Flushing Dual Lumen Catheters

For patients with a dual lumen valved catheter, we are teaching the patient and primary caregivers to do their own daily infusions of an antibiotic. Our policy states that the valved catheters can be flushed weekly with normal saline when not-in-use. One lumen is "not-in-use." Do we teach the family to only flush it weekly? Or do we teach them to rotate the use of the lumens?

My first thought is that when only a single antibiotic is required, a dual lumen catheter, with or without an integral valve, is definitely not required. There are studies showing that more lumens increases the risk for catheter-related bloodstream infection. The number of needed lumens must be an important part of the pre-insertion patient assessment for their vascular access needs. If your team is only provided with dual lumen catheter, with or without an integral valve, for use in all patients, this is a serious situation that you should work to correct.

On the other hand, this could be a patient that had multiple therapies prescribed when the catheter was placed and a dual lumen catheter was needed. Now that the patient is going home and continuing their own infusions, the issue of how to manage the extra lumen becomes important. This brings up the question of exchanging the dual lumen catheter for a single lumen catheter prior to discharge.

I am not aware of any published evidence to help with answering these questions, so we must examine the risk associated with each option and choose what is best for each patient. When changes in infusion therapy leaves an unnecessary or extra lumen, some will choose the exchange procedure so that the patient only has to manage one lumen. As stated, single lumen catheters have a lower risk of CRBSI because there are fewer hubs to manage. But there are risks associated with the exchange procedure. I am not aware of studies that have examined the complication risks associated with the exchange procedure and there is concern for infection. The exchange procedure must be performed on the external catheter segment that is not sterile. I would consider factors such as the patient's ability to perform the required flushes and the costs associated with those flushes versus the cost and risk of a catheter exchange. Valved catheters may recommend weekly flushes, however nonvalved catheters must be flushed at least once per day with saline and heparin. Also, is the patient immunocompromised and/or hypercoaguable? These factors could increase the risk of catheter exchange making it less of a possibility. If the patient will be receiving the infusion therapy through a continuous ambulatory infusion pump with the nurse visiting daily to change the cassette, the home care nurse can also flush the extra lumen without any problem.

That still leaves us with the question of how to manage the extra lumen when a single lumen catheter has not been chosen and an exchange is determined to be a greater risk than managing an extra lumen. Again, we must look to the evidence and I am afraid there is not an evidence-based answer to this question. All valved catheters are flushed with saline only and the frequency can be no more than weekly according to some manufacturer's instructions for use. You should always know what is recommended by the manufacturer of the specific catheter in use. Some think that alternating lumens for the antibiotic infusion will reduce the risk of CRBSI because of exposing both lumens to the antibiotic. This concept conflicts with what is known about biofilm. Infusing antibiotics do not penetrate the intraluminal biofilm and would make no difference in the risk of CRBSI. So there truly is no answer for this question and I would say that both practices are acceptable. You can use one lumen dedicated for infusion and only flush the extra lumen weekly with a valved catheter, at least daily with a nonvalved catheter. Or you can alternate the lumens for infusion. We simply do not have any data upon which to decide which is the best method.

Best of all would be to choose the number of lumens based on the patient's infusion needs from the beginning. But as we have discussed prescribed therapy can change. The choice of lumens is based on what is the easiest for the patient and caregiver to perform.