Saline for Locking Central Venous Catheters - Not a Good Idea!

I have always been skeptical of using saline alone for flushing and locking central venous catheters, but until now the evidence has been very limited. While searching the literature for a new manuscript about heparin, I found a new article that provides more information.

Cesaro, et.al conducted a randomized trial in children with cancer and newly inserted tunneled, cuffed catheters. They compared one cohort with heparin flushing and a "standard cap" (their term) to saline only flushing with a positive displacement needleless connector. There were 203 patients and more than 75,000 catheter days. The experimental cohort has twice the rate of occlusion and almost triple the rate of bacteremia.

There has been a small study of a similar type in patients with PICCs. Bowers, et.al found a 6% occlusion rate with saline only flushing and a positive displacement needleless connector. This rate was not statistically significant, possible because the study had only 102 patients. The authors went on to quantify the cost of declotting 6% of their PICCs annually and reported that even this small number was too costly.

Evidence is growing that saline alone is not sufficient for locking any central venous catheter. I know there are numerous issues with heparin and we need alternatives, but there is no alternative locking solution that has been cleared for market by the US FDA at this time. So we keep waiting and using heparin or obtain one of the alternative solutions from a local compounding pharmacy. Neither are good options, but those are the only choices currently. I would encourage everyone to obtain and read these recent articles and apply them to your evidence-based practice. Click on the highlighted authors name above to get to the reference information and abstract.

Using a PICC before the Xray Results

We are a 5 member PICC Team and do a large number of insertions per month. The question I have is about using a PICC before the x-ray has been read. A few of us feel that the PICC is the best peripheral IV you will ever have. Some tell our staff that they can use the PICC as a peripheral IV but not as a central line until the x-ray has been read. As long as you have a good blood return why can't you use this line for peripheral fluids?


No catheter inserted to be a central venous catheter should ever be used for any infusion until the actual tip location has been confirmed. The reason is very simple - you do not actually know where the catheter tip is located until you have the results of a chest xray. The catheter tip could be angled toward the head in the internal jugular vein or in the contralateral subclavian vein. In those cases, the infusion is flowing against the blood flow. Retrograde infusion into the intracranial venous sinuses can lead to neurological complications. Also the tip can be impinging on the vein wall, increasing the risk of thrombosis which is compounded by the infusion. Infusion of any fluid or medication could be into any number of smaller tributary veins which would increase the risk of thrombosis. So, a flush with normal saline and locking with heparin is all that should go through any central venous catheter until the tip location is actually known.

You may be concerned about the length of time that is required to receive the information about the tip location from radiology. There are 2 things that can change this situation.

The PICC Team can take on the responsibility of assessing the chest xray for tip location, avoiding the wait for a radiologist to read the film. This has been considered within the scope of nursing practice in many areas of quite some time and it continues to grow today. You will need to have the knowledge and skill to assess the chest xray. Please notice that I did not say that the nurse is "reading the xray" as this is only within the medical scope of practice. We offer an online continuing education course in assessing chest xrays for catheter tip location. Learn more by clicking here.

The other change is to use new technology that will identify the tip location immediately during the insertion procedure. There are several types of catheter tip locating devices currently available. Also, you can use the ultrasound probe to rule out jugular placement immediately after insertion. Another approach currently involves the use of ECG to determine changes in the P wave to know when the catheter tip is at the level of the SA node, which is at the top of the right atrium. A new technology from Vasonova is very promising. To learn about this, click here. Other promising technology on the horizon will use an infrared light device to detect the catheter's tip location. While changes in technology seem very promising, the current standard of practice is to obtain a post-procedure chest xray. Use of this new technology will probably change this standard, but that has not happened yet.

Your concept of a PICC being the best peripheral IV is erroneous. Although you have made the veinpuncture into a peripheral vein, the catheter is advanced into the thorax where it can and does go into a number of alternative locations. These locations have been well-documented to lead to catheter complications such as thrombosis, vessel erosion, and many other issues. I would also be very concerned about having the primary care staff nurses known when you could or could not use this catheter for central venous infusion with your approach as there is no consistency among your PICC team. The current national standard of care is to avoid using any central venous catheter until you have adequate confirmation of the tip location. This will provide the safest approach for your patients.

Parenteral Nutrition in Neonates- Peripheral or Central Catheter?

I've been to the National Association of Neonatal Nurses and others and cannot find a standard for my question. I'm looking for protocols regarding infusing total parenteral nutrition (TPN) and fat emulsion through a short peripheral catheter in a neonate.

You have a great reason to be concerned about this practice. First, we have traditionally divided parenteral nutrition into "total" or TPN and "peripheral" or PPN. Those classifications have now virtually gone by the wayside. The guidelines and standards of practice from the American Society of Parenteral and Enteral Nutrition use the term "parenteral nutrition". ASPEN recommends that a central venous catheter be used due to the high osmolarity of most PN formulations. Click here to access the ASPEN documents.

The Infusion Nursing Standards of Practice states that the maximum osmolarity that should be infused through a peripheral vein is 600 mOsm per liter. All parenteral nutrition formulaes are above this level. Pharmacy literature uses maximum concentration of 900 mOsm per liter. Some formulas with very low concentrations of dextrose may fall below this level. The Infusion Nursing Standards are reviewed by pediatric and neonatal experts, so inclusion of the lower level indicates these experts acceptance of the maximum of 600 mOsm.

The new textbook, Infusion Nursing- An Evidence-Based Approach, includes a chapter on infusion therapy in children and was co-authored by two pediatric and neonatal nursing experts. They state that 10% dextrose is the largest concentration that should be infused through a peripheral vein and recommend that concentrations greater than 10% be infused through a peripheral vein.

Both 10% and 20% IV fat emulsion products are isotonic and can be infused via peripheral veins. Infusion with the other PN components can decrease the irritation caused by the hypertonicity of the PN solution. However, the dextrose content should not exceed 10% and the total osmolarity should not exceed 600 mOsm per liter, although some may extend this to 900 mOsm per liter. The number and condition of veins in most neonates are quite limited, therefore the risk of peripheral thrombophlebitis must be weighed against the risk of inserting a central venous catheter.

These 3 resources would establish the national standard of practice.

Time Interval for Repeat Chest Xrays

Do you know of any research articles written that investigate the occurrence of PICC tip malpositioning after a PICC is inserted and initially confirmed?
We are trying to make evidence-based practice changes with regards to INS standard 42; practice criteria N., “If the patient is receiving long-term or chronic therapies, repeat radiographic study should be performed to confirm catheter tip location, according to organizational policies and procedures”. Our hospital is trying to determine what an acceptable time period should be to perform periodical chest films to re-confirm tip location in patients receiving long-term therapy.

The tip of any central venous catheter, including PICCs, can migrate. This is well documented to occur with migration from the original superior vena cava-right atrial junction to the internal jugular vein, the contralateral subclavian vein, and into the right atrium. Conventional thought has related the risk of this problem to changes in intrathoracic venous pressure and arm movement. More recently, a poster at the 2009 INS conference provided details of animal studies showing that aggressive, rapid, or forceful techniques for flushing catheters can also lead to tip migration.

The challenge is that the problem occurs sporadically and spontaneously. There is no pattern and therefore, no available recommendations for the frequency for repeat chest radiographs to assess tip location. A patient with pneumonia and severe coughing may have the catheter tip noted on a routine chest xray to be in the internal jugular vein but a repeat xray within a short period of time shows it to be in the SVC-RA junction.

So there is no way to create an evidence-based time interval for a repeat chest xray. Your policies and procedures should address the signs and symptoms of tip migration that would provide clinical indications for a repeat chest xray. This would include, but not be limited to, lack of a blood return, difficulty with flushing or infusing, complaints of hearing a running stream or gurgling sound, strange pain or discomfort in the neck, back, shoulder, or chest, cardiac arrhythmias, or changes in respiratory or cardiac status. Retrograde perfusion of infused medications into the intracrainal venous sinuses has also lead to neurological conditions. I wish it were as easy as a specific time to recommend a repeat chest xray, but this is a decision based on clinical evidence. So this requires infusion nurse specialist with indepth knowledge of the patient and catheter and potential outcome.

Prefilled Syringes and Expelling the Air

I'm hoping you can advise us on removing the air from our pre-filled flush syringes. We have new staff who have been doing this differently than our policy calls for and I want to make sure we are doing everything we can to protect our patients as well as make their infusion at home as easy as possible. My question is: Does pulling back on the pre-filled syringe to the break the seal before expelling the air increase the patient's risk of infection?

Prefilled syringes for catheter flushing are packaged in 2 different ways - aseptic filling and terminal sterilization. Aseptically filled syringes are virtually the same as batch filling in your hospital pharmacy. A syringe is filled with sterile fluid under aseptic conditions such as a laminar air flow work bench and capped. The filled syringe is then packaged without additional sterilization. Terminally sterile syringes are filled, capped, sterilized and then placed in a clear overwrap package. Both processes result in a product that is sterile within the fluid pathway and the male luer tip of the syringe, although a terminally sterile product has a higher level of sterility. It is important to note that terminally sterile products should not be confused with a completely sterile product that can be added to a sterile field. These syringes are filled, capped, packaged in a strong overwrap and then sterilized, resulting in a product that is sterile on all surfaces.

I am not sure if you are using an aseptically filled or terminally sterile prefilled syringe. All will have a plastic overwrap that serves as a dust cover. So the space in the distal syringe barrel outside the fluid area will be clean but not necessarily sterile. You will need to expel the air before use and this should be done by pushing forward on the plunger rod rather than pulling back.

There is another issue - after attachment to the catheter hub, the plunger rod must be pulled back to aspirate for a brisk blood return from all catheters. This is a national standard from the Infusion Nurses Society and the Oncology Nursing Society. After you have pushed forward to expel the air, there should be a small space to allow you to aspirate to check for a blood return from the catheter.

For a terminally sterile prefilled syringe, this action should not add to the risk of catheter-related bloodstream infection. These syringes have been sterilized after filling. The type of plastic overwrap is intended to prevent dust and other particles from coming into contact with the syringe barrel. While the distal barrel is not labeled as "sterile", there has not been a reported outbreak of infection associated with these syringes.

For aseptically filled syringes, the risk could be greater because there is no sterilization process after filling the syringe. There have been outbreaks of infection reported with aspetically filled syringes, although not directly attributed to any contamination of the distal syringe barrel.

To read additional information about the misuse of prefilled syringes, click here and then go to Volume 4, No 4. Scroll through the issue to the second story - Misuse of prefilled flush syringes
Implications for medication errors and contamination.

Ultrasound for Short Peripheral Catheters by Primary Care Nurses

I am a PICC insertion nurse working through Interventional Radiology. My hospital currently does not have a vascular access team for the placement of Peripheral IV's. The Nurses in the ICU and trauma units as well as the med-surg floors place their own IV's. The Trauma portion of the Hospital has purchased Site-Rites to allow the physicians to place central lines. I was approached by a nurse who has questions about the placement of Peripheral IV with the use of these ultrasounds due to the fact of their goals to reduce the use of short term central lines. I am concerned with this practice. I would like your views on this subject. My question to you is there information on this specific technique? Is this a practice that should be discouraged or perhaps at least approached delicately.

There are several published studies supporting the use of ultrasound for placing short peripheral IV catheters in specialty areas such as ED. These studies report a greater success rate with venous cannulation, making the nurse and patient more satisfied - initially. The downside is that we do not have data on the clinical outcome with these US-inserted catheters. US requires one of two techniques to insert a short peripheral catheter. The static approach uses the US to locate the vein and mark the spot. The probe is then set aside and the venipuncture proceeds as it normally would. This uses an expensive piece of equipment for a very limited purpose. The other method is called the dynamic method where the nurse continues to hold the US probe while making the venipuncture. This utilizes the benefits of the US, however it requires dramatic changes in technique or a second person. We need one hand to hold skin traction during venipuncture and catheter advancement and one hand to hold the catheter. This does not leave a hand to hold the probe. So either a second person is involved or the skin traction is sacrified. This is where the lack of clinical data on catheter outcomes is a problem. Do this catheters produce a greater amount of phlebitis or infiltrations?

Another issue is the length of time those catheters will actually dwell and again there is no data. Even if the primary care nurses are successful with getting the catheter in, it might only last for a few hours before it fails. Then the procedure must be repeated, driving up the costs of care. To avoid this situation, there must be a comprehensive approach to all vascular access assessment and proactively choosing the correct device that has the greatest likelihood of reaching end of therapy with the minimal number of devices used. Turning staff nurses loose with an US machine will never achieve this goal.

US is also designed to locate veins that are deep in the tissue, usually between 10 to 20 mm. The superficial veins used for short peripheral catheters lie in more superficial tissue usually between 3 to 9 mm. So US may be more beneficial for bariatric patients or those with severe obsesity where the superficial veins are deeper in the tissue.

The other issue is the huge learning curve with US. It usually requires ~50 insertions to become comfortable with using US for a PICC insertion. I am not aware of how many attempts it would take to reach this goal for a short peripheral catheter insertion.

There is no doubt that the use of US is a benefit in the hands of the correct professional but I would not favor trying to get all primary care nurses skillful with its use.

There is a newer and better technology for this purpose - infrared light devices. I gave a presentation on this at the INS conference this year and will soon be putting this up as an online CE course. More on that later. So to answer your question, I would approach the use of US in this situation with serious caution.

Masks for Changing Needleless Connectors??

I work in Vascular Access at a large teaching facility. They have instituted a new policy requiring a mask and sterile gloves for all cap changes. What gives with this? It doesn't make sense.

If correct technique is used then why would you contaminate sterile gloves by removing the old caps or even exposing an open catheter to air while you remove dirty gloves (after removing the old caps) and don sterile ones?

You raise some valid points but first, let me see if I understand what you are asking. Your facility now requires that the change of a needleless connector on the hub of all vascular access devices be changed while you are wearing a mask and sterile gloves. You did not provide the exact procedure that your facility has implemented for this, so I can not make any judgments about that.

I can understand the driving force behind this new recommendation - no reimbursement for hospital acquired bloodstream infection. Your question included the phrase "If correct technique is used" and there is a lot of details in that simple qualifier. We know that correct technique in cleaning needleless connectors has not been properly identified through research. This would include what agent to use for cleaning, how long should it be cleaned, what scrubbing techniques, and length of drying time. There are no real answers to any of these issues yet. We also know that these connectors can become heavily contaminated and do grow biofilm, the primary cause of catheter-related bloodstream infection (CRBSI).

We also know that air embolism is on this same list of outcomes that will no longer be reimbursed. Therefore you must use appropriate technique to clamp the catheter when changing any administration set or needleless connector. You can NEVER leave a catheter open while you change gloves and I don't think this is what your facility had in mind.

I do not completely understand the requirement for sterile gloves as these needleless connectors and catheters hubs are definitely not sterile. Maybe the prevailing thought was that regular exam gloves may be contaminated and they did not want to take this chance. Since this is a teaching hospital, I would imagine that your patient acuity is very high and therefore has more risk factors for infection. I can easily see the benefits of a mask while doing any catheter care, however I am not aware of any research that has identified masks during dressing or connector changes as an appropriate method to prevent CRBSI.

I would recommend that you track down the people who originated this policy and ask more questions. You need to know more about the thoughts that went into these recommendations. I would be very interested in what those thoughts are. So please share them when you located the people responsible.