Remember when CVCs only appeared in intensive care units? Patients are now being discharged with them still in place. Once used primarily for patients receiving vesicant chemotherapeutic agents or total parenteral nutrition (TPN), CVCs are now used for all types of infusion therapies, including antibiotics, monoclonal antibodies, steroids, blood transfusions, hydration, parenteral solutions, and blood sampling in a variety of settings. CVCs also may be utilized when the patient has limited or no peripheral vein access. With earlier discharges of patients who still require infusion therapy, many hospitals send patients to acute care facilities, long-term care facilities, or home with a CVC. With over five million CVC insertions each year, nurses need to be knowledgeable about the potential problems that may develop when caring for patients with these devices.^1,2

CVC classifications

Types of CVCs include nontunneled catheters; tunneled catheters, such as Hickman or Groshong, and implanted devices, such as Port-A-Cath or InfusaPort; and peripherally inserted central catheters (PICC).² Specially trained nurses can insert PICC lines and in some states, nontunneled catheters; physicians or surgeons insert other CVCs. Generally, the physician, nurse, and patient choose the device based upon the type of therapy, patient condition, and length of therapy.³ According to catheter manufacturers, CVCs cannot be used to inject contrast media with a power injector. The extremely high pressure of the injector will cause the catheters to rupture. However PICC catheters that have been FDA-approved for use with power injectors are currently on the market. These catheters will have an imbedded notation on the catheter hub. A new implanted port has also been approved for use with power injectors. When palpating the port, the nurse will feel a triangular-shaped port, as opposed to the usual round shape. Only this port can be used with high pressure power injectors. The patient may also be wearing a purple wrist band. It is the nurse’s responsibility to use each CVC appropriately.

CVC complications

There are over 20 CVC-related complications. Nurses are responsible for assessing the CVC for complications each time the catheter is flushed or used for the infusion of IV solutions or medications. Three common complications are catheter occlusion, when the catheter lumen is occluded with blood, fat, or drug precipitate; catheter malfunction, which is evidenced by an absence of blood return; and pinch-off syndrome, when there is an intermittent blood return.

Catheter occlusion

In many institutions, central venous access requires the use of an infusion pump to control the rate of fluid administration of IV medications and solutions; if the pump signals an occlusion, or you are unable to flush the CVCs, check for mechanical difficulties — kinks in the IV extension tubing or catheter; clamps closed on IV tubing, catheter, or extension tubing; or infusion pump failure.^4,5

If investigation reveals no mechanical problems, and you are still unable to flush the catheter or the infusion pump continues to alarm, check for drug incompatibilities in recent infusions. For example, if a continuous infusion of an IV solution containing 5% dextrose was not cleared from the tubing before phenytoin (Dilantin) was given as a push or intermittent dose, the medication may have interacted with the dextrose within the catheter and formed a precipitate.⁴ Sodium bicarbonate and hydrochloric acid can be used to clear drug precipitates from the catheter lumen, and ethanol alcohol can be used to clear lipid or fat deposits from the catheter lumen. However, the most common reason for intraluminal occlusion is that the catheter is clotted with blood. Alteplase (Cathflo Activase) is the only Food and Drug Administration-approved drug to clear catheters that are clotted with blood. As always, the nurse must obtain an order from the physician before instilling any declotting agent into a patient.³

Catheter malfunction — absence of blood return

CVCs allow direct access into the largest veins of the body. Proper catheter tip placement is in the distal one-third of the superior vena cava (SVC), or atrial/caval junction, which has a blood flow of 2,000 ml/min. This allows all IV solutions, including vesicant and hyperosmolar fluids, to be infused without damage to the vein wall. It is the nurse’s responsibility to have radiographic confirmation of the anatomical location of the catheter tip prior to flushing or infusing through any CVC. If the catheter tip is outside the vena cava, the catheter tip is in a high-risk area for complications and should not be used. A physician order of “OK to use” is not valid. The catheter tip must be confirmed in the vena cava.^1,2,7

The human body reacts to any foreign body. In the case of CVCs, the body sees the catheter as a foreign object and attempts to isolate it by producing biofilm and fibrin which covers the entire outer catheter surface, including the catheter tip, like a sock. Fibrin sheath formation begins immediately after the catheter is inserted. Virtually all outer catheter surfaces are totally covered within 10 days of catheter insertion. Bacteria can become imbedded in the fibrin sheath, thereby increasing the risk of catheter-related sepsis.⁴ Proper assessment of CVCs also includes obtaining a substantial free-flowing blood return (3 cc) with the catheter tip radiographically confirmed in the SVC. The inability to obtain a free-flowing substantial blood return is a sign of the formation of a fibrin sheath. The clinician may be able to flush and infuse IV fluids with no difficulty, but be unable to withdraw 3 cc of blood. The vacuum created by the negative pressure of withdrawal pulls back the flap that is formed by the fibrin sheath, covering the catheter tip opening, which prevents blood from entering the catheter lumen. The appropriate nursing intervention is not to use the catheter until a blood return can be established.^1,4

When a fibrin sheath forms along the length of the catheter, IV fluids may be diverted back along the outer surface of the catheter to the insertion site. IV fluid may leak into an implanted port pocket or leak out of the catheter exit site. Assess the condition of the skin around the insertion site of the catheter. There should be no swelling, redness, pain, or irritation, and no leakage of drug-smelling fluid around the site.³

Currently, alteplase (Cathflo Activase) is the thrombolytic drug approved by the FDA for clearing occluded catheters. It easily clears occlusions due to fibrin sheath formation or clotted blood within the catheter lumen, restoring a substantial free-flowing blood return and allowing infusion of IV fluids without leakage at the insertion site. There have been no reported incidents of alteplase-induced systemic fibrinolysis.⁶

Before instilling the drug, the contents of the catheter are aspirated. Two mg of reconstituted alteplase is instilled in the catheter. After 60 minutes, the catheter is aspirated for a blood return and if successful, the catheter is flushed with NSS. If the first instillation is unsuccessful‚ a second instillation of alteplase may be needed. The earlier the nurse recognizes the symptom of fibrin sheath formation and treats the problem, the more successful the treatment.^3,7

If alteplase fails to restore catheter patency, a cathetergram and venagram can be obtained. Both are contrast X-rays that can be useful in identifying catheter-related complications.⁷ The cathetergram provides information about the catheter’s condition, while a venagram provides information about the condition of the vein.⁵

Pinch-off syndrome

If a blood return is only obtained when the patient’s arm on the same side as the catheter insertion site, is raised parallel to the shoulder, this is a symptom of pinch-off syndrome. This indicates the catheter is compressed between the clavicle and first rib. Each time the arm is raised, the catheter compression is relieved, and a blood return is obtained. The pinched catheter can fracture as a result of the bone’s continuous movement and compression. Pinch-off syndrome is a serious catheter-related complication that requires the nurse to stop using the catheter and notify the physician immediately to surgically reposition the catheter. The catheter is most likely to break within six months of insertion.⁴ The patient may be asymptomatic until the nurse flushes the catheter or attempts to infuse through the catheter. The result can be serious injuries to the chest wall and chest organs.^1,3

Nursing management

Preventing CVC complications begins with regular assessment and proper nursing management of the CVC. Routinely assess insertion sites, ease of flushing, and quantity and quality of blood return. CVC dressing changes should be done weekly and also when the dressing is damp, loose, or soiled. According to the CDC, the skin cleansing agent of choice for all CVC dressing changes is chlorhexidine. Published research data shows that chlorhexidine reduces catheter-related blood stream infections (CRBSI) by 50% compared to Iodine-based products. Chlorhexidine has a residual skin effect for 48 hours compared to alcohol, which has a residual effect for 15 minutes. The correct method for cleansing the skin for CVC dressing changes is to use a side-to-side, and up-and-down motion while employing friction. No research data or best practice evidence validates concentric circles as a skin cleansing method. Transparent dressing, without gauze, should be used to cover the catheter skin junction site in order to assess for catheter site complications.^2,5

CVCs require routine flushing to prevent blood clotting within the catheter lumen. The flush should remove all IV solution and mechanically rinse the inner catheter walls. To completely clear the line, the volume of the flush needs to equal the internal volume of the catheter, including port septum and extension tubing, plus an additional 1 cc to 2 cc, depending on institutional policy.^5,6 Remember, all CVC catheters have an internal luminal volume of 1cc or less. Always use a 10 cc or larger syringe when flushing CVCs to lessen the pressure exerted against the catheter.² The larger the barrel of the syringe, the lower the exerted pressure on the catheter. Catheter end caps and extension tubings should be changed weekly with the dressing change, and after blood draws.⁵

To follow a SASH (saline-administer-saline-heparin) technique, flush the catheter with the recommended volume of NSS, administer the medication, flush again with the appropriate amount of NSS, and finally, instill heparin (10 units heparin per 1 cc), allowing the heparin to dwell in the catheter until the next use.⁵ For patients who receive frequent intermittent IV antibiotics or other medications through the catheter, especially those at risk of bleeding, you may reduce the amount of heparin flushed into systemic circulation by eliminating the heparin dwell between uses until an extended period (more than four hours) without access occurs. This will prevent heparin-induced thrombocytopenia (HIT).^5,7 Remember to flush the catheter, not the patient.

When clearing the catheter with normal saline after blood sampling or blood transfusion, flush vigorously with a minimum of 10 cc to 20 cc of NSS to clear the line completely.⁴ Be aware of potential drug or solution incompatibilities among IV fluid therapies and parenteral nutrition admixtures. Adequate flushing between administrations of incompatible solutions will clear the catheter lumen and avoid precipitation.⁵ Catheter lumens or CVCs not being used for continuous IV infusions should be flushed every 24 hours.^5,7

In acute care and skilled nursing facility settings, central venous access is of value for both patients and nurses. Many patients rely on the integrity of CVCs for continued care in their own homes. Long-term placement avoids repeated restarting of peripheral IV sites, and use of the CVCs for blood sampling eliminates frequent venipuncture. Nurses can safely administer vesicant and irritant medications, as well as parenteral nutrition, in alternative care settings by carefully maintaining CVCs.