Bubbles in the line

[lillinny]

We have been doing this for about 4 months.  Lately we have noticed (as we hook my husband to the cartridge lines) there are bubbles in the cartridge line that we are hooking to the line in hubby's arm.  Last night there were so many that we abandoned tx.

We shake and rap the lines on the cartridge and do the filter.  We do it for probably 15 minutes.  We do not stop til the lines are clear of bubbles.  when I hook my husband up, I let the blood flow to end of line and then when I hook up the saline, I pull back til the bubbles come out as much as the syringe will allow me to pull.  Then tap til the bubbles go to the top and put the blood back in. 

So have no idea why we are getting the bubbles and what to do about it.  Center said to ignore if they are small bubbles. . .   Any suggestions?  Ideas? 

[greg10]

Here are some of the possibilities, please forgive me if some of them are obvious to you:
(1) The cycler has to be on code 23 and still priming while you are tapping and rapping (or "snapping") the lines.
(2) The cartridge can be removed from the holder and tapped against the palm of your hand and you will notice the bubbles being sucked out from the bottom of the cartridge into the two lines and eventually into the saline bag. 
(3) "Bleed" the air out of the air port on the cartridge by holding the air port (post filter port) higher than the cartridge while the cartridge is in the holder.  Just loosen the cap (wear clean gloves) and let the air and saline drip out together.  Use the small pink drain container to catch the fluid (let the container rest on top of the counter top of the Pureflow.  Alternatively, use a syringe and draw out the air bubbles and keep the syringe there for further priming (steps 4 & 5 below and attached picture).
(4) Allow the cycler to keep priming on code 23 for another 10 minutes.  You don't have to watch it or tap and rap during this time.
(5) The priming should be almost done.  Do step 3 and bleed out the air/saline again.  You should not longer see much air trapped in the upper part of the cartridge next to the air line.
(6) Now press the red stop button to take the cycler off code 23 and the priming pump will stop.  Before you clamp the 9 clamps (2x yellow, 2x red, 2x blue, 2x white & 1x green), bleed the air out of the T-connector (next to the white clamp) by loosening the cap and let the air-saline drip out into a catch container.  You should not bleed the air-saline out of the T-connector while the cycler is on 23.  This is because the T-connector is on the "low side" of the pressure loop while the cycler is on code 23 and will suck in air.

----------------------

(1) If you are getting air in the lines after you have done the priming properly, you may have a loose Luer connector that is allowing air to be sucked into the system.  This could be from the venous or arterial connectors (more likely), blue and red, respectively.  Alternatively air could be coming from the T-line saline port connector (more likely) or from the post filter port itself.  In these cases the arterial connector and the T-line saline port connector are on the low pressure side and therefore more likely to draw in air.

(2) Remove any air bubbles through the air port (post filter port) with a syringe containing 300u to 500u of heparin in 2 to 3 ml of saline.  Let the bubble rise into the syringe and push the blood-saline-heparin back into the filter port until the filter port is devoid of air bubbles as much as possible. (see attached in the posts below).  This should be done without the first 15 minutes of treatment to prevent the air bubbles from causing clots from prolong blood exposure to air.

I will update this list further if there is any demand for it.

[lillinny]

Thank you.  Most of that we do but do not hold off and let it continue for 10 minutes and when we prime the filter we were not holding it upright.  Will do that!  Thank you!  We appreciate the help and time you took to do it!

Last night there was a bubble in the arterial line we found before we connected that line to hubby's line.  We removed cap and held it up (machine was off) and air did raise to the top and it worked.  Just making me crazy that we didn't have this problem for first 2+ months.  Seems like there is always something!

[greg10]

I am glad things are better this time.  The reason for the arbitrary ten minutes (or more) at code 23 (steps 4 and 5 above) is that we found there are more bubbles in the system that will be caught in the top of the filter near the air port (post filter port) after further priming at code 23.  We use the ten minutes for other preparations such as weighing, taking blood pressure, temperature, checking warmer, preparing access site etc.

There is another step that we do to eliminate air once the patient has been connected via the access to the cycler and I have added to the list above.  We will remove any air bubbles through the air port (post filter port) with a syringe containing 300u to 500u of heparin in 2 to 3 ml of saline.  Let the bubble rise into the syringe and push the blood-saline-heparin back into the filter port until the filter port is devoid of air bubbles as much as possible. (see attached).

[lillinny]

Thank you!!!     We have been leaving it for 10 mins now.  That seems to help.  I think that we may have been over reacting.  Center sez not to worry about the bubbles unless there are a lot of them. . . but. . . it is easier said than done when it is you body!