MrIvanDrago - CPAP|Bi-PAP Therapy Journey

[MrIvanDrago]

Quick Question. I have searched the board and have a simple question. What is a good Insp.Time vs. Exp.Time (Ratio) with CPAP therapy? Just trying to get an idea.

[Crimson Nape]

According to Google:

Inverse Ratio Ventilation - StatPearls - NCBI Bookshelf
National Institutes of Health (.gov)  Apr 6, 2023

A typical I:E ratio for most situations would be 1:2. If we apply this ratio to the patient above, the 6-second breath cycle will break down to 2 seconds of inspiration and 4 seconds of expiration. Changing the I:E ratio to 1:3 will result in 1.5 seconds of inspiration and 4.5 seconds of expiration.

- Red

[MrIvanDrago]

According to Google:

Inverse Ratio Ventilation - StatPearls - NCBI Bookshelf
National Institutes of Health (.gov)  Apr 6, 2023

- Red

I saw that searching with Google, however, I rarely ever see OSCAR reports on this board with folks within that ratio.

[Crimson Nape]

I just checked my averages for last night, and it equates to 1:1.63.

- Red

[MrIvanDrago]

I just checked my averages for last night, and it equates to 1:1.63.

- Red

Ok thanks, that's around where I am as well.

[THEVGE]

I am more like 1:1,1 no matter the settings on my CPAP. Don't feel like having an issue with a stable respiratory rate of between 13-15 (measurements by smart watch). My therapy is not working well yet, waiting for BiPAP to solve flow limitations (my AHI has always been < 1).

Interesting question I wanted to ask as well. Following.

[Sleeprider]

You cannot necessarily rely on the Oscar reported inspiratory and expiratory median times. These are actually reported by the machine in question and is invariably inaccurate in all Philips machines and may be inaccurate in Resmed devices, especially where expiratory flow approaches zero and/or in the presence of cardiogenic oscillation. I often ask members for zoomed images of the flow rate so I can confirm or refute the reported statistics. Most of the time in healthy individuals, the respiratory ratio falls into a normal range from 1:1 to 1:3, and I have observed the majority of I:E ratios are close to one to 1.5. Inspiration time that is confirmed to be longer than expiration time is normally attributable to flow limitation, and abnormally long expiration is often asthma or COPD.

Historic trivia: Originally Sleepyhead displayed an I:E ratio, but it was incorrectly calculated as Texpiration/Tinspirationx100 and produced a number like 65.0, which was off by a factor of 100, meaning inspiration was .65 the time of expiration. It was decided back in February 2019 that Oscar should not report the I:E ratio due to the inaccurate reporting of inspiration and expiration times by the machines, general confusion on the part of Oscar users and the fact the legacy calculation was simply wrong. Ultimately, Oscar is a "Reporter" of information provided by the devices and today, Oscar does not report the I:E ratio for this reason, and it has not been reported since Sleepyhead 1.1.0. Here is a legacy image of Sleepyhead:

[THEVGE]

Thanks for your explanation Sleeprider!

[MrIvanDrago]

I have read about the differences between the Dreamstation 2 vs. ResMed Aircurve 10; however, I am having an issue with dry mouth/eyes since switching to the ResMed machine.

They were set to similar settings (Pressure 15.5 C-Flex of 3.0 vs. 17.0/13.0 PS of 4.0), but since using the Aircurve as of 10/1/23, I wake up in the morning with dry, puffy eyes that feel really 'heavy.' I did not have this problem with the DreamStation 2. I know the pressure is set a little higher, but these settings were recommended to me by a sleep tech since he said I was better suited for a bi-level as I was holding onto CO2 from reviewing my charts. 

I tried 17.0/12.0 PS 4.0 for a few nights and eyes still feel the same and had a few events.

Any answers as to why this happens, and are there any remedies? 
I use an F30 FFM mask. 

Attached are my last Dreamstation 2 session and two recent night's Aircurve sessions.

Dreamstation 2 Dashboard (9/29/23, Pressure 15.5 C-Flex of 3.0) 
(F30 Mask, No Dry Mouth/Eyes) 

[attachment=55657]

 ResMed Aircurve 10 Dashboard (10/26/23, 10/27/03, 17.0/13.0 PS 4.0)
(F30 Mask, Dry Mouth/Eyes) 

[attachment=55659]

[attachment=55661]

[Sleeprider]

Well you are certainly cursed with a plethora of perfect 0.00 results.

What we clearly have here is an opportunity to reduce pressure, perhaps significantly. Your leak rate is zero, so if you're getting air in your eyes, it is coming from the mask vent or is taking a shortcut through your tear ducts. Let's try reducing EPAP to 9.0. If you want fixed pressure, use IPAP 13.0 and if you want to try auto-pressure, the Vauto mode, EPAP min 9.0, IPAP max 15.0, PS 4.0. Reducing pressure below a threshold where air shoots up your tear ducts is our objective, and we can probably back off pressure even more. Let's start with this and get some feedback. Try to determine if there is any leakage at the bridge of your nose through the mask. We might want to try a mask liner or swap mask styles to get something that fits under the nose like the P30i.