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+--- Thread: What's a "minute vent"? (/Thread-What-s-a-minute-vent)
What's a "minute vent"? - hegel - 07-25-2021
and moreover, is there a normative range for inhalation and exhalation?
and is it a 'minute'--i.e. tiny--or a minute--i.e. time oriented--vent?
RE: What's a "minute vent"? - Gideon - 07-25-2021
It's a respiratory term. It's the amount of air you ventilate in a minute.
RE: What's a "minute vent"? - hegel - 07-25-2021
Thanks. So my median minute vents hovers around 6; my median insp. time is around 1.80 and my median exp. is around 2.50. The exp (expiration I presume) is always a tad higher than my insp. (inspiration?).
Are these typical, normal numbers?
RE: What's a "minute vent"? - Geer1 - 07-26-2021
Inspiration time is the average time you spend inhaling. Expiration time is the average time you spend exhaling. Tidal volume is the average volume you breath in per breath. Respiration rate is the average breathing rate/minute. Tidal volume * respiration rate gives you minute ventilation which is the average volume of air you breath per minute.
Inspiration rate is usually over 1 second and commonly around 1.5 seconds, expiration rate is usually around double the inspiration rate and 2.5-3 seconds is common. You have to take both statistics from OSCAR with a grain of salt because they can be easily influenced by things like cardiogenic oscillations and rem breathing which confuse the machine (it thinks positive flow is inspiration and negative flow is expiration but in reality some things like cardiogenic oscillations can cause positive flow during expiration). If you want to check actual inspiration/expiration times it is better to measure them yourself and average a few examples through the night.
For example my inspiration time is regularly reported as over 2 seconds and often longer duration than my expiration time but if I actually measure it then it is regularly around 1.3-1.5 seconds with 2.5-3 seconds expiration. The reason is that I have cardiogenic oscillations that cause flow rate to momentarily cross zero flow rate before my expiration finishes so the machine stops measuring expiration and prematurely switches to measuring inspiration even though I haven't yet started inspiratory effort.
RE: What's a "minute vent"? - selfcoacher - 11-19-2021
(07-26-2021, 12:06 AM)Geer1 Wrote: For example my inspiration time is regularly reported as over 2 seconds and often longer duration than my expiration time but if I actually measure it then it is regularly around 1.3-1.5 seconds with 2.5-3 seconds expiration. The reason is that I have cardiogenic oscillations that cause flow rate to momentarily cross zero flow rate before my expiration finishes so the machine stops measuring expiration and prematurely switches to measuring inspiration even though I haven't yet started inspiratory effort.
How does your breathing feel when Resmed adjusts pressure at inappropriate times as a result of incorrect detection of new inspiration cycle?
RE: What's a "minute vent"? - Geer1 - 11-19-2021
(11-19-2021, 11:13 AM)selfcoacher Wrote: How does your breathing feel when Resmed adjusts pressure at inappropriate times as a result of incorrect detection of new inspiration cycle?
It only occurs when sleeping so not sure what it feels like, I do not believe it causes enough issue to wake me up. Since these cardiogenic oscillations are quick the pressure doesn't increase that much unless using a machine with minimum inspiration time that locks in the increasing pressure. In that case having a properly set trigger sensitivity will help avoid premature triggers (works for me on my vauto).
RE: What's a "minute vent"? - mesenteria - 11-21-2021
When you breathe normally, the timing is commonly thus:
a. draw in breath:
b. exhale by relaxing. Two, three..,;
c. draw in next breath;
d. exhale by relaxing...two...three...
You draw breath into yourself more quickly than you exhale, but the difference is small. Notice that you don't normally hold your breath in, and then allow it to exhaust as your diaphragm relaxes. Instead, you breathe in, and immediately expel what's in your lungs. Between breaths is a sort of refractory period while your blood CO2 rises and triggers the next intake.
RE: What's a "minute vent"? - Sleeprider - 11-21-2021
Usually these terms can be found by searching the Definitions in our Wiki. http://www.apneaboard.com/wiki/index.php/Definitions#S.2C_T.2C_U
Tidal Volume - The amount of air that is inspired or expired in an ordinary breath. Usually expressed in milliliters per second (mL/sec). Used with the respiratory rate to calculate Minute Vent. (Minute Ventilation in L/min = (Tidal volume in mL/1000) * (Respiratory rate in breaths per minute)
RE: What's a "minute vent"? - smfkdol9392 - 08-07-2022
Is it possible what you are describing is also happening in my case, here?
If so, would that also affect my tidal volume number?
Thank you.
(07-26-2021, 12:06 AM)Geer1 Wrote: Inspiration time is the average time you spend inhaling. Expiration time is the average time you spend exhaling. Tidal volume is the average volume you breath in per breath. Respiration rate is the average breathing rate/minute. Tidal volume * respiration rate gives you minute ventilation which is the average volume of air you breath per minute.
Inspiration rate is usually over 1 second and commonly around 1.5 seconds, expiration rate is usually around double the inspiration rate and 2.5-3 seconds is common. You have to take both statistics from OSCAR with a grain of salt because they can be easily influenced by things like cardiogenic oscillations and rem breathing which confuse the machine (it thinks positive flow is inspiration and negative flow is expiration but in reality some things like cardiogenic oscillations can cause positive flow during expiration). If you want to check actual inspiration/expiration times it is better to measure them yourself and average a few examples through the night.
For example my inspiration time is regularly reported as over 2 seconds and often longer duration than my expiration time but if I actually measure it then it is regularly around 1.3-1.5 seconds with 2.5-3 seconds expiration. The reason is that I have cardiogenic oscillations that cause flow rate to momentarily cross zero flow rate before my expiration finishes so the machine stops measuring expiration and prematurely switches to measuring inspiration even though I haven't yet started inspiratory effort.