Nitrogen Wash Out

Specialties CRNA

Published

I need to give an inservice to the med/surg staff on assisting with intubations. Can anyone tell me the reason for "nitrogen wash out" pre intubation?

When I was taught to assist they said to remove the pillow, but I see on several internet sources they recommend leaving it under the head and neck. Has that changed, or did I just learn wrong?

If you have any points that should be emphasized during my inservice I'd love to hear them. Pet peeves, or things that nurses don't normally know that they should.

Thanks for your help.

Specializes in ECMO.
What!!!? No one ever told me that one. So are you saying that if I use 100% O2 on someone in severe respiratory distress I could be contributing to the problem? Just so I express myself accurately I am about to go off the deep end with this information. Someone please tell me that it is not significant unless long term, or something...

The only cautions I've heard of with O2 have been with premature infants and COPD patients.

long term FIO2 above 50% can lead to reabsorption atelectasis. nitrogen is perfusion limited, but oxygen is diffusion limited. so if nitrogen is washed out and 100% O2 are in the alveoli, that oxygen will tend to leave the alveoli completely (causing atelectasis), assuming the ACM is normal. oxygen difussion is limited by the integrity of the ACM and not by blood flow. so that could cause the alveoli to collapse. AARC has guidelines, but 100% o2 should not be denied, but long term it can cause more harm than help.

anyone can correct me if im wrong.

im in a BS RT program. CRNA > RRT

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Specializes in Anesthesia.
...... 100% o2 should not be denied, but long term it can cause more harm than help.

Please define long term.

d

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Specializes in ECMO.
Please define long term.

d

ive read that in as little as 24hrs 100% FiO2 can cause pulmonary damage.

more info...100% FiO2 for 2 hrs can decrease DLCO and for 24-60hrs can decrease VC.

oxygen toxicity, caused by long term 100% O2, can cause trachea bronchitis, substernal CP, decreased VC, lung compliance, increased PA-a O2 gradient, decreased mucociliary mobility, interference with surfactant, etc. lots of problems can arise

this is what ive read about 100% O2.....it may be OK if i can be brought down to 70% within 2 days or 50% or less within 5 days. (reasons why I still dont know)

and of course high FiO2 has to be used for resuscitation, cardiopulmonary instability, pt transport, bronchodilator tx, bronchial hygiene, and PEEP/CPAP.

hope this helps, sorry bout the long answer

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Specializes in Anesthesia.
ive read that in as little as 24hrs 100% FiO2 can cause pulmonary damage..........

OK then, but therefore oxygen toxicity is more a long-term ICU ventilator patient concern than it is a run-of-the-mill everyday anesthesia concern.

Many anesthesia providers, myself included, prefer to run inhalation agents in pure oxygen for most patients, as that has been shown to help minimize PONV.

Of course there are a thousand correct ways to skin any given cat.

d

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Many anesthesia providers, myself included, prefer to run inhalation agents in pure oxygen for most patients, as that has been shown to help minimize PONV.

I have NOT been taught that in school or heard it from my preceptors. In fact my professors have emphasized the need to avoid atelectasis and tissue damage by running N2O or air with our O2. Tell me more!

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Specializes in Anesthesia.
I have NOT been taught that in school or heard it from my preceptors. In fact my professors have emphasized the need to avoid atelectasis and tissue damage by running N2O or air with our O2. Tell me more!

Really! Well, there certainly are a thousand ways to skin this cat. A quick Google gives us these two refs:

Grief R, Laciny S, Rapf B, Hickle R, Sessler D: Supplemental oxygen reduces the incidence of postoperative nausea and vomiting. Anesthesiology 1999; 91:1246-52

and

http://www.outpatientsurgery.net/2000/os09/os09f1.htm

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I know this is an old post, but I think some are confusing oxygen toxicity with nitrogen washout. Oxygen toxicity occurs due to oxidative damage to various organs, mainly lungs, causing an ARDS-like state. This occurs with >60% FiO2 for 24-48 hours.

Nitrogen washout occurs all but instantaneously. This is why is it used as a diagnostic test to measure closing volume. It is well known that this can cause alveolar collapse, but may not be clinically relevant in most patients.

Well studied and documented that lower FiO2 reduces atelectasis. Better off giving a NK-1 antagonist for PONV.

See "Mechanisms of atelectasis in the perioperative period" Hedenstierna G, Edmark L. Best Pract Res Clin Anaesthesiol. 2010 Jun;24(2):157-69.

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