Any experts on PSI for nebulizer compressors???

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ehtansky21

New member
We just received our new precision medical 50 PSI compressor. I read somewhere that 25 PSI is a good PSI to use. But our respiratory therapist told us to just stick with 8 PSI. We go to the University of Minnesota CF clinic, and they want CFers to be nebbing something the whole time they are vesting. So it seemed like that was her reasoning for the 8 PSI. I am wondering though, if there is a specific PSI that gets the solution deeper in their lungs, thus being more effective. I understand the whole nebbing the whole time they are vesting, so we could just have them neb sterile saline if needed. blessings, missa
 
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Ratatosk

Administrator
Staff member
I'd read somewhere as well that a higher PSI was better to get a finer mist/particles deeper in the lungs for pulmozyme and albuterol/atrovent -- I use 30 psi for those. And 20 something -- I thought it was 26, could've been 23 for tobi. one of the concerns with the portable nebulizers, such as the Pari Trek is that the psi is too low to adequately get tobi in the lungs. I recall when our first Pari became faulty it took 45-50 minutes to run thru a vial of Tobi, when it should take 20 minutes. I do recall when DS was in the hospital 4 years ago they would run regular saline .9 (?) thru the neb after we were done with albuterol/atrovent and pulmozyme. I believe the CFF has something on their website about proper psi proper settings and neb cups for certain drugs. May have also read something on Ronnie Sharpes webpage.... Can't recall off the top of my head.
 
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Murphysmama

Guest
Not an expert by any stretch but we recently got a mobilaire compressor (after 2 vios compressors went down in under a year) and were told between 30-32 psi for pulmozyne. We were also advised that it's critical to have it right and it's dependent on the medication, compressor, and nebulizer. If the psi is too low the particles are too big and if it's too high too small. In researching I was very surprised to learn that pulmozyne has only been 'approved' (tested by drug company) for very specific compressors. I had visions of a cute train one for ds but didn't want to take any chances by going w a not approved set up. It's probably a function of not testing a bunch of compressors but I had assumed they were all good. Still learning every day :)
 
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scrapper1264

New member
We got our 50 PSI last year and our setting is at 25 for everything except Pulmozyme which is 30. Pulmozyme's quantity is not as important as the rest. When I get home I will look for the name of the handout that our CF center provided us.
 
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Werner G

Guest
All the different values for PSI that you guys are mentioning give a hack of a spread (8-32 PSI)!

"Ehthansky21": please check with your respiratory therapist! The RT probably meant a flow rate of 8lpm (liters per minute) not PSI!! 8PSI sounds rather low. 8lpm is one of the standards used in hospital settings for aerosol treatments but I haven’t heard of 8PSI as a standard.

The Variables:
a) More PSI is not always the solution: PSI is the backpressure measured between the compressor and the nozzle of a nebulizer. As "Murphysmama" said the higher the PSI the finer the droplets. However, the respirable range (for aerosol deposited in the lungs) is 1-5 microns. If the droplet size is below 1 micron it has a tendency to be exhaled again. If the droplet is greater than 5 micron it may not deposit in the lung but in the mouth or throat.
b) Impact of medication on PSI: There is less pressure (PSI) needed to generate an aerosol in the respirable range with aqueous solutions (for instance saline or Albuterol). To get an aerosol with the same droplet consistency from a viscous solution like Tobramycin (oily substance) higher pressure (PSI) is needed to overcome the higher viscosity. That may be the reason why you were not happy with your PARI Trek experience nebulizing because its small design comes along with a small compressor that can only deliver a certain amount of pressure (PSI). Somebody taking a saline treatment might just be fine with the performance of his/her PARI Trek.!
c) Nebulizers and PSI: The nebulizer design may play a major role. T- piece nebulizer designs (like Hudson Updraft, Salter, etc.) may need higher PSI whereas breath-enhanced/breath-activated nebulizers (PARI LC Plus, PHILLIPS Sidestream Plus, MONAGHAN Aeroeclipse, etc.) for proper valve system function would be designed to allow for proper operation already with lower PSI.


What is the proper PSI now:
Based on the variables above each combination of your 50PSI compressor, medication and nebulizer may need its own pressure setting. I would suggest to find out the proper PSI as follows for each nebulized medications you have to deal with:
1) Find out in the medication package insert which compressor nebulizer combination was used in the clinical trials that led to the FDA clearance of the drug
2) Once you know the approved compressor/nebulizer combination check with the manufacturer (usually they are the same for compressor and nebulizer) and ask for the PSI setting for the combination.
2a) Some manufacturers have the compressor settings - like operating pressure - directly on their sales aids to back up any clinical claim. For example PARI gives its operating pressure in bars (1bar=14.5PSI) for its nebulizers
2b) Sometimes nebulizer manufacturers only measure LPM (Liters per minute) instead of PSI to express the conditions under which nebulizer performance is achieved. Once you got the LPM then your respiratory therapist with his/her flow-meter can help you to dial in the right PSI.

Hope that helps. Just came across this topic in the forum – so I am late in chiming in but nebulizers are an area of interest for me.
 
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