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Vascular Access Devices: Meeting Patients' Needs.

Traditionally, infusion therapy has been managed most commonly by using peripheral catheters, which often mandates repeated venipunctures. Frequently, all peripheral veins may be exhausted before a central venous catheter is even considered. Most clinicians contend that the potential side effects of this approach, such as peripheral phlebitis and infiltration, appear minimal when compared to the risk associated with central catheters. Central venous catheters are often avoided due to the risks of pneumothorax, brachial nerve plexus injuries, and infection. Further, the unavailability of physicians skilled in central device insertion techniques often precludes these procedures. Therefore, only patients receiving long courses of antineoplastic drugs or parenteral nutrition may have an alternative vascular access device (VAD) inserted. Consequently, the nursing staff spend considerable time and resources in initiating multiple peripheral restarts. Patient outcomes include peripheral vein wasting, local tissue damage, and increased pain and costs.

When the choices were limited to short, peripheral catheters or nontunneled central catheters, this approach was adequate. However, multiple types of VAD are now available allowing patients to have the device tailored to their particular need (see Table 1). Increasing patient acuity, prevalence of chronic diseases affecting the vasculature, and complexity of medication regimens now encourage clinicians to limit the use of peripheral catheters and consider alternative devices.
Table 1.
Vascular Access Devices

    VAD Types           Insertion Site            Tip Location

Short Peripheral    Veins of upper and       Close to insertion
                    lower extremities.       site.
                    Jugular veins in neck.

Midline             Basilic, cephalic, or    Upper arm in axilla,
                    median veins of the      distal to
                    antecubital region.      the shoulder.

Midclavicular       Basilic, cephalic, or    Subclavian vein or
(See Limitations    median veins of the      proximal
for Use)            antecubital region.      axillary vein.

Peripherally        Basilic, cephalic, or    Lower superior vena
Inserted Central    median veins of the      cava at 3rd
Catheters (PICC)    antecubital region.      intercostal space,
                                             Neonates and
                                             pediatrics: Inferior
                                             vena cava above
                                             hemidiaphragm when
                                             veins of the lower
                                             extremity are used.

Nontunneled,        Distal subclavian,       Superior vena cava. If
Percutaneous        internal or external     femoral vein is used,
Centrally           jugular, femoral         tip will be in the
Inserted            veins.                   inferior vena cava.

Tunneled            Enters distal            Superior vena cava.
                    subclavian or proximal
                    axillary vein, tun-
                    neled in subcutaneous
                    tissue to exit chest

Implanted Ports     Enters distal            Superior vena cava.
                    subclavian or proximal
                    axillary vein with
                    port pocket close to
                    this location.
                    Antecubital placement
                    same as PICC; also
                    placed in arterial or

                         Indications           Contraindications
    VAD Types              for Use                  for Use

Short Peripheral    IV fluids for            TPN or any solution
                    replacement/hydration,   with a dextrose
                    Most IV medications,     content over 10%.
                    although many cause
                    significant local
                    phlebitis; some cause
                    tissue necrosis if
                    extravasation occurs.

Midline             IV fluids for            TPN or any solution
                    replacement and          with a dextrose
                    hydration. Most IV       content over 10%.
                    medications admixed in   Vesicant medication.
                    an iso-osmotic or near
                    iso-osmotic manner.

Midclavicular       IV fluids for            TPN or any solution
(See Limitations    replacement and hydra-   with a dextrose
for Use)            tion. Most IV            content over 10%.
                    medications admixed in   Continuously infused
                    an iso-osmotic or near   vesicants.
                    iso-osmotic manner.

Peripherally        All types of IV          Anomalies of the
Inserted Central    fluids, medications      central venous
Catheters (PICC)    and nutrition.           structure related to
                                             disease process.
                                             Thromboses of the
                                             innominate, or
                                             superior vena cava.

Nontunneled,        All types of IV          Anomalies of the
Percutaneous        fluids, medications,     central venous
Centrally           and nutrition.           structure.
Inserted            Hemodynamic              Thromboses of the
                    monitoring. Primarily    subclavian,
                    Primarily seen in        innominate, or superi-
                    acute care settings.     or vena cava. Burns,
                                             radiation, surgeries
                                             at insertion site.

Tunneled            Long-term, frequent,     Thromboses of the
                    ongoing need for all     subclavian,
                    types of fluids,         innominate, or superi-
                    medications.             or vena cava. Superior
                                             vena cava syndrome.
                                             Cardiac tamponade.

Implanted Ports     Long-term,               Thromboses of the
                    intermittent need for    subclavian,
                    all types of fluid,      innominate, or superi-
                    medications              or vena cava. Superior
                                             vena cava syndrome.
                                             Cardiac tamponade.

    VAD Types               of Use

Short Peripheral    Changes in peripheral veins
                    related to age, disease
                    process, nutrition or fluid
                    balance status, and previ-
                    ous use.

Midline             Lack of veins in antecubital
                    region related to disease
                    process, nutritional or fluid
                    balance status, surgery or
                    accidents. Inability to
                    advance catheter to pre-
                    ferred tip location related to
                    presence of venous valves,
                    scarring, sclerosing.

Midclavicular       Recently published research
(See Limitations    now pointing to a higher
for Use)            complication rate with this
                    tip location. Should be used
                    ONLY when anatomical and
                    pathophysiological reasons
                    prohibit tip advancement
                    into the SVC. Requires care-
                    ful assessment of all factors
                    such as type and length of
                    therapy, disease process,
                    and medical history.

Peripherally        Lack of peripheral veins due
Inserted Central    to disease, nutritional/fluid
Catheters (PICC)    balance status, surgery,
                    accidents. Inability to
                    advance catheter to SVC
                    due to pathophysiology.

Nontunneled,        Fluid volume deficit.
Percutaneous        Respiratory diseases.
Centrally           Curvatures of the spine.
Inserted            Tracheotomy.

Tunneled            Patient preferences.

Implanted Ports     Patient preferences.

The Intravenous Nurses Society (INS) recently introduced a position paper identifying nurses as the most qualified professionals to select the best VAD for each patient. In this view, nurses with special knowledge and experience in infusion therapy can combine the nursing process with knowledge of treatment modalities, IV delivery systems, and management and prevention of complications to provide quality care.

The Decision Components

Making the best choice of VAD for patients requires nurses to understand the range, characteristics, indications, and benefits of currently available devices. By combining this information with data gathered from a thorough patient assessment, infusion needs, setting, and provider, nurses can select the best VAD for the job.

The best way to begin choosing a VAD is to start with the patient as illustrated in Figure 1. The patient is at the core of a decision model with all information-gathering activities flowing from the center.


The Patient

The primary diagnosis indicates the type of therapy needed but also provides information about the risk factors for catheter-related infection and thrombosis formation. Immuno-suppressed, frail elderly, and pediatric patients up to age 12 months have an increased risk of local or bloodstream infections with the catheter as the source (Perucca et al., 1995a).

Hypercoaguable states may be acquired or congenital. Acquired states include cancer, trauma, surgery, pregnancy, parturition, and the use of oral contraceptives (Bridgen, 1997; Rosendaal, 1997). Congenital hypercoaguable states include antithrombin III deficiency, protein C and protein S deficiencies, and activated protein C resistance (Bertina, 1997; Bridgen, 1997). At present, the connection between congenital conditions and the presence of VAD-related thrombosis is unknown. However, it is prudent to know if these conditions are present in patients requiring infusion therapy. Other factors adding to the risk of thrombosis include trauma to the vein wall on catheter advancement, and nutritional and fluid imbalances.

The medical history should be checked for information regarding allergies to medications, food, and other substances. Many solutions and supplies used in conjunction with VAD insertion and management produce allergic reactions. Latex is found in the tourniquet, tubing, syringes, and injection caps. Allergies to tropical fruit such as kiwi, avocados, and bananas may indicate a cross-sensitivity to latex (Jackson, 1995). Iodine allergies indicate the need to eliminate povidone-iodine in skin preparation processes. When signs and symptoms of hypersensitivity begin immediately after VAD insertion, it is easy to assume a reaction to the catheter polymer or plastic. Attempts to produce an immune response from these synthetic polymers have produced minimal reaction, although natural proteins such as latex easily produce immunoglobulin E (Black, 1992; Leung, Halpern, & Gerswhin, 1993).

The patient's history of the number and type of previous VADs can indicate the likelihood of vasovagal reactions, stenosis, and hyperplasia in vein walls. Patients with a positive history of vasovagal reactions are 7.5 times more likely to have a reaction during venipuncture (Pavlin, Links, Rapp, & Nessly, 1993). Extremities used for dialysis grafts or fistulas, and those affected by previous mastectomies or paralysis should not be used for midline or peripherally inserted central catheters (PICC) (Perucca, 1995b). Stenosis and hyperplasia result in a narrow vein lumen. This makes catheter advancement more difficult and creates areas of poor blood flow leading to thrombosis.

Patients' personal preference is one of the most important factors to consider when choosing a VAD. For long-term therapies, patients must integrate the VAD care and therapy infusion into their lifestyle. Success with the solution infusion, reduction of VAD complications, and compliance with care regimens will improve if patients are involved in the decision. Other social factors include their support system within the family and significant others. Will there be an extra pair of hands to manage the therapy? What visual and manual dexterity problems does the patient have?

The Therapy

The number and type of medications and solutions given by intravenous infusion are constantly increasing. The typical nursing information includes the dose and frequency, indications, contraindications, and side effects. Infusion therapy requires close communication with the pharmacist to obtain information about the final admixture of each infusate. This includes the solution used for dilution, osmolarity, and pH of the final admixture. Midline catheters should only be used for solutions that are iso-osmotic or near isoosmotic, usually less than 500 mOsm/L with a pH between 5 and 9.

Viscosity and temperature are factors associated with blood transfusions and solutions with high dextrose content. Blood will run slower through longer lines such as PICCs. This may warrant the infusion of blood through a short peripheral catheter to ensure infusion within the time limits. Rate of infusion and the volume of infusion will determine the size of the lumens used for infusion. Manufacturers' package inserts provide maximum rates achievable with each device.

Many medications can irritate tissue and others, known as vesicants, will produce local tissue damage if they escape from the vein into surrounding tissue. While infiltration is usually associated with peripheral catheters, this complication can occur at the insertion site of a nontunneled percutaneous catheter, the venotomy end of a tunneled catheter, and an implanted port pocket (Ingle, 1995; Mayo & Pearson, 1995).

The anticipated length of therapy is a critical factor in choosing the appropriate VAD. While there are no strict standards of practice, guidelines indicate that short peripheral catheters are useful when the therapy will last up to 1 week. Midline catheters are useful for therapies lasting 2 to 4 weeks and PICCs for up to 1 year (INS, 1997a, b, & c).

Questions about length of therapy are inevitably linked to questions about how long each device should be allowed to remain in place, although these should be treated as separate issues. Studies have lead to standards of practice and guidelines establishing that short peripheral catheters should be changed every 48 to 72 hours (INS, 1998; Pearson, 1996). In "Guidelines for Prevention of Intravascular Device-Related Infections," written by a Centers for Disease Control advisory group, no recommendations were made for the replacement for midlines, PICCs, nontunneled percutaneous, tunneled catheters, or implanted ports (Pearson, 1996).

Multiple medications and complex regimens require access to routinely updated compatibility information. Incompatibility is defined as a "physiochemical phenomena" and is seen as precipitation, haziness, color or viscosity changes, or gas formation (Trissel, 1996). Compatibility studies are performed and published after new medications are introduced; thus this body of knowledge changes constantly. Frequent combinations include parenteral nutrition and antibiotics, antineoplastic regimens and pain management, thrombolytic agents and antibiotics, bronchodilators and steroids, vasopressors, and numerous medications. Multiple therapies may be managed by close attention to timing doses, simultaneous administration by piggybacking into injection sites, admixture in common fluid containers, or infusion into separate lumens or VADs. Catheter lumen occlusion, infusion of particulate matter, and ineffective therapies can be the outcome when proper attention is not given to assessing medication compatibility.

The Health Care Workers

Knowledge, skill, attitude, and availability are the key criteria influencing which VADs can and should be offered to patients in health care settings. Many facilities have initiated programs where nurses with appropriate skills and knowledge insert midline catheters and PICCs. Advanced practice nurses are involved in practice partnerships with interventional radiologists and are inserting tunneled catheters and implanted ports.

If not managed appropriately, a nurse-inserted PICC program may be viewed as encroaching on medical practice. Good communication, confidence in the expertise of each professional, and mutual respect for the contribution of each discipline are key factors in a successful VAD service. These programs can be managed in ways that not only benefit the involved professional, but more important, patients.

Early intervention by the vascular team can eliminate the vicious cycle of peripheral venipuncture, failed sites, and repeated venipuncture. Failed peripheral sites result in missed medication doses, altered medication blood levels, and poor clinical responses. These problems are avoided when skilled professionals are available to insert the appropriate catheter and meet patients' needs when they are identified. Patient assessment should occur early in the course of treatment before the need becomes critical.

For patients to be active partners in choosing and caring for VADs, health care professionals must facilitate learning. This involves choosing appropriate teaching strategies for individual learning styles, use of demonstration catheters and anatomical models, and written materials appropriate for each age and educational level. While the time to facilitate this learning is often limited, the learning technologies such as videos, close circuit TV, and computer-based education can be used to deal with the ever-present time limitations.

VAD Characteristics

Plastics or polymers used to make catheters include Teflon[R], polyurethane, and silicone elastomer. Teflon (Dupont, Wilmington, DE) is used to make short peripheral catheters. It forms a stiff plastic tube and remains stiff inside the vein. Polyurethanes (Ocrilon[R], Johnson & Johnson Medical, Inc. and Vialon[R], Becton-Dickinson, Inc.) are a large group of polymers ranging from stiff to soft. After insertion, poly-urethanes respond to body heat by becoming softer. Due to its ability to tolerate greater pressures, thin wall catheter construction is possible. This allows for smaller outer and inner catheter diameters without sacrificing flow rates. Silicone elastomer is a soft material that reduces the potential for irritation and perforation but sacrifices ease of insertion. Different mechanical properties require thicker wall construction to achieve mechanical strength, resulting in larger lumen size (Hadaway, 1995; Maki & Ringer, 1991).

The outer diameter is defined as the catheter width from the outer surface of one wall through the center to the outer surface of the opposite wall This measurement is important to determine if the catheter is appropriate for the lumen of the vein. Lumen or internal diameter is the width from one inside wall to the opposite inside wall. This measurement is only applicable when the catheter lumen is circular. Multiple lumen catheters may have lumens shaped as an oval, eclipse, or D. Internal diameter affects the internal catheter volume, flow rate, and pressure rating (Lawson & Vertenstein, 1993).

VAD sizes are expressed in gauge, millimeter, and French size, although the latter only applies to the outer diameter. Millimeter measurements are the same as the outer diameter measurement. French size is the millimeter measurement multiplied by three (for example, an outside diameter of 3 mm is a 9 French catheter) and applies only to the outer dimension. Gauge size was originally used to measure wire and needle size but is also used for catheter size. It usually refers to the outer diameter, but can be used to denote the internal diameter (Lawson & Vertenstein, 1993).

The gauge size of a noncircular lumen is determined by measuring the cross-sectional surface area. The gauge size of a circular lumen with the same surface area is then chosen for the product label (Lawson &Vertenstein, 1993).

The number of lumens required is determined by the number and types of therapies to be infused. Single, double, and triple lumens are common; however, multiple lumens present an increased risk of infection because of multiple manipulations. The increased potential for infection must be weighed against the need for complex therapies and the potential for incompatibilities.

PICC, midline, and tunneled catheters are now available with valves located in two places -- on the internal end of the catheter (Groshong[R], Bard Access Systems, Inc.) and inside the catheter hub (Clampless Valved Catheter[R] Catheter Innovations, Inc.). Both types have pressure-sensitive valves that allow for infusion and aspiration and remain closed when no positive or negative pressure is applied. Both types have instructions for flushing with saline only, eliminating heparin flush solutions and decreasing the risk of air emboli.

External and internal catheter configurations vary. Multiple lumen catheters are designed with staggered and nonstaggered lumen exit ports. Staggered exit ports mean that fluid flows from each lumen at different points. Nonstaggered exit ports mean that fluid flows from each lumen at the same point. The clinical significance of staggered exit ports has not been firmly established. Important considerations include the vein diameter and volume of blood flow at the tip location, the position of the tip inside the vein, and the rate and concentration of incompatible infusates. When lumens are staggered, some brands may have staggered external pigtails and some may not.

There are three methods of VAD insertions: over-the-needle, through-the-introducer, and Selnger technique. Short peripheral catheters are designed over-the-needle. PICC and midline catheters are inserted with a through-the-introducer process. The introducer may be a break-away needle or peel-away sheath. Break-away needle methods can result in catheter damage on insertion, resulting in catheter breakage and possible emboli during the dwell time or removal of the device. PICCs and other percutaneous nontunneled central catheters can be inserted with the Seldinger technique. This method involves venipuncture with a small needle; inserting a guidewire facilitating removal of the needle; enlarging the puncture site with a vessel dilator or scalpel blade; followed by threading the catheter over the guidewire. Tunneled catheters and implanted ports combine the Seldinger technique for vein entry with surgical techniques to create the tunnel or port pocket.

Manufacturer information may be confusing because of the terms "distal" and "proximal." These terms indicate a relationship to a central point. Design engineers identify themselves as the central point of reference, while health care professionals use the patient as the central point. To engineers, distal refers to the catheter end inserted into the patient and proximal refers to the external end. Health care professionals usually reverse these terms, indicating the proximal end as the one closest to the center of the patient.

Research studies of outcomes from catheter tip locations are demonstrating that the lowest risk of thrombosis is seen when the superior vena cava (SVC) is used. Catheter tip locations in the mid-clavicular locations (innominate, subclavian, or proximal axillary veins) are associated with a 60% to 62% incidence of thrombosis, while SVC tip locations have only a 16% to 21% incidence (Brown-Smith, Stoner, & Barley, 1990; Kearns, Coleman, & Wehner, 1996). A new position paper from the National Association of Vascular Access Networks (NAVAN) supports the use of the superior vena cava as the preferred catheter tip location. Midclavicular tip locations should only be considered when anatomical or pathophysiologic conditions prohibit advancement into the SVC. This may include surgically created changes, chest tumors, and superior vena cava syndrome (NAVAN, 1998).

A Proactive Approach

Early patient assessment and insertion of the appropriate VAD requires a high level of expertise in this special body of knowledge and a collaborative practice environment including nurses, physicians, and pharmacists. With this approach, patients benefit by experiencing decreased pain and complications. Health care providers benefit through a better use of human resources and products. Payers benefit by decreased costs.

A recent study from a children's hospital tracked data on numbers and costs of peripheral venipuncture attempts by staff RNs, physicians, and an IV nurse clinician. For a 2-week period the cost of labor and materials for unsuccessful attempted IV insertions was $10,392 in a total of 656 attempts. Physician attempts resulted in the lowest success rate with 321 unsuccessful attempts out of 416; staff RNs had 111 unsuccessful attempts out of 197; and the IV nurse clinician had one unsuccessful attempt out of 43. The number of attempts for the IV nurse clinician was low relative to the other providers because this clinician was called only for the most difficult insertions. An estimated annual loss of $270,192 resulted from these unsuccessful venipuncture attempts (Frey, 1998).

Another study compared the cost of midline catheters with the cost of multiple peripheral venipunctures to deliver a complete course of therapy in 23 patients. By analyzing the frequency and cost of peripheral venipunctures prior to inserting the midline catheter, the authors projected the cost if peripheral venipunctures had been used to deliver the entire course of therapy. These projected cost were compared to the cost of insertion and care of the midline catheter. By using the midline catheters, the authors reported a cost savings of $11,844 or an average age of $515 per patient (Thomson, 1993).

More controlled studies analyzing cost are needed. However, each facility can examine their cost of providing vascular access. Are repeated peripheral venipunctures used when a midline catheter would have been a better choice? Are tunneled catheters used when a PICC would have been less traumatic and cheaper? The current emphasis on cost containment demands a close examination of all costs related to vascular access including the device, supplies and equipment needed for insertion, and the labor cost of insertion and management. Assessment by knowledgeable nursing clinicians functioning in a consultative role, followed by insertion of the most appropriate VAD by the expert health care professional, decreases total cost of infusion therapy.

Patients have a wide variety of needs; therefore, an extensive array of VADs are needed to meet those needs. However, changing traditional ideas and practices are not easy tasks. The amount of information needed to make the most appropriate choice demands a collaborative practice environment with good communication among all disciplines. This will require individual and organizational change.


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Lynn C. Hadaway, MEd, RN,C, CRNI, is Principal, Hadaway and Associates, Milner, GA.3
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Author:Hadaway, Lynn C.
Publication:MedSurg Nursing
Date:Oct 1, 1999
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