Provide clarification on this article regarding Ti Min and Max settings

[Michaely6]

I found this article regarding insomnia and resmed vpap ti max, min, trigger, and cycle settings interesting. I was confused on how he set the the exhale to. 5 to 6 seconds. Is that even possible on vauto? Can someone provide clarification on how he set the vpap ti and timax to reach the desired effect that he is referring to and to get the same I:E ratio as below. 

BTW this is just to test it out. 

I did not post the link because I did not know if I was allowed to but I will copy and paste a piece from it. 

"I apply the principle of the 4-7-8 breathing method as follows:

1. Set the Inhale at 1.1 seconds to 1.2 seconds using the TI Min and TI Max settings; and

2. When setting the exhale, I allow 5.5 to 6 seconds to exhale, before the machine prompts me to start inhaling again, by using Trigger sensitivity of High.

To achieve 5.5 to 6 seconds to exhale, I use Pressure Support of between 5.0 to 5.6 cmH2O. In addition, to overcome Central Sleep Apnea (refer Blog Post “Reduce Central Sleep Apnea caused by CPAP”), I use Cycle sensitivity of high/ very high.

With these machine settings, the inhale:exhale or I:E ratio is 1:5 (one to five). That is, my inhale time is only 20% of the total time that I exhale. Just before I go to sleep, my breathing normally slows down to 7 to 9 breaths per minute. Once asleep, my breathing will go back up to 14 breaths per minute.

When reviewing the whole night and due to different sleep stages; the median ratio is about 1:2.7. This median ratio is far better than when I was using the CPAP machine when I:E ratio was 1:1 or even worse at 0.8:1. I was spending more time inhaling or breathing in air than I was exhaling. This is one of the main reasons that I had many issues using the CPAP machine!

In addition, I use very low pressure on exhale (EPAP) of 4.2 cmH2O and minimum inhale (IPAP) of between 9.2 cmH2O to 9.8 cmH2O. By using these settings, you are breathing out against very low pressure when initially going to sleep and when you wake up during the night. By doing so will assist you to stop insomnia as well as overcoming other issues caused by using a CPAP machine. Note that these settings are despite my maximum or top pressure may go over 15 cmH2O during the night.

Should you be having issues with your sleep apnea therapy; CHANGE what you are doing so that you can wake up feeling refreshed and energized each day.

“Have courage. Be adventurous and Go for it! Overcome your fear.”

[Sleeprider]

The 4-7-8 breathing technique is a form of conscious breathing used by some people to relax. I am not aware of its application to PAP therapy, and the kinds of settings you are suggesting do not look like anything I would suggest anyone try. I'm going to need a better hint at what source your are reading to come up with this.

In my opinion you can use the Ti Min setting to encourage a longer inspiration time, but I have only done this to help individuals with erratic or short inspiration times. Ti Max is the maximum time that IPAP pressure will be maintained, but the machine will cycle to EPAP as soon as spontaneous exhale occurs, regardless of the setting. The Resmed Vauto allows for Ti Max to be set up to 4-seconds, and Ti Min can be set to enforce IPAP for that period of time. I assume, that setting the Ti Min too long will simply result in you fighting the machine and cycling to exhale in the normal time, but exhaling against IPAP pressure. The Vauto is meant to work with you, and using setting that are not compatible with your normal respiration rate and timing will not have the hoped for results.

A lot of the things you have quoted from a blog do not appear to be something workable with treatment emergent central apena. The use of 5.0 to 5.6 PS will typically make CA worse, and I have found increasing sensitivity of trigger, along with higher Ti Min is effective. Increasing sensitivity of cycle as suggested in your post seems counter-productive.

[Michaely6]

The 4-7-8 breathing technique is a form of conscious breathing used by some people to relax. I am not aware of its application to PAP therapy, and the kinds of settings you are suggesting do not look like anything I would suggest anyone try. I'm going to need a better hint at what source your are reading to come up with this.  

In my opinion you can use the Ti Min setting to encourage a longer inspiration time, but I have only done this to help individuals with erratic or short inspiration times. Ti Max is the maximum time that IPAP pressure will be maintained, but the machine will cycle to EPAP as soon as spontaneous exhale occurs, regardless of the setting.  The Resmed Vauto allows for Ti Max to be set up to 4-seconds, and Ti Min can be set to enforce IPAP for that period of time.  I assume, that setting the Ti Min too long will simply result in you fighting the machine and cycling to exhale in the normal time, but exhaling against IPAP pressure.  The Vauto is meant to work with you, and using setting that are not compatible with your normal respiration rate and timing will not have the hoped for results.

A lot of the things you have quoted from a blog do not appear to be something workable with treatment emergent central apena.  The use of 5.0 to 5.6 PS will typically make CA worse, and I have found increasing sensitivity  of trigger, along with higher Ti Min is effective.  Increasing sensitivity of cycle as suggested in your post seems counter-productive.

Yeah I was honestly just curious about the article but it was nothing that I thought would benefit me at all. Thanks for the feedback.

[Matt00926]

You can't set an exhalation time set in stone on the VAuto, but by manipulating other variables such as the Ti min and cycle sensitivity, and/or rise time if you disable easybreathe, that ends up changing the exhalation time for most people. Generally something as simple as changing the cycle setting will effect the I:E ratio greatly. That's why when ResMed made the S9 VPAP COPD model back in the day it came programmed with a default rise time of 150ms, to make the exhalation phase of the breath longer to reduce the chance of air trapping. Some people have a problem getting air in, and some people have a problem getting air out.

I have seen a higher trigger sensitivity help people in this regard. Ti min and max I advise the majority of people not to touch - the defaults work for most people. Ti min is mostly helpful if you have a restrictive lung disease and/or for whatever reason you can't sustain a normal inspiratory time on your own. Sometimes by trying to fix something you end up creating another issue. For example, with too high of a Ti min when you sleep we all breathe somewhat more shallow, so you could be forcing yourself to keep the inhalation phase even though you are trying to exhale.

[Michaely6]

You can't set an exhalation time set in stone on the VAuto, but by manipulating other variables such as the Ti min and cycle sensitivity, and/or rise time if you disable easybreathe, that ends up changing the exhalation time for most people. Generally something as simple as changing the cycle setting will effect the I:E ratio greatly. That's why when ResMed made the S9 VPAP COPD model back in the day it came programmed with a default rise time of 150ms, to make the exhalation phase of the breath longer to reduce the chance of air trapping. Some people have a problem getting air in, and some people have a problem getting air out.

I have seen a higher trigger sensitivity help people in this regard. Ti min and max I advise the majority of people not to touch - the defaults work for most people. Ti min is mostly helpful if you have a restrictive lung disease and/or for whatever reason you can't sustain a normal inspiratory time on your own. Sometimes by trying to fix something you end up creating another issue. For example, with too high of a Ti min when you sleep we all breathe somewhat more shallow, so you could be forcing yourself to keep the inhalation phase even though you are trying to exhale.

Great explanation Matt! Makes alot of sense. I had an issue with getting air in so Increased my trigger sensitivity to very high. I noticed that a very high trigger sensitivity allows one to increase pressure support much higher without triggering central apneas. Any idea why this is? If I set trigger back to medium, so many central apneas will appear.

[Matt00926]

It's only a guess, but maybe during a time when the brain wants to send signals not to breathe, the higher trigger sensitivity means that even a slight effort by the user will result in an inhalation occurring. Without the breathe sometimes it results in a build up of CO2, and a loss in O2. This could happen more during REM sleep when the breathing muscles are not as active in the breathing process.