VAPOX and Vent-as-Bag
In a concept piece called Preoxygenation. Reoxygenation and Delayed Sequence Intubation in the Emergency Department, I outlined a concept which I called: the vent as a bag. Why would we use the unpredictable and unmeasured BVM, when instead we could use a purpose-built, strictly internally regulated machine like a ventilator. I had stopped talking about the idea when numerous people told me it was unfeasible in their environment–however, I continued this practice for my own patients throughout my practice.
Recently, Grant et al. published a case series using the same concept–they have dubbed their vision of it VAPOX.
Ventilator-assisted preoxygenation: Protocol for combining non-invasive ventilation and apnoeic oxygenation using a portable ventilator (DOI: 10.1111/1742-6723.12524)[cite source='doi']10.1111/1742-6723.12524[/cite]
their protocol is very similar to the one I have used:
Non-Invasive SIMV
- Respiratory rate of 6–8 breaths per minute
- Pressure support 0 cm water (I never bothered unless pt had severe acidosis–the authors used PS of 10)
- Positive end expiratory pressure starting at 5 cm water (titrate up to 15 if not getting sats > 95% in preox)
- Fraction inspired oxygen 1.0
- Vt 550 ml
- Inspiratory Flow (30 lpm)
See Grant et al.'s paper for their protocol
Also consider getting some mask straps
And Remember the Nasal Cannula at 15 lpm
For More
See the EMCrit Preoxygenation Page
Now on to the Podcast…
Additional New Information
CPR-Vent Trial showed mech vent as bag is safe and feasible
Another RCT in Chest showed the same [10.1016/j.chest.2024.02.020]
More on EMCrit
- Podcast 65 – A Primer on BVM Ventilation with Reuben Strayer(Opens in a new browser tab)
- EMCrit 206 – ApOx, ENDAO, & PreOx Update(Opens in a new browser tab)
- Preoxygenation, Reoxygenation and Deoxygenation(Opens in a new browser tab)
Additional Resources
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Professor
Nassau University Medical Center
No conflicts of interest (coi).
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Too difficult? Too complex? Really?
No. It’s just laziness. Learn the vent, learn from an RT, get equipment staged in the ED…. Do what you have to do to be good to the patient.
Using the vent as a bag is safe, and smart. It also frees up cognitive loading as you don’t need to constantly worry about the BVM being perfectly done.
Hello, ED RT here;
I’ve been use this technique sporadically in our ED. Works great in high stress situations so other logistics of the intubation can be prepared for. Personally I use AC with low flows, instead of SIMV. On our ED vents, in addition to the normal macro parameters measured (vt, ve, PIP) I also show leak in LPM. 20-50 is target max for leak compensation
Why AC over SIMV? In DSI SIMV would be preferred no?
Bravo! This techniques extends to the prehospital environment as well. Lee County Department of Public Safety/EMS has dramatically reduced dependency on bag-mask ventilation in favor of using a SIMV transport ventilator for most, if not all, conditions that require ventilation. For all the patient safety reasons that you have identified, this paradigm shift has proved to be very successful in reducing provider variability.
I’m curious, for this particular use, would pressure control be a preferable mode to avoid opening of the lower esophageal sphincter? You could set P_h to 20cmH2O for example, as I worry with a more leaky system you might reach higher peak pressures with a volume control mode as the vent attempts to deliver the set volume. I suppose using 30L/m flow rate is to help minimize that effect. As you said, the primary goal is oxygenation in this patient, which is well accomplished with PC as well. Also, are you suggesting this can be a hands free operation once… Read more »
you still need the manual jaw thrust after you push the meds. straps only keep you from having to hold during 3 minute preox. PC works fine as well.
HI I am a ED registrar working in perth. Just listened to this podcast today. I liked the idea of using the vent to pre oxygenate but two questions came to mind. First of all am presuming that you can deliver higher FIO2 using the vent instead of a bag mask? Also usually we do not bag while the patient is apneic, so if you had a your vent set to 8 bpm then during the apneic period you will still be delivering breaths. Does that not incerase your risk of gastric insufflation and thereby incease vomitting?
I love this paper and this concept. To address a certain patient scenario- if you had a super tachypenic patient with salicylate OD or DKA would you alter the rate on the vent to something above 6-8 breaths per minute during the apneic period in order to maintain that respiratory compensation? Do you think there would be any benefit to doing this and would it be safe?
Steve
https://emcrit.org/podcasts/tube-severe-acidosis/
Gotcha- sorry I forgot that you had talked about that already way back in episode 3. Looking forward to incorporating this into my practice.
thanks Scott. this idea of VAPOX has intrigued me since the paper came out . Its true that after your mentioned it in your early podcast, it fell out of focus and no one really talked about it till now. My own interest has been fuelled by issue in prehospital care of using multiple oxygen sources for RSI preox and NIPPV in general. As well recent papers have questioned the benefit of Nasal ApoX and I must admit my thinking on this has changed as well, particularly in prehospital care WE have to carry our own oxygen with us to… Read more »
yep-not a limitation I have. If you use VAPOX with breaths during apnea, no gain or need for apneic ox or NC for preox. Would strongly recommend you get some mask straps–makes the preox much easier.
Billy Lifeguard 1 flight nurse. I also worry about risk for vomiting during the apox period. Could you educate me more about this. I really appreciate your podcast btw. It is used in large part as our training source with our Helicopter EMS service! It has changed how I think about medicine and airway management. Keep up the good work!
Who is managing these vent settings? And are you promoting this practice to facilities that don’t have RTs readily available? Please see the attached article. https://www.aarc.org/app/uploads/2016/05/White-Paper-SAFE-INITIATION-AND-MANAGEMENT-OF-MECHANICAL-VENTILATION.pdf
RTs are the best to provide this type of airway management and they are the ones who know how to bag a patient correctly – with proper rate, peep, VT, etc.
Sincerely – a practicing RT
Thanks so much for sharing your opinion on this matter.
A concern is that the Oxylog 3000plus has alarms off in NIV – compensates well for leak but no alarms.
The paper in JEMAustralasia used Hamilton ventilators which may be different.
Would waveform capnography be enough, to add to alertness, to stay safe with this technique?
if that is true of the oxylog, I would keep it in invasive mode throughout preox and apox. i wind up doing this in pretty much any vent. the leak tolerance feature is not worth that much.
or said better, better make sure the alarms are back on after the patient is intubated
Scott, In anesthesia, occasionally when performing MAC cases we may give our patients a little bit too much propofol, requiring either assisted ventilation or increasing our FiO2 via NC/FM. One thing I do and have seen done by many, is place a Nasal Trumpet (lubed with lidocaine jelly), then take the end off of a 7.0 ETT, attaching it to the trumpet, This can then be connected to the circuit and patient placed on the vent at settings similar to those in the VAPOX protocol. When doing anesthesia in a remote setting without a vent, it easily attaches to a… Read more »
I have seen this as well and even the dual nasal trumpet connectors. A very workable solution.