APRV Vent Mode

We've just started using it in our facilty a few months ago. It's really great for all kinds of patients, they don't have to be next to death to be a candidate for APRV. The ventilator mode used is bi-level, and while bi-level is just a tad different than APRV, in that the low peep used in bi-level is generally not 0, and in APRV the ventilator uses the release time as an auto-peep generator.

It's amazing to see the x-rays of these people before, and after bi-level.

This mode of ventilation should be started early, at the first signs of trouble. One of the docs told me the other day that once they get so far into ARDS on say AC/PC, it's hard to switch them over to bi-level because they have no reserve for changes that big.

Another consideration is fluid status. A patient who is very fluid dependant might need a few liters of fluid before bi-level is started....

This is also a weanable vent mode... you can wean them down to cpap settings and extubate from it. It's really quite interesting.

here's an article that explains it quite well

http://www.aacn.org/pdfLibra.NSF/Files/ci120205/$file/ci120205.pdf

And, TennRN, I know you read that article, just thought I'd post it for everyone else. :)

And, as a final comment... you are totally right, it should be used early on. :)

In the trauma unit I am from, 80% of the time we ventilate with Dragers using APRV. This mode of ventilation allows the adjustment of inspiratory and exp time so that you administer long inspirations and very short exhalation. Somewhat like PC c inverse ratio, but pressure delivery in rapid shots. (difficult to explain, but easy to feel in circuit) This promotes recruitment by not allowing alveolar collapse. Also, you can administer high pressure s detrimental elevations of peak airway pressures. Weening is accomplished by dropping pressure and stretching expiration time. Pt's love this mode. You will never see a pt on a paralytic gtt on this mode since it is so well tolerated s drastically increased PAP.

We use this mode usually before we decide to put the patient on the Ocillator, which is usually the last mode of treatment.

What`s a difference bettwen APRV and BIPAP ventilation mode? It`s look like the same thing to me.

Anybody?

They work in two totally different ways. But the biggest difference is that APRV has a pressure maintained in the lungs that the patient breathes spontaneously above that releases to a lower level at a preset interval. Whereas with BiPAP the patient initiates a breath and gets the pressure delivered at that time. there is a lower level of pressure maintained in the lungs with exhalation, but it is the lower level of pressure. Does that make sense? It's very late and I'm about to pass out.

APRV has allways been a tough "sell" to our pulmonologists in Casper. Often by the time it is considered, usually by the most talented RT's, it is deemed futile or at best experimental. It has been my experience in the past that APRV when employed early and often is helpful in avoiding ARDS or at least decreasing the duration of the disease. Also, while transthorasic flow return issues can be present with high pressures, this can be dealt with, with inotrops if tolerated. Count of the RT to guide this therapy, they are skilled at recognizing sutle and hidin changes in lung compliance. :rotfl: