Strategies to prevent infection
Several professional and government agencies have published evidenced-based guidelines for the prevention of CABSI.2,12 The following summarizes interventions  and their rationales  for practices that will reduce risk of CABSI . Further description is provided of the central line bundle elements as well as additional interventions aimed at reducing microorganisms around the catheter exit site, minimizing microorganisms originating at the catheter hub, and minimizing risks related to contaminated infusate.

Catheter selection
The intravascular catheter and insertion site that carry the lowest risk of complications and are most appropriate for the type and duration of intravenous (IV) therapy should be selected. Peripheral IV catheters (Figure 1 and 2) are frequently utilized, and the incidence of bloodstream infection resulting from their use is very low when compared with infection rates for CVCs.10 If a central line is the most appropriate choice, the subclavian site is preferred over the femoral or jugular sites as it is associated with a lower risk of infection. (Figure 3) If intravenous therapy is to exceed 6 days, it is recommended that a peripherally inserted central catheter (PICC) or a midline catheter be considered.2 Note that a midline catheter is considered a peripheral catheter and should be selected only when the intended infusion therapy is appropriate for peripheral IV administration. As a result of CMS no longer paying for vascular catheter-related infections that occur in the hospital, and the low risk of infection with peripheral IV catheters, it is likely that many clinicians are taking a closer look at the appropriateness of a peripheral IV catheter versus early placement of a CVC.

Catheter insertion and replacement
Healthcare professionals involved in CVC insertion and care should receive appropriate training and education, and the professional inserting the catheter should demonstrate competence.2,12           

Because migration of microorganisms from the skin at the catheter insertion site to the catheter tip is the most common source of bloodstream infection for peripherally inserted, short-term catheters, attention to infection-prevention procedures at the time of catheter insertion is a critical step in infection prevention. Hand hygiene should be performed with an alcohol-based product or antiseptic before insertion. The use of maximal sterile barrier precautions is an important component of the central line bundle. For the professional who places the CVC (including placement via a guidewire exchange) and those assisting, this means strict adherence with hand hygiene and wearing cap, mask, sterile gown, and sterile gloves. A large sterile drape should be placed over the patient, covering the patient from head to toe, with a small opening at the site of insertion.2,12
        
Skin disinfection is an essential step, needed to remove microorganisms residing on the patient’s skin that may contaminate the catheter site. Options for CVC insertion-site disinfection include 2% chlorhexidine-based antiseptic, 70% alcohol, an iodophor, or tincture of iodine if there is a contraindication for chlorhexidine. Using 2% chlorhexidine is preferred due to its superiority in reducing CVC-related colonization and potential bloodstream infection.13,14 The antiseptic must be allowed to dry before catheter insertion. If povidone-iodine is used, it should remain on the skin for at least 2 minutes for optimum effectiveness.

Site assessment, care, and dressings
The catheter site should be checked daily, and dressings should be changed if they become wet, loosened, or visibly dirty. Site care should be performed regularly in conjunction with dressing changes. This includes regular removal of the catheter dressing, disinfection of the skin surrounding the catheter exit site, and re-application of a sterile dressing. Aseptic technique is required when providing site care; this includes hand hygiene and use of sterile gloves and mask when dealing with central vascular access devices.15 As with site disinfection at the time of catheter replacement, 2% chlorhexidine preparations are the preferred skin disinfectant for patients older than two months of age.2,12 The use of topical antibiotic creams or ointments is not recommended during catheter insertion or dressing changes.
           

Maintaining a clean, dry, and occlusive dressing is important to protect the catheter insertion site and reduce the risk for infection. Either sterile gauze or a sterile transparent semi-permeable dressing may be used to cover the site. Transparent sterile dressings allow visualization of the catheter site and less manipulation, as they are changed less frequently. Gauze dressings are an appropriate choice for the patient who is experiencing site drainage, who perspires excessively, or who has a sensitivity reaction to transparent dressings. The research supporting the choice of dressing is limited, and the evidence does not support one choice over another. In a systematic review of controlled trials that compared the effects of gauze and tape versus transparent dressings, there was no evidence of difference in the incidence of infectious complications. It is important to note, however, that the studies were from small samples and there was a high level of uncertainty regarding risk for infection related to type of dressing.16            

For short-term CVCs the dressing should be changed at least every 2 days if gauze is used and every 7 days if a transparent dressing is used.2 The dressings on tunneled CVCs (e.g., Hickman, Broviac) should be changed no more than once per week until the site has healed.2

Attention to the catheter hub and needless injection caps
Colonization and CABSI may occur with longer-term catheters when the catheter hub becomes contaminated. Failure to disinfect the cap when accessing the infusion device or administration set for flushing or medication administration is recognized as a significant problem. The Institute for Safe Medication Practices (ISMP) documented17 infection-control problems, including failure to disinfect the injection cap/valve when accessing the infusion for flushing or medication administration. The 2009 Joint Commission National Patient Safety Goals have a specific recommendation to “use a standardized protocol to disinfect catheter hubs and injection ports before accessing the ports.”18 The Infusion Nurses Society and ISMP clearly recommend that the injection or access port be aseptically cleansed with an approved antiseptic, usually 70% alcohol, prior to use. While there are no specific evidence-based guidelines documenting the optimal disinfectant or duration of cap disinfection, the “scrub the hub” mantra is frequently cited, emphasizing the importance of friction when disinfecting.

Maintaining catheter patency
An initial saline (0.9% NaCl) flush is used to assess catheter patency and to aspirate for blood return from the catheter prior to its use. If there is no blood return, the catheter should be considered non-functioning and a determination made as to whether it should be replaced. Use of thrombolytic drugs is very effective in restoring patency, including ability to withdraw blood, and should be consistently considered in reducing the risk of catheter replacement.           

Although there have been studies linking heparin to biofilm formation, heparin still remains the solution of choice to prevent clots within the catheter. There are some catheters and needleless injection connectors that require only saline for flushing. The frequency of catheter flushing is dependent on the clinical setting.2

Administration sets
Administration sets, including secondary sets, should be replaced at 72–96 hours. However, tubing used to administer blood, blood products, or lipid emulsions should be replaced within 24 hours of infusion. Also of note, the Infusion Nurses Society (2006) makes a separate and distinct recommendation for administration set changes to be done every 24 hours for infusions that are administered via a capped IV catheter and the IV tubing is disconnected from the patient’s catheter after each infusion. When an intermittent infusion is repeatedly disconnected and reconnected for the infusion, there is much more manipulation of the tubing and at the catheter/injection cap or valve, increasing the risk for contamination and potential catheter-related bloodstream infection.

Integrity of parenteral solutions
Contaminated infusate is considered an uncommon cause of CABSI; nonetheless, parenteral solutions should always be mixed in the pharmacy, where quality control can be maintained, using aseptic technique under a laminar-flow hood. It is important that the infusion solution and container are carefully assessed prior to administration Containers that are cracked, turbid, or have particulate matter should be disposed of immediately. If sterility is compromised, the medication vials should be discarded.    

It is recommended that single-dose medication vials and single-use prefilled heparin and saline flush syringes be used whenever possible, so as to prevent contamination that can occur from frequent accessing.2  (Figure 5) Any medication left in single-dose vials should be discarded. The top of the medication vial should be cleaned with alcohol prior to access, and only a sterile device should be used to withdraw the medication. 

Catheter replacement
CVCs should not be routinely replaced, but peripheral venous catheters should be replaced at least every 72–96 hours in adults to prevent phlebitis. In pediatric patients, peripheral IV catheters may remain in place until no longer required, and are removed only if a complication occurs.