Weekly blog: The Harms of Oxygen Therapy

From my slides presented at this week's adverse events and deaths rounds:

* Too much oxygen can be dangerous
* This danger is preventable
* Shortness of breath DOES NOT equal need for oxygen

* Hypoxia (Sa02 below 90-92% in normal lungs and 88% in COPD/hypercapnic lungs) means that oxygen is likely required

Examples: Cornet et al, 2012 Jama Internal Medicine
http://archinte.jamanetwork.com/article.aspx?articleid=1108704

Acute MI (DOI: 10.1002/14651858.CD007160.pub3)
* RR mortality 2

CHF
* No RCT; increases afterload, increases LVEDP and decreases cardiac output

Post cardiac arrest
* OR 1.8 death

Ischemic stroke
* In RCT 40% death in O2 group vs 17% no O2 (p<0.01)

COPD* Mortality with TITRATED O2 (88-92) vs. usual care RR 0.2

What about in palliative care? (Campbell ML J symptom pain management 2013)

* The majority of patients who were receiving oxygen at baseline experienced no change in respiratory comfort when oxygen was withdrawn, 

* Oxygen provides little benefit in non-hypoxemic patients. 

* Oxygen may be an unnecessary intervention near death 

* Potential to add to discomfort through nasal dryness and decreased mobility

Other harms:

* Length of stay likely increased with failure to wean

* Decreased mobility as patient attached to tank

* Financial harm -- costs of oxygen (it isnt free!)