Case
Thanks to Joe Chiang
Severe DKA; Obtunded with pH 6.65, PaCO2 18, Bicarb 5
Pt’s mental status is worsening
The decision is made to intubate
Should you give NaBicarb?
Probably won’t help as patient is already breathing at their maximum. Unless they blow off the Bicarb-generated CO2, they won’t increase their pH significantly.
What you need
Properly fitted NIV mask
Ventilator, not a NIV machine
Someone who knows how to work the vent
Normal intubation stuff
If available, Quantitative ETCO2
Procedure
- Place pt on pseudo-NIV
Settings are
Mode Volume SIMV
Vt 550 ml
FiO2 100%
Flow Rate 30 lpm
PSV 5-10
PEEP 5
RR 0
- Attach ETCO2 and observe value
- Push the RSI Meds
- Turn the Resp Rate to 12
- Perform jaw thrust
- Wait 45 seconds
This violates the tenets of RSI, but keeping the pt alive is probably more crucial right now.
Most experienced operator should intubate the patient
- Attach the ventilator
- Confirm tube placement by observing ETCO2
- Immediately increase Respiratory Rate to 30
- Change Vt to 8 cc/kg predicted IBW
- Change Flow Rate to 60 lpm, this si the normal setting for intubated patients (forgot to mention this in the audio)
Why 30 BPM? Listen to the podcast.
- Make sure ETCO2 is at least as low as it was when you started
- Check ABG
- Pat yourself on the back
Podcast: Play in new window | Download (5.9MB)
Hi, my name is Scott Weingart. 
{ 9 comments… read them below or add one }
Thanks for the useful info. It’s so interesting
It would be interesting to have this great approach modified if ED has no quantitative ETCO2. Thanks.
You can definitely manage without quantitative, in which case you just have to go by the 240 ml/kg/min, which translates to 30 breaths per minute if you set the tidal volume to 8 ml/kg. Just make sure to get the post-tube abg with alacrity.
Great podcast, and I really like the idea of using a regular ventilator in a non-invasive way. Occasionally, I have two or more people requiring BiPap at the same time with only one BiPap machine available.
What would the disadvantage of setting the initial respiratory rate to 12 breaths per minute using the NIV mask and using this to pre-oxygenate the patient? Certainly the SIMV mode would allow spontaneous breaths, and you wouldn’t have to remember to change the rate once you’ve paralyzed the patient.
Also, do you generally leave the vent mode on SIMV once the patient is intubated, with the settings you mentioned above?
Thanks!
Mike
only disadvantage is the patient may not tolerate the machine breaths, otherwise no problem. i don’t generally use simv once the pt is intubated, my take on vent management is in two of the later podcasts. just search the site for “dominating the vent.”
Scott
Scott-
We discussed this recently and the question of why SIMV came up? Could you explain your take on SIMV vs. PRVC or even BVM in this situation?
Thanks!
BVM is almost always a flail. BVM at high rates is just plain dangerous. PRVC would be fine but it is a more complex mode than straight SIMV, and I try to keep vent stuff as easy as possible. There will be no inherent advantage to PRVC.
Hey Scott,
Very cool concept! One question ….any attempts in the past taking the rate beyond 12 during the “pseudo NIV” phase???
thanks!!
You absolutely can, but you are balancing additional breath-induced gastric insufflation with the need to keep down CO2. You can make a determination on a per-patient basis.