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Central venous access devices
Lynn C. Hadaway RN, C, CRNI, MEd 

Nursing2009 Critical Care
September 2008 
Volume 3 Number 5
Pages 26 - 33

Central venous access devices (CVADs) are ubiquitous in modern healthcare, and are available in numerous designs, shapes, and sizes for insertion in several areas of the body. This overview focuses on nursing care to maintain CVADs and prevent complications, based on the recently updated Infusion Nursing Standards of Practice.1

CVAD location, end to end

After a CVAD is inserted and before anything is infused through it, verify and document the anatomic location of the CVAD tip. If the CVAD was inserted at the bedside, obtain a chest X-ray. If it was inserted in the radiology department, fluoroscopy may be used to confirm tip location.

A statement from the radiology department that the CVAD is in a good location isn't sufficient. Although a written report may take days to appear on the patient's medical record, obtain and document verbal confirmation of the tip's correct anatomic location. If the patient has been transferred from another facility with a catheter in place, confirm tip placement with a chest X-ray.1

Exactly where the CVAD tip should rest is controversial. Most practitioners prefer to place it in the distal end of the superior vena cava, at or near its junction with the right atrium. Others prefer to place it in the right atrium, as it may cause less fibrin formation, but this position also raises the patient's risk of dysrhythmias. So far, no research has established which site is better; however, national standards of practice, Food and Drug Administration (FDA) guidelines, studies, and CVAD manufacturers' instructions recommend placement in the superior vena cava. Guidance documents from the FDA state that the intracardiac tip location isn't recommended.2 The Infusion Nursing Standards of Practice recommends that all members of the healthcare team collaboratively address CVAD tip location if the superior vena cava isn't used.1

Besides tip location, you need to document the CVAD insertion site—most often an upper extremity vein, subclavian vein, or jugular vein. If a CVAD is inserted via the femoral vein, obtain a chest X-ray to confirm placement in the inferior vena cava above the diaphragm.

If a catheter tip's intended location is distal to the diaphragm, it's not considered a CVAD.

Preventing infection

Catheter-related bloodstream infections (CRBSIs) take a tremendous toll on patients and eat up nursing time and other healthcare resources. Recent reports suggest that by paying close attention to many aspects of catheter care, you may be able to reduce these infection rates to zero.3

* Hand hygiene. Perform meticulous hand hygiene before touching any component of the CVAD, administration set, or fluid containers. Use an alcohol-based hand sanitizer unless your hands are visibly soiled—then use soap and water. Wear gloves if you may come in contact with blood; for example, while changing needleless connection devices or flushing the device. If you did other procedures first, perform hand hygiene and put on gloves (clean or sterile, as appropriate) before beginning any aspect of care involving the CVAD. Perform hand hygiene again after removing your gloves.

Artificial nails, nail polish, and nail extenders have been associated with outbreaks of CRBSI, so don't wear them if you perform catheter care.1,4,5

* Skin antisepsis. Chlorhexidine gluconate is the preferred agent for skin preparation at the insertion site.4 Although whether chlorhexidine should be used on nonintact skin is somewhat controversial, clinical evidence points to a lower risk of CRBSI when this antiseptic is used to clean the skin during dressing changes.6

The available chlorhexidine products also contain isopropyl alcohol, which can be problematic because some brands of CVADs made of certain types of polyurethane may not tolerate alcohol exposure. However, this isn't true of all polyurethane CVADs. Because of this variation, your facility's policies and procedures for cleaning insertion sites should be based on instructions for the specific brands of catheters in use. But in general, never apply alcohol-containing agents directly to a CVAD's external portion unless you know it's acceptable for that brand of catheter.

Chlorhexidine also can be applied to the insertion site in the form of a round dressing impregnated with chlorhexidine. These dressings reduce the risk of catheter colonization, exit-site infections, CRBSI, and costs of care.7–10

* Hub antisepsis. Microorganisms can be transferred into the catheter lumen from the luer-lock threads of the catheter hub and from the surface of the needleless connector used for attaching syringes and administration sets. Blood, drug precipitates, and tape residue can accumulate in the luer-lock threads and provide a medium for organisms to grow. Changing needleless connectors and administration sets can sweep this debris into the catheter lumen.

Although numerous reports cite the catheter hub as the source of infection, no studies have examined the best method for cleaning the threads.11 Anecdotal reports from nurses include using an alcohol pad to encircle the exterior hub surface and rotating the hub to remove debris.

The connection surface of a needleless connector also requires careful attention with each use. Again, research hasn't identified the best agent or method for cleaning this surface, but we do know that lack of cleaning can increase the presence of organisms inside the device. A 15- second scrub of the connection surface with alcohol or chlorhexidine/alcohol has been shown to prohibit microorganism entry on the surface.12–15

The correct method for administering medications directly through the catheter requires a saline flush to assess patency, followed by the medication and another saline flush. Depending on the design of the catheter and needleless connector, heparin flush solution may be used as the final flush solution. Because this procedure requires three or four connections to the needleless device, plan to use three or four alcohol pads—one before each connection.

CVAD management guidelines

Routine catheter assessment, catheter stabilization, dressing changes, and catheter flushing protocols may be specific to the type of catheter and its insertion site. Follow the manufacturer's guidelines and your facility protocols for these interventions. In addition, remember the following general guidelines.

* When performing your patient assessment, carefully palpate the area around the insertion site through the dressing. If the patient has tenderness or discomfort, investigate for infection. Assess surrounding areas for erythema, warmth, and edema. If the patient has a peripherally inserted central catheter (PICC), assess the entire arm. Erythema, tenderness, and edema could indicate phlebitis or vein thrombosis.
* For all types of CVADs, assess the patient's external chest wall for engorged superficial veins, which could indicate vein thrombosis. Other signs and symptoms of vein thrombosis include difficulty moving the neck or jaw, ear pain, and headache.
* Perform a comprehensive pain assessment. Ask your patient about any unusual pain or complaints. Chest discomfort could be associated with the catheter's position in the vein, especially if it was inserted from the left side and isn't long enough to reach the lower third of the superior vena cava. Instead, the catheter may abut the wall of the right upper superior vena cava. If the patient says he hears a running water sound or gurgling noises on the side of catheter insertion, the catheter tip may have migrated, usually into the jugular vein. Stop the infusion until the catheter tip is located on a chest X-ray.
* If you can't aspirate brisk blood return from the catheter or you can't flush the catheter without resistance, injecting a contrast agent under fluoroscopy can diagnose the problem.
* If your patient has a PICC, don't use the insertion arm for obtaining blood pressure (BP) readings or blood samples. When the BP cuff compresses the arm, it can bring the vein wall in contact with the catheter, increasing the risk of vein damage and thrombosis. Additional venipunctures in the area of a PICC could damage the PICC or a vein close to it.
* If you can't use the patient's opposite arm for BP and other venipunctures, perform BP measurement and venipuncture distal to the PICC insertion site.
Stabilization advice

A manufactured catheter stabilization device is the recommended way to secure a CVAD. These devices contain an adhesive anchoring pad to help reduce catheter dislodgment and the need for removal and reinsertion.16,17 However, sterile tape and surgical strips also are acceptable methods of catheter stabilization. Sutures and a dressing alone aren't sufficient. In fact, sutures are associated with needle-stick injuries and should be avoided whenever possible. And because sutures break the skin, they increase the potential for irritation and infection. If a suture site appears inflamed, the sutures should be removed and replaced with a manufactured stabilization device.

The Infusion Nursing Standards of Practice no longer list dressings as stabilization devices. Although dressings protect the insertion site and skin, there's no evidence that they enhance catheter stabilization. The chosen stabilization method or device should let you assess the catheter insertion site easily and shouldn't alter the flow of blood or fluid through the catheter. Taking care not to dislodge the catheter, remove the stabilization device when you change the dressing so you can clean the patient's skin thoroughly.

At each dressing change, document the external catheter length; if it's changed, the internal tip location also has changed. If this change is significant, the altered tip location could increase the risk of complications such as vein thrombosis and dysrhythmias.

Dressing changes

Transparent semipermeable membrane dressings or tape and gauze are acceptable for all CVADs. However, gauze dressings have several disadvantages: They don't let you see the insertion site, and they must be changed every 48 hours. In contrast, transparent dressings let you see the insertion site and can be left in place for up to a week if they remain clean, dry, and intact. No matter what type of dressing you use, change it immediately if it becomes soiled, wet, or loose.

When you remove a transparent dressing, pull up a small section on each side and pull laterally. The dressing should easily release from the skin and catheter. Never remove a dressing by pulling away from the insertion site; you could accidentally dislodge the catheter. Observe the insertion site for drainage, edema, and color or temperature changes. Take note of any changes in the surrounding skin, which could indicate maceration or indicate that the dressing was applied to skin still wet with the antiseptic agent.

Clean the skin around the insertion site and let it dry thoroughly. Although chlorhexidine-alcohol combinations dry very quickly, povidone-iodine requires a drying time of at least 2 minutes.4 Next, apply a skin protectant solution to prevent skin irritation and prolong dressing integrity. When the skin is dry, apply a new catheter stabilization device and a sterile dressing.

Don't apply antiseptic or antimicrobial ointment to the insertion site unless it's a hemodialysis catheter. Accord ing to the CDC, povidone-iodine antiseptic ointment should be applied to the hemodialysis catheter site after catheter insertion and at the end of each dialysis session as long as the ointment doesn't interact with the catheter material.4 Check the manufacturer's directions to see if povidone-iodine ointment can be used safely with the patient's type of catheter.

Label the site with the type, size, and length of cath eter; the date and time of dressing change; and your initials. In the medical record, document your site assessment, condition of the insertion site, your interventions if problems were noted, and the patient's response to any interventions.

Because water can be a source of microorganisms and has been documented to lead to CRBSI, tell the patient to protect the catheter dressing from water when he's bathing.

Facts about flushing

Flushing the catheter keeps incompatible drugs or fluids apart and maintains lumen patency. Use 0.9% sodium chloride solution to flush the catheter before and after each dose of medication. The initial flush lets you assess the catheter's patency and removes any heparin left if the catheter was used previously. Flush with 5 to 10 mL of 0.9% sodium chloride solution in a 10-mL syringe, paying close attention to the ease of flushing.

Never apply force if you feel resistance because even with a 10-mL syringe you risk rupturing the catheter. If you encounter resistance, stop and investigate the cause. For example, look for a closed clamp on the catheter or tubing. Check to see if an in-line filter is clogged—a sign that it's doing its job by preventing particulate matter from entering the bloodstream. Assess the insertion site for occlusion from the stabilization device or dressing.

If you don't find any external problems, consider the many possible internal causes of resistance. For example, if the CVAD was inserted through the subclavian vein, ask the patient to change his arm position. If this removes the resistance, the cause may have been pinch-off syndrome, which occurs when the catheter is compressed between the clavicle and first rib.18 Other possible causes include catheter occlusion from thrombus or drug precipitate, or fibrin or thrombus in the vein around the catheter tip.18 If you can't determine the problem, notify the healthcare provider, who may order a chest X-ray or a catheter contrast study using fluoroscopy.

After infusing medication, flush the catheter with 0.9% sodium chloride solution to ensure that the complete dose has entered the bloodstream.

Heparin lock—or not?

Because of the potential for heparin-induced thrombocytopenia (HIT), using heparin to lock the catheter is becoming more controversial. Labels on heparin lock solution now include warnings about HIT, so many healthcare facilities are trying to eliminate the use of heparin by switching to needleless intravenous (I.V.) connectors that can be flushed with 0.9% sodium chloride solution only.

Flush solution: Keep it clean

Because of the risk of contamination and infection, multiple-dose vials and large-volume fluid bags aren't recommended as sources for flush solution.19,20 Single-dose flush solution containers such as prefilled syringes and single-dose vials are the standard of practice.1 To reduce the risk of contamination, enter syringes and vials labeled for single use only once; because the solutions are preservative-free, don't use half of the fluid for flushing before the medication and half for flushing after the medication.

Wrestling with reflux

Blood reflux into the catheter lumen after flushing—which increases infection risk—is a common problem caused by traditional syringe design. Here's what happens and what you can do about it: After the 0.9% sodium chloride solution is flushed into the catheter from the syringe, the gasket on the end of the syringe's plunger rod is compressed. To detach the syringe from the catheter hub, you have to release pressure on the plunger rod. This causes the gasket to expand and draws blood back into the catheter lumen. To overcome this issue, use prefilled syringes designed specifically for catheter flushing. If these syringes aren't available, leave 0.5 to 1 mL of 0.9% sodium chloride solution in the syringe to prevent compression of the plunger rod gasket.

Another flushing technique that has gained widespread acceptance is the turbulent or stop-start technique. In this technique, you attach the syringe and inject the flush fluid with a rapid alternating push-pause motion. The theory is that turbulent fluid flow is more likely to dislodge material on the sides of the channel through which the fluid is flowing. Although this technique may help remove whole blood from the catheter lumen, it doesn't remove blood components that are firmly adhered to the catheter wall. Also, the technique isn't evidence-based.

For details on flushing needleless devices, see Implement the proper flush.

Removing the catheter

Nurses with documented competency in the procedure can remove percutaneously inserted CVADs, such as PICCs and nontunneled subclavian or jugular inserted central venous catheters. Check your facility's policy and your state's scope of practice to avoid liability issues.

To reduce the patient's risk of venous air embolism during CVAD removal, place him supine. (Sitting up increases the risk that air will be pulled into the venous system.) Stop the flow of fluid through the catheter. Remove the dressing and catheter stabilization device. Slowly withdraw the catheter from the vein using short gentle strokes. As you withdraw the last 5 to 10 cm, have the patient perform a Valsalva maneuver. As the catheter clears the vein and skin, immediately place pressure on the insertion site with dry gauze to control bleeding and prevent air from entering.

If the catheter tip needs to be cultured, don't let it drag over the skin during removal. Have a coworker cut the catheter's distal end with sterile scissors and let the tip fall into a sterile container while you hold pressure on the insertion site.

Once hemostasis has been achieved, quickly replace the dry gauze with gauze containing an antiseptic ointment. The ointment will provide an additional seal to close the skin-to-vein tract left on catheter removal. Secure this dressing with tape or a transparent semipermeable membrane dressing. Tell the patient to leave the dressing on for at least 24 hours until the site has closed.

If you encounter resistance when attempting to withdraw the catheter from the vein, stop. Don't try to forcefully withdraw the catheter; it could be kinked or knotted. Forceful removal could fracture the catheter and cause embolization.

Most commonly encountered when removing a PICC, resistance typically is caused by smooth muscle spasm inside the vein wall. Encourage the patient to relax and take deep breaths. Wait a few minutes, then try again.

If you continue to feel resistance, place a dressing on the catheter. Don't secure the catheter with traction, which would exacerbate the problem. Tell the patient to drink warm liquids and keep the extremity covered, warm, and dry. Several hours may pass before the vein relaxes enough for you to remove the catheter. If all else fails, the healthcare provider may prescribe a medication such as nitroglycerin to relax smooth muscle and allow catheter removal.

Another cause for resistance during catheter removal is vein thrombosis. Ultrasound can be used to quickly diagnose this problem. The patient may need an infusion of a low-dose fibrinolytic before the catheter can be removed.

A smooth line

Knowing how to manage a CVAD and recognize problems early can help you provide safe infusion therapy and reduce your patient's risk of complications.

Implement the proper flush

Correct flushing technique is imperative with needleless devices. You'll need to know which type of device is being used, although the product packaging may not state how the device functions.

* For negative fluid displacement devices, use a positive-pressure flushing technique. For example, when using a blunt cannula device, withdraw the blunt cannula from the split septum before the syringe is empty. This lets fluid fill the space taken by the blunt cannula. When using a mechanical valve, maintain pressure on the syringe plunger rod, then close a clamp on the catheter or extension set located between the needleless connector and the patient.
* For positive fluid displacement devices, flush without the positive-pressure technique, which would prevent the internal mechanism from functioning. If hospital policy and procedure call for the catheter clamp to be closed, wait a short period for fluid displacement to occur, then close the clamp.
* Neutral displacement devices aren't dependent on flushing technique, so any technique can be used.
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