- Email: [email protected]
Selection of vascular access devices and nursing care
Selection of Vascular Access Devices and Nursing Care Mary Nell Winslow, Lindsey Trammell, and Dawn Camp-Sorrell
Objective: To provide an overview of the patient selection criteria for a vascular access device (VAD) and its maintenance care. Conclusions: The availability of different types of devices has led to confusion on the part of many health care professionals as to which device is the best for their purpose. Selecting the appropriate VAD is an interdisciplinary decision based on patient characteristics, type of therapy, support system availability, and cost. Numerous controversial issues surround the care of VADs, and research results have not yet resolved these practice issues. Although various procedures are used throughout the country, it can be reasonably concluded that the fun-
damental requirement for successful maintenance of a VAD is strict adherence to established care protocols. Implications for nursing practice: Assessment of the need for a VAD is an ongoing process. Nurses are in a perfect position to assess the factors that precede device selection, including the frequency of access, type of intravenous therapy, and the condition of the patient's peripheral veins. The vast array of devices demands specialized knowledge in selecting the appropriate VAD, providing correct care, and evaluating the device once inserted or implanted.
A
tion and with repeated movement within the vessel. Polyurethane is a firmer material that allows for ease of insertion and then softens on contact with bodily fluids, thus preventing vessel damage. All VADs have impregnated radiopaque material to allow for easy visualization during radiographic and fluoroscopic examination. Generally, VADs have an open distal tip except for the Groshong catheter, which has a closed distal tip with a threeway valve. 2 A further description of VAD designs and insertion techniques can be reviewed in the article by Hadaway elsewhere in this issue.
TREMENDOUS increase in the availability of vascular access devices (VADs) has occurred in the past two decades. This development has been necessitated by the increase in patients requiring complex intravenous (IV) therapies in the hospital as well as alternative settings. Consequently, this mass production of quality VADs has led to a cumbersome process in selecting the best device for which the subsequent care may be controversial. Selecting the appropriate device is an interdisciplinary decision based on device design, patient characteristics, type of therapy, available support systems, and cost. This article reviews the various VADs available, patient selection criteria, and the maintenance care for each device. OVERVIEW OF VADs
Three major categories of long-term VADs are (1) tunneled catheters, (2) peripherally inserted central catheters (PICCs), and (3) implanted ports. Although VADs vary in design, all types can be used for blood withdrawal, blood product administration, and long-term IV therapy. The distal tip of the VAD's catheter lies in the superior vena cava, above the right atrium. Immediately after implantation and confirmation of placement, the device can be used for IV therapy. VAD catheters are composed of silicone or polyurethane material with a variety of intemai and outer diameters available. Silicone does not change after manipulation and is the most flexible material identified.1 Therefore, it is less likely to be damaging to the vasculature both during inserSeminars in Oncology Nursing, Vol 11, No 3 (August), 1995: pp 167-173
Copyright © 1995 by W.B. Saunders Company
SELECTION OF VADs
The vast array of VADs demands specialized knowledge in selecting the appropriate device, providing correct care, and evaluating the device once in place. Assessment of the need for a VAD is an ongoing process and nurses are in the perfect position to assess the factors that precede selecFrom the University of Alabama and Hospital at Birmingham, Birmingham, AL. Mary Nell Winslow, MSN, RN, OCN: Nurse Practitioner, Internal Medicine, Kirklin Clinic, University of Alabama at Birmingham; LindseyTrammell, MSN, RN, OCN: Oncology Clinical Nurse Specialist, Comprehensive Cancer Center, University of Alabama at Birmingham; and Dawn Camp-Son'ell, MSN, RN, FNP, OCN: Oncology Nurse Practitioner, University of Alabama Hospital at Birmingham. Address reprint requests to Mary Nell Winslow, MSN, RN, OCN, 2253 Chapel Rd, Birmingham, AL 35226. Copyright © 1995 by W.B. Saunders Company 0749-2081/95/1103-000355.00/0
167
168
WlNSLOW, TRAMMELL, AND CAMP-SORRELL
tion. 3 Ideally, selection is based on input from the patient, significant other, nurse, physician, and surgeon. This multidisciplinary approach permits consideration of the different types of devices and addresses the patient's needs. Although the optimal timing of VAD insertion is before the initiation of therapy, established criteria for selecting the best VAD are not available. Generally, patients requiring intensive IV therapy for more than 3 months benefit from placement of a VAD. PICCs are predominantly used in patients requiring several weeks or months of IV therapy, whereas ports and tunneled catheters are usually selected for treatment lasting longer than 6 months. Overall advantages and disadvantages of VADs must be considered when selecting a device (Table 1). Other factors to consider include the VAD design, type of therapy, patient's self-care ability, cost, and maintenance care.
VAD Designs The length and gauge of the catheter must be considered when selecting the appropriate device. Higher flow rates, easier blood withdrawal for sampling, and increased accuracy in evaluating central venous pressures are possible with larger
gauge catheters. Smaller gauge catheters are available for pediatric or elderly patients with small fragile veins. Multiple lumens are available for patients requiring multiple blood withdrawals or simultaneous IV therapies. Different VAD designs are available to meet the patient's needs. Tunneled catheters. The Broviac catheter, the first tunneled device, appeared on the market in 1975 for the administration of hyperalimentation, and the Hickman catheter followed in 1979. 4,5 Both are similar in design; however, the Hickman catheter has a larger gauge. Tunneled catheters are available with single, double, or triple lumens to meet various therapeutic needs. Tunneled catheters require placement in an operative suite; therefore, patients who are unstable to undergo surgery are not candidates. Tunneled catheters are selected for patients undergoing aggressive IV treatment, such as bone marrow transplants, that require the need for multiple lumens. Additionally, patients who experience prolonged myelosuppression will benefit from a tunneled catheter because a needle is not left in place through the skin, which increases the chance for infection or bleeding. Tunneled catheters are not the best device for patients with cachexia, inadequate neck veins, or
Table 1. Advantages and Disadvantages of VADs Type of VAD
Advantages
Disadvantages
PICCs
No danger of chest injury on insertion Economical placement Easy to remove RN can insert No puncturing of skin after insertion Not a surgical procedure to place External portion can be repaired Dual lumens available
Restricts activities Body image affected Difficult to perform self-care Routine daily to weekly maintenance May not be sutured to anchor May collapse with blood withdrawal Must have occlusive dressing in place at all times
Tunneled catheters
Tunnel with Dacron cuff to anchor in subcutaneous tissue Can be used for central venous pressure monitoring No puncturing of the skin after placement Triple-lumen catheter available External portion can be repaired Additional antimicrobial cuff available Easy to remove
Requires physician to place May require physician to remove Surgical procedure for placement Daily to weekly site care Body image may be affected Restricts some activities Higher maintenance requirements
Implanted ports
Double lumen available Minimal maintenance care Minimal interference with activities Body image less affected
Requires physician to place Requires physician to remove Surgical procedure for placement Higher initial cost Requires puncturing of the skin to access Can interfere with MRI, CT scan, or radiation procedures
Abbreviations: RN, registered nurse.
SELECTION OF VADs
open chest wound. The patient's body image can be affected, because the external portion of the catheter is a constant reminder of his or her illness. The patient and/or significant other must be able to provide dally to weekly catheter care. Implanted ports. Implanted ports of various designs have been available since the 1980s. 6 Basically, the device is composed of a portal body and a catheter to access the venous, arterial, peritoneal, or epidural body systems. Double-lumen ports are available for the administration of simultaneous IV therapy. Most ports are accessed from the top; some may be accessed from the side; and others are domed, allowing access from either side or the top. Antecubital ports are implanted peripherally. Implanted ports require minimal care and flushing; therefore, they are a suitable selection for the elderly who have poor visual acuity, poor manual dexterity, or no significant other to assist with care. When patient compliance is questionable, port placement is the best selection. Excellent candidates for a port include patients receiving IV chemotherapy that will not cause prolonged myelosuppression or need triple lumens. On the other hand, patients undergoing treatments that cause prolonged myelosuppression, such as bone marrow transplants, are not good candidates because of the potential for bleeding or infection at the needle insertion site. Only a small bump reveals the port's location; therefore, an external portion is not exposed to remind patients of their diseases or to affect their body images. In addition, because the port is completely under the skin, activities are not restricted; thus, children are excellent candidates. Port placement is not recommended for patients in whom there will be difficulty in accessing or when there is limited area available on the anterior chest wall, such as obese patients and patients with chest wall radiation fibrosis, cachexia, opened chest wounds, or a mastectomy site. 2 At present, there are no specific indications for when to insert an antecubital port. This device may be inserted to meet short-term or long-term therapeutic needs. Some patients prefer a PICC or tunneled catheter because of their fear of needles or pain associated with port access. PICCs. The PICC is a long-term device that is inserted by a trained registered nurse. Since the introduction of the PICC, adaptations to the design have made it ideal for the elderly as well as the
169
young. 7 PICCs are not as effective for rapid, largevolume infusions, and small-gauge PICCs are not recommended for blood sampling because of the potential for the catheter to collapse. PICCs are a good selection for the patient who has had chest injury, radical neck dissection, radiation fibrosis to the chest, fungating chest tumor, neck veins that cannot be cannulated, patients who are malnourished, or patients who are physically unstable to undergo a surgical procedure. Adequate peripheral veins, such as the cephalic or basilic, are necessary for PICC insertion. PICCs require daily care, and a second person may need to be present to assist with daily care. Body image can be affected, and activities are restricted with PICCs, because the exit site is in the antecubital area. Because a PICC is not tunneled and may not be sutured, an occlusive dressing is required over the exit site at all times to prevent dislodgement. For patients who participate in frequent exercise or strenuous manual work or who have active children, a PICC may not be the best device because of the risk for dislodgement or limitation in mobility of the upper extremity.
Type of Intravenous Therapy VADs are appropriate selections for bolus, intermittent, or continuous infusions. However, special circumstances must be considered to ensure delivery of drug therapy and patient safety. For example, implantable ports require a right-angle, noncoring needle with an occlusive dressing during continuous infusion to prevent needle dislodgement. With a tunneled catheter or PICC, the infusion can be connected directly to the catheter hub, thus decreasing the risk for accidental disconnection. For continuous administration of a vesicant, a P1CC or tunneled catheter may be the best selection if the patient is active, because movement could dislodge the needle from the port.
Self-Care Ability A crucial consideration when treatment is administered in the outpatient or home setting is the patient's self-care ability or the availability of family members to care for the VAD. With the increase in health care delivery in the outpatient setting, VAD care is no longer the responsibility of the nurse. This responsibility has changed to the patient or family. Self-care elements to be considered include competency level, manual dexterity, visual acuity, home environment, and caregiver
170
WINSLOW, TRAMMELL, AND CAMP-SORRELL
support. Often, implantable ports are used with pediatric and elderly patients, because the port requires minimal care. A deliberate and diligent nursing assessment of each factor will facilitate the most appropriate VAD choice for the individual patient.
Cost The current climate of cost containment and health care reform has required that all health care providers closely examine dollars spent while ensuring quality patient care. McCready et al s compared the cost and durability of implanted devices versus nontunneled percutaneous devices. The initial insertion expense of the nontunneled device was less than the port; however, when the device was used longer than 6 months, the port was more economical when maintenance costs were evaluated. In contrast, nontunneled percutaneous devices are less expensive to insert; however, they are more expensive to maintain and replace as necessary. 9 Unfortunately, few references are available that provide in-depth analysis of costs related to VAD placement and maintenance. Insertion cost is based on the type of device, insertion kit, and the area of placement, ie, the operating room versus the clinic. 8'1° See the article by Hadaway elsewhere in this issue for a discussion of insertion-costs. Maintenance care is based
on the type of protocol that is being performed, such as the type of dressing, frequency of dressing change, type of flush, frequency of flush, type of injection cap, and frequency of cap changes. For example, the cost for maintaining a single-lumen tunneled catheter with a transparent dressing changed every 5 days and flushed with heparin solution daily would range from $40 to $150/ month. MAINTENANCE CARE
Care of VADs includes flushing, accessing, blood withdrawals, dressing changes, clamping techniques, and cap changes (Table 2). Although various procedures are used throughout the country, it can be reasonably concluded that successful VAD maintenance is the result of strict adherence to established protocols. Because the research literature does not provide definitive measures for care, and controversial issues remain, oncology nurses are accountable for reviewing the literature for the latest research findings. The Oncology Nursing Society II and the Intravenous Nursing Society ~2 provide recommendations for VAD care based on clinical and scientific evidence that can be used to develop standardized procedures.
Flushing Regardless of the VAD type, routine flushing is required at designated intervals to cleanse the in-
Table 2. Care of VADs
VAD
Flushing Routine*
Bolus Flushing
Tunneled catheters
1 mL to 3 rnL daily to weekly with HS** Maintain positive pressure
Before and after reed with 5 mL of compatible solution
PICCs
1 mL to 2 mL daily with HS** Maintain positive pressure
As above
Ports
2.5 to 5 mL of HS** every 8 hours
As above
Abbreviations: HS, heparin solution; NS, normal saline. * Flush all lumens. ** Groshong catheters use 5 mL of NS flush weekly.
Dressing/Cap Changes Remove old dressing Use aseptic technique Inspect site Cleanse site from catheter outward Cover site with occlusive dressing Change injection caps every 5-7 days As above plus Pull old dressing upward to remove If skin closure dressings are used, change during dressing change As above
Blood Withdrawal (Discard Method) Withdraw 3-5 mL of blood and discard Withdraw blood samples Flush with 5 to 10 mL of NS, then HS or resume fluids
SELECTION OF VADs
ternal diameter of the catheter from fibrin build-up and debri. Compatible flushes of 5 to 10 mL should be used before and after administering drugs or withdrawing and administering blood products to cleanse the catheter. Solutions used to cleanse the catheter include heparin sodium, sodium chloride, and urokinase. Heparin sodium inhibits the conversion of prothrombin to thrombin and fibrinogen to fibrin, thus inhibiting fibrin build-up. Various heparin concentrations, 10 U/mL to 1,000 U/mL, have been used for flushing with the most common concentration being 100 U/mL. IL13 Sodium chloride is an aqueous fluid having approximately the same osmotic pressure and composition as extracellular fluid, which cleanses the internal catheter. Urokinase converts plasminogen to plasmin, which dissolves fibrin or clot formation. 14 Excessive force should never be used when flushing a VAD. The syringe size directly affects the amount of pressure created by the force of the plunger, ie, the smaller the syringe, the greater the pressure on pounds per square inch. High pressure may damage the catheter; therefore, syringes less than 3 mL are avoided. 15 The type of solution, volume, and frequency of flush continues to he an area of controversy. :3"19 Randomized prospective studies examining the relationship of the type of device, patient characteristics, patency, infection occurrence, and cost are necessary to standardize flushing protocols.
Accessing Injection ports and luer junctions are cleansed before accessing to prevent introduction of microorganisms. Implanted ports are accessed aseptically with a noncoring needle after appropriate skin preparation. Gloves are worn during the procedure, but in some cases, particularly with immunosuppressed patients, masks and gowns may also be used. 2° Because accessing a port requires a needle stick, a local anesthetic may be used to decrease the pain associated with needle insertion. Once the port has been located by palpation, the needle and extension tubing, primed with fluid, are inserted perpendicularly through the skin into the reservoir against the port backing (needle stop). Once the port is accessed, the needle should not be rocked or tilted to avoid damage to the septum. After access, the needle is secured to the skin, and an occlusive dressing is applied. 21 When deaccess-
171
ing a VAD, positive pressure is maintained on the syringe barrel to prevent reflux of blood into the catheter.
Blood Withdrawals Several techniques can be used to obtain blood samples, including discarding, reinfusing, mixing, or using a vacutainer or a syringe. The most commonly reported procedure in the adult population is the discard method. 22 Blood is withdrawn, the sample is collected, and the VAD is flushed with normal saline. The amount discarded varies from 3 to 10 mL. With the reinfusion method, the discard or first sample collected is reinfused into the patient after the sample is obtained. This method is commonly used in neonates and children to prevent a decrease in blood volume. 23 In the mixing method, blood is withdrawn and immediately reinfused into the patient. After repeating this procedure up to four times without removing the syringe, the blood sample is collected. 23 The purpose is to dilute the heparin or saline flush before taking a sample. Vacutainers can be used by inserting into the injection cap on the catheter hub, which reduces the risk of inadvertent needle sticks and blood contamination. However, vacutainers may not be possible with PICCs or the Groshong because the pressure within the collecting tube may collapse the catheter. 2 A syringe can be attached directly to the catheter hub or through an injection cap to obtain a sample; however, the likelihood of needle sticks and blood contamination is increased. If the VAD is connected to an infusion, all infusions are discontinued for at least 1 minute before drawing a sample. If any samples appear grossly inaccurate, the blood sample should be redrawn through a peripheral site. 11'24'25 Because heparin adheres to the internal catheter lumen, blood for coagulation studies is drawn peripherally unless the VAD is maintained with normal saline. Aminoglycoside levels can also be erroneous when collected from a VAD. 25 However, some institutions draw coagulation or drug levels after other blood samples are obtained or after discarding 10 mL or more of blood. Another alternative is obtaining a peripheral sample by finger lancet or collection tube technique. 24
Dressing Changes Exit site care and dressing changes are necessary to control infection and assess the surrounding
172
area. The technique includes cleansing the skin at the exit site outwardly and applying a dressing. Few studies have compared the efficacy of cleansing agents alone in VAD c a r e . 26'27 Cleansing agents used include alcohol, iodophors, chlorhexidene gluconate, and hydrogen peroxide, n Alcohol is effective against most gram-positive and gram-negative organisms as well as many fungi and viruses. Concentrations between 70% and 92% provide a rapid reduction in microbial counts on the skin; however, no residual effect is seen. 26'27 Iodophors are complexes that have a wide range of activity against gram-positive and gram-negative bacteria as well as tubercle bacillus, fungi, and viruses. Povidone-iodine (10%) is the most commonly used agent and has a minimal residual effect before drying. Chlorhexidene gluconate is more effective against gram-positive bacteria than gram-negative bacteria, viruses, and fungi. Chlorhexidene has a strong affinity for the skin and remains chemically active for up to 6 hours after application. Hydrogen peroxide is an effective cleansing agent against bacteria, but it interferes with tissue granulation and should be avoided. However, crusted exudates can be easily removed with half-strength peroxide and normal saline. The use of ointments after cleansing the exit site is controversial. Antimicrobial ointment, such as iodophor, is a semisolid preparation that prevents pathogenic action of microbes. An antibiotic ointment, such as neomycin, destroys or inhibits the growth of microorganisms. The value of using an antimicrobial ointment lacks evidence supporting its use in preventing infection. The occurrence of Candida species colonization with the use of a polymicrobial ointment has been demonstrated. 28'29 The Center for Prevention and Disease Control recommends that the dressing be changed every 48 hours if ointments are used. 3° Current data both support and dispute the use of gauze and transparent dressings.31-36 Mixed results have been obtained when investigators, using both retrospective and prospective designs, compared the effectiveness of these two dressing types. Until prospective, multisite randomized studies are conducted in which cleansing protocols, dressing protocol, type of dressing, type of device, patient characteristics, and the educational component of personnel applying the dressing are all studied, it will be difficult to determine which type of dressing reduces the infection rate. Gauze dressings are made of mesh material that
WINSLOW, TRAMMELL, AND CAMP-SORRELL
provides no occlusive barrier; however, they act as a sponge and are secured in place by tape. These dressings should be changed every 48 hours. 3° Transparent dressings are semipermeable film with a significant moisture vapor rate that allows for visualization of the exit site while providing a barrier to extrinsic liquids and microorganisms. These dressings are changed every 5 to 7 days. 3° When gauze is placed under a transparent dressing, it is considered the same as a gauze-and-tape dressing. 12
Clamping Clamps are used as needed when accessing or deaccessing VADs to prevent air embolism or blood backflow. Many VADs are available with clamps on the catheter (eg, the tunneled catheter). Sharp-edged clamps should never be used on the catheter, because damage can occur. Other VADs are clamped from the extension tubes, such as PICCs or ports. If clamping is not possible, the patient should perform the Valsalva maneuver whenever the catheter is open to air. Groshong catheters do not require clamping if the valve is functioning properly. Clamping will damage Groshong catheters.
Cap Changes Various types of caps are available, including luer-lock with latex septum, reflux valve, or needleless system cap. Before accessing an injection cap, the area is cleansed vigorously with alcohol or povidone-iodine. 37 Small-gauge needles no longer than 1 inch are used to maintain the integrity of the injection cap septum. Caps are changed weekly when access is infrequent. The cap should be changed if blood can not be completely flushed from the injection cap after blood withdrawal or if any signs of blood, precipitates, cracks, or leaks are noted. SUMMARY
VADs are indicated for many patients with cancer who require reliable long-term vascular access. A large variety of VADs are available, and nurses are in an ideal position to assess the factors that precede VAD selection, such as type of therapy, patient characteristics, VAD design, and cost. The care of VADs remains a source of clinical controversy. Oncology nurses need to continuously review the literature for new studies and incorporate pertinent findings into clinical practice.
SELECTION OF VADs
173
REFERENCES 1. Cervera M, Dolz M, Herraez J, et al: Evaluation of the elastic behavior of central venous PVC, polyurethane and silicone catheters. Phys Med Biol 34:177-183, 1989 2. Camp-Sorrell D: Advanced central venous access: Selection, catheters, devices, and nursing management. J Intraven Nurs 13:361-370, 1990 3. Orr M, Ryder M: Vascular access devices: Perspectives on designs, complications, and management. Nutr Clin Pract 8:145-152, 1993 4. Broviac J, Cole J, Scribner B: A silicone rubber atrial catheter for prolonged parenteral alimentation. Surg Gynecol Obstet 136:602-606, 1973 5. Hickman R, Buckner C, Cliff R, et al: A modified right atrial catheter for access to the venous system in marrow transplant recipient. Surg Gynecol Obstet 148:871-885, 1979 6. Niederhuber JE, Ensminger W, Gyves JW, et al: Totally implanted venous and arterial access system to replace external catheters in cancer treatment. Surgery 92:706-712, 1982 7. Bottino J, McCredie KB, Groschel D, et al: Long-term intravenous therapy with peripherally inserted silicone elastomer central venous catheters in patients with malignant diseases. Cancer 43:1937-1943, 1979 8. McCready D, Broadwater R, Ross M, et al: A casecontrol comparison of durability and cost between implanted reservoir and percutaneous catheters in cancer patients. J Surg Res 51:377-381, 1991 9. Raad I, Davis S, Becker M: Low infection rate and long durability of nontunneled silastic catheters. Arch Intern Med 153:1791-1796, 1993 10. Broadwater JR, Henderson MA, Bell JL, et al: Outpatient percutaneous central venous access in cancer patients. Am J Surg 160:676-680, 1990 11. Oncology Nursing Society: Access Device Module. Pittsburgh, PA, Oncology Nursing Press (1995) 12. Intravenous Nursing Standards of Practice. J Intraven Nurs 13:S1-$98, 1990 (suppl) 13. Andersen K, Holland JS: Maintaining the patency of peripherally inserted central catheters with 10 units/cc heparin. J Intraven Nurs 15:84-88, 1992 14. Fraschini G: Urokinase prophylaxis of central venous ports reduces infections and thrombotic complications. NAVAN Fifth Annual Conference Syllabus, September 1993 (abstract 3) 15. Conn C: The importance of syringe size when using implanted vascular access devices. NAVAN 3:11-18, 1993 16. Peterson FY, Kirehhoff KT: Analysis of the research about hepadnzed versus nonheparinized intravascular lines. Heart Lung 20:631-642, 1991 17. Tuten SH, Gueldner SH: Efficacy of sodium chloride versus dilute heparin for maintenance of peripheral intermittent intravenous devices. Appl Nurs Res 4:63-71, 1991 18. Kelly C, Dumenko L, McGregor SE, et al: A change in flushing protocols of central venous catheters. Oncol Nuts Forum 19:599-605, 1992 19. Cunningham RS, Bonam-Crawford D: The role of fibrinolytic agents in the management of thrombotic complications associated with vascular access devices. Nurs Clin North Am 28:899-907, 1993
20. Schulmeister L: A comparison of skin preparation procedures for accessing implanted port. J Intraven Nurs 10:45-57, 1987 21. Camp-Sorrell D: Implanatable ports: Everything you always wanted to know. J Intraven Nurs 15:262-273, 1992 22. Keller CA: Methods of drawing blood samples through central venous catheters in pediatric patients undergoing bone marrow transplant: Results of a national survey. Oncol Nurs Forum 21:879-884, 1994 23. MacGeorge L, Steeves L, Steeves RH: Comparison of the mixing and reinfusion methods of drawing blood from a Hickman catheter. Oncol Nuts Forum 15:335-338, 1988 24. Fagerman KE: Erroneous tobramycin sampling in home intravenous therapy avoidable with modified blood draw. J Intraven Nurs 17:135-137, t994 25. Franson TR, Rich PS, Quebbeman El, et al: Aminoglycoside serum concentration sampling via central venous catheters: A potential source of clinical error. J Parenter Enteral Nutr 11:77-79, 1987 26. Larson E: Guideline for use of topical antimicrobial agents. APOC for infection control practice. Am J Infect Control 16:253-266, 1988 27. Larson E: Does antiseptic make a difference in intravascular device related complications? Heart Lung 23:90-92, 1994 28. Maki DG, Band JD: A comparative study of polyantibiotic and iodophor ointments in prevention of vascular catheter-related infection. Am J Med 70:739-744, 1981 29. Norden CW: Application of antibiotic ointment to the site of venous catheterization: A controlled trial. J Infect Dis 120:611-615, 1969 30. Center for Prevention and Disease Control: Guidelines for Prevention of Intravascular Infections. Guidelines Nosocomial Infections. Atlanta, GA, Center for Prevention and Disease Control, 1981 31. Aly R, Bayles C, Malbach H: Restriction of bacterial growth under commercial catheter dressings. Am J Infect Control 16:95-100, 1988 32. Hoffman KK, Weber J, Samsa GP, et al: Transparent polyurethane film as intravenous catheter dressing. JAMA 267: 2072-2076, 1992 33. Wille JC, Blusse van Oud Alblas AB, Thewessen EA: A comparison of two transparent film-type dressings in central venous therapy. J Hosp Infect 23:113-121, 1993 34. Conly JM, Grieves K, Peters B: A prospective, randomized study comparing transparent and dry gauze dressings for central venous catheters. J Infect Dis 159:310-319, 1989 35. Petrosino B, Becker H, Christian B: Infection rates in central venous catheter dressings. Oncol Nurs Forum 15:709717, 1988 36. Dickerson N, Horton P, Smith S, et al: Clinically significant central venous catheter infections in a community hospital: Association with type of dressing. J Infect Dis 160:720721, 1989 37. Salzman MB, Isenber H, Rubin LG: Use of disinfectants to reduce microbial contamination of hubs of vascular catheters. J Clin Microbiol 31:475-479, 1993
Objective: To provide an overview of the patient selection criteria for a vascular access device (VAD) and its maintenance care. Conclusions: The availability of different types of devices has led to confusion on the part of many health care professionals as to which device is the best for their purpose. Selecting the appropriate VAD is an interdisciplinary decision based on patient characteristics, type of therapy, support system availability, and cost. Numerous controversial issues surround the care of VADs, and research results have not yet resolved these practice issues. Although various procedures are used throughout the country, it can be reasonably concluded that the fun-
damental requirement for successful maintenance of a VAD is strict adherence to established care protocols. Implications for nursing practice: Assessment of the need for a VAD is an ongoing process. Nurses are in a perfect position to assess the factors that precede device selection, including the frequency of access, type of intravenous therapy, and the condition of the patient's peripheral veins. The vast array of devices demands specialized knowledge in selecting the appropriate VAD, providing correct care, and evaluating the device once inserted or implanted.
A
tion and with repeated movement within the vessel. Polyurethane is a firmer material that allows for ease of insertion and then softens on contact with bodily fluids, thus preventing vessel damage. All VADs have impregnated radiopaque material to allow for easy visualization during radiographic and fluoroscopic examination. Generally, VADs have an open distal tip except for the Groshong catheter, which has a closed distal tip with a threeway valve. 2 A further description of VAD designs and insertion techniques can be reviewed in the article by Hadaway elsewhere in this issue.
TREMENDOUS increase in the availability of vascular access devices (VADs) has occurred in the past two decades. This development has been necessitated by the increase in patients requiring complex intravenous (IV) therapies in the hospital as well as alternative settings. Consequently, this mass production of quality VADs has led to a cumbersome process in selecting the best device for which the subsequent care may be controversial. Selecting the appropriate device is an interdisciplinary decision based on device design, patient characteristics, type of therapy, available support systems, and cost. This article reviews the various VADs available, patient selection criteria, and the maintenance care for each device. OVERVIEW OF VADs
Three major categories of long-term VADs are (1) tunneled catheters, (2) peripherally inserted central catheters (PICCs), and (3) implanted ports. Although VADs vary in design, all types can be used for blood withdrawal, blood product administration, and long-term IV therapy. The distal tip of the VAD's catheter lies in the superior vena cava, above the right atrium. Immediately after implantation and confirmation of placement, the device can be used for IV therapy. VAD catheters are composed of silicone or polyurethane material with a variety of intemai and outer diameters available. Silicone does not change after manipulation and is the most flexible material identified.1 Therefore, it is less likely to be damaging to the vasculature both during inserSeminars in Oncology Nursing, Vol 11, No 3 (August), 1995: pp 167-173
Copyright © 1995 by W.B. Saunders Company
SELECTION OF VADs
The vast array of VADs demands specialized knowledge in selecting the appropriate device, providing correct care, and evaluating the device once in place. Assessment of the need for a VAD is an ongoing process and nurses are in the perfect position to assess the factors that precede selecFrom the University of Alabama and Hospital at Birmingham, Birmingham, AL. Mary Nell Winslow, MSN, RN, OCN: Nurse Practitioner, Internal Medicine, Kirklin Clinic, University of Alabama at Birmingham; LindseyTrammell, MSN, RN, OCN: Oncology Clinical Nurse Specialist, Comprehensive Cancer Center, University of Alabama at Birmingham; and Dawn Camp-Son'ell, MSN, RN, FNP, OCN: Oncology Nurse Practitioner, University of Alabama Hospital at Birmingham. Address reprint requests to Mary Nell Winslow, MSN, RN, OCN, 2253 Chapel Rd, Birmingham, AL 35226. Copyright © 1995 by W.B. Saunders Company 0749-2081/95/1103-000355.00/0
167
168
WlNSLOW, TRAMMELL, AND CAMP-SORRELL
tion. 3 Ideally, selection is based on input from the patient, significant other, nurse, physician, and surgeon. This multidisciplinary approach permits consideration of the different types of devices and addresses the patient's needs. Although the optimal timing of VAD insertion is before the initiation of therapy, established criteria for selecting the best VAD are not available. Generally, patients requiring intensive IV therapy for more than 3 months benefit from placement of a VAD. PICCs are predominantly used in patients requiring several weeks or months of IV therapy, whereas ports and tunneled catheters are usually selected for treatment lasting longer than 6 months. Overall advantages and disadvantages of VADs must be considered when selecting a device (Table 1). Other factors to consider include the VAD design, type of therapy, patient's self-care ability, cost, and maintenance care.
VAD Designs The length and gauge of the catheter must be considered when selecting the appropriate device. Higher flow rates, easier blood withdrawal for sampling, and increased accuracy in evaluating central venous pressures are possible with larger
gauge catheters. Smaller gauge catheters are available for pediatric or elderly patients with small fragile veins. Multiple lumens are available for patients requiring multiple blood withdrawals or simultaneous IV therapies. Different VAD designs are available to meet the patient's needs. Tunneled catheters. The Broviac catheter, the first tunneled device, appeared on the market in 1975 for the administration of hyperalimentation, and the Hickman catheter followed in 1979. 4,5 Both are similar in design; however, the Hickman catheter has a larger gauge. Tunneled catheters are available with single, double, or triple lumens to meet various therapeutic needs. Tunneled catheters require placement in an operative suite; therefore, patients who are unstable to undergo surgery are not candidates. Tunneled catheters are selected for patients undergoing aggressive IV treatment, such as bone marrow transplants, that require the need for multiple lumens. Additionally, patients who experience prolonged myelosuppression will benefit from a tunneled catheter because a needle is not left in place through the skin, which increases the chance for infection or bleeding. Tunneled catheters are not the best device for patients with cachexia, inadequate neck veins, or
Table 1. Advantages and Disadvantages of VADs Type of VAD
Advantages
Disadvantages
PICCs
No danger of chest injury on insertion Economical placement Easy to remove RN can insert No puncturing of skin after insertion Not a surgical procedure to place External portion can be repaired Dual lumens available
Restricts activities Body image affected Difficult to perform self-care Routine daily to weekly maintenance May not be sutured to anchor May collapse with blood withdrawal Must have occlusive dressing in place at all times
Tunneled catheters
Tunnel with Dacron cuff to anchor in subcutaneous tissue Can be used for central venous pressure monitoring No puncturing of the skin after placement Triple-lumen catheter available External portion can be repaired Additional antimicrobial cuff available Easy to remove
Requires physician to place May require physician to remove Surgical procedure for placement Daily to weekly site care Body image may be affected Restricts some activities Higher maintenance requirements
Implanted ports
Double lumen available Minimal maintenance care Minimal interference with activities Body image less affected
Requires physician to place Requires physician to remove Surgical procedure for placement Higher initial cost Requires puncturing of the skin to access Can interfere with MRI, CT scan, or radiation procedures
Abbreviations: RN, registered nurse.
SELECTION OF VADs
open chest wound. The patient's body image can be affected, because the external portion of the catheter is a constant reminder of his or her illness. The patient and/or significant other must be able to provide dally to weekly catheter care. Implanted ports. Implanted ports of various designs have been available since the 1980s. 6 Basically, the device is composed of a portal body and a catheter to access the venous, arterial, peritoneal, or epidural body systems. Double-lumen ports are available for the administration of simultaneous IV therapy. Most ports are accessed from the top; some may be accessed from the side; and others are domed, allowing access from either side or the top. Antecubital ports are implanted peripherally. Implanted ports require minimal care and flushing; therefore, they are a suitable selection for the elderly who have poor visual acuity, poor manual dexterity, or no significant other to assist with care. When patient compliance is questionable, port placement is the best selection. Excellent candidates for a port include patients receiving IV chemotherapy that will not cause prolonged myelosuppression or need triple lumens. On the other hand, patients undergoing treatments that cause prolonged myelosuppression, such as bone marrow transplants, are not good candidates because of the potential for bleeding or infection at the needle insertion site. Only a small bump reveals the port's location; therefore, an external portion is not exposed to remind patients of their diseases or to affect their body images. In addition, because the port is completely under the skin, activities are not restricted; thus, children are excellent candidates. Port placement is not recommended for patients in whom there will be difficulty in accessing or when there is limited area available on the anterior chest wall, such as obese patients and patients with chest wall radiation fibrosis, cachexia, opened chest wounds, or a mastectomy site. 2 At present, there are no specific indications for when to insert an antecubital port. This device may be inserted to meet short-term or long-term therapeutic needs. Some patients prefer a PICC or tunneled catheter because of their fear of needles or pain associated with port access. PICCs. The PICC is a long-term device that is inserted by a trained registered nurse. Since the introduction of the PICC, adaptations to the design have made it ideal for the elderly as well as the
169
young. 7 PICCs are not as effective for rapid, largevolume infusions, and small-gauge PICCs are not recommended for blood sampling because of the potential for the catheter to collapse. PICCs are a good selection for the patient who has had chest injury, radical neck dissection, radiation fibrosis to the chest, fungating chest tumor, neck veins that cannot be cannulated, patients who are malnourished, or patients who are physically unstable to undergo a surgical procedure. Adequate peripheral veins, such as the cephalic or basilic, are necessary for PICC insertion. PICCs require daily care, and a second person may need to be present to assist with daily care. Body image can be affected, and activities are restricted with PICCs, because the exit site is in the antecubital area. Because a PICC is not tunneled and may not be sutured, an occlusive dressing is required over the exit site at all times to prevent dislodgement. For patients who participate in frequent exercise or strenuous manual work or who have active children, a PICC may not be the best device because of the risk for dislodgement or limitation in mobility of the upper extremity.
Type of Intravenous Therapy VADs are appropriate selections for bolus, intermittent, or continuous infusions. However, special circumstances must be considered to ensure delivery of drug therapy and patient safety. For example, implantable ports require a right-angle, noncoring needle with an occlusive dressing during continuous infusion to prevent needle dislodgement. With a tunneled catheter or PICC, the infusion can be connected directly to the catheter hub, thus decreasing the risk for accidental disconnection. For continuous administration of a vesicant, a P1CC or tunneled catheter may be the best selection if the patient is active, because movement could dislodge the needle from the port.
Self-Care Ability A crucial consideration when treatment is administered in the outpatient or home setting is the patient's self-care ability or the availability of family members to care for the VAD. With the increase in health care delivery in the outpatient setting, VAD care is no longer the responsibility of the nurse. This responsibility has changed to the patient or family. Self-care elements to be considered include competency level, manual dexterity, visual acuity, home environment, and caregiver
170
WINSLOW, TRAMMELL, AND CAMP-SORRELL
support. Often, implantable ports are used with pediatric and elderly patients, because the port requires minimal care. A deliberate and diligent nursing assessment of each factor will facilitate the most appropriate VAD choice for the individual patient.
Cost The current climate of cost containment and health care reform has required that all health care providers closely examine dollars spent while ensuring quality patient care. McCready et al s compared the cost and durability of implanted devices versus nontunneled percutaneous devices. The initial insertion expense of the nontunneled device was less than the port; however, when the device was used longer than 6 months, the port was more economical when maintenance costs were evaluated. In contrast, nontunneled percutaneous devices are less expensive to insert; however, they are more expensive to maintain and replace as necessary. 9 Unfortunately, few references are available that provide in-depth analysis of costs related to VAD placement and maintenance. Insertion cost is based on the type of device, insertion kit, and the area of placement, ie, the operating room versus the clinic. 8'1° See the article by Hadaway elsewhere in this issue for a discussion of insertion-costs. Maintenance care is based
on the type of protocol that is being performed, such as the type of dressing, frequency of dressing change, type of flush, frequency of flush, type of injection cap, and frequency of cap changes. For example, the cost for maintaining a single-lumen tunneled catheter with a transparent dressing changed every 5 days and flushed with heparin solution daily would range from $40 to $150/ month. MAINTENANCE CARE
Care of VADs includes flushing, accessing, blood withdrawals, dressing changes, clamping techniques, and cap changes (Table 2). Although various procedures are used throughout the country, it can be reasonably concluded that successful VAD maintenance is the result of strict adherence to established protocols. Because the research literature does not provide definitive measures for care, and controversial issues remain, oncology nurses are accountable for reviewing the literature for the latest research findings. The Oncology Nursing Society II and the Intravenous Nursing Society ~2 provide recommendations for VAD care based on clinical and scientific evidence that can be used to develop standardized procedures.
Flushing Regardless of the VAD type, routine flushing is required at designated intervals to cleanse the in-
Table 2. Care of VADs
VAD
Flushing Routine*
Bolus Flushing
Tunneled catheters
1 mL to 3 rnL daily to weekly with HS** Maintain positive pressure
Before and after reed with 5 mL of compatible solution
PICCs
1 mL to 2 mL daily with HS** Maintain positive pressure
As above
Ports
2.5 to 5 mL of HS** every 8 hours
As above
Abbreviations: HS, heparin solution; NS, normal saline. * Flush all lumens. ** Groshong catheters use 5 mL of NS flush weekly.
Dressing/Cap Changes Remove old dressing Use aseptic technique Inspect site Cleanse site from catheter outward Cover site with occlusive dressing Change injection caps every 5-7 days As above plus Pull old dressing upward to remove If skin closure dressings are used, change during dressing change As above
Blood Withdrawal (Discard Method) Withdraw 3-5 mL of blood and discard Withdraw blood samples Flush with 5 to 10 mL of NS, then HS or resume fluids
SELECTION OF VADs
ternal diameter of the catheter from fibrin build-up and debri. Compatible flushes of 5 to 10 mL should be used before and after administering drugs or withdrawing and administering blood products to cleanse the catheter. Solutions used to cleanse the catheter include heparin sodium, sodium chloride, and urokinase. Heparin sodium inhibits the conversion of prothrombin to thrombin and fibrinogen to fibrin, thus inhibiting fibrin build-up. Various heparin concentrations, 10 U/mL to 1,000 U/mL, have been used for flushing with the most common concentration being 100 U/mL. IL13 Sodium chloride is an aqueous fluid having approximately the same osmotic pressure and composition as extracellular fluid, which cleanses the internal catheter. Urokinase converts plasminogen to plasmin, which dissolves fibrin or clot formation. 14 Excessive force should never be used when flushing a VAD. The syringe size directly affects the amount of pressure created by the force of the plunger, ie, the smaller the syringe, the greater the pressure on pounds per square inch. High pressure may damage the catheter; therefore, syringes less than 3 mL are avoided. 15 The type of solution, volume, and frequency of flush continues to he an area of controversy. :3"19 Randomized prospective studies examining the relationship of the type of device, patient characteristics, patency, infection occurrence, and cost are necessary to standardize flushing protocols.
Accessing Injection ports and luer junctions are cleansed before accessing to prevent introduction of microorganisms. Implanted ports are accessed aseptically with a noncoring needle after appropriate skin preparation. Gloves are worn during the procedure, but in some cases, particularly with immunosuppressed patients, masks and gowns may also be used. 2° Because accessing a port requires a needle stick, a local anesthetic may be used to decrease the pain associated with needle insertion. Once the port has been located by palpation, the needle and extension tubing, primed with fluid, are inserted perpendicularly through the skin into the reservoir against the port backing (needle stop). Once the port is accessed, the needle should not be rocked or tilted to avoid damage to the septum. After access, the needle is secured to the skin, and an occlusive dressing is applied. 21 When deaccess-
171
ing a VAD, positive pressure is maintained on the syringe barrel to prevent reflux of blood into the catheter.
Blood Withdrawals Several techniques can be used to obtain blood samples, including discarding, reinfusing, mixing, or using a vacutainer or a syringe. The most commonly reported procedure in the adult population is the discard method. 22 Blood is withdrawn, the sample is collected, and the VAD is flushed with normal saline. The amount discarded varies from 3 to 10 mL. With the reinfusion method, the discard or first sample collected is reinfused into the patient after the sample is obtained. This method is commonly used in neonates and children to prevent a decrease in blood volume. 23 In the mixing method, blood is withdrawn and immediately reinfused into the patient. After repeating this procedure up to four times without removing the syringe, the blood sample is collected. 23 The purpose is to dilute the heparin or saline flush before taking a sample. Vacutainers can be used by inserting into the injection cap on the catheter hub, which reduces the risk of inadvertent needle sticks and blood contamination. However, vacutainers may not be possible with PICCs or the Groshong because the pressure within the collecting tube may collapse the catheter. 2 A syringe can be attached directly to the catheter hub or through an injection cap to obtain a sample; however, the likelihood of needle sticks and blood contamination is increased. If the VAD is connected to an infusion, all infusions are discontinued for at least 1 minute before drawing a sample. If any samples appear grossly inaccurate, the blood sample should be redrawn through a peripheral site. 11'24'25 Because heparin adheres to the internal catheter lumen, blood for coagulation studies is drawn peripherally unless the VAD is maintained with normal saline. Aminoglycoside levels can also be erroneous when collected from a VAD. 25 However, some institutions draw coagulation or drug levels after other blood samples are obtained or after discarding 10 mL or more of blood. Another alternative is obtaining a peripheral sample by finger lancet or collection tube technique. 24
Dressing Changes Exit site care and dressing changes are necessary to control infection and assess the surrounding
172
area. The technique includes cleansing the skin at the exit site outwardly and applying a dressing. Few studies have compared the efficacy of cleansing agents alone in VAD c a r e . 26'27 Cleansing agents used include alcohol, iodophors, chlorhexidene gluconate, and hydrogen peroxide, n Alcohol is effective against most gram-positive and gram-negative organisms as well as many fungi and viruses. Concentrations between 70% and 92% provide a rapid reduction in microbial counts on the skin; however, no residual effect is seen. 26'27 Iodophors are complexes that have a wide range of activity against gram-positive and gram-negative bacteria as well as tubercle bacillus, fungi, and viruses. Povidone-iodine (10%) is the most commonly used agent and has a minimal residual effect before drying. Chlorhexidene gluconate is more effective against gram-positive bacteria than gram-negative bacteria, viruses, and fungi. Chlorhexidene has a strong affinity for the skin and remains chemically active for up to 6 hours after application. Hydrogen peroxide is an effective cleansing agent against bacteria, but it interferes with tissue granulation and should be avoided. However, crusted exudates can be easily removed with half-strength peroxide and normal saline. The use of ointments after cleansing the exit site is controversial. Antimicrobial ointment, such as iodophor, is a semisolid preparation that prevents pathogenic action of microbes. An antibiotic ointment, such as neomycin, destroys or inhibits the growth of microorganisms. The value of using an antimicrobial ointment lacks evidence supporting its use in preventing infection. The occurrence of Candida species colonization with the use of a polymicrobial ointment has been demonstrated. 28'29 The Center for Prevention and Disease Control recommends that the dressing be changed every 48 hours if ointments are used. 3° Current data both support and dispute the use of gauze and transparent dressings.31-36 Mixed results have been obtained when investigators, using both retrospective and prospective designs, compared the effectiveness of these two dressing types. Until prospective, multisite randomized studies are conducted in which cleansing protocols, dressing protocol, type of dressing, type of device, patient characteristics, and the educational component of personnel applying the dressing are all studied, it will be difficult to determine which type of dressing reduces the infection rate. Gauze dressings are made of mesh material that
WINSLOW, TRAMMELL, AND CAMP-SORRELL
provides no occlusive barrier; however, they act as a sponge and are secured in place by tape. These dressings should be changed every 48 hours. 3° Transparent dressings are semipermeable film with a significant moisture vapor rate that allows for visualization of the exit site while providing a barrier to extrinsic liquids and microorganisms. These dressings are changed every 5 to 7 days. 3° When gauze is placed under a transparent dressing, it is considered the same as a gauze-and-tape dressing. 12
Clamping Clamps are used as needed when accessing or deaccessing VADs to prevent air embolism or blood backflow. Many VADs are available with clamps on the catheter (eg, the tunneled catheter). Sharp-edged clamps should never be used on the catheter, because damage can occur. Other VADs are clamped from the extension tubes, such as PICCs or ports. If clamping is not possible, the patient should perform the Valsalva maneuver whenever the catheter is open to air. Groshong catheters do not require clamping if the valve is functioning properly. Clamping will damage Groshong catheters.
Cap Changes Various types of caps are available, including luer-lock with latex septum, reflux valve, or needleless system cap. Before accessing an injection cap, the area is cleansed vigorously with alcohol or povidone-iodine. 37 Small-gauge needles no longer than 1 inch are used to maintain the integrity of the injection cap septum. Caps are changed weekly when access is infrequent. The cap should be changed if blood can not be completely flushed from the injection cap after blood withdrawal or if any signs of blood, precipitates, cracks, or leaks are noted. SUMMARY
VADs are indicated for many patients with cancer who require reliable long-term vascular access. A large variety of VADs are available, and nurses are in an ideal position to assess the factors that precede VAD selection, such as type of therapy, patient characteristics, VAD design, and cost. The care of VADs remains a source of clinical controversy. Oncology nurses need to continuously review the literature for new studies and incorporate pertinent findings into clinical practice.
SELECTION OF VADs
173
REFERENCES 1. Cervera M, Dolz M, Herraez J, et al: Evaluation of the elastic behavior of central venous PVC, polyurethane and silicone catheters. Phys Med Biol 34:177-183, 1989 2. Camp-Sorrell D: Advanced central venous access: Selection, catheters, devices, and nursing management. J Intraven Nurs 13:361-370, 1990 3. Orr M, Ryder M: Vascular access devices: Perspectives on designs, complications, and management. Nutr Clin Pract 8:145-152, 1993 4. Broviac J, Cole J, Scribner B: A silicone rubber atrial catheter for prolonged parenteral alimentation. Surg Gynecol Obstet 136:602-606, 1973 5. Hickman R, Buckner C, Cliff R, et al: A modified right atrial catheter for access to the venous system in marrow transplant recipient. Surg Gynecol Obstet 148:871-885, 1979 6. Niederhuber JE, Ensminger W, Gyves JW, et al: Totally implanted venous and arterial access system to replace external catheters in cancer treatment. Surgery 92:706-712, 1982 7. Bottino J, McCredie KB, Groschel D, et al: Long-term intravenous therapy with peripherally inserted silicone elastomer central venous catheters in patients with malignant diseases. Cancer 43:1937-1943, 1979 8. McCready D, Broadwater R, Ross M, et al: A casecontrol comparison of durability and cost between implanted reservoir and percutaneous catheters in cancer patients. J Surg Res 51:377-381, 1991 9. Raad I, Davis S, Becker M: Low infection rate and long durability of nontunneled silastic catheters. Arch Intern Med 153:1791-1796, 1993 10. Broadwater JR, Henderson MA, Bell JL, et al: Outpatient percutaneous central venous access in cancer patients. Am J Surg 160:676-680, 1990 11. Oncology Nursing Society: Access Device Module. Pittsburgh, PA, Oncology Nursing Press (1995) 12. Intravenous Nursing Standards of Practice. J Intraven Nurs 13:S1-$98, 1990 (suppl) 13. Andersen K, Holland JS: Maintaining the patency of peripherally inserted central catheters with 10 units/cc heparin. J Intraven Nurs 15:84-88, 1992 14. Fraschini G: Urokinase prophylaxis of central venous ports reduces infections and thrombotic complications. NAVAN Fifth Annual Conference Syllabus, September 1993 (abstract 3) 15. Conn C: The importance of syringe size when using implanted vascular access devices. NAVAN 3:11-18, 1993 16. Peterson FY, Kirehhoff KT: Analysis of the research about hepadnzed versus nonheparinized intravascular lines. Heart Lung 20:631-642, 1991 17. Tuten SH, Gueldner SH: Efficacy of sodium chloride versus dilute heparin for maintenance of peripheral intermittent intravenous devices. Appl Nurs Res 4:63-71, 1991 18. Kelly C, Dumenko L, McGregor SE, et al: A change in flushing protocols of central venous catheters. Oncol Nuts Forum 19:599-605, 1992 19. Cunningham RS, Bonam-Crawford D: The role of fibrinolytic agents in the management of thrombotic complications associated with vascular access devices. Nurs Clin North Am 28:899-907, 1993
20. Schulmeister L: A comparison of skin preparation procedures for accessing implanted port. J Intraven Nurs 10:45-57, 1987 21. Camp-Sorrell D: Implanatable ports: Everything you always wanted to know. J Intraven Nurs 15:262-273, 1992 22. Keller CA: Methods of drawing blood samples through central venous catheters in pediatric patients undergoing bone marrow transplant: Results of a national survey. Oncol Nurs Forum 21:879-884, 1994 23. MacGeorge L, Steeves L, Steeves RH: Comparison of the mixing and reinfusion methods of drawing blood from a Hickman catheter. Oncol Nuts Forum 15:335-338, 1988 24. Fagerman KE: Erroneous tobramycin sampling in home intravenous therapy avoidable with modified blood draw. J Intraven Nurs 17:135-137, t994 25. Franson TR, Rich PS, Quebbeman El, et al: Aminoglycoside serum concentration sampling via central venous catheters: A potential source of clinical error. J Parenter Enteral Nutr 11:77-79, 1987 26. Larson E: Guideline for use of topical antimicrobial agents. APOC for infection control practice. Am J Infect Control 16:253-266, 1988 27. Larson E: Does antiseptic make a difference in intravascular device related complications? Heart Lung 23:90-92, 1994 28. Maki DG, Band JD: A comparative study of polyantibiotic and iodophor ointments in prevention of vascular catheter-related infection. Am J Med 70:739-744, 1981 29. Norden CW: Application of antibiotic ointment to the site of venous catheterization: A controlled trial. J Infect Dis 120:611-615, 1969 30. Center for Prevention and Disease Control: Guidelines for Prevention of Intravascular Infections. Guidelines Nosocomial Infections. Atlanta, GA, Center for Prevention and Disease Control, 1981 31. Aly R, Bayles C, Malbach H: Restriction of bacterial growth under commercial catheter dressings. Am J Infect Control 16:95-100, 1988 32. Hoffman KK, Weber J, Samsa GP, et al: Transparent polyurethane film as intravenous catheter dressing. JAMA 267: 2072-2076, 1992 33. Wille JC, Blusse van Oud Alblas AB, Thewessen EA: A comparison of two transparent film-type dressings in central venous therapy. J Hosp Infect 23:113-121, 1993 34. Conly JM, Grieves K, Peters B: A prospective, randomized study comparing transparent and dry gauze dressings for central venous catheters. J Infect Dis 159:310-319, 1989 35. Petrosino B, Becker H, Christian B: Infection rates in central venous catheter dressings. Oncol Nurs Forum 15:709717, 1988 36. Dickerson N, Horton P, Smith S, et al: Clinically significant central venous catheter infections in a community hospital: Association with type of dressing. J Infect Dis 160:720721, 1989 37. Salzman MB, Isenber H, Rubin LG: Use of disinfectants to reduce microbial contamination of hubs of vascular catheters. J Clin Microbiol 31:475-479, 1993