If you have a BVM (Bag Valve Mask resuscitator), you should not need naloxone. The problem is inadequate respiration, not inadequate naloxonation.

- Rogue Medic

Does an Oxygen Saturation of 100% Mean an Overdose?


 

Are we harming patients with oxygen?[1]

This will offend many in the oxygen religion, but we should start thinking of oxygen overdose.

What is our use of oxygen for everything based on?

Received wisdom from authority figures. We need to stop using authority and tradition as excuses to harm people.

Tom Bouthillet, Kelly Arashin, and Mike McEvoy discuss the harms of oxygen and the evidence of harm.
 

Go listen to the podcast, or watch the video.
 

Then reconsider your answer to my question.

Are we overdosing our patients, when we raise their oxygen saturation to 100%?

What if the origin sat was 94%?

What if the origin sat was 74%?

What if the origin sat was 54%?

Does the original oxygen saturation matter?
 

Would we have the same worries if the drug (oxygen is a drug) is morphine, NTG, midazolam, or even amiodarone?

Why do we grant the beliefs of the religion of oxygen such immunity from examination?

 

According to Mike McEvoy, the goal is 92% to 96%.

Not 97%.

98% is worse.

99% is much worse.

100% is as bad as it can get – even worse than hypoxia.

 

Go listen to the podcast, or watch the video.
 

A couple of points. Mike McEvoy states that the intensive care community has been familiar with this since the 1990s. This has been studied, and there has been evidence of harm since at least as early as 1950.
 

The administration of 100 per cent oxygen may actually be contraindicated in patients in whom oxygen saturation of arterial blood is normal.[2]

 

This was a decade before we found out that internal mammary artery ligation is nothing more than a placebo surgery.[3] That extremely popular procedure was done away with so quickly, that few people even remember the use of internal mammary artery ligation as a treatment for angina?

Oxygen has tradition behind it encouraging us to keep killing patients.

We should have been smart enough to reconsider our devotion to received wisdom and authority in 1950.

Many of us still refuse to learn.

This is why we need evidence before applying treatments to everyone.

How many hundreds of thousands of patient have we killed with oxygen and our refusal to require evidence of improved outcomes?
 


 

Go listen to the podcast, or watch the video.
 

Footnotes:

[1] EMS 12-Lead podcast – Episode #11 – Are we harming patients with oxygen?
EMS 12 Lead Podcast
EMS 12 Lead
Page with podcast and video podcast.

[2] One hundred percent oxygen in the treatment of acute myocardial infarction and severe angina pectoris.
RUSSEK HI, REGAN FD, NAEGELE CF.
J Am Med Assoc. 1950 Sep 30;144(5):373-5. No abstract available.
PMID: 14774103 [PubMed - indexed for MEDLINE]
 

In five patients with angina pectoris the administration of 100 per cent oxygen did not favorably influence the onset or duration of pain or the electrocardiographic alterations induced by standard exercise. On the contrary, oxygen therapy actually appeared responsible for more pronounced and persistent electrocardiographic changes in several patients.

[3] An evaluation of internal-mammary-artery ligation by a double-blind technic.
COBB LA, THOMAS GI, DILLARD DH, MERENDINO KA, BRUCE RA.
N Engl J Med. 1959 May 28;260(22):1115-8. No abstract available.
PMID: 13657350 [PubMed - indexed for MEDLINE]

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Comments

  1. Can’t do the podcast now but based on this article, if a person with a room air spo2 is at 98-100% they are self-over-medicating with oxygen. I know that too much oxygen is bad but with numbers like this it is hard to convince the masses. So what is the solution? Are we going to be doing ABGs in the medic now? Or continue to ‘wing it?’

    • Also, should our pulse oximeters read over 100%? Is that possible?

    • Alan W. Rose,

      Can’t do the podcast now

      When you get a chance, it is definitely worth listening to.

      but based on this article, if a person with a room air spo2 is at 98-100% they are self-over-medicating with oxygen.

      No.

      They are getting room air.

      They do not need supplemental oxygen, unless they are actually complaining of being short of breath. Conditions such as carbon monoxide toxicity is one example of a condition that could cause this.

      I know that too much oxygen is bad but with numbers like this it is hard to convince the masses. So what is the solution? Are we going to be doing ABGs in the medic now? Or continue to ‘wing it?’

      We will wing it.

      Venous blood gasses will probably be available in the ambulance eventually, then we will have a better idea for some patients.

      Even the AHA does not recommend supplemental oxygen as long as the oxygen saturation is at least 94%.

      EMS providers administer oxygen during the initial assessment of patients with suspected ACS. However, there is insufficient evidence to support its routine use in uncomplicated ACS. If the patient is dyspneic, hypoxemic, or has obvious signs of heart failure, providers should titrate therapy, based on monitoring of oxyhemoglobin saturation, to ≥94% (Class I, LOE C).36

      Part 10: Acute Coronary Syndromes
      2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
      http://circ.ahajournals.org/content/122/18_suppl_3/S787.full#sec-1

      That is for ACS, but not for cardiac arrest.

      The AHA makes the following unsupported claim –

      Empirical use of 100% inspired oxygen during CPR optimizes arterial oxyhemoglobin content and in turn oxygen delivery; therefore, use of 100% inspired oxygen (FIO2=1.0) as soon as it becomes available is reasonable during resuscitation from cardiac arrest (Class IIa, LOE C).

      Part 8: Adult Advanced Cardiovascular Life Support
      2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
      http://circ.ahajournals.org/content/122/18_suppl_3/S729.full

      One of the reasons that oxygen may cause harm is that high concentrations of oxygen act as an arterial vasoconstrictor.

      Giving more oxygen can paradoxically result in less delivery of oxygen to the organs that might actually be low in oxygen.

      The statement by the AHA is not empirical, even though they claim that it is.

      Maybe someday, the AHA will require that we have a good evidence-based reason to give drugs, but until then we are stuck with their “approved interpretation” of the inadequate research.

      The 2005 ACLS ACS recommendation was also not strongly recommending supplemental oxygen.

      Administer oxygen to all patients with overt pulmonary congestion or arterial oxygen saturation <90% (Class I). It is also reasonable to administer supplementary oxygen to all patients with ACS for the first 6 hours of therapy (Class IIa). Supplementary oxygen limited ischemic myocardial injury in animals,31 and oxygen therapy in patients with STEMI reduced the amount of ST-segment elevation.35 Although a human trial of supplementary oxygen versus room air failed to show a long-term benefit of supplementary oxygen therapy for patients with MI,30 short-term oxygen administration is beneficial for the patient with unrecognized hypoxemia or unstable pulmonary function. In patients with severe chronic obstructive pulmonary disease, as with any other patient, monitor for hypoventilation.

      Part 8: Stabilization of the Patient With Acute Coronary Syndromes
      2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
      http://circ.ahajournals.org/content/112/24_suppl/IV-89.full#sec-21

      .

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