[Treatment] PAC (Pressure Assist Control) Mode

[airbusA346]

Hi

Has anyone used PAC (Pressure Assist Control) mode on a Resmed NIV (Lumis)?

What is it like compared to ST and iVAPS mode?

[Gideon]

Why are you asking about PAC?

Note what the following modes are designed to treat.
Do you have Neuromuscular disease?

• VAuto Automatically adjusts pressure in response to flow limitation, snore and obstructive apneas; Pressure Support (PS) is fixed throughout the night and can be set by the clinician. It Treats OSA, non-compliant OSA
  

• S (Spontaneous) Senses when the patient is inhaling and exhaling, and supplies appropriate pressures accordingly. Both treatment pressures are preset: inspiration (IPAP) and expiration (EPAP). It treats Non-compliant OSA and COPD
  

• ST (Spontaneous/Timed) Augments any breaths initiated by the patient, but also supplies additional breaths if the breath rate falls below the clinician’s set “backup” respiratory rate. It Treats COPD, Neuromuscular disease (NMD), Obesity Hypoventilation Syndrome (OHS) and other respiratory conditions
  

• T (Timed) Supplies a clinician-set respiratory rate and inspiratory/expiratory time, regardless of patient effort. It Treats COPD, Neuromuscular disease (NMD), Obesity Hypoventilation Syndrome (OHS) and other respiratory conditions
  

• iVAPS (intelligent Volume-Assured Pressure Support) Maintains a preset target alveolar minute ventilation by monitoring delivered ventilation, adjusting the pressure support and automatically providing an intelligent backup breath. It Treats COPD, Neuromuscular disease (NMD), Obesity Hypoventilation Syndrome (OHS) and other respiratory conditions
  

• ASV (adaptive servo-ventilation) Targets the patient’s minute ventilation, continually learning the patient’s breathing pattern and instantly responding to any changes. It treats Central or mixed apneas, complex sleep apnea, Periodic Breathing (PB)
  

• ASVAuto Provides an ASV algorithm plus expiratory positive airway pressure (EPAP) that automatically responds on the patient’s next breath to flow limitation, snore and obstructive sleep apneas. It Treats Central or mixed apneas, complex sleep apnea, Periodic Breathing (PB)
  

• PAC (Pressure Assist Control, also known as Pressure Control) The inspiration time is preset in the PAC mode; there is no spontaneous/flow cycling. Inspiration can be triggered by the patient when respiratory rate is above a preset value, or delivered at a set time at the backup rate. It Treats Neuromuscular disease (NMD), pediatric patients
  
  

[airbusA346]

Why are you asking about PAC?

I'm asking because my hospital have switched my Lumis to this mode of ventilation to see if it resolves my on going issues with desaturations and drops in volumes.

I have been on ST mode since March 2018 for OSA and nocturnal hypoventilation.  I have never felt refreshed and am still tired.  Many changes in ST didn't help and I started recording my oxygen levels in December which showed they weren't stable throughout the night.  After an home oximeter study and two in hospital TOSCA studies they couldn't see and desaturations and after much pushing for them to do something.  They performed a polysomnography in August which finally showed to them that my oxygen levels weren't stable on NIV (dropping to 60%).  So they assigned a physiologist to sort out my issues.  She studied my machine data and found my minute ventilation wasn't good, so she tried me on iVAPS with different pressures, respiratory rates and Ti Maxes over the last two weeks.  They haven't helped resolve the issues, so she mentioned trying a different machine to my consultant who suggests as a last resort with this machine to try PAC mode.

I have Cerebral Palsy, Right Sided Hemiplegia, Hydrocephalus, Scoliosis, OSA, Nocturnal Hypoventilation. Plus I struggle to breath while on my back and sides when not using the ventilator. I still don't know what is causing the nocturnal hypoventilation

[SarcasticDave94]

I'm not familiar with PAC or know lots about Cerebral Palsy, but my guess is with you stating a struggle to breathe, this combo of information is probably the reason. Again I'm guessing as I'm not certain, you may actually need this PAC for ventilation as intended.

[Sleeprider]

This would be my first exposure to this therapy mode and I hope you will keep us advised of your progress. While I’m not in any position to argue the value of PAC, I wonder if it might be worthwhile to ask your physiologist to compare the merits of PAC vs ASV or iVAPS. Both of the latter intelligently target minute vent.

[airbusA346]

This would be my first exposure to this therapy mode and I hope you will keep us advised of your progress. While I’m not in any position to argue the value of PAC, I wonder if it might be worthwhile to ask your physiologist to compare the merits of PAC vs ASV or iVAPS. Both of the latter intelligently target minute vent.

iVAPS has been tried and they've decided it's failed, so they are trying me on PAC and if that doesn't work, trying a different machine has been mentioned... not sure what machine though.

[Gideon]

Thanks for the history, it will help us help you.
I have not heard of another PAC user on the forum, but we have users with good general knowledge.

How will it feel? I don't know.  My guess, based on the description, is that it will be at least similar to an ST.

[SarcasticDave94]

Certainly keep us posted. We'll do whatever we can to help out. Best wishes this is successful.

[airbusA346]

So PAC mode was a partial success!

My volumes are more stable through the night but I'm still getting desaturations.

They've decided that PAC mode is the best one for me, but I've maxed the Lumis out. So the consultant will be arranging an admission where I'll be tried on a Resmed Stellar 150 ventilator.

They will also look at adding oxygen while I'm there. They won't trial it at home, because they can't monitor my CO2, whereas at the hospital they can use TOSCA.

[Sleeprider]

Yours is an interesting and unique case. Thanks for keeping us posted here at its a new approach. The more we know about what leads to this recommedation, the more helpful this will be to someone that may have a similar problem in the future. Thanks for sharing.