Pressure bag pump flush systems

Hi, i'm currently studying about pressure bag pump flush systems for invasive monitoring transducer. I hope a few question still puzzling me.
When we monitor for invasive line such as CVL and arterial line, we will put pressure at 300mmHg to ensure it infusing 3mL/hr to make sure the lines is patent and to prevent blood back flow from the arterial.
But what I don't understand is how did the 300mmHg deliver exactly 3ml/hr? is there some kind like a calculation or what. If possible some literature as a facts to prove it.

Another question, I have been to 2 different hospital which give different ways of practice. Hospital A practice is if we use double transducer for CVL and Arterial line, then pump 300mmHg, it will give 3mL/Hr each line. So total volume is 6mL/hr (both). It was proven with experimental evidence which it exactly gives 3mls/hr each.

Hospital B practice is if we use the same double tranducer for both lines, then pump 300mmHg, it will give 3mL/Hr. But, it will deliver to both lines. Meaning total volume deliver is 3mL/Hr (both). They rationale is that because they use different set of tranducer where it was calculated by drop factor (which I'm not sure what brand they are using). So, even when they pump 300 mmHg, when it goes into each lines, it will automatic divided into 2. Means 1.5mL/hr each.

But, this discussion going deeper with a question mark:
"How does a same pressure (300mmHg)for double transducer work to give more volume than single transducer?"
"Can a pressure be divided into 2 lines?"
"How does it explain the mechanism of the pressure system in single and double transducer?"
"Can a different IV set transducer affect the systems?"

Please do me a favor. If possible, I need a facts or literature as an evidence for each answer. I have been searching in google, but I still haven't got a clue.. Thank you for giving feedback. Really appreciate it.
In my unit, they use pressure bags in the OR and we put the transduced line on a pump when they roll out. Problem solved--then we know exactly how much volume they are getting I work peds, though, so 3mL/hr adds up faster than it does with adults, and we run it slower based on weight.

Quote from walkingthecowIn my unit, they use pressure bags in the OR and we put the transduced line on a pump when they roll out. Problem solved--then we know exactly how much volume they are getting I work peds, though, so 3mL/hr adds up faster than it does with adults, and we run it slower based on weight.

I'm not really sure what you're asking OP. There are a couple of ways of connecting multiple transducers to a pressure bag. One would be to directly connect two transducers to the two ports on a fluid bag, another would be use a splitter that connects usually 3 different transducers (Art, PA, CVP) to a single pressure bag using a single spike. If the pressure bag is at 300, then the pressure upstream of each transducer will also be 300, which will typically result in about 3ml/hr going through each transducer. The only reason that 3ml/hr would be split is if you split the pressure lines below the transducer, which wouldn't be of much use.

So, if we use a 1 spike with multiple transducer and put it on 300mmHg pressure, it will still give the same exact volume to the patient's line? for example pressure at 300mmHg will give 3mL/hr each lines, right? Please correct me if I'm wrong.What do you mean by "split the pressure lines below the transducer"? Can you explain it more? Thank you.

Quote from MunoRNYou're putting a transduced line in a pump? I'm not sure how that would work since the stiffer tubing wouldn't work in a pump to begin with, but also it wouldn't be usable as a transduced line since the pump would interfere with the continuous fluid column between the patient and the transducer.

Quote from suzikjgSo, if we use a 1 spike with multiple transducer and put it on 300mmHg pressure, it will still give the same exact volume to the patient's line? for example pressure at 300mmHg will give 3mL/hr each lines, right? Please correct me if I'm wrong.

Quote from chareYou still have a continuous fluid column from the patient to the transducer. Aside from the fact that it lacks the fast flush device, from the transducer distal to the patient there is not difference. However, unlike the standard set, you connect a standard IV administration set to the proximal side of the transducer.

Quote from suzikjgSo, if we use a 1 spike with multiple transducer and put it on 300mmHg pressure, it will still give the same exact volume to the patient's line? for example pressure at 300mmHg will give 3mL/hr each lines, right? Please correct me if I'm wrong.

Quote from MunoRNI was referring to the idea of putting the pump distal to the transducer, although I don't see how it would work to put the pump between the pressure bag and the transducer since then you would loose the 300 mmhg pressure at the transducer, which is needs to transduce accurately.

Quote from chareIf you use the standard transducer it always delivers 3 mL/hour. The neonatal transducer is designed to be used with an infusion pump, at rates as low as 1 mL/hour.When we receive patients post op, anesthesia always uses the flush bag. If the patient weighs less than 15 kg we routinely change the transducer. While it is anectdotal at best, I have yet to see any difference in either ABP or CVP.

Quote from MunoRNDo neonatal transducers not require an elevated pressure upstream from the transducer?

OP, not sure if you got your question answered or not, so I will add:If you took your pressure bag set up to 300mmhg which is attached to the two transducers (one bag - two transducers) and you unscrewed the connection between them.....fluid doesn't drip out at 3ml/hr or 6ml/hr. It POURS out fast! What makes the fluid run at 3ml/hr is that that is all the transducer will allow to flow through. So each transducer allows 3ml/hr through it = total 3ml x 2 transducers = 6ml/hr.To MunoRN, I also work PICU. If you are under 10kg, your transduced lines run at 1ml/hr. Children over 10kg generally are also put on a pump at 3ml/hr out of habit, but they can also just be set up with a pressure bag and a normal 3ml/hr transducer. The only issue I have ever had with this is that sometimes after drawing blood, the transduced line pump wants to beep occlusion and I have to set the pump to run at 5ml/hr or so for 20 seconds or so to repressurize the line, then I can turn it back down to 1ml/hr again.