Tuesday, October 21, 2014

Wednesday, July 22, 2009 Fatcat, Community Member, asks

Q: is there a formula that they use to determine the oxygen flow amount?

My dad has COPD and has been on 4 liters at home for a few months, but he just went into the hospital and when he came out, they put him on 3 and said he should never have been on 4.  How do we know? 

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Answers (1)
Kathi MacNaughton, Health Pro
7/31/09 8:13pm

Prescribing oxygen therapy is somewhat of a balancing act. Most people with COPD will do well for a long time on what is called low-flow supplemental oxygen therapy. This is usually somewhere in the range of 2 to 4 liters per minute, though it can vary from person to person.


The patient/family should never adjust the rate for oxygen without consulting the physician first. Inhaling too much oxygen can actually cause problems with COPD because the person may start breathing more slowly or more shallowly. That results in not getting rid of carbon dioxide, one of the waste products of breathing.


The goal is to keep the flow rate as low as possible, while still keeping your dad's respiratory status stable and minimizing COPD symptoms. If 3 liters per minute will do it, great!


Your role is to follow the doctor's instructions to the letter. If you're not comfortable with your dad's management of his treatment plan, you might consider getting him evaluated by a respiratory expert, called a pulmonologist.


Let me know if you have any other questions, OK? I'm in the same boat as you, caring for a mom with COPD. So I know the caregiver role can be stressful. But I am also a nurse and can help interpret the medical stuff when it doesn't make sense. Smile


Take care,


Kathi MacNaughton, Health Pro
7/31/09 8:15pm

Excuse me... I meant to say, if you're not comfortable with your dad's doctor's management of the treatment plan...

Chris W, Community Member
1/15/10 5:21pm

The majority of knowledgeable pulmonologists now prescribe oxygen "to maintain a minimum oxygen saturation of (typically) 92%". The myth that too much oxygen can cause carbon dioxide retention, while having been taught for many years, has never been proven while allowing oxygen levels to drop is a proven cause of death. It is recommended that  people check on the pooklet written by the late world renowned pulmonologist Dr. Tom Petty " Your Personal Oximeter - A Guide for Patients"

Kathi MacNaughton, Health Pro
1/15/10 7:58pm

Thanks for this info, Chris. I wasn't familiar with Dr. Petty (not the 70s rocker!), but a search for the booklet you mentioned quickly turned up lots of info. Thanks for that lead. The booklet is terrific; it can be downloaded here:

Your Personal Oximeter: A Guide for Patients


It's well worth reading, and I intend to share it with my mother. Even her doctor told her she could get "too much" oxygen, so obviously Dr. Petty's findings are not that well understood by non-pulmonologists.


So, thanks again for your help... Kathi

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By Fatcat, Community Member— Last Modified: 12/26/10, First Published: 07/22/09