Here is a bit of follow-up on prior EMCrit discussions and some new stuff for Janu-Airway
For all of the shownotes, come to the EMCrit Preox Page
Now on to the Wee…
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An ED Intensivist from NY. No conflicts of interest (coi).
Latest posts by Scott Weingart (see all)
- COVID19 – Awake Pronation (aka the Pig Roast) A guest write-up by David Gordon, MD - April 6, 2020
- EMCrit Wee – Webinar I Gave to Pulm/Crit Care Fellows on Avoiding Intubation and Initial Ventilation of COVID19 Patients - April 4, 2020
- EMCrit 269 – Rationing of Critical Care and Ventilators in COVID19 with Reub Strayer - March 31, 2020
Two issues. 1) the problem you should be aware of with high flow is that while it works great for apneic oxygenation, it physically gets in the way of bag valve mask ventilation (or I should say any mask ventilation) because you can’t create a good seal with the high flow tubing in the way. With a normal nasal cannula, a seal with the mask is no problem. With high flow, the tubing is bigger/harder – so you can’t seal (and thus if you want to give more peep with a mask u can’t for example). 2) is more of a comment/question. I’m a huge peep fan….. Which is why I like the idea of using a machine and not a bvm with a peep valve. But no matter what you set the peep valve to…. Once the bvm deflates all the way, you lose your peep. So you are basically only getting peep during the expiration phase of the bvm and then ultimately losing it in the time you are waiting for the next breath. On the one hand, slow controlled bvm is important so you don’t inadvertently go to a higher pressure with your excitement and blow up… Read more »
NC @ 15 will fully pressurize the PEEP valve regardless of pt ventilations. No need to squeeze. Thought I taught you that before you left. Vent manages pressure, but not flow–need the NC even with the vent. Always NC! Some of the high-flow systems make BVM tough, some do not. I mentioned this in the podcast.
Cannula even with vent for sure…. Always…..That’s obvious. That’s not a question. I just wasn’t aware that a bvm with peep valve hooked up to O2 nc maintained your set peep (say up to 15). Really? I must have missed that very importent point! I’m not quite understanding the physics though how the cannula maintains the pressure in the peep valve with a bvm though…..
NC @ 15lpm is actually a lot of pressure. If there is a mask-seal you have pressurized the airway to the extent of the release set by the peep valve.
[…] Weingart has an update on techniques and physiology of preoxygenation for us in a new Emcrit wee. […]
Dr. Weingart,
After following your podcasts, I do use apneic oxygenation routinely in RSI and really believe in it. We have considered protocolizing it and the following questions have come up:
I often have patients with shunt hypoxia on CPAP already. They are holding on but it becomes clear we will perform a controlled RSI for a deteriorating state. Perhaps the patient is 92% on CPAP of 12 and 100% fiO2. In these patients, would you temporarily take off the CPAP mask to place the nasal cannula to use for apneic oxygenation, risking desaturation? Is the nasal cannula still useful in severely shunted patients?
Thank you for the amazing education you provide that has elevated so many clinicians and helped so many patients!
I am a hospitalist who works in an ICU with the assistance of a telemedicine ICU.
Mike
Wow ! It makes a lot of sense. I was expecting a 2 lines answer to my case, not a 20min Wee and 2 videos of rat lungs 😉 Thank you for that
If i remembered the peep on my patient was 10 cm H20, i’ll reach for 15cm H20 next time.
Fred
Hi Scott,
Great post.
In your reply to Josh Farkas on his webiste, you quote an RCT using standard (non-high flow) nasal cannulae. I’m struggling to find this. Can you point me in the right direction?
Thanks,
Stacy Turner
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