I am wondering if anyone has read literture regarding increased blood pump speed related to increased access failure. We have been looking into larger bore needles (14 ga.) and QB of 500-600. When changing these parameters related to their kt/v we are able to decrease run times. Any literature regarding this issue?

Janelle,

The use of pre-pump arterial pressure monitoring will help validate the delivery of 500-600 ml/min blood flows. Please reference the post from 3/00: Is Arterial pressure monitoring necessary?

Access blood flow rate measurements for fistula patients are also helpful. A fistula may have a low access blood flow measurement below 400 ml/min. If the hemodialysis treatment blood flow rate is higher than the access blood flow rate, recirculation can result. A blood flow rate of 500-600 ml/min set on the blood pump does not always equal a true 500-600 ml/min of extracorporeal blood flow.

The difference between the blood pump speed and the actual extracorporeal blood flow may be why the clearances do not improve with the faster blood pump speed.

Deborah


[This message has been edited by Deborah Brouwer (edited 07-03-2000).]

Janelle,
I would do a Medline literature search using "neointimal hyperplasia" ( also try "intimal hyperplasia") and "vascular access for hemodialysis" as your key words.

There is thought to be a link between use of higher blood flows ( more turbulance in the access) and increased access problems. It still needs to be proven scientifically but I believe there are papers out there that discuss this possible link.

There is currently an NIH Consortium forming to look into this and other access related issues. Hopefully we will get an answer to this problem from there.

In the meantime, I agree with Debbie. Monitoring pre-pump arterial pressure and making blood flow adjustments and /or needle gauge selection accordingly should help to minimize potential damage to the access.

You can access Medline via Pubmed from RenalWEB. Click on "Links" at the top of the home page, and go to nephrology resources.

Good luck !

i have worked for years at units where all male pts run 4 hours and all females run 3.5-3.75 hours regardless of their kt/v. Needless to say, our patients do very well. We get concerned when the urr drops towards 70 and the kt/v drops towards 1.65. All pts start at 3 days a week from day one. If we use a cath, their time is increased until a permanent access is used. we use 15g needles on all developed accesses. We even get high urr's with 16 and 17g needles on new accesses because of increased time until we use 15g needles on the access.