Gambro AK 200 Clotted pressure lines

[Sleepyhead]

Hello

I have a big problem with blood clotting in pressure lines (the lines that attach to the transducers) - both the A and the V.

It is usually the V that causes the problem and it quite often fills with blood right at the start of treatment.  Of course, after a few hours' dialysis, it becomes really clotted and the venous pressure reading just stays the same.  THis is OK if the reading is within the parameters but this doesn't always happen and then alarms go off.  I have tried to get rid of the blood by attaching a syringe to the line and  pushing air back down the line.  However, this fills the bubble chamber with air and then I have to let the air out to bring the level up again (not easy in single needle as I have to wait for the venous pump to start turning and there is only a small window after the venous pressure override has been pressed).  Once I damaged the filter on the line by trying to push air down the tube and it left blood all over the transducer and part of the inside of the machine.

Last night, the A clotted as well and, luckily, I managed to get this clear quite quickly (again, by pushing air down the line). 

However, what I would really like to do is stop the blood getting into the pressure lines in the first place.  Has anyone else ever had this problem?  If you did, did you manage to resolve it or is it just something that has to be lived with?
 

[Sleepyhead]

I should also have said that I use Kimal lines and the bubble chamber has to be filled almost to the top which means that there is a very small air gap between the blood and the venous pressure line.  It would be interesting to know why the bubble chamber was made like this.  Every other bubble chamber I have used has about half an inch of space at the top!

[Sleepyhead]

I tried reducing the fluid in the bubble chamber when priming.  I just filled it up to about 1/2 inch below the top of the chamber.  I could then press the flashing "air detect" button without getting alarms.  Before the priming finished, the machine had filled the chamber up to about 1/4 inch from the top.  There was still blood in the arterial pressure line but none in the venous unless there was a venous pressure alarm during the night.

/I also found that having a little bit of saline in the arterial line before putting myself on helped because the blood didn't clot so much.  However, I am not sure how it got there!