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The use of intravascular (IV) drugs and fluids has increased significantly in the past three decades due to their proven effectiveness in treating a wide array of diseases. This treatment modality necessitates long-term use of vascular access devices (VADs); however, maintaining vascular access throughout the course of treatment can be a challenge. Serious complications may develop or treatment delayed if vascular access cannot be maintained. Phlebitis and extravasation are other potential complications when smaller, more fragile blood vessels are used. Treatment often becomes a painful, dreaded ordeal especially for patients with limited or damaged blood vessels.
Selecting the appropriate device, providing continuous maintenance care, and troubleshooting complications requires specialized knowledge. A wide array of vascular access devices is available, and every device incurs a risk of complication. Although insertion complications can be life threatening, they occur less frequently1-4 (Table 1). Catheter-related infections and occlusions are the most serious complications, as well as the most frequently reported.5 Therefore, this article will focus on catheter-related infections and occlusions.
AN OVERVIEW OF VASCULAR ACCESS DEVICES
Peripherally inserted central catheters (PICCs), tunnel catheters, and implantable ports are the types of long-term VADs used.6-7 They are referred to as long-term because the catheter tip lies in the distal third of the superior vena cava, and the device can be maintained for months to years.3 Despite the unique design of each VAD, all types can be used to administer fluids, medication, blood products, and hyperalimentation or to obtain blood samples. VADs are available in single or double lumen design, with an open or one-way valve catheter distal tip. Newer, technologically advanced devices have systems that allow for power injection of contrast material.7
Peripherally inserted central catheters were initially developed in the 1980s. They were used mainly for venous access in patients receiving home care. A PICC insertion site is peripheral with the exit site at or above the antecubital area of the arm.
Tunnel catheters, available since the mid-1970s, are used for long-term administration of hyperalimentation and bone marrow transplant patients.7 This type of catheter is tunneled through subcutaneous tissue and anchored within the tunnel by one or two cuffs located on the catheter. Tunnel catheters exit on the anterior chest and are the only device available in a triple lumen design.
Implantable ports were introduced in 1982 in an effort to reduce VAD infection rates.8 Ports differ from other VADs in that the portal body is in a pocket created completely under the subcutaneous tissue and accessed using a noncoring needle. Care and maintenance of implantable ports and monitoring for complications must be emphasized with increased use of these devices.
The reported infection rate of VADs ranges from 0.8% to 27%.3,4 The true incidence of VAD infection is difficult to measure because the definitions of infections are not standardized. Adherence to strict hand-washing and aseptic techniques and patient/caregiver education are effective preventive measures.9 Surveillance of infection rates help monitor the occurrence of VAD infections, the type of infections that develop, use of antibiotics, hospital stay, and the need for VAD removal. Dressings protect the VAD exit or insertion site from infective organisms on the caregiver’s hands and the patient’s skin. However, studies evaluating the effect of dressing type (gauze vs transparent) and frequency of dressing change on the incidence of infectious VAD complications involved small sample populations; therefore, the data is insufficient for establishing standard-of-care recommendations.10,11 Cleansing the skin to remove potentially infective organisms is a vital step in infection prevention. Chlorhexidine has been found to be the most effective agent for pre- and postinsertion cleansing. The solution should be applied with friction without contaminating the site and allowed to air dry for approximately 30 seconds.7,11
Although some facilities require clinicians to wear a mask while changing the dressing, infections are more often associated with bacteria on the skin than with respiratory organisms. Using full aseptic technique for VAD insertion may prevent infection;6 however, routine use of sterile drapes, masks, gowns, and gloves is not proven to lower the incidence of infection.10 Cleansing the hub before and after connecting tubing or a syringe is also necessary because bacteria can be introduced through the catheter hub. A higher risk of infection is associated with longer device placement; therefore, the need to maintain a VAD should be routinely assessed. Removal is recommended once it will not be used.9,11
Risk factors that increase the incidence of catheter-related infections include neutropenia, femoral catheterization, prolonged duration of catheter placement, hyperalimentation, and substandard maintenance care.9,11 Organisms may adhere to and multiply on the surface of the catheter or skin, causing a catheter-related infection in the hub, tunnel, port pocket, exit site, or bloodstream (Table 2). Infection can also develop in a thrombus in which bacteria or fungi colonize. It then becomes a constant source of seeding to the bloodstream. Many bacteria excrete a polysaccharide matrix that coats the catheter.6 The matrix bonds the organism to the catheter, rendering systemic antibiotics ineffective. The most common organisms associated with VAD infections include gram-positive bacteria, mainly Staphylococcus aureus, and coagulase-negative staphylococci.4 Symptoms of a catheter-related infection are local erythema, edema, or purulent drainage. Systemic infection can also include fever, chills, hypotension, and malaise.