Breathing pattern identification, Flow limitations and posture

[SingleH]

Thanks for the clarification.

I have uploaded a few screenshots of his first full night on S mode.

He did have multiple clusters of apneas on the pressure settings I left him on, so I will need to increase the pressure further. The waveforms were not as stable as in the tests and the mid dip issues are present quite often which I think that has thrown off his respiration rate figures.

There is also a frequent little peak at the end of the exhalation/start of the inhalation. This smaller peak sometimes goes about the zero line also. 


[attachment=55205][attachment=55206][attachment=55207]

[SingleH]

I'm wondering if trigger sensitivity being set to very high is causing it to detect something and then think its an inhalation. I see the little pre inhalation spikes match with the increase in masp pressure only for a brief period. This little mid breath spikes in pressure vary in size from very small to quite large.

I will drop sensitivity down to high or medium for now.

[Sleeprider]

I normally increase trigger sensitivity in cases where we want to trigger IPAP for occasional CA events. Your dad seems to have adequate spontaneous breathing that the higher trigger is not needed. In your close-up you highlight 4 places you suspect trigger may have affected expiration time, but only the first two actually show inspiratory flow (above zero). Remember as long as expiration remains below zero, it remains expiration and could be something as simple as a swallow or other pause in exhale. I think trigger at medium or low is appropriate and may settle some of the incorrect triggers during expiration.

Inspiratory flow looks to be flow limited, but in a more normal manner. The double peak is the result of an initial peak flow rate that hits obstruction that releases or where respiratory effort overcomes the resistance resulting in a second peak. Normally, we increase PS slightly to address this. You should look at titrating PS in increments of 0.2 cm to avoid big changes at this point. Smaller increments should help you to narrow down the optimum where this flow limit is mostly negated. In your closeup, I count 22 breaths per minute, of which 11 have double peaks. So we're at 50% now. Let's set a goal of 20-30%. That is of course arbitrary, but a decent measure of improvement.

[SingleH]

Thanks. Just to clarify when increasing PS, does it matter how I achieve the 0.2 increment?

Should I increase IPAP by 0.2 or decrease EPAP by 0.2. I'm assuming if he is still getting apneas its better to increase the IPAP rather than reduce the EPAP?

[Sleeprider]

That's correct. EPAP protects obstruction, and as long as you don't reduce below that threshold, it is a valid way of increasing PS without increasing peak IPAP pressure. If EPAP is close to the obstructive threshold, prefer an increase in IPAP. All we're trying to do is get a bit more PS or separation of IPAP-EPAP to recruit more mechanical assistance to inspiration.

[SingleH]

ok all clear. Unfortunately I got the machine swapped out due to the noise and the new machine is doing exactly the same thing but worse. I noticed the dying calf noise doesnt seem to appear until you get up in pressures, so I can only assume they didnt test at a sufficient pressure. I tried increasing it 16 but the new machine was doing the calf noise plus a high pitched noise. The F&P machine he has is very very quiet.

I was wondering what does your machine sound like at higher pressures like 14-17. I see you have your Vauto set to 9-18 have you heard it when its running at high pressures?

[SingleH]

I am a bit short of time now, and for the next few days, so I have not looked at all of your charts.  Not sure what is behind the low Spont. Triggering but low Spont. cycle will be because you reduced Ti max.  Others may disagree bit I would be inclined to increase that, initially at least, not decrease it.  Focus on trigger before cycle.

The spont Trigger seems to have resolved itself during testing and is now reporting about 97% on average. Spont cycle seems to be between 60 to 80%. I did increase both Ti Max and then later Ti min as I wanted to see if the increased Timin would reduce the machine getting confused by his "double inhalations", but could really tell any difference.

On a separate note I observed when the unit is in iVAPS mode and left doing its own thing with pressures it sometimes finds a pressure setting that results in the nice domed waveforms for short periods. I then tried to export those pressure settings to the S Mode to see if I could replicate that, but not been able to. I'm wondering if some element of the way the iVAPS mode delivers the pressure differently affects the waveform.

[Sleeprider]

If you have examples of iVAPS and S-mode, the way the machine delivers pressure can be visualized in the Mask Pressure chart. You can post Flow Rate and Mask pressure from both modes and any difference in pressure delivery will be easily interpreted.

[SingleH]

Hi Sleeprider,


I have attached a couple of screenshots displaying a comparison between Ivaps and S mode. Unfortunately due to the noise issue its been hard to do a proper thorough comparison of the two modes. Whilst the waveforms are not always perfect in the Ivaps mode they do seem to appear more often vs S-mode which seems to be better than cpap but still somewhat more erratic.

In the meantime I have got an Aircurve 10 VAuto coming which Im hoping will yield better results. Any tips for setting this up. Is it a case of starting on a Pressure support of 4 again and observing the machine?

[attachment=55831][attachment=55832][attachment=55833]

[Sleeprider]

On the Vauto, I would suggest starting with EPAP min 9, maximum pressure 18.0 and PS 6.0. It appears you may need to keep TiMin at 0.5 to 0.8 to guard against early cycling, and keep trigger sensitivity high.