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[Equipment] S9 VPAP Auto, meaning of settings - Printable Version

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S9 VPAP Auto, meaning of settings - JJJ - 08-16-2020

I used an S9 Autoset until it died a couple years ago, and I got the clinician manual for it. Now I am trying to set up my recently acquired gently used S9 VPAP Auto, and there are a number of settings for which I have no explanation. Here is the list, together with what the current setting seems to be:

PS         4.0
Ti Max   2.0   
Ti Min    0.3
Trigger   Med
Cycle     Med


If someone can clarify what those abbreviations stand for I would appreciate it. Oh, and my settings are 15-25 with no ramp or other comfort and convenience features, so I also don't know if the above settings are what I should be using. Thanks in advance!


RE: S9 VPAP Auto, meaning of settings - staceyburke - 08-16-2020

Bilevel positive airway pressure (BPAP), Variable positive airway pressure (VPAP), or bilevel is a continuous positive airway pressure (CPAP) mode used during noninvasive positive pressure ventilation. Bilevel refers to two pressures delivered for every breath cycle; an inspiratory positive airway pressure (IPAP) and expiratory positive airway pressure (EPAP). Pressure Support (PS) is the difference between IPAP pressure and EPAP pressure. BPAP can be described as a Continuous Positive Airway Pressure system with a time-cycled change of the applied CPAP level. CPAP, BPAP and other non-invasive ventilation modes have been shown to be effective management tools for chronic obstructive pulmonary disease and acute respiratory failure.
Often BPAP is incorrectly referred to as "BiPAP". BiPAP® is the name of a portable ventilator manufactured by the Philips-Respironics Corporation; it is just one of many ventilators that can deliver BPAP.

Ti max ti min
Cycle sensitivity sets the level of inspiratory flow below which the device changes from IPAP to EPAP. High cycle setting is recommended when shortened Ti is needed, such as for COPD or if the patient complains that the breaths are too long. Low cycle is recommended when longer Ti is needed for neuromuscular diseases, weak respiratory effort, or stiff lungs, or if the patient complains that the pressure seems to switch from IPAP to EPAP too quickly. BiPAP can be triggered by spontaneous, timed or spontaneous/timed (ST) modes. In spontaneous mode, inspiration is only triggered when the device senses a flow change. Large leak may cause the trigger to fail if the device does not appropriately adjust. Timed mode triggers at a fixed rate and makes no attempt to synchronize with the patient’s breathing, which can result in breath stacking and patient discomfort.

Trigger
Pressures generally range from EPAP minimum of four to IPAP maximum of 25–30. Most devices use a flow trigger to determine when to change to IPAP. The trigger is set above zero flow to sense a significant patient effort.

Cycle
The flow cycle algorithm changes to EPAP when the flow drops below a percentage (eg, 25%) of the peak flow so the patient will not encounter resistance to exhalation.24 Shape cycling algorithm uses shape of flow,25 and volume cycle algorithm uses exhaled volume to cycle to EPAP. There can be significant variation between devices in terms of how quickly pressure levels are met and whether a device has a delay or premature cycle, especially in the setting of leaks.26 If there is a mismatch between the patient’s respiratory cycle and the device control cycle there can be patient discomfort.


RE: S9 VPAP Auto, meaning of settings - JJJ - 08-16-2020

@staceyburke

Thanks a million for all the information!


RE: S9 VPAP Auto, meaning of settings - Sleepster - 08-17-2020

(08-16-2020, 05:24 PM)JJJ Wrote: Oh, and my settings are 15-25 with no ramp or other comfort and convenience features, so I also don't know if the above settings are what I should be using. Thanks in advance!

On that machine you have two levels of pressure, IPAP is pressure when you inhale, and EPAP is the pressure when you exhale. The difference between the two is the PS, which in your case is 4.

The machine lets you set the minimum EPAP, which in your case I'm guessing is 15. So that means you start the night with a EPAP of 15 and a IPAP of 19.

The machine also lets you set the maximum IPAP, which I'm guessing is 25. This means that as the sleep session progresses your IPAP may rise to as high as 25, and you EPAP would then be 21.

I don't think you need to mess with the other settings until you get these settings tweaked to meet your needs.


RE: S9 VPAP Auto, meaning of settings - JJJ - 08-18-2020

(08-17-2020, 11:44 AM)Sleepster Wrote:
(08-16-2020, 05:24 PM)JJJ Wrote: Oh, and my settings are 15-25 with no ramp or other comfort and convenience features, so I also don't know if the above settings are what I should be using. Thanks in advance!

On that machine you have two levels of pressure, IPAP is pressure when you inhale, and EPAP is the pressure when you exhale. The difference between the two is the PS, which in your case is 4.

The machine lets you set the minimum EPAP, which in your case I'm guessing is 15. So that means you start the night with a EPAP of 15 and a IPAP of 19.

The machine also lets you set the maximum IPAP, which I'm guessing is 25. This means that as the sleep session progresses your IPAP may rise to as high as 25, and you EPAP would then be 21.

I don't think you need to mess with the other settings until you get these settings tweaked to meet your needs.

From OSCAR I see the PS is different between the Dreamstation and the S9 - i.e., the S9 is apparently fixed (currently at 4.0) and on the Dreamstation it seems to be set at a range of 2.0 to 8.0.
  • Dreamstation: "Min EPAP 15.0 Max IPAP 25.0 PS 2.0-8.0 (cmH2O)," and EPAP min 15, IPAP min 17
  • S9: "PS 4.0 over 15.0-25.0 (cmH2O)," and EPAP min 15, IPAP min 19

Now that I see those figures it explains why I've felt that the pressure on the S9 is higher. It looks like the PS can only be a fixed number on the S9, but can be variable on the Dreamstation. The higher IPAP pressure on the S9 doesn't really bother me, but I have a constant struggle with leaks, and the higher the pressure the worse it makes the leaks.

On both machines the PS is what the machine was set to when I got it. All I ever did was set the 15-25 pressures and turn off the comfort and convenience things. Here is some data from OSCAR for the last night on the Dreamstation (August 13) and the S9 (August 17):

Dreamstation (AHI 1.71)
EPAP 15.00 15.00 15.00 16.00
IPAP 17.00 17.00 18.00 19.10
PS 2.00 2.00 2.50 4.10
Minute Vent. 0.13 6.00 16.88 70.38
Resp. Rate 8.70 13.80 17.20 20.82
Leak Rate 0.00 16.00 56.00 60.00
Total Leaks 14.00 61.00 100.00 104.00
Snore 0.00 0.00 0.00 1.00
Insp. Time 0.20 2.44 3.70 8.74
Exp. Time 0.24 1.80 2.70 5.64
Tidal Volume 13.33 440.00 1160.00 5783.33

S9 (AHI 1.68)
EPAP 15.00 15.12 16.04 16.36
IPAP 19.00 19.12 20.04 20.36
Minute Vent. 2.00 8.13 12.95 30.00
Resp. Rate 2.00 15.00 17.80 31.40
Resp. Event 0.00 0.00 0.00 7.00
Flow Limit. 0.00 0.00 0.00 0.42
Leak Rate 0.00 0.00 31.20 45.60
Snore 0.00 0.00 0.06 0.22
Insp. Time 0.44 1.36 1.60 1.98
Exp. Time 1.00 2.58 3.36 10.00
Tidal Volume 200.00 540.00 880.00 2440.00

I have no idea what PS I should set these machines to, but I note that the with the Dreamstation set to a PS range of 2.0 to 8.0, on the 13th it started at 2.0 and never went over 4.1, with a 95% of 2.50. Looking at the past couple of weeks Dreamstation data the maximum PS never went over 5.50. I consider that data as kind of a titration, so maybe I should raise the PS on the S9. But if I do that the minimum IPAP will go up, but that will increase the leaks.

It's really hard to figure out how to tweak these things!