access devices (VADs). For example, the stiffness of catheter material led to thrombosis development, 2"6 complete vessel erosion, and fluid extravasation into the pleural cavity. Fortunately, the use of rigid materials, such as polyethylene and polyvinyl chloride, has greatly decreased. Some devices that are constructed of rigid materials may still be used for plasmapheresis. Currently, polyurethanes, silicone elastomer, and elastomeric hydrogel are the most frequently used materials in the manufacture of VADs. Although each material differs in composition, all materials are regulated by the Center for Devices and Radiological Health at the Food and Drug Administration (FDA). 7 Polyurethanes are biocompatible materials that can be made rigid, semirigid, or flexible with good physical strength. After insertion the body temperature causes softening of the material. The versatility of polyurethane provides the ability to manufacture thin-walled catheters that can tolerate higher infusion pressures without sacrificing lumen size and the resultant decrease in flow capability. Silicone elastomer is a soft, extremely flexible material. The potential for thrombosis and vessel perforation is reduced; however, it is not completely eliminated, s-l° Different mechanical properties of silicone necessitates thicker catheter walls

I

CATHETER MATERIALS A biomaterial is defined as a natural or synthetic substance that interfaces with living tissue for a significant period of time. A biomaterial device is an instrument or apparatus that can be used to diagnose, treat, or prevent disease without causing a

From Menlo Care, lnc, Menlo Park, CA. Lynn C. Hadaway, BS, RN, C, CRNI: Clinical Nurse Educator, Menlo Care, Inc. Address reprint requests to Lynn C. Hadaway, BS, RN, C, CRNI, 917 Morgan Dairy Rd, Milner, GA 30257. Copyright © 1995 by W.B. Saunders Company 0749-2081/95/1103-000255.00/0 154

Copyright © 1995 by W.B. Saunders Company

Seminars in Oncolog7 Nursing, Vol 11, No 3 (August), 1995: pp 154-166

COMPARISON OF VADs

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Table 1. Vascular Access Devices Peripherally Inserted Central Catheters

Midline

Tunneled

Elastomeric hydrogel Silicone elastomer Polyurethane 24 g to 16 g 3 to 8 inches

Elastomeric hydrogel Silicone elastomer Polyurethane 23 g (1.9F) to 16 g (4.8F) 15 to 27 inches

Yes

Yes

Basilic, cephalic, or median cubital veins of antecubital region

Tip location

Upper arm in axilla, distal to the shoulder; neonates and pediatric locations may be midthigh to upper thigh if lower extremity is used

Method of insertion

Over-the-needle (Landmark only) or through-theintroducer with breakaway needle or peelaway sheath

Indications

IV solutions for replacement/hydration; most IV medications, admixture should be isoosmotic to decrease chemical vein irritation Solution with dextrose content more than 10% to 12.5%; continuously infused vesicants; lack of antecubital veins suitable for catheter insertion and advancement

Material used Available gauge length Double lumens available Insertion site(s)

Limitations of use

Implanted Ports

Apheresis Catheters

Silicone elastomer

Silicone elastomer Polyurethane

2.7F to 12.5F 29.5 to 42.7 inches Yes

4F to 12F 19.7 to 34.5 inches

Basilic, cephalic, or median cubital veins of antecubital region

Enters vein at the proximal cephalic, axiilary, or distal subclavian and exits chest wall at a lower, predetermined site

Right internal jugular preferred; also subclavian and femoral

SVC; innominate, subclavian, proximal axillary may also be chosen depending on patient condition and type of infusate; IVC in neonates or pediatrics when lower extremity insertion site is used Through-the-introducer with break-away needle, peel-away sheath, or short overthe-needle catheter; Seldinger over-wire SVC or IVC location--all types of fluids, nutrition, medications; if tip is in other veins, solution should be isoosmotic Lack of antecubital veins suitable for catheter insertion and advancement; anomalies of central venous structure; thrombosis of veins

SVC or IVC if SVC cannot be cannulated

Enters vein at the antecubital or subclavian site with suture line closing port pocket close to this location; may be at numerous other anatomic locations, such as peritoneal, arterial, and epidural SVC or IVC if SVC cannot be cannulated

Seldinger overwire or cutdown with surgically created tunnel

Seldinger over-wire or cutdown with surgically created pocket for port

Seldinger over-wire or cutdown

All types of fluids, medications, and nutrition

All types of fluids, medications, and nutrition

Hemodialysis, apheresis

Anomalies of central venous structure; thrombosis of veins

Anomalies of central venous structure; thrombosis of veins

Anomalies of central venous structure; thrombosis of veins

Yes

Silicone elastomer Polyurethane 8.4F to 11.5F 5.4 to 18 inches Yes

SVC

Abbreviations: SVC, superior vena cava; IVC, inferior vena cava; IV, intravenous.

to achieve strength, thus either internal lumen size is decreased or outer diameter is increased. Elastomeric hydrogel is a unique combination of two polymers--polyurethane cross-linked with hydrogel. Medical hydrogels are wettable polymers that retain a large amount of water within the structure but do not dissolve in water. Some refer to hydrogels as resembling living tissue in their phys-

ical properties more than any other synthetic biomaterial. 1 Elastomeric hydrogel catheters (Aquavene; Menlo Care, Inc, Menlo Park, CA) have an equal distribution of polyurethane to provide strength and hydrogel, which allows absorption of water from the blood, causing the catheter to soften and expand. There is a thin layer of solid polyurethane on the internal wall that prevents ab-

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LYNN C. HADAWAY

sorption; therefore, the Aquavene is not affected by the flow of fluids and medications through the catheter lumen. Hydration of the catheter wall only occurs from the outer wall in contact with the bloodstream. 11A2 Catheter materials are radiopaque, allowing for visualization of the catheter tip on initial insertion or the complete catheter if a problem should develop. The ease in visualizing catheters is related to the size of the catheter, the radiological techniques used (such as oblique angles), and the machine settings (such as increasing the killivolts). Questions are asked frequently about the possibility of some patients being hypersensitive to various catheter materials. At the present time, cellmediated immune response to synthetic polymers does not appear to be a widespread occurrence. Attempts to stimulate the immune response to synthetic polymers have produced minimal occurrence compared with natural proteins. 13 Other studies have reported no histamine release in blood samples challenged with extracts of silicone elastomer and elastomeric hydrogel. 14 Possible explanations for untoward events during catheter insertion include vasovagal reactions, physical stimulation of mast cells by excessive trauma, irritation to the nerves of the upper arm and shoulder, and true allergic reactions to other materials used in the procedure, such as Latex gloves. ~s Another issue relating to catheter material is the potential for material changes with the infusion of antineoplastic drugs. One study reported that the internal catheter surface of silicone roughened and polyurethanes showed staining after infusion of doxorubicin, bleomycin, carmustine, cisplatin, 5-fluorouracil, ifosfamide, methotrexate, and vincristine. 16 Four types of polyurethane and two types of silicone catheters were studied. The alterations differed between each catheter for a specific drug; however, the clinical significance of these alterations is unknown, and more research is needed. The product literature should be studied regarding the use of solutions for cleaning and dissolving drug precipitates. DESIGNS OF VADs

The material used to manufacture the catheter lying in the vein is only one aspect of the entire device. Other features of the catheter need to be

considered, such as the lengths, diameters, lumens available, valves, preattached extensions and hubs, and portal body characteristics.

Length of the Catheter Catheter length may be measured and recorded by the manufacturer in centimeters, inches, or both. Total catheter length may include three sections: (1) length advanced into the vein, (2) the hub or connector, or (3) any portion not intended for insertion into the vein. This information is vital to determine accurate internal volume when managing obstructions from thrombosis or drug precipitate that require instillation of solutions. Additionally, any change in the original external catheter length would indicate that the internal tip location has changed. This is important for midline and PICCs, because these devices are more affected by movement of the extremity. Adequate nursing assessment can only be done if these lengths have been documented after the initial insertion and this information is accessible during the life of the catheter.

Diameter The catheter size may be measured in French or gauge. French size equals the outside diameter of the catheter in millimeters multiplied by three. For instance, a catheter with an outer diameter of 2 mm would be sized 6 French. Gauge measurements were first used to designate the size of wire or needles, usually rigid and cylindrical, and have no mathematical conversion. Gauge may be used to indicate the outer or inner diameter of a catheter and range from 13 to 28, with the smaller number being the largest size. 17 Consideration of the outer diameter of the catheter in relation to the diameter of the vein lumen is crucial, especially for midlines and PICCs inserted through peripheral veins. If the catheter is too large, blood flow around the catheter may be inadequate to dilute the medication being infused, resulting in increased chemical irritation to the vein. Mechanical irritation may be increased because of catheter motion against the vein wall. Internal diameters are important to ascertain the internal volume, flow capabilities, and pressure ratings. The polymer material determines the wall thickness and the inner diameter. Single-lumen catheters usually have a rounded shape of the inner and outer wall, which simplifies measurement for

COMPARISON OF VADs

157

both French and gauge. Although multiple-lumen catheters may have a round outer wall, a crosssectional view reveals separate lumens with a circle, oval, D shape, or kidney shape. Assigning an exact French or gauge measurement to these shapes becomes more difficult. Therefore, flow rates reported by each manufacturer may be a better method of assessment.

Lumens All devices are available with single and double lumens. Tunneled catheters are available with three lumens. Considerations should be given to the flow rates achievable with each lumen, the shape and size of the external hub for securing, and the length of preattached extensions. The configuration of the internal tip of the catheter varies: some have all lumens ending side-by-side or nonstaggered, and others have staggered lumen exit sites. The distance between staggered lumen exit sites range from 0.5 to 2 cm. Plasmapheresis catheters are designed with staggered lumens that have a separation of 2.5 cm. This catheter is designed to have maximum separation and to reduce mixing of processed blood being returned to the patient with the blood being withdrawn for processing (Fig

Fig 1. PermCath Dual Lumen Catheter designed for apheresis and hemodialysis. Note the Dacron cuff nearly halfway down the tubing as well as the staggered lumens. (Reprinted courtesy of Quinton Instrument Co, Seattle, WA.)

1). 18

The concept that multiple-lumen catheters with a staggered tip design offered the best catheter configuration was first studied by using an in vitro venous flow model designed to simulate the circulatory system. Two known incompatible drug therapies, phenytoin and total parenteral nutrition, were administered through the model. Although this study demonstrated that precipitate formed on the lumen exit tips that were nonstaggered, the clinical significance of this phenomenon has yet to be determined, and more research is needed. 19

Valves Implanted ports, tunneled catheters, and PICCs are available with three-way valves close to the internal tip. These valves open outward for infusion and inward for aspiration and are closed when in the neutral position.

Cuffs Cuffs made of Dacron are found on tunneled catheters (Fig 1), ports designed for intraperitoneal and epidural placement, and long-term plasma-

pheresis catheters. They remain in the subcutaneous area several centimeters away from the skin surface. Tissue grows into the collagen cuff, and after several weeks it provides a mechanical barrier to the migration of microorganisms down the path of the catheter and into the vein. Another type of cuff, Vita-cuff (Vitafore Corp, San Carlos, CA), was originally used for short-term central catheters and is now available on tunneled and plasmapheresis catheters. This collagen cuff is impregnated with silver ions, offering a mechanical and chemical barrier in the immediate postinsertion period. The collagen is completely absorbed within several weeks, allowing time for tissue growth into the cuff and providing a long-term barrier.

Portal Body Characteristics of Implantable Ports Portal bodies of implanted ports are available in a wide variety of shapes, sizes, and materials. The portal body contains an internal reservoir covered with a septum made of a dense, resealable material, usually silicone. Located on the posterior side, suturing holes are available to implant the

158

port to the fascia. Close to the floor of the portal body, the catheter is either preattached by the manufacturer or attached at the time of implantation. The shape of ports may be round, square, oval, or hexagonal, and therefore they can be implanted in many different anatomic locations. Materials used in the manufacture of the portal body can be polysulfone, stainless steel, titanium, or a combination. Compatibility of implanted ports with diagnostic imaging methods, such as magnetic resonance imaging (MRI), has been investigated. One recent study of 29 implanted ports composed of titanium, plastic, and several combinations of materials showed that all produce an artifact on MRI. 2° Ports made of stainless steel produce the greatest amount of local or regional image distortions. However, ports constructed of plastic were found to have some image distortions from the silicone septum. Radiologists and MRI technologists may be able to alter the imaging parameters to decrease the distortion when they are aware of the type of port material. A port designed for intraosseus infusion is currently in clinical trials (Osteoport; LifeQuest Medical, Inc, San Antonio, TX), and it varies from other port designs (Fig 2). The portal body contains the same silicone septum with a cone-shaped reservoir. The threaded metal cannula exits from the posterior side of the portal body and is usually placed in the iliac crest. The Osteoport has been used for infusion of analgesics, antineoplastics, antibiotics, fluid, and blood products. Additional investigations are underway to define its role in vascular access. 21 Latest port designs include the OmegaPort (Norfolk Medical, Skokie, IL) (Fig 3), which can be

LYNN C. HADAWAY

Fig 3. Dual-lumen OmegsPort with rounded septum and reservoir. (Reprinted courtesy of Norfolk Medical, Skokie, IL.)

accessed from many angles and has a rounded reservoir to improve the flow. 22 Another unique design is the Cath-Link 20 (Bard Access Systems, Salt Lake City, UT). This device replaces the reservoir with a funnel-shaped port. It has a multilayered silicone septum that can be accessed with any conventional over-the-needle catheter. A 1-inch needle catheter extends through the septum layers and into the lumen of the port catheter, thus eliminating the dead space for collection of residues. 23

Plasmapheresis Catheters Catheters designed for hemodialysis are also used for plasmapheresis. Although plasmapheresis can be performed with two large-gauge, short peripheral catheters, the number of available venipuncture sites and frequency of the procedure may foster the need for a more reliable long-term access. Two types of devices are available: (1) a short-term device constructed of rigid material and (2) a long-term access usually made of silicone elastomer (Fig 1). All are designed with dual lumens, and each lumen may have multiple holes to reduce the recirculation of treated blood. Some manufacturers may refer to the lumen used for blood withdrawal as the arterial side and the lumen used for blood return as the venous side; however, the actual catheter tip location is usually the superior vena cava. Both types of catheters have largebore tubing with a clamp extending from each lumen. VENOUS ANATOMY

Fig 2. Osteoport, designed for intraosseus infusion and currently in clinical trials. (Reprinted courtesy of LifeQuest Medical, Inc, San Antonio, TX.)

It is imperative that the nurse is cognizant of the anatomic position and structure of the major vessels associated with the venous system. Anatomy of the arm and axilla is important for PICC and midline catheter insertion. Understanding the cen-

COMPARISON OF VADs

159

tral venous system assists the nurse in recognizing complications as a result of catheter malposition. 24 Veins located in superficial connective tissue are best suited for venipuncture, because they can easily be palpated and punctured. Deep veins are usually enclosed in a protective sheath with arteries of the same name and lie deep within the muscle. Deep veins are accessed by cutdown rather than percutaneously, and catheters are advanced into these veins from superficial sites. Perforating veins connect superficial veins with deep veins and could be one cause of unanticipated catheter tip locations. The basilic vein begins on the ulnar side of the forearm and moves into the medial aspect of the antecubital area (Fig 4). At this location it is a superficial vein, but it becomes a deep vein above the fold of the arm where it descends beneath the tissue and can no longer be palpated. The basilic vein is the preferred site of insertion for a midline, PICC, or antecubital port because it is the straightest venous pathway to the central system

"..~ Basilic vein Optimal Midline tip placement Cephalic - vein

cephalic vein

/~.'~

IN ]

- - Median cubital vein

Basilic vein

vein

Median antebrachial vein

Fig 4. The superficial veins of the antecubital fossa used for midline cather, PiCC, and antecubital port insertion. (Reprinted with permission of Menlo Care, Inc, Menlo Park, CA.)

and has the largest diameter. At the lateral edge of the chest, the basilic vein becomes the axillary vein. The cephalic vein arises on the radial side of the forearm, ascending the arm on the lateral side of the antecubital region to the shoulder. At the infraclavicular fossa, it becomes a deep vein as it curves to join other veins. At this point the pathway of the cephalic vein can vary greatly, sometimes joining the axillary vein or the external jugular vein or branching into two veins with one branch in each direction. It is for this reason that PICCs may be directed into the jugular network. The diameter of the cephalic vein is not as great as the basilic and is usually considered the last choice for catheter insertion. At the antecubital region, the median cubital network connects the cephalic vein with the basilic and is frequently used for catheter insertion. Careful assessment with a tourniquet may show anatomic variations at this location, with some patients having median antecubital cephalic and median antecubital basilic veins and others have one median cubital vein. A large perforating vein is located beneath the median cubital network connecting to the ulnar and radial veins in the deep tissue. Small, flexible midline catheters of PICCs, especially those without guidewires, could pass through the perforating veins rather than advance up the ann. In the shoulder, the axillary vein extends from the lateral edge of the chest to the lateral edge of the first rib where it becomes the subclavian vein. It continues to the sternal edge of the clavicle where is angles upward as it arches over the rib and under the clavicle (see Fig 4 in the article by Ingle [p 187]). The external jugular vein is superficial, located on the outer border of the neck and joining the subclavian vein. The internal jugular is a deep vein joining the subclavian vein at its proximal end. On each side of the thoracic inlet, the innominate (or brachiocephalic) vein is formed by the merger of the internal jugular and subclavian vein. The left innominate arches over the heart and is approximately 6 cm in length, with the right being approximately 3 cm in length. The two innominate veins unite at the lower border of the first rib to form the superior vena cava, which extends to the lower border of the third rib or third intercostal space. The superior vena cava joins the right atrium on the posterior side of the heart and

160

LYNNC.HADAWAY

on radiograph is seen in the fight mediastinal border.

inches to the proximal end of the upper extremity with the tip level with the axilla yet distal to the shoulder. At this location, the vein diameter, especially that of the basilic vein, is larger than in the hand and forearm and thus will dilute the infused solution with a greater blood flow or hemodilution. In neonatal and pediatric patients, the lower extremity could be used with the catheter tip located in the upper thigh. The catheter tip does not reach the veins beyond the extremity, and radiographic confirmation of tip location is not necessary. ~'25

SITES AND METHODS OF INSERTION

Midline catheters, PICCs, and peripherally implanted ports are inserted into veins of the antecubital region. This site offers several advantages over conventional subclavian or jugular insertions. Veins in the upper extremity can be easily palpated and distended with a tourniquet; successful insertion is not as dependent on patient factors, such as hydration and ability to withstand the Trendelenburg position, and risk of injury to the lungs is diminished.

PICClnser~on

Assessment of the venipuncture site and accurate measurements are key components of PICC placement. The entire extremity should be examined for previous injuries, anomalies, or surgically created changes that might prohibit catheter advancement. Venipuncture sites close to sites of previous phlebitis or infiltration, cellulitis, or other skin disorders should be avoided. The dominant extremity may have more accessible venipuncture sites; however, it may be more difficult if the patient is caring for the catheter. Catheter placement should be avoided in extremities with restricted movement, paralysis, or problems with venous return. Measurement for superior vena cava placement should begin at the selected venipuncture site and follow the venous pathway up the arm, across the shoulder to the fight side of the sternal notch, and then down to the third intercostal space. Several centimeters should be added to this length to allow for taping or suturing of the catheter hub. PICCs are inserted from the antecubital area into the central venous system with the tip residing in the superior vena cava. Other tip locations, such as the innominate, subclavian, and axillary vein, have been used. 26-29 Decisions about catheter tip location should weigh anatomic considerations,

Midline Catheter Insertion

A variety of methods for percutaneous placement of midline catheters and PICCs are available, including over-the-needle; through an introducer, including a break-away needle, peel-away sheath, or regular short peripheral catheter; and Seldinger, which requires the catheter to be advanced after a guidewire has been placed in the vein. Midline catheters may be inserted using an over-the-needle technique with a design similar to a winged needle or "butterfly" (Landmark Midline Catheter; Menlo Care, Inc, Menlo Park, CA, "Landmark" is a registered trademark of Menlo Care, Inc). The venipuncture is made holding the folded wings, and the needle is retracted into the needle safety tube on the external end of the catheter, followed by catheter advancement by pulling a sheath that covers the catheter. This design offers a smaller puncture site, less blood contact, and a protected needle (Fig 5). Some midline catheters may be inserted by a through-the-introducer technique, which is covered in the discussion on PICCs. A midline catheter is advanced for several

Soft, PliableWings ~-~)S NeedleGuard heathTab (~ ~ ] Cannula/Stylet Lock Mechanism Assembly

Fig5.

Peel AwaySheath ,

,

;

Silicone Needle Plig ~ Safety Tube

;

.

Luer lock Catheter Hub

.

.

.

.

.

.

.

.

.

S~let Hub and Wire

Components of the Landmark Midline Catheter with over-the-needle design and needle safety tube. (Reprinted courtesy of Menlo Care, Inc, Menlo Park, CA; "Landmark" is a registered trademark of Menlo Care,

Inc.)

COMPARISON OF VADs

161

such as curvature of the vein and vein diameter; changes in vascular structure resulting from disease or surgery; and physiological factors, such as velocity of blood flow against the type of solution to be given. It is recognized that other tip locations distal to the superior vena cava may not be appropriate for infusing hyperosmolar nutrition solutions, drugs that might lead to tissue necrosis with extravasation, or other hypertonic solutions. 26'28 PICCs are inserted using a through-the-introducer technique. The introducer may be a metal needle designed to break in half or a plastic sheath designed to peel apart. Once the venipuncture is made with the introducer, the PICC is slowly advanced through the distal side of the introducer. Some PICCs have a plastic sheath encasing the catheters thus providing the ability to feel venous obstructions; however, gloved hands do not touch the catheter being inserted. Once the PICC has reached the predetermined tip location, the sheath is removed and the introducer is withdrawn from the vein and peeled apart (Fig 6). This technique creates a larger puncture in the vein, which may cause bleeding around the exit site during the first

~

few hours, necessitating a dressing change. Blood contact is likely during the entire procedure. Personnel protective equipment for catheter insertion includes gowns or aprons, mask with face shield, gloves, and shoe covers. Introducers designed to diminish blood contact during the insertion procedure are currently being studied. Another method of PICC insertion is the use of a short-term peripheral catheter witha stylet. After venipuncture, the stylet is removed, and the PICC is advanced through the short catheter to the desired location. The short catheter is removed by pulling it over the external end of the PICC. This procedure is only possible for PICCs that do not have the hub connector attached by the manufacturer (Groshong PICC). Any excess catheter length is trimmed on the external end, and the hub connector is attached. Some PICCs use the over-wire Seldinger method similar to the method used to insert subclavian catheters (Cook PICC, Cook Critical Care, Bloomington, IN). The venipuncture is made with a needle, and blood is obtained in the syringe. The syringe is detached, and a guidewire is advanced

S-L-O-W-L-Y

Fig 6. Steps in performing venipuncture with a peel-apart Centermark PICC introducer. (Reprinted courtesy of Menlo Care Inc, Menlo Park, CA; "Centermark" is a registered trademark of Menlo Care, Inc.). (A) Begin insertion of the PICC; (B) insert the Centermark into the introducer, and position the PICC shield; (C) slowly advance the PICC through introducer; (D) remove PICC shield from the distal side of the PICC; {E} retract the introducer from the vein; and (F) remove the introducer by peeling it apart.

162

through the needle 5 to 10 cm into the vein. The needle is removed over the wire, and a peel-away sheath introducer is advanced into the vein over the guidewire. The wire is removed, and the catheter is advanced through the sheath. Once the PICC is in position, the sheath is withdrawn and peeled apart.

Tunneled Catheter Insertion Tunneled catheters are surgically inserted and are designed to separate the point of vein entry from the skin exit site. Because of the risk of thrombosis and other serious cardiac complications, it is now recommended that the superior vena cava is the optimal tip location. 7'9 Tunneled catheter insertions use the Seldinger method described above or cutdown techniques that require a surgical incision and subcutaneous resection to reach the vein. The cutdown technique requires more manipulation of the skin and subcutaneous tissue, thus increasing the risk of infection. The insertion site selected may be an axillary, cephalic, or subclavian vein. However, the point of vein entry should be lateral to the junction of the clavicle and the first rib, because the movement of the clavicle could cause compression of the catheter and catheter transection. 3°'3~ Different instruments may be used to create the subcutaneous tunnel, including Kelly forceps, intestinal probes, trocar needles, uterine sounds, or disposable tunnelers. 32 Considerations for instrument selection include the diameter of the tunnel created and the angle at which the catheter must curve to enter the vein. Tunnels larger than the catheter may extend the time required for tissue growth to the cuff, thus increasing the possibility of a tunnel infection. A sharp angle where the catheter crosses the subcutaneous tissue to enter the vein could restrict flow through the catheter lumen. After accessing the vein, the tunnel is created from the vein entry site to the exit site. The catheter is pulled from the skin exit site through the tunnel to the vein entry site. The cuff is properly positioned, and excess catheter length is trimmed. The catheter is then threaded into the vein.

Implanted Port Insertion Insertion techniques for implanted ports vary with the intended catheter location. Venous and arterial placement is done using the Seldinger technique or cutdown technique with the surgically

LYNN C. HADAWAY

created pocket housing the portal body close to this site. Ports for venous access can be implanted in the infraclavicular fossa and in the midarm to upper arm for peripheral ports. The catheter of a peritoneal port is inserted through an umbilical incision and tunneled upward to the point located over the lower rib cage. Epidural catheters are threaded into the epidural space, and the catheter is tunneled anteriorly to the port pocket over the lower rib cage. Placement of the portal body over a bony prominence is necessary to stabilize the port during access. Port bodies should not be placed too deeply under the subcutaneous tissue because palpating and accessing is difficult. The suture line closing the port pocket should not be located over the sept u m . 33,34

Plasmapheresis Catheter Insertion Plasmapheresis catheters are inserted using procedures similar to those described. The rigid catheters designed for short-term use are inserted percutaneously using the Seldinger method. The internal jugular is the preferred site, because it provides a straighter path to the superior vena cava and eliminates the need for the catheter to curve over the first rib at the insertion site. Some researchers have found a high rate of subclavian vein stenosis, and they relate it to the required curve in the catheter as it follows the subclavian vein. 35 The long-term devices are surgically inserted with the same tunneling techniques as other cuffed catheters. OTHER CONSIDERATIONS OF INSERTION

Confirmation of the catheter tip location by a chest radiograph is recommended by the Standards of Practice of the Intravenous Nurses Society, 36 Access Device Guidelines from the Oncology Nursing Society, 37 and the Central Venous Catheter Working Group, 7 which is a professional advisory group to the FDA. Some obtain both an anterior-posterior and lateral view because catheter tip position in the azygos vein can be visualized more easily with the lateral view. 38 The use of external measurement alone as the means of determining tip location may lead to complications if the catheter tip passed into small venous tributaries or one of the jugular veins. The increasing demand for home care services has resulted in some PICCs being inserted in the home where radiology is not

COMPARISON OF VADs

readily available. In this situation, the catheter tip is located in the proximal axillary or subclavian vein; thus, these are called midclavicular catheters. Success has been reported with a unique catheter-locating system (Cath-Finder, available with the P.A.S. Port; Sims Deltec Inc, St. Paul, MN). The antecubitally inserted catheter contains a guidewire with a special sensor in the internal tip. During and after catheter placement, a locator wand is passed over the anticipated tip location. The wand transmits a low-level, high-frequency electromagnetic signal detected by the sensor in the guidewire. A red light and an audible beep is observed when the locator wand is over the internal tip. Several studies report accuracy of the system in predicting tip location by comparison to radiograph examination39"4°; however, an x-ray examination is recommended until larger studies are conducted. 39 A frequently discussed issue is the practice of trimming a PICC or midline catheter to the desired length. The primary concerns include thrombosis formation around an uneven catheter tip and contamination while measuring and trimming the catheter. Most product literature contains some statements about trimming; however, there does not appear to be consensus about the methods. Some manufacturers recommend a blunt cut, whereas others recommend a 45 ° angle. Before trimming, the guidewire inside the lumen of the catheter must be retracted and stabilized in some manner. Any protective sheath should be lifted, and the trim should be made only to the catheter itself. Cutting the sheath and guidewire at the same time may increase the possibility of uneven catheter edges and guidewire damage. Other decisions to be considered include the use of scissors or a scalpel, the accuracy of anatomic measurements to ensure that the catheter length will be accurate, and a method to ensure that the catheter remains intact upon removal. Alternatives to cutting catheters include using securing devices of the excess external length. One PICC (Groshong) is designed to be cut on the external end with the external hub attached after insertion. POSTINSERTION CARE

Immediately after insertion, all catheters should flush easily and have an adequate blood return. If this does not occur, the catheter tip is probably in

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an obstructed position. For a catheter tip outside the superior vena cava, obstruction may be caused by venous valves, scarring, sclerosing, venospasm, or bifurcations. Repositioning the catheter by withdrawing in small segments may be necessary to resolve this problem with PICCs or midline catheters. For midline catheters and PICCs, observe the insertion site and complete venous pathway. For tunneled catheters, observe the venous insertion site, exit site, and tunnel path. For implanted ports, observe the port pocket and suture line. The presence of erythema, edema, drainage, or tenderness should be noted. For any through-the-introducer device, bleeding is anticipated within the first few hours after insertion. For patients with low platelet counts or other alterations in clotting factors, a pressure dressing, application of ice, or elevation of the affected extremity may be required. The size and character of any hematoma and pulses distal to the site should be monitored. After insertion, documentation should include the length and size of catheter inserted and the length of the external portion. Each dressing change should include a measurement of the external amount of catheter. If this external measurement changes, the internal tip location has changed as well. This is especially important for PICCs and midline catheters, because the movement of the arm may cause the catheter to migrate inward or outward. If tip location of a centrally placed catheter is suspected to have changed, a chest radiograph should be obtained followed by an assessment of the patient's vascular access needs to determine whether a device change is needed. At no time can a dislodged portion of any catheter be re-advanced into the vein. VAD REMOVAL

Begin by teaching the patient about the procedure to minimize any anxiety. For percutaneously placed devices, such as PICCs or midline catheters, the dressing should be carefully removed. Scissors should not be used to remove tape or the dressing from any VAD, because the catheter could be accidently cut. The catheter should be slowly and gently withdrawn in short segments, and pressure on the insertion site must be avoided until the entire catheter has been withdrawn from

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the vein. If resistance is encountered as the catheter is withdrawn, force should never be applied with excessive traction, because the catheter could break. Reasons for resistance include venospasm or constriction, phlebitis, valve inflammation, thrombophlebitis, fibrin sheath, and venous thrombosis. If venospasm or constriction are suspected, a dressing should be reapplied and methods initiated to relax the vein, such as applying heat to the vein in the upper arm, axilla, and hand; flushing the catheter with normal saline; keeping the extremity covered and warm; encouraging the patient to drink warm liquids; and applying a tourniquet only if the catheter has been retracted far enough so that pressure will not be applied to a portion of vein where the catheter is still located. Medical intervention with other radiographic techniques, such as a venogram, may be necessary if thrombosis is suspected. In such cases, administration of urokinase, may be required. Removal of ports requires a minor surgical procedure. The port pocket must be incised and the sutures holding the portal body removed, then the catheter can be withdrawn from the vein. Removal of tunneled catheters and long-term cuffed plasmapheresis catheters may be accomplished by two methods. A surgical procedure may be necessary if (1) sutures around the cuff are present or suture information is unknown, (2) tissue/cuff ingrowth is excessive, (3) compression between the clavicle and first rib has caused catheter damage, (4) a tunnel or catheter infection is present or suspected, or (5) when cuff removal is requested for cosmetic reasons. Using local anesthesia, an incision is made, and tissue growth is dissected from the cuff, followed by gentle pulling to remove the cuff and catheter together. An alternative method requires pressure applied for several minutes causing the adhesions to break away from the cuff or the cuff to break away from the catheter. With both methods, pressure may be needed at the vein insertion site to control bleeding. 4~ COST OF VADs

Although no large definitive studies have examined the cost of one type of device versus another, some articles contain cost information. Thomson 42 documented a cost savings of $11,844 in 23 patients or $515 per patient with a midline catheter when compared with the cost of multiple periph-

eral venipunctures. Dwell times ranged from 3 to 51 days, and analysis of costs included other necessary equipment, such as dressing change kits, nursing time, and home visits if applicable. Kyle and Myers 27 listed the average insertion costs, excluding surgeon and anesthesia fees, for PICCs at $265, $1,020 for an implanted port, and $1,155 for a tunneled catheter. Abi-Nader43 reported the cost of PICC insertion at $715 including all supplies, fee for nursing time, chest radiograph, and radiologist fee. Harwood et a144 conducted an indepth analysis of material, labor, and overhead cost for insertions of a peripheral catheter, a midline catheter, and an implanted port. For peripheral catheter insertion, total material, labor, and overhead cost were the lowest at $46.83. Total costs for midline insertion was $95.57; for an implanted port total costs were $1,019.96. The average cost per day to maintain a midline catheter became lower than that for a peripheral catheter by the sixth day of therapy, and the implanted port's cost per day reached the break-even point on the 20th day of therapy. 44 Cost will vary between each institution or agency because of quantity discounts in the purchase of products, the amount and types of supplies used during the insertion procedure, differences in the costs of health care professionals' time (registered nurse v physician), and overhead costs.

NURSING EDUCATION

The insertion of midline catheters and PICCs has become accepted nursing practice in most states. Frequent questions arise about becoming certified to insert these devices. Many catheter manufacturers, professional organizations, and education companies offer a variety of methods to obtain the skills necessary to insert these catheters. However, the use of the term "certified" is misleading, because it does not exist outside the place of employment. The insertion of midline catheters and PICCs by nurses represents an expansion of nursing practice and the employment of new technology. Therefore, it is imperative that each individual health care organization establishes its own criteria for competency with these devices as well as develops policies, procedures, and practice guidelines or protocols. Important aspects to be considered would include identifying the amount and type of experience needed before beginning the learning

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process, participation in some type of learning process to obtain the required knowledge of vascular anatomy, physiology of blood flow, infection control measures, patient assessment, nursing care, and complication management; a method of supervised clinical experience with actual device inser-

tion; and a periodic reassessment of skills. Competency assessment should be a process integrated with the quality improvement process in each organization rather than a rigidly fixed process of skill testing.

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17. Lawson M, Vertenstein MJ: Method for determining the internal volume of central venous catheters. J Intraven Nurs 16:148-155, 1993 18. Thompson L: Central venous catheters for apheresis access. J Clin Apheresis 7:154-157, 1992 19. Collins JL, Lutz RJ: In vitro study of simultaneous infusion of incompatible drugs in multilumen catheters. Heart Lung 20:271-277, 1991 20. Shellock FG, Nogueira M, Morisoli M: MRI and vascular access ports: Ex vivo evaluation of ferromagnetism, heating, and artifacts at 1.5 tesla. J Magn Reson Imaging (in press) 21. Kuhn J, Smith L, Walder A, et al: Initial experience with a new intraosseous infusion device--The Osteoport. Proc Am Soc Clin Oncol 12:439, 1993 (abstr 1517) 22. Deswarte J: Experience with residue in the reservoirs of implanted ports. J Vasc Access Networks 3:16-18, 1993 23. Walker S, Calzone K: Trial results with a new peripherally placed implantable central venous access port. Bard Cath-Link 20 TM NAVAN 1:7-11, 1994 24. Guyton AC (ed): Textbook of Medical Physiology (ed 88). Philadelphia, PA, Saunders, 1991 25. Andrews P: Increased dwell time with the Landmark® Midline Catheter: Clear indication of a technique-related learning curve. J Vasc Access Networks 1:14-20, 1991 26. Brown JM: Peripherally inserted central catheters: Use in home care. J Intraven Nurs 12:144-150, 1989 27. Kyle KS, Myers JS: Peripherally inserted central catheters: Development of a hospital based program. J Intraven Nurs 13:287-290, 1990 28. Masoorli S, Angeles T: PICC lines: The latest home care challenge. RN 90:44-51, 1990 29. Masoorli S, Lingle M: PICC lines: Benefits and complications. Caring Magazine 90:42-44, 1990 30. Aitken DR, Minton JP: The "pinch-off sign": A warning of impending problems with permanent subclavian catheters. Am J Surg 148:633-636, 1984 31. Rubenstein RB, Alberty, RE, Michels LG, et al: Hickman catheter separation. J Parenter Enter Nutr 9:754-757, 1985 32. Waddell BE, Martindale RG: The uterine sound as a convenient, cost-effective method for creating the subcutaneous tunnel for long-term venous catheters. J Parenter Enter Nutr 18:81-82, 1994 33. Viall CD: Daily access of implanted venous ports: Implications for patient education. J lntraven Nurs 13:294-296, 1990 34. Camp-Sorrell D: Implanted ports: Everything you always wanted to know. J Intraven Nurs 15:262-273, 1992 35. Cimochowski GE, Worley E, Rutherford WE, et al: Superiority of the internal jugular over the subclavian access for temporary dialysis. Nephron 54:154-161, 1990

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36. Intravenous Nurses Society: Intravenous nursing standards of practice. J Intraven Nurs 13:$38, 1990 (suppl) 37. Oncology Nursing Society: Module I: Access Device Guidelines: Catheters. Pittsburgh, PA, Oncology Nursing Society, 1989 38. Lum P, Soski M: Management of malpositioned central venous catheters. J Intraven Nurs 12:356-365, 1989 39. Starkhammar H, Bengston M, Kay DA: Cath-Finder catheter tracking system: A new device for positioning of central venous catheters. Early experience from implantation of brachial portal systems. Acta Anaesthesiol Scand 34:296-300, 1990 40. Morris P, Buller R, Kendall S, et al: A peripherally

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implanted permanent central venous access device. Obstet Gynecol 78:1138-1142, 1991 41. Pessa ME, Howard ILl: Complications of HickmanBroviac catheters. Surg Gynecol Obstet 161:257-260, 1985 42. Thomson S: I.V. therapy: A financial feasibility study. Nurs Manage 24:68A-68G, 1993 43. Abi-Nader JA: Peripherally inserted central venous catheters in critical care patients. Heart Lung 22:428-434, 1993 44. Harwood, IR, Greene LM, Kozakowski-Kock JA, et al: New peripherally inserted midline catheter: A better alternative for intravenous antibiotic therapy in patients with cystic fibrosis. Pediatr Pulmonol 12:233-239, 1992