APRV Set-Up at its Simplest
from the original description: Crit Care Med 1987;15(5):459
PV Curve
Setting Tlow
Study of APRV
Theory/Physiology/Reviews of APRV
APRV Network
then click on banner for COVID19 rescue to get all of the documents mentioned
More Stuff
Additional New Information
More on EMCrit
- EMCrit 335 – APRV TCAV for Lung Rescue Made Simple with Rory Spiegel
- EMCrit – Ghali Grills 1 – When to Use APRV
- IBCC chapter: Guide to APRV for COVID-19
- EMCrit Wee – The Philosophy of APRV – TCAV with Nader Habashi
Additional Resources
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Greetings from México how do you set de presure support over the peep high.
Do hoy use vt EF 6 or 7 ml x ards weight
Example phigh 25 psop 30 he has 5 of support so he es Breathing over 30 cm h20 that coauld cause lung injury
no PS–it ruins the advantages of spont breathing. If your vent has it, use automatic tube compensation. if not, use nothing
We use 980 puritan bennett so we can use tube compensation an target a vt of 6 per ibw?
We are thinking on early aprv in covid patients on the basis that do to lack lack of assistance we cant prone al px only 20 uci beds the rest will be ventilated on común wards
What about diaphragmatic myotrauma
Arturo, if I may and please forgive me if I misunderstood… we are utilizing pressures rather than volumes (you asked if we were setting 6 or 7 ml/kg)… we don’t have an APRV option in our ventilators (and its all theoretical at this point as I have yet try it on a patient) but setting a pressure controlled mode (matching plateau pressures if you have them already) with a long inspiratory time in a set frequency will steal from the expiratory time setting up an APRV situation. the key is maintaining the pressure over a longer period of time and… Read more »
I was able to use APRV (Bivent in SVI vent) as a rescue mode on one of these patients Thursday night and it may have saved him from coding. I started on Phigh 30 (Pplat measured at 30 on prior setting) Plow 0 T high 4.0s Tlow 0.5s. This was around 50-60% of the PEFR. This gave me a set rate of 13 and I:E 8:1 with ABG Pa02 increase from 55 to 104 in about 2 hours (prior settings PRVC PEEP 20 Fio2 100% Vt 400 RR 18). Unfortunately our advocacy for this mode is falling on deaf ours… Read more »
Hi, I’m a little confused, if we say that one phenotype of Covid is high compliant, and should be careful in using standard ARDS peep/fio2 tables, with high peep in standard vent modes, why is then APRV with a high Phigh beneficial? Are we then at risc of causing lung trauma?
Great post though! Thanks for your commitment for doctors and patients!
standard modes will always have higher pressures than APRV even if you set the PEEP low on the standard mode
Mean airway pressure should be higher in APRV. Do you mean that the driving pressure is typically higher in conventional modes?
Should have consolidated my thoughts in one post…
Lower driving pressures definitely sound lung protective to me, but higher mean airway pressures in compliant patients may drop the cardiac output, so one has to balance out these effects. Most people are not familiar with using APRV in compliant, spontaneously breathing patients…
I was asking myself the same thing as Erlend Berge does. Even though I have zero experienc in daily routine with APRV (coming from an european country) I can absolutely understand the concept of APRV in the covid-19-Patients with „Phenotype H“. Since these patients have more or less what you would call a „typical“ ARDS with low compliance and high recruitability, the concept of high mean airway pressure as well as long inspiratory /short expiratory time in order to improve recruitment and prevent derecruitment makes a lot of sense. (especially after listening to your first podcast, second podcast about TCAV… Read more »
Glad you put something out there on APRV/Bilevel. I have been using this as my mode of choice immediately upon intubation of these COVID patients with pretty good response from the pulmonary side of things. I think if you wait to use it as a rescue mode, it’s already too late and there’s been hours/days/weeks of atelectrauma (which will then get you real ARDS). I agree with the terminology Josh used in that the disease process is “malignant atelectasis”. Have gotten all the benefits with no side effects since doing this (decrease sedation, decrease FIO2, have not needed to paralyze… Read more »
For those of you using the Drager Evita V-500 for APRV. While in the APRV setting screen you can choose the additional settings menu and select Auto Release. Here you will be able to set your Exp. Termination to your desired percentage of exp. flow, usually 75% and if needed you can adjust for COPD and asthma to 50%. This makes the mode more user friendly and will avoid having to guess or calculate the T-Low to obtain your desired exp. flow percentage. Please note that when you confirm this setting you will no longer see T-Low displayed on the… Read more »
If the pt is not acidotic/hi pCO2, should we perhaps put them on pure CPAP for an hour or two for recruitment and then switch over to giving them the release?
Thanks for this. This is my method of APRV as well (I didn’t train with Dr. Habashi, but I did train in Baltimore and the influence seeps out!), and there aren’t many resources for people to refer to if they want to understand it. As you touched on, one of the big limitations is simply that others may not understand what you’re doing, which creates issues and potentially risk — ie. other providers/RTs/nurses/etc may not be prepared to troubleshoot it, wean it, etc. But in most cases I would much rather go to APRV than escalate to PEEPs of 20… Read more »
how do you set the PS in APRV on a bennett 840?
Is the PS added on top of the Mean airway pressure ( i think it is…), or on top of peep high or what?? here is one video where this guy says if you have to set the PS ABOVE the P high!?!?!?!? is that really correct, im afraid to make some lungs explode 😛
https://youtu.be/f7bPcvF0m_o?t=436
(video should start at the correct time)
Gabriel
I personally wouldn’t set any PS. It ruins some of the advantages of APRV according to Habashi and his crew.
Gabriel, you essentially end up with your PS establishing the maximal peak pressure during the breath, instead of the Phigh. If your Phigh isn’t too high, you could probably have some PS on top of that without hitting scary pressures. If it’s already 30, maybe not (although some of the hardcore APRV people still believe these higher pressures are okay, due to the idiosyncrasies of the mode). Whether it’s actually useful to have is another matter. It does improve ventilation somewhat for whatever that’s worth…
okay this APRV stuff works holy shit. we never used this at our department, i asked the the head of ICU if i may try it, we have an obese, proned, covid patient, her fio2 went from 75 to 45 % in couple hours. And her CO2 was fine too, went up a bit but nothing crazy. Just one more question, to actually get to something like 75 percent of peak exp flow my time low was 0,4 seconds, even a bit less like 0,35 but then the mechanics looked too weird so i went up to 0,4 seconds and… Read more »
yes, go as low as you need to, the worse the lung compliance, the shorter the Tlow
Dear community, one more question…… On the Bennett 840 using APRV with cutting expiratory flow at 75% is it possible to calculate the intirinsic peep? or do we just assume that at 75% of Peak exp Flow we ll get about the right amount of peep and volume and should be happy with that. ( i just need to be prepared for possible questions from my boss, we never used aprv here before) The pressure curve on my patient yesterday fell to about 5 cm h20 but from what i found out this is not at all representative of the… Read more »
Dear Dr Scott. I´m writting you from South America (Ecuador). These days I´ve been trying APRV in COVID patients in a local Quito´s hospital. Its amazing how patients with 50% Spo2 in the begining change to 91-95% in a period of 4 to 5 h. Ultimately I had a problem with a patient who rised his MV (14) and his respiratory rate (40). I checked for sedation it was ok (RASS 0), then looked for acid base disorder was ok too. How can we evaluate and solve problems like this? what are the parameters we can chage since shortening T… Read more »
Hi Scott, thanks for this write up.
What kind of effects on the right heart do you see with the high PEEP of APRV? I know there’s a recent paper showing improved outcomes and improved CI in post-cardiac surgery patients with use of APRV, but I wonder if a limitation of APRV in a primarily medical ICU population would be the prevalence of pulmonary hypertension and right heart strain (as seen in covid patients as well when they progress to a more fibrotic stage of disease).
Thanks
Kevin
it is a v. similar ? to PEEP’s effect on ICP. If you find the right setting, then regardless of the level, it is shed by the pt’s lung compliance and despite the amount, should have little effect on R heart. Overpeeping of course will be deleterious. Spont breathing and recruitment should also have salutatory effects.