Is there anything wrong with the setup above ? (beside the sticky tape that holds the system to the IV pole).

I was really reluctant to write about this because we have been set up and placed hundreds (ah hem!) of A-line and I believe we know very well about it..

But, often time that I saw the set up (unused) left in the room just looks like one in the picture, it is flooding on the floor. Moreover, once I contaminated the upper part tubing (the part that bring the fluid from the bag to the transducer) and I was replacing it with the regular IV tubing and then the person who worked with, tried to tell me that I have to use the tubing that is for A-line setup. !

You can skip this if you already what am I trying to say. And I believe most of us know.

For the one who is not sure whether you know or not, try answer these questions.

-How much the pressure in the pressure bag we need for the set up ?

-Is there any differences of pressurizing between setup for CVP, PA catheter and A-line ?

-Should we fill up the drip chamber to prevent the air ?

-Did you get any clues from the previous questions and know now what am I gonna say ?

Yes, speaking of pressure in the bag. As we are all known that the A-line catheter that opened directly to the blood stream (and also the same way the CVP and the PA catheter) has transmitted the mechanical force through the saline in the tubing and go to the transducer which is like a metal disc that sense and convert the mechanical force into the electrical values.

So the upper part of the tubing that bring the heparinized saline to the system doesn't have to do anything with the monitoring system, it will not cause excessive ringing or disturb the natural frequency and so any tubing that carry the fluid to the system is fine.

If we don't pressurize the heparinized saline bag, the system is still working. But for over period of time with no intermittent flushing, the thrombus formation will occur at the very tip of the catheter.

That is how the continuous flushing system come, the system contains the valve the will let go the fluid one way only to the patient and the pressurized heparinized saline is the only driving force though the valve. The recommended pressure is 300 mmHg regardless of which range of pressure (Arterial, CVP or PA) that gonna be monitored. With 300 mmHg driving pressure, the valve will permit the continuous infusion at 3 ml/hr and that's minimal enough to not disturb the pressure values.

About the drip chamber, many of us prefer to fill up this part because of air-phobia. But the recommendation is to leave some air in the drip chamber, so that we can observe the drip at 3 ml/hr which is about 30 drops/hour of 1/2 drop per min.

So, my belief is - if somebody knows the system will automatically drip at 3 ml/hr, when he/she setup the system should have clamped the stopcock in case that the system might not be used for a long time. Otherwise we will see a flooding !, and also the bag is losing the pressure. (well that after many days, though)

Prasert.

References

-Instruction for use (TRANSPAC) Disposible transducer Monitoring Kit. Abbott Critical Care Systems.