Breathes per minute

[PatOnCPAP]

Hi guys and gals,

Is there a way to see on our machines (Resmed Auto 10) or on Oscar how many breathes per minute/hour we are taking during the night? I know there is the respiratory rate thingy but I dont quite understand it and its a rate. Or if someone could explain it to me.

The reason I'd like to know is I suffer form CFS/ME, as well as moderate OSA/CA, and one of the suggested problems with unrefreshing sleep from the CFS/ME is that our ANS is out of wack, which could cause hyperventilating.

So, I went off the CPAP for a night and just used Snorelab to record my breathing and there seems to be a much faster breathing rate there going on at night than what I do during the day. But I'd love to be able to see it in recorded numbers. It could be a really helpful tool for me and others to understand why our sleep is so unrefreshing. I would then even be able to run the CPAP during the day (as I work at home) and then compare those numbers with the night ones.

Thanks in advance.

Pat

[SleepyPaolo]

Respiratory rate is exactly what you're looking for.
It is a measure of breaths per minute. Normal resting RR is somewhere between 12 and 20.
Tidal volume is the volume of air inhaled and exhaled per breath. Minute vent is RR x TV.
OSCAR gives you a graph over time as well as statistical information like average, 95%, max.

[PatOnCPAP]

Thanks for the reply. I'm still struggling with understanding the graph though. What do those figures under Min, Med, 95% and Max mean? Is there anywhere that will just show you took a total of "x" amounts of breathes over a certain time period?

[SleepyPaolo]

Med is the median (middle value) respiratory rate for the night. It’s roughly analogous to the average value. It’s the value I’d expect to be somewhere between 12 and 20 (12 to 20 breaths per minute). That the one you want. If it says 15 it means your average breaths per minute for the night is 15.

The 95% value means that 95% of the nigh was at or below this value.
Min seems to always be 0, which makes sense.
If you go to the respiratory rate graph you can look at the rate at any specific time you pick.

The median is the most useful value.

[rick blaine]

Hi PatOnCPAP,

Most of the time, and for most people, how often they breathe both asleep and awake is between 12 and 15 times a minute. And if they were on an APAP machine, it would count up the number of breaths and divide it by the total number of minutes it was on to give the average per one minute.

Another word for average is median. So that's what median is – the average.

But people can and do vary across, say, six hours of sleep. And every now and then, the breathing slows down. It might go as low as six breaths a minute, for a few minutes. That is the minimum rate.

People can also breathe a bit faster, sometimes – even while asleep. And the highest number of breaths per minute is the maximum.

Please note that if you take a series of very rapid breaths – say, six – but in 10 seconds – and only for 10 seconds – and just that one time – and then slow down again, the machine will record that as if you had breathed that fast for the whole minute.

So maximums are misleading.

And because maximums can be misleading, a useful variant is the rate you were at or under for 95 per cent of the time. It gives more of a representative 'spread'. And the key thing to remember is: it is AT OR UNDER.

That number is the 95 per cent rate.

But the number to concentrate on is the median or average.

[rick blaine]

I should add that in terms of hyper-ventilating or not, the breathing rate isn't the only thing to focus on. The other key number is 'tidal volume'.

That is the amount of air which, like the tide, goes in and out 'as the world turns'.

If you were to blow up a balloon, that would be 'forced expiratory volume'. A lot of air. And then after that, you would need to take in a pretty much equal 'inspiratory volume'. A lot of air. You might even take the deep breath before you did the blowing. Still a lot of air.

But when you're not blowing up balloons or doing something very active, such as jogging, that tidal volume is around 500 cc per breath in men and 440 cc per breath in women.

And the tidal volume multiplied by the average number of breaths per minute gives 'minute ventilation'. And when that is too high, you can call it hyper-ventilating. With the effect, if it is continued over time, of blowing off too much CO2, and making the blood more alkaline.

For the normal, average person, and when sedentary, 6 litres per minute is a good number.

[PatOnCPAP]

Thanks to all the replies. Excellent! Now I understand it.

[JDS74]

Rick,

Your explanation is quite good and clear. Thank you for posting a very helpful explanation.

One small correction though. The use of the word Median as interchangeable with Average.
Average is the total of the measurements divided by the number of measurements.
Median, on the other hand, is that value for which 50% of the values are less and 50% are greater (works best if there are an odd number of values.)

For example, consider the set of data: ( 1, 1, 1, 1. 5, 10, 10,10,10 )
The average is 7 and the median is 5.

Frequently for large and well-behaved sets of data the average and median can be quite close.
In the example set above, suppose that the 5 is changed to 3 and two of the 1's are changed to 2 ( 1, 1, 2, 2. 3, 10, 10,10,10 ). Then the average is still 7 but the median is now 3.

[rick blaine]

Hi JDS74,

I know what the arithmetic mean is, and the median, and the mode. I also know the formulae for calculating standard deviation and also for correlation.

I was keeping it simple based on an educated guess as to how much detail the OP needed to know. It's a skill I developed when I worked as a senior desk editor on a national publication.

Let me ask you something – do you know the one about "Forgive me writing you this very long letter. I did not have the time to write you a shorter one"?

[palerider]

Hi JDS74,

I know what the arithmetic mean is, and the median, and the mode. I also know the formulae for calculating standard deviation and also for correlation.

I was keeping it simple based on an educated guess as to how much detail the OP needed to know.

That's no excuse for dumbing things down. Dumbing things down is part of the reason there's so many stupid people today.

[zonker]

Let me ask you something – do you know the one about "Forgive me writing you this very long letter. I did not have the time to write you a shorter one"?

this reminds me of one of my many pet peeves...people who say "got a quick question" particularly when writing on a forum.

who cares how quickly you type?

[Miss Emerita]

Pat, in addition to looking at Median, 95%, and Max, you can look at the respiration graph and see how your respiration rate fluctuated over the course of the night. Just read the information in relation to the numbers on the vertical axis over there on the left of the respiration rate graph.

I wouldn’t be surprised if you see a fair amount of variation. For example, when I have REM sleep, my respiration rate often goes up. It also goes up sometimes when I have a period of wakefulness. It is steadier when I’m just zzzing along.

[PatOnCPAP]

Pat, in addition to looking at Median, 95%, and Max, you can look at the respiration graph and see how your respiration rate fluctuated over the course of the night. Just read the information in relation to the numbers on the vertical axis over there on the left of the respiration rate graph.

I wouldn’t be surprised if you see a fair amount of variation. For example, when I have REM sleep, my respiration rate often goes up. It also goes up sometimes when I have a period of wakefulness. It is steadier when I’m just zzzing along.

Cool. Thanks. I'll take note of that too!

[ChicagoGranny]

Median and mode walk into a bar. The bartender says, “I’m glad your buddy is not with you today. He’s mean.”

[Dog Slobber]

Median and mode walk into a bar. The bartender says, “I’m glad your buddy is not with you today. He’s mean.”

I thought he was just average.