Check out video atVentilator Lung Injury

This message has been edited. Last edited by: GaryMefford,

That is pretty cool. It seems to show that

1) derecruitment and recruitment occur for each alveoli as an all or nothing action
2) the damage occurs when one expanded alveoli tugs at one which is closed, the bad function at the junction.

The whole video could be put to music. Don Ho's tiny bubbles and "Function at the Junction" take off.

It would be interesting to take a pig with really bad ARDS and then compare alveolar action with

ARDSnet
APRV
HFOV

Another thing that I found very interesting was the fact that alveoli opened at a fairly consistent rate all the way up the pressure curve. Whenever they opened at the higher pressures they opened with a violent pop. As you say it would be very interesting to directly view results of different strategies on lung tissue. This years open forums looked at similar questions. On page 1520 of Nov. 05 Resp Care upper right is a submission by a group from SUNY, probably same lab that made the video in the link. They don't seem to be gathering data much favoring the APRV camp. Kenneth Miller and the folks at Lehigh Valley Hospital in Allentown Pa did their comparison of ARDSnet and APRV and are not finding much difference in results, RC Journal same issue page 1511. The one on early use of HFOV from Michael Hewitt and the group from Memorial Herman in Houston, same issue page 1535, seems to be demonstrating a lower overall disease severity "We feel that a much earlier intervention with HFOV than in the past with this population of patients may prevent the development of the commonly seen ARDS scenario". Considering the clip, the ability to ventilate while holding pressures in a narrow range will minimize those violent pops and the breakdown of the function at the junction. Between that and what we see in the clip, might there be the beginnings of a case for a protective effect of early and routine use of HFOV? Or perhaps it goes back to, choose a basic strategy either way and do it well. Don't leave out the possibility of updates and improvement, but best and consistent application of either of the three you mention should get you improved results. These strategies are becoming available to more RC department's bag of tricks. These three and who knows what's next, but we are getting better tools, which allow us with knowledge of technical and clinical application to pull more through the ARDS gauntlet than ever before. Sure beats all over the days when we were still chasing perfect ABGs in flow restricted modes, and no consideration of pressures with the folks these strategies benefit.

This message has been edited. Last edited by: GaryMefford,

I had seen this video elsewhere on the net but, What a beautiful picture of VILI. Demonstrates beautifully the biotrauma which can occur due to shearing when alveoli remain closed. Also shows how powerful PEEP is at opening a lung and just how fast it can recruit. The third thing which stands out for me is the utmost importance of adequately opening a lung and maintaining it.
To quote Dr. Papadakalos : "PEEP saves Lives".
Thanks for posting this.