The information here provided
educational purposes only and it is not intended, nor implied, to be a
for professional medical advice. Always consult your own physician or
healthcare provider with any questions you may have regarding a medical
What Setting is Correct?
I recently received the following
email from Tom in Florida.
just purchased a pulse oximeter.
I am getting a reading from 92-95 while on 2 litres of oxygen. Is this
a safe range? I'm SOB with very little exertion.
I responded as follows.
it strange that even the manual that comes with a pulseox doesn't
tell you good from bad readings? What we do know is that Medicare will
pay for oxygen for those whose readings are below 88 percent. Many
physicians suggest that patients stay above 90 percent. Otherwise, I
little information directed to patients about the question you ask,
except as directed toward
airline pilots who are flying uncompressed aircraft above 5,000 feet.
In the article "Hypoxia,
Oxygen, and Pulse Oximetry," Dr. Fred Furgang suggests
requirements for pilots so those pilots are adequately oxygenated
without wasting the oxygen their planes are carrying. He suggests pilot
start supplemental oxygen
when an oximeter reading is below 90 percent and continue to monitor
saturation every 15 minutes. Dr. Furgang suggests keeping the pilot's
saturation at 91-92 percent for
remedial tasks and at 93-94
percent for tasks that require reasoning and/or physical action. To me
that means rest or sleep in the lower range, but don't argue with my
spouse, carve a turkey, or drive the car unless I am in the
So, if you aren't flying an plane in the stratosphere, what oxygen
should you be comfortable with? The best place to answer this question
is in your doctor's office. To help with the discussion, collect
information about the times you are short
of breath. What were you doing? What was your oxygen setting? What was
your saturation and pulse readings? If your saturation was below 90,
how long did it take to recover and at what oxygen setting?
the other hand, being SOB is only indirectly related to a need for
oxygen. When my chest feel tight and unable to expand, the problem is
often eased with a puff of albuterol or a nebulizer treatment. I find
that tightening of the chest is also be related to a lung infection,
particularly when my pulse rate are elevated.
Can you set oxygen too high? From a conservation point-of-view, the
answer is "Yes." Setting your portable too high means exchanging or
refilling oxygen units more frequently than necessary.
From a medical point-of-view, the best authorities I can find
say No, you cannot set your oxygen too high.
myth that too much oxygen causes a carbon dioxide (CO2)
retainer to stop breathing has never been verified or documented.
Recent and ongoing research, particularly that which is being done by
Richard Casaburi and his colleagues is increasingly showing that higher
saturation does not pose a risk for those who retain CO2.
assumption that everyone with a diagnosis of
chronic obstructive pulmonary disease should therefore have their
oxygen treatment drastically restricted is dangerous. Where there is a
suspicion of a retention of carbon dioxide, further history should be
sought to avoid increasing hypoxia in an already exhausted patient."
(Source: Inglis, Andrew et al. Letter
to editor. (British Medical
Journal, 31 March 2001)
may be surprised to
learn that many oxygen users only require oxygen
at night. Here are the symptoms that cause
physicians to believe nighttime oxygen is required.
cause may be apnea--the
absence of spontaneous
respiration. Sleep apnea occurs when
nighttime breathing stops many times. Severe snoring may be a sign of
apnea, particularly when accompanied by any of the above symptoms. For
more information, see the American
Sleep Apnea Association.
second cause may be
reduced oxygen levels in the blood as you sleep. During the day, such
factors as level of activity and weather
conditions have the greatest influence on oxygen consumption. Some of
us desaturate in hot weather, whereas others desaturate in cold
weather. Some of us can predict stormy weather by becoming more
breathless as the atmospheric pressure drops. When we are at rest,
under moderate or extensive exercise, or digesting a large meal all
impact oxygen consumption.
nice dome-shaped diaphragms, which move air in
and out of the lungs very efficiently, our lungs are in a
constant state of over-inflation, causing our diaphragms to flatten and
be unable to single handedly move air in and out of our lungs without
some help. It is the skeletal muscles of the chest, shoulders, and
abdomen that take help.
you sleep, the
skeletal muscles go to sleep. Your breathing becomes
shallow and breathing frequency decreases. The work of
breathing at night is turned back to the flattened diaphragm, which is
adequately do the job and ventilation of the lungs falls to as low as
half that during the daytime.
is the first thing
a doctor checks when you are diagnosed with COPD.
Perhaps you, like me, went on oxygen during the night only and wondered
why not also during the day? Now you know. You perhaps now understand
why doctors prescribe sleep studies--studies where you are connected to
a recording oximeter while you sleep.
- Unusual sleepiness during the day may be caused by
inability to get
quality sleep at night.
- Increased shortness of breath when lying down.
condition often sleep with multiple pillows or in a recliner.
- Waking up suddenly at night short of breath.
- Morning headaches caused by noctural hypoxia.
record both saturation and pulse. Pulse/oximeters
three sizes—portable, handheld, and finger. All
are self-contained and run on batteries.
are noninvasive and
have a probe that clips to the finger. A cable connects to probe to
portable, handheld, and wrist oximeters. The probe of the finger oximeter is
built into its casing, so the entire unit sits on the finger when in
- Portables, which have a lot of
bells and whistles, are about the size and weight of a hardback novel.
- Handhelds are about the size of a large TV remote.
- Wrist oximeters which are worn like watches.
oximeters clip on the finger.
Some oximeters have features
that might be important to you.
- Has a probe that attaches to the ear.
- Can store readings overnight.
- Sounds an alarm (important when a caregiver is
I have not heard from oximeter owners a
single bad word about any of the above brands.
|*Since 2004, Nonin has added an additional warranty year at no additional cost.
All oximeters have a warranty from the manufacturer. My personal experience is that oximeters
last many years after any warranty expires, even when one is soaked in
water. Remember that a warranty does not cover accidental damage. I
suggest you use the lanyard to carry it about your neck. The one
problem with that is your oximeter will catch food you drop and will
need periodic disassembly and cleaning. Follow the instructions for
cleaning that appear in your user manual.
is quite a bit of competition among sellers of oximeters. Prices vary
from between $200 and $400. Some sellers offer free shipping while
others offer lower prices.
An oximeter is a medical device approved by the FDA. As such, it can
only be sold by a licensed pharmacy and requires a prescription signed
by a licensed physician. Many distributors ignore these requirements.
I do not usually recommend any particular distributor of any
product when there are many to choose from. I do, however, in this case
This distributor is a pharmacy owned by a physician who, when asked
will write a prescription for you. You will also find included with
your oximeter Tips for Using Oximetry in Home Oxygen Therapy written by this physician. If you are a member of Pulmonary Paper, expect a $50 discount. by Brent Blue, M.D.
not cover the purchase by patients, many
insurance companies will. If you are not on Medicare, your insurance
company may pay for an oximeter.
example, Aetna covers a
pulse oximeter for home use for members
with DME benefits who have ANY of the following conditions.
To be reimbursed, you
may find it necessary to write a Letter of Necessity to your insurance
company. Such a letter should be signed by your physician. For an
example of such a letter see A Sample Letter of Necessity.
wean the patient from home oxygen
change in the patient's
physical condition requires an adjustment in the liter flow of their
home oxygen needs
determine appropriate home oxygen liter flow
for ambulation, exercise, or sleep
monitor patients on a
ventilator at home.
Mangus, Mark, Sr. RRT,RPFT,RCP
Oximetry Recording. (Orlando: Rotech Healthcare, Inc.,
Clinical Practice Guideline: Pulse Oximetry
of Pulse Oximetry
Furgang, Fred. Hypoxia,
Oxygen, and Pulse Oximetry.
Operator’s Manual for
the 9500 Onyx Finger Pulse Oximeter. (Plymouth,
MI: Nonin Medical, Inc., 2002)
© 2005 Copyright
Peter M. Wilson, Ph.D.
Founder of PortableOxygen.org
have permission to
print this document for your personal use. You also have permission to
print, copy, and distribute this document to oxygen users and their