What is a normal tidal volume and Peak flow

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Slinky
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Re: What is a normal tidal volume and Peak flow

Post by Slinky » Wed Sep 03, 2008 12:17 pm

Shucks, Willie, I don't know if it is the addition of the S8 ResLink that can provide the Tidal Volume, the upgrade to a Resmed S8 AutoSet Vantage or the upgrade to the Resmed VPAP Auto (bi-level) that gives the additional Tidal Volume, Minute Ventilation and Respiratory Rate. Too many changes too fast for me to remember. BillBolton or DSM should be able to answer this for you tho. Maybe even Velbor tho I think he has stayed w/his S7 rather than moving up to the S8.

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Re: What is a normal tidal volume and Peak flow

Post by Slinky » Wed Sep 03, 2008 12:20 pm

It might help, wlo. But I "think" I remember reading that nebulizing meds "can" raise the HR and interfere w/sleep. REMEMBER,TODAY "AIN'T" MY DAY!!! You've got nothing to lose, except maybe a little sleep for one night, and a lot to gain if it improves your night time breathing so I'd try it.

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Re: What is a normal tidal volume and Peak flow

Post by Georgio » Wed Sep 03, 2008 12:22 pm

Looks like the future thing will be for patients to have their own medical labs set up at home and they will be their own techicians...

Yes, the insurance companies have won and the future of our health care system is to treat yourself.....!

Thanks for the tips on machines. They gave me the S8 Escape, which is the right name because it's a cheap escape for insurance co.

Thanks.
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Slinky
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Re: What is a normal tidal volume and Peak flow

Post by Slinky » Wed Sep 03, 2008 12:35 pm

If you've had that Escape less than 30 days, TAKE IT BACK. Politely, diplomatically, BUT FIRMLY INSIST that they provide you w/the Resmed S8 II Elite w/EPR. Most insurance company pay be HCPCS code, NOT by brand or model. Don't let them hand you that B.S. that your insurance won't pay for more than the Escape. If you've done your homework and called your insurance company and asked what local DME suppliers they are contracted with and have the option of more than this DME supplier to get your equipment from - shop the other suppliers to find one who will provide what you want and then tell your current supplier either they provide you w/the Resmed S8 Elite II w/EPR or you will go elsewhere. But you HAVE to do this w/in the first 30 days, 45 days MAXIMUM.

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Strapparatus

Re: What is a normal tidal volume and Peak flow

Post by Strapparatus » Wed Sep 03, 2008 12:54 pm

Accuracy is not as important as precision.
I doubt seriously that all of the formulas have been factored in logarithms for the equipment you use in the home.
For example, loss of volume due to heated humidification. Loss of volume due to Pouseille's law, etc. This is 1st year Respiratory Therapy information. We would also have to calcultate BTPS (body temperature pressure saturated) or the relative humidity in the gas (air).
Basically, a lot of variables that have to do with tidal volume inhaled, or tidal volume exhaled. I forgot to mention Vt (dead space) which would/ should be included / excluded depending on the equipment. There are lots of studies available on mechanical ventilation and the factors that describe accurate or precise VT (exh) or VT (inh) although not sure about this
in reference to noninvasive positive pressure ventilation. My guess is the manual for your equipment would provide a clear
reference +/- 100 mls or a measurement in L/min accuracy as these have to pass FDA specifications and various medical regulations before they are approved for distribution. Consult your manual in the appendix or in the specifications section.

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Re: What is a normal tidal volume and Peak flow

Post by -SWS » Wed Sep 03, 2008 12:59 pm

Guest Strapparatus wrote:I am not convinced that these cpap machines can really accurately measure tidal volume or peak flow. Normally, that is done with a machine such as a spirometer. It seems that with a cpap pushing air out, the leaks with equipment and other variables, that these numbers are more a a general indicator rather than something that we can use against "normals". I would be interested in the thoughts of any respiratory therapists or other trained professionals reading this post - how accurate do you think any of these readings from cpap/bilevel really are?
These specs were recently posted by StillAnotherGuest in StillAnotherThread:
Image
Last edited by -SWS on Wed Sep 03, 2008 1:27 pm, edited 1 time in total.

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Snoredog
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Re: What is a normal tidal volume and Peak flow

Post by Snoredog » Wed Sep 03, 2008 1:11 pm

Strapparatus wrote:Accuracy is not as important as precision.
I doubt seriously that all of the formulas have been factored in logarithms for the equipment you use in the home.
For example, loss of volume due to heated humidification. Loss of volume due to Pouseille's law, etc. This is 1st year Respiratory Therapy information. We would also have to calcultate BTPS (body temperature pressure saturated) or the relative humidity in the gas (air).
Basically, a lot of variables that have to do with tidal volume inhaled, or tidal volume exhaled. I forgot to mention Vt (dead space) which would/ should be included / excluded depending on the equipment. There are lots of studies available on mechanical ventilation and the factors that describe accurate or precise VT (exh) or VT (inh) although not sure about this
in reference to noninvasive positive pressure ventilation. My guess is the manual for your equipment would provide a clear
reference +/- 100 mls or a measurement in L/min accuracy as these have to pass FDA specifications and various medical regulations before they are approved for distribution. Consult your manual in the appendix or in the specifications section.
I guess it depends on who you are asking, Wendy asking about her flow rate being reported by her AdaptSV or Slinky rambling on and on in response to someone high jacking this thread with their non relevant Resmed cpap questions.

But yes the AdaptSV does have a section in the manual for reporting the Control accuracy of the device, but it may not
line up pasting:
Control aCCuraCy
Parameter Range Accuracy
IPAP Min 4 to 30 cm H
2O ± 5 cm H2O*
IPAP Max 4 to 30 cm H
2O ± 5 cm H2O*
EPAP 4 to 25 cm H
2O ± 5 cm H2O*
Breath Rate 4 to 30 BPM Greater of ± 1 BPM or
± 10% of the setting (when
measured over a 4 minute
period)
Timed Inspiration 0.5 to 3.0 seconds ± (0.1 + 10% of the setting)
seconds
Ramp Duration 0 to 45 minutes ± 10% of the setting
Rise Time 1 to 6 ** ± 25%***
* Dynamic pressure accuracy is ± 5 cm H
2O measured at the patient end of the circuit
with a Whisper Swivel II and varying flow conditions. Static pressure accuracy is
± 2 cm H
2O measured at the patient end of the circuit with a Whisper Swivel II and
no patient flow.
** The range of values correspond to tenths of seconds (e.g., a setting of 4
indicates a Rise Time of 0.4 seconds).
*** Measured at the patient end of circuit with a Whisper Swivel II exhalation
device and no patient flow.
measured Parameter aCCuraCy
Parameter Accuracy
Respiratory Rate Greater of ±1 BPM or ±10% of reading when
measured over a four minute period
Exhaled Tidal Volume ± (25 + 0.15 of reading) ml
Exhaled Minute
Ventilation ± (1 + 0.15 of reading) L/min
Leak Rate ± (5 + 0.15 of reading) L/min
someday science will catch up to what I'm saying...

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Re: What is a normal tidal volume and Peak flow

Post by Slinky » Wed Sep 03, 2008 1:15 pm

WATCH IT, SnoreDog. You old goat. Yer gonna get a broom whacked about your head and shoulders if you don't straighten up and fly right!!

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Re: What is a normal tidal volume and Peak flow

Post by wlo2008 » Wed Sep 03, 2008 1:16 pm

Slinky wrote:It might help, wlo. But I "think" I remember reading that nebulizing meds "can" raise the HR and interfere w/sleep. REMEMBER,TODAY "AIN'T" MY DAY!!! You've got nothing to lose, except maybe a little sleep for one night, and a lot to gain if it improves your night time breathing so I'd try it.

Yes it can raise the HR a bit, but I plan on doing this 2 hours prior to sleep. So I should be back to normal with my HR by then and still have a good treatment for the night.

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Re: What is a normal tidal volume and Peak flow

Post by wlo2008 » Wed Sep 03, 2008 1:17 pm

Slinky wrote:WATCH IT, SnoreDog. You old goat. Yer gonna get a broom whacked about your head and shoulders if you don't straighten up and fly right!!

LOL....you guys crack me up

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StillAnotherGuest
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Hold Your Horses...

Post by StillAnotherGuest » Wed Sep 03, 2008 1:56 pm

I think before anybody does any dial-wingin' for tidal volume and peak flow, you better pick the right parameters. The parameter suggested for tidal volume
Strapparatus wrote:Normal tidal volume for individuals is based on weight in kg (10-15 ml/kg).
is way too high for any clinical situation. Resting tidal volume is more in the range of 5 - 7 ml/kg (maybe 8 ml/kg if you subscribe to the AVAPS approach). The 10-15 ml/kg formula really gets absurd when you get out the 100 kg guys. A 1500 ml tidal volume is ridiculous.
Strapparatus wrote:peak flow is based on age and height and gender. Peak flows decrease incrementally with age, height and gender.
google: nomogram for peak flows and seek out a chart to determine your normal.
That's a PFT parameter that nothing to do with this discussion.
Strapparatus wrote:For example, loss of volume due to heated humidification. Loss of volume due to Pouseille's law, etc. This is 1st year Respiratory Therapy information. We would also have to calcultate BTPS (body temperature pressure saturated) or the relative humidity in the gas (air).
Basically, a lot of variables that have to do with tidal volume inhaled, or tidal volume exhaled. I forgot to mention Vt (dead space) which would/ should be included / excluded depending on the equipment. There are lots of studies available on mechanical ventilation and the factors that describe accurate or precise VT (exh) or VT (inh) although not sure about this
in reference to noninvasive positive pressure ventilation.
The most important variable would undoubtedly be V/Q. Just about all of these guys (except one)are spontaneously breathing.


SAG
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Slinky
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Re: What is a normal tidal volume and Peak flow

Post by Slinky » Wed Sep 03, 2008 3:27 pm

Oh, wow! Be still my heart! Even w/my COPD I still fall w/in "normal" reference ranges some of the time? Except when I'm awake, alive and kicking. Thanks for the clarification, SAG.

110 lbs = 49.9 kg. And 5 x 49.9 = 249.5, or 7 x 49.9 = 349.3 and 8 x 49.9 = 399.2. (I think - Shut up, SnoreDog! ).

I have a Peak Flow Meter and we will NOT go into how I do with that!!!

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Re: What is a normal tidal volume and Peak flow

Post by dsm » Wed Sep 03, 2008 3:53 pm

Guest wrote:I am not convinced that these cpap machines can really accurately measure tidal volume or peak flow. Normally, that is done with a machine such as a spirometer. It seems that with a cpap pushing air out, the leaks with equipment and other variables, that these numbers are more a a general indicator rather than something that we can use against "normals". I would be interested in the thoughts of any respiratory therapists or other trained professionals reading this post - how accurate do you think any of these readings from cpap/bilevel really are?

Two comments I'd make are

1) The data isn't super accurate but is better than none (why fly blind ?)

2) The data I look for is the relativity. From what I know are good nights (backed up by SpO2 data), over time I can
see trends & when a bad night occurs I can see a relativity to the good nights - after a year or two of looking at such
data I am satisfied I have a pretty good idea of what is happening.

But, it does get tricky looking at other people's data, even if from the same model machine. It tells a comparative story
but compared to what ? - one really needs to know a fair bit about the person (weight, height, general health, exercise
patterns, drinking habits, smoking, etc: ).

DSM
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Re: What is a normal tidal volume and Peak flow

Post by dsm » Wed Sep 03, 2008 4:30 pm

Wendy,

I've commented in the Bipap Auto SV thread from looking at your data. But I think SAG would be a far better
member to get advice from. I am thinking your Av Tidal flow is too low & am wondering why your machine
settings are sooo low - if you have some medical condition that caused the RT to set Epap at 5 then it is
hard for others to offer safe advice.

My own common sense tells me (rightly or wrongly) that lifting all the settings on your machine, should
increase your tidal flow & averages but at what cost I don't know.

Your situation really boils down to how competent and attentive your RT is and how accurately the RT set
up your machine plus the extent the RT is tuning it.

Good luck on this.

DSM
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Re: Hold Your Horses...

Post by Banned » Wed Sep 03, 2008 4:38 pm

StillAnotherGuest wrote:I think before anybody does any dial-wingin' for tidal volume and peak flow, you better pick the right parameters. The parameter suggested for tidal volume
Strapparatus wrote:Normal tidal volume for individuals is based on weight in kg (10-15 ml/kg).
is way too high for any clinical situation.
I think Strapparatus may have gotten a little un-strapped and misread the part that said, "use 10-15 ml/kg to inflate your tires". Even my AVAPS shipped with a shiny, new, Respironics Tire Gage.

As I understand SAG, Tidal Volume is a range between 5-8 ml/kg of ideal body weight, as in BMI (Body Mass Index). If you base your calculations on http://www.freedieting.com/tools/ideal_body_weight.htm, you should get an idea where you stand.

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