Thursday, February 18, 2010

Studies on Backpriming

I just read your Nursing2004 article on back priming. It was very helpful to have the technique spelled out so clearly. The pictures were great. I have no bibliography listed for this article. I am specifically looking for a research-based article comparing back-priming with using a new tubing for each new secondary med. Can you give me some guidance?

Unfortunately, this is an area of clinical practice that has received no attention and no research. There are several studies on IV administration sets, but many of them have purposefully excluded any examination of secondary piggyback sets and primary intermittent sets. The remaining studies have included no information about these additional set uses for medication delivery, so we are left to wonder if they did or did not include them. Virtually all administration set studies have looked at the length of time a primary continuous set can be left in use without increasing the risk of bloodstream infection. I am sorry to say but there are no studies, especially studies comparing different methods.

For anyone interested, the article mentioned in the question is
Hadaway L. I.V. Rounds: Delivering multiple medications via backpriming. Nursing2004. 2004;34(3):24, 26.

The absence of studies means that we are left to base practices on general principles of infection prevention. Any time an IV administration set is connected and reconnected, there is concern about several issues. One is how to maintain the male luer end of that set in a protected manner. As you know, the sterile components of all IV sets are the fluid pathway, the spike on the upper end and the male luer on the lower end. When removed from the packaging, both ends are covered with a plastic cap to maintain their sterility. With each use, the sterility of the male luer end must be maintained by adequate covering with either a new blunt plastic cannula or a new sterile dead end cap. It is not acceptable to use the foil package of an alcohol pad or to leave these male luer ends uncovered, yet it is frequently done.

There is another practice called looping, where the male luer end is inserted into a needleless connection higher on the same set. There is no evidence to support this practice and therefore it is not recommended, yet it is frequently done.

The second issue to consider is how well the needleless connectors are being cleaned before each attachment of a set or syringe. While we do not have copious amounts of data, we do have some information showing us that one quick swipe with an alcohol pad is not sufficient. We do have one small study showing that 15 seconds of vigorous scrubbing of all surfaces - top and sides - with both 70% alcohol or chlorhexidine gluconate/alcohol combination products will prevent passage of microorganisms through the connector. So you will need to consider how well your nursing staff performs this cleaning step with each and every attachment to the primary continuous infusion set and/or the catheter hub.

Finally the backpriming method brings up issues of compatibility. It may not work as well in critical care units where there are numerous drugs admixed in the primary fluids. In those situations, normal saline is used as the "carrier" fluid and all secondary sets are piggybacked into this line. All backpriming is done with the normal saline, eliminating the concerns about drug incompatibility.

The bottom line is that current thoughts from experts in the field focus on frequent connection and disconnection as a source of introducing microorganisms into the administration set and/or catheter. These organisms attach to the plastic catheter where they form a biofilm. Breakage of this biofilm with introduction into the bloodstream is what produces bloodstream infection. Therefore we must do everything possible to reduce or eliminate the introduction of these organisms into the system. Keeping secondary sets attached to the primary administration set is considered to be best practice. The backpriming technique facilitates this practice and eliminates the risk associated with connection and reconnection.

2 comments:

Anonymous said...

I am also very interested in this topic as our department does use new different secondary tubing for each drug. I am bringing this issue to our practice council this month to discuss the use of backpriming and using the same secondary tubing for multiple drugs. If you use the backpriming method, and the primary IV fluids are compatible with each of the medications being delivered by the secondary tubing, is there any need to check the compatibility between each medication given via secondary tubing?

Lynn Hadaway Associates, Inc. said...

The backpriming method should be sufficient to flush the small amount of residual drug from the secondary set back into the empty fluid container. This should mean that there would be no reason to be concerned about compatibility between the different piggybacked medications. The only time this could be an issue would be if the piggybacked medication was known for adhering to the plastic tubing. This is common with insulin and nitroglycerin, however those are not drugs that would usually be piggybacked. I would not want to piggyback into a primary continuous set with either of those drugs mixed in the primary fluid either. So my opinion is that compatibility between the various secondary medications would be less of an issue. Of course there are no studies to refer to about this practice. I would recommend that your practice council consult with a pharmacist knowledgeable about IV drug compatibility information just to be sure. I just checked some recent compatibility information on Vancomycin and found conflicting compatibility information when given with ampicillin, several of the cephalosporins, nafcillin, piperacillin, ticarcillin and tigecycline. I would recommend that you assess the common combinations prescribed by physicians in your facility and then assess the compatibility of those combinations. Please let us know your decisions or any other concerns that others may bring up.