Re: C-pap, Bi-pap ?'s

June 5, 2004

-

Hi ,

I thought this file, created by Figgy, at the Adult Mito site might

be of interest to you- I know it cleared up a lot of my confusion...

Amy

IVUN

International Ventilator Users Network

Back to page 1 of IVUN News - Spring 2000, Volume 14, No. 1

Oxygen is NOT for Hypoventilation in Neuromuscular Disease

E.A. Oppenheimer, MD, FCCP

Editor's Note: The IVUN office continually hears from people with

post-polio or other neuromuscular diseases and conditions being

inappropriately prescribed O2 therapy. This anecdotal evidence

(confirmed by the Mayo Clinic case series) supports the need for

accurate information from the physicians most expert in the pulmonary

aspects of neuromuscular disease to be disseminated more widely to

alert people to the reasons why they should be wary of O2 therapy.

If progressive respiratory failure occurs in people with

neuromuscular disease, an abnormal nocturnal oximetry study is often

an early indication that hypoventilation is occurring. There are

significant periods of decreased oxygen levels in the blood or

hypoxemia during sleep when lying flat, in addition to decreases in

vital capacity (VC), maximum inspiratory force (MIF), and maximum

expiratory force (MEF). Decreased oxygen saturation (SaO2) combined

with increasing carbon dioxide (CO2) retention or hypercapnia are the

hallmarks of hypoventilation. This is sometimes called ventilatory

pump failure, due to the weakened respiratory muscles.

Patients with neuromuscular diseases who are developing progressive

respiratory failure due to respiratory muscle weakness will die

unless mechanical ventilation is used. The rate of progression is

often hard to predict. Some patients seem suddenly to experience life-

threatening hypercapnic respiratory failure. They may not have been

aware of gradually increasing symptoms and signs, particularly since

they are often not physically active and are often not being

regularly monitored with simple pulmonary function tests.

Administering oxygen does not provide assistance to the weakening

respiratory muscles, but gives both the patient and the doctor the

false impression that appropriate treatment is being provided. While

in fact hypoventilation is mistaken for an oxygen transfer problem.

Indeed, administering oxygen can mask the problem. Also there is a

danger of causing respiratory depression by giving oxygen. Oxygen is

NOT the treatment for hypoventilation. It will improve the SaO2, but

not the hypoventilation and may increase the danger of dying of

sudden respiratory failure.

In hypercapnic respiratory failure due to hypoventilation, the SaO2

falls due to the rise of the CO2. The alveoli in the lungs (tiny gas

exchange units) should clear most of the CO2 out with each breath.

Instead, with hypoventilation, CO2 accumulates and thus there is

decreased room in the alveoli for oxygen. When mechanical ventilation

using room air is provided, it lowers the CO2 in the alveoli,

corrects the SaO2, and rests the respiratory muscles. The ventilator

should be adjusted to achieve a normal SaO2, on room air. If oxygen

is being administered, one cannot use noninvasive oximetry to tell

whether enough assisted ventilation is being provided; repeated

arterial blood gas specimens (ABGs) would be needed.

When there is respiratory failure in neuromuscular patients (ALS,

post-polio, SMA, muscular dystrophy, etc.) who have no additional

pulmonary disease that impairs oxygen transfer, the ventilator set-up

is adjusted to:

 be comfortable for the patient;

 achieve SaO2 of 95% or higher on room air (this can be

measured

with a finger-sensor oximeter);

 assist the patient to effectively cough and clear

secretions;

 provide improved oral communication (if vocal communication

is

possible).

It has been common for people using noninvasive nasal ventilation

(NPPV) with a bi-level positive pressure unit to use inadequate

settings; frequently, they are not monitored with clinical evaluation

and oximetry. The EPAP is often set too high – usually it should

not

be higher than 3-4 cm H2O; the IPAP is set too low – usually it

needs

to be 12-16 cm H2O and adjusted to achieve an oxygen saturation of

95% or higher.

Some situations may require administering oxygen, such as pneumonia

due to infection or aspiration. If this occurs in patients with

respiratory muscle weakness and hypoventilation, then it is important

to provide both assisted ventilation and supple-mental oxygen, and

use ABGs to monitor them.

Address: E.A. Oppenheimer, MD, FCCP, Pulmonary Medicine

(eaopp@...).

References

 Bach, J.R. (1999). Guide to the evaluation and management of

neuromuscular disease. Philadelphia, PA: Hanley & Belfus. Gay, P.C.,

& Edmonds, L.C. (1995). Severe hypercapnia after low-flow oxygen

therapy in patients with neuromuscular disease and diaphragmatic

dysfunction. Mayo Clinic Proceedings, 70(4), 327-330.

 Hsu, A., & Staats, B. (1998). " Postpolio " sequelae

and sleep-

related disordered breathing. Mayo Clinic Proceedings, 73, 216-224.

 Krachman, S., & Criner, G.J. (1998). Hypoventilation

syndromes.

Clinics in Chest Medicine, 19(1), 139-155.

Additional Observations about Oxygen in Neuromuscular Disease

 Anita Simonds, MD, FRCP, Royal Brompton Hospital, London,

England

(a.simonds@...)

I agree completely with Dr. Oppenheimer that assisted ventilation is

the appropriate therapy for alveolar hypoventilation. Apart from a

limited number of situations such as pneumonia or lung fibrosis,

oxygen therapy is usually inappropriate and may prove hazardous.

Clearly, in an acute pneumonia O2 therapy can be entrained into the

ventilator system. Fortunately, in the United Kingdom, this message

is getting across to healthcare workers and patients. There is still

some inequity in providing noninvasive ventilation, but the situation

is improving.

 S. Krivickas, MD, Instructor in PM&R, Harvard Medical

School,

Director of EMG, Spaulding Rehabilitation Hospital

(LKrivickas@...)

The analogy that I often use in regard to patients with respiratory

failure from neuromuscular disease is that their lungs are like a

deflated balloon that they are not strong enough to inflate. To

inflate the balloon, mechanical assistance to force air into the

balloon is needed. Blowing oxygen across the mouth of the balloon

(the equivalent of using supplementary oxygen delivered by nasal

cannula) will do nothing to inflate the balloon.

The case series published by the Mayo Clinic (see reference to Gay &

Edmonds, 1995) demonstrates the dangers of administering as little as

1 to 2 L/min of nasal cannula oxygen. Patients with a variety of

neuromuscular disorders experienced marked CO2 retention; several

became obtunded and required intubation or died when they were placed

on 0.5 to 2 L of nasal cannula oxygen.

For more information on breathing problems of polio survivors, go to

Post-Polio Breathing and Sleep Problems by Headley and Fischer

Back to page 1 of IVUN News - Spring 2000, Volume 14, No. 1

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-- In , " DeMoss " wrote:

>

> seems to be having more problems with her breathing.She

pretty much stays on O2 24/7 now.with the o2 her level is staying @

95-98,which is very good, but she just wears herself out breathing so

hard.I've called it belly breathing before but it's even more than

that now,I don't even know how to explain it.

> She has had deminished lung volume for some time,doesn't inflate

base well,very shallow breaths.

> My ? is would c-pap or bi-pap help with this? What is the

difference in the two? Can either be used as needed or once on one is

it something you need 24 hrs a day?

> All help appreciated.

> Thanks,,Mom to

>

June 5, 2004

I'm glad you posted. I was getting concerned. I'm sure takes up much

of your time.

There is a super article that answers your question on the difference of

bi-pap and cpap in the Quest magazine. It may be in the mito files (I think

it is) but it can also be accessed on the MDA site. They recommend bi-pap

for those with neuromuscular diseases as they can be adjusted to do

different things. I use my cpap only at night (that is what they were

designed for), but they are using them for people who are coming off a

ventilator or who are struggling but not ready for a vent. I know of people

who have used cpap with a trach for years and can still spend time off the

cpap when in certain situations.

If you can't locate the article, e-mail me privately and I will send it to

you as an attachment (I am 98% sure I have it on the computer)

laurie

>

> Reply-To:

> Date: Fri, 4 Jun 2004 22:57:01 -0500

> To: >

> Subject: C-pap, Bi-pap ?'s

>

> seems to be having more problems with her breathing.She pretty much

> stays on O2 24/7 now.with the o2 her level is staying @ 95-98,which is very

> good, but she just wears herself out breathing so hard.I've called it belly

> breathing before but it's even more than that now,I don't even know how to

> explain it.

> She has had deminished lung volume for some time,doesn't inflate base

> well,very shallow breaths.

> My ? is would c-pap or bi-pap help with this? What is the difference in the

> two? Can either be used as needed or once on one is it something you need 24

> hrs a day?

> All help appreciated.

> Thanks,,Mom to

>

June 5, 2004

Hi ,

How are you and doing today? I am sorry to hear about 's

trouble breathing. I have had trouble breathing from day one, but as

I got older my lung muscles got a bit weaker. I am now on what is

called a VPAP almost 24 hours a day. I have been on a pap machine

since I was in Junior High. When I was younger it was just something

I used when I had trouble breathing or when I was asleep. By using it

while asleep, it allowed my body to get total rest because I wasn't

having to work as hard to breathe. This also gave me more energy the

next day than if I had slept without the machine. Before I went on

the machine full time, I would often put it on while resting, just to

give my lung muscles a break. It is not something that HAS to be

used 24 hours a day, but it CAN be used 24 hours a day if needed

I do have diminished breathe sounds in the lower lobes, even on the

machine, and when I am sick I have diminished breathe sounds in all

the lobes. Without the machine I breathe VERY shallow.

Here is a piece from a post that I posted in April. Hope some of it

helps. In it I explained the differences between the different pap

machines Just a side note - if the pulmo mentions a trach, let him

know about Non-Invasive ventilation. I use non-invasive ventilation,

and a quick summary would be that the patient uses a face mask

instead of the trach. A face mask can be used with cpap and bi-pap,

which is common for sleep apnea patients. BUT it can also be used

with VPAP and even a typical ventilator, like the LTV 1000. There is

an article (I think it is the same one that was already mentioned by

Laurie) written by Dr. Bach which is available on the MDA website. It

covers non-invasive ventilation very well. If you can't find it on

the website, just let Laurie or I know. I also have a copy of it on

my computer.

*************************

The thing I would suggest is to get a sleep study to determine which

type of machine you need. If this isn't an option, I would suggest

carefully going over with your pulmo exactly what you need the

machine to do for you. You will need a perscription to get any type

of pap machine.

If you just need it to keep your airway open, that is what a cpap

does. If you need it to inhale and exhale by your command, that is

what a bi-pap does. If you need it to initiate breaths for you, that

is what a bi-pap ST does. If you need it to totally breathe for you

like a vent, VPAP II ST-A does that.

Auto-paps are c-paps that adjust themselves regulary based on how you

are breathing. They are wonderful because you don't need a lot of re-

titration. The doc sets a pressure range (lik 7 cm's to 15 cm's) and

then based how much help or pressure you need, the machine adjusts to

that pressure. I have never used an auto-pap but I know people who

have and they are very happy with them. So, as you can see, it really

depends on exactly what you need the machine to do for you in order

to choose what machine will work best for you. Like Laurie said, it

is usually better to go with a DME to buy a machine and mask because

they are in your area if you need help fixing it or adjusting it.

*********************

If you have any more questions, just email me or post here. Let me

know if you want some info on the best types of masks. Good luck

with everything, and I hope that can breathe easier soon!

Keep Smiling,

Nikki

>

> seems to be having more problems with her breathing.She

pretty much stays on O2 24/7 now.with the o2 her level is staying @

95-98,which is very good, but she just wears herself out breathing so

hard.I've called it belly breathing before but it's even more than

that now,I don't even know how to explain it.

> She has had deminished lung volume for some time,doesn't inflate

base well,very shallow breaths.

> My ? is would c-pap or bi-pap help with this? What is the

difference in the two? Can either be used as needed or once on one is

it something you need 24 hrs a day?

> All help appreciated.

> Thanks,,Mom to

>

June 6, 2004

Thanks Nikki and everyone. I printed the article " Breathe Easy " off the MDA

site.

I will be calling 's doc tomorrow.I also intend to call MDA,she has been

seen at thier clinic once before,maybe they too can offer suggestions.

has had a very bad ear infection for about 2 weeks now.She's had a round

of antibotic, 2 Roceffin (sp) shots and ear drops.She goes back to the doc again

tomorrow,hopefully this will take care of it.As all of you know a virus or

infection is so hard on the body,it just takes all her energy trying to get

better.

Again, THANKS ! I'll probably have more question after talking to the doc and

MDA.

I don't post often but I want you ALL to know you're in my prayers and thoughts.

,Mom to