Short thread on vent mode preference differences between #PedsICU and adult ICU land because I’ve seen some references to each that aren’t exactly right. Namely SIMV vs Assist Control. #covid19

First misunderstanding: SIMV can’t trigger the vent without PS. That was true with IMV. Set rate, every 60/R seconds a breath was delivered. The S part, for synchronized, introduced a window where patient can trigger, if no trigger, then breath is delivered #COVID19 #PedsICU

It’s not the same as assist control, where every trigger delivers a breath, but it approximates it. #PedsICU #covid19

So why does the #PedsICU world still not uncommonly use SIMV whole the adult world prefers AC? The simple reason is respiratory rates. Both on the high end and the low end. #covid19

It’s not uncommon in the #PedsICU to have infants with respiratory rates in the 30s to 40s, and sometimes even faster. In AC, they can easily get to a point where they are breath stacking due to time cycling. #covid19

By using SIMV with pressure support, those additional breaths are flow cycled, usually much shorter and at less, but not zero, risk of breath stacking. #covid19 #pedsICU

On the weaning side, the difference between a normal respiratory rate of 20-30 in an infant means cutting the SIMV rate gives a lot more PS breaths. In adults with a rate of 10-12, you don’t get far down on the rate before you ought to be in a spontaneous mode #covid19 #PedsICU

And none of this is absolute. People use all sorts of combos. My only pet peeve is SIMV in a patient on a vec gtt, because that’s silly. #pedsICU #covid19