Is there a protocol out there that only uses A/C mode and CPAP mode with Pressure support?I have a Pulmonary physician that only uses these 2 modes to wean his pt.s.No SIMV is used.

Go to www.rcjournal.com

then click on Clinical Practice Guidelines

at the top is the latest Evidence Based Guidelines for discontinuing ventilator support.

What's being advocated is a daily spontaneous breathing trial (SBT) for those whom qualify. Qualification means being on FIO2 .5, Peep equal/less than 8, hemodynamically stable, etc. NOT NIF or VC, or any "weaning parameter".

So from full support to an SBT. If the SBT results in failure, back to full support. If the SBT is successful then extubate, unless airway issues.

Clearly A/C can be used as full support.

At our institution we use A/C (840 with either VC or VC+) and then go to Spont mode (with PS only set per Tube Compensation).

SIMV is a lousy "weaning" mode and a lousy support mode. IMO it has little if any place left as a mode to be used.

I disagree that SIMV is a lousy weaning mode. At our center we almost exclusively wean from SIMV + PS. Our patients' RR will be decreased until 10 or 5 and then, we'll do an SBT on CPAP and extubate. If your patient is on A/C, whenever they try to initiate a breath, they get the full parameters. It has been my experience that SIMV dramatically improves comfort and thus shortens vent time. We also have implemented a therapist-driven weaning protocol whick allows us to quickly wean patients. It has proven to be quite succesful.

So your patient is on an SIMV mode and you "wean" it down"? What logic does this come from? The recent consensus conference just advocates a daily SBT and then a return to "full support". While this is not defined per mode, what this means to me is a mode in which each breath is adequately unloaded per both resistive and elastic load. A/C in one of the hybrid PC/VC modes, seems to fit that bill quite nicely. I suppose one could use SIMV and enough PS (with looking at VT),...but why delude yourself that is any different essentially than A/C. Now before the SBT what in the world would weaning the rate down first do to effect the SBT outcome? Those supported breaths aren't contaminating the patient? A failed SBT is really enough of a daily workout. If, in A/C mode, the patient can assist/initiate the breath they are moving their muscles, albeit in a fashion which hopefully doesn't lead to fatigue (which SIMV rate reductions run the needless risk of doing before the SBT.).

A needlessly schizophrenic breathing mode, mandatory breaths mixed with PS, is now infused on a daily SBT protocol in similar schizophrenic fashion.

Why do all that needless monkeyinig around with reducing the rate before the SBT? Just go straight to SBT and don't waste your time nor needlessly run the risk of fatiguing the patient before the SBT. Either embrace the consensus guidelines or reject them, but don't try to have it both wasy.

When I got out of school SIMV was all the rage. Looking back it was an absurd way to just sell new ventilators and bill for extra ventilator hours when such was extremely profitable.

I stand by my statement, SIMV is a lousy support mode and a lousy weaning mode. Institutions which persist in it's use should strongly reconsider. At the last teaching hospital I worked at SIMV was the default mode, going to A/C would usher in angst. Regularly new residents and interns would whisper to me something like "back in Chicago (insert city) if we used SIMV it was a big 'no-no'". Slowly the word is getting out.

I haven't read any studies, but know that at least 3 of the hospitals in my area that do the same. No simv used in the ICU/ only AC and CPAP with PSV.

we use a/c,usually prvc,until the pt is ready to wean. then change to cpap with ps of 20. we then wean the ps to 5 while maintaing a rr less than 25 and a vt greater than 400. once the pt is on 5 and 5 we do a sbt and extubate. i have been in the feild 12 years and this system seems to work very good.

I work in a major medical center and we use almost no SIMV. It has no place in an ICU.

Yeh for the AC-SBT crowd. After over 30 years in the field I've learned that our only advantage is to keep up with what works and try to teach our residents (or better yet, the attendings) that we are aware of what the evedence shows. Study after study by such notables as Amato, Brochard, Marini, and Macintyre, have all showed that SIMV is the slowest and most inefficient method of weaning. I believe is was Marini who was able to show that when the SIMV rate provided less than 80% of the total work of breathing, any futher reduction in rate had absolutly no effect on the work done by the patient. So where's the weaning? Kaczmarek did a wounderful study where he tied in the natural rhythmic nature of respiratory patterns and was quite detailed in describing the difficulties and tremendous time consumed in properly synchronizing SIMV to an actively breathing patient.

Look, I know that 85% of our patients will survive "in-spite" of the way we ventilate them. But if our goal is to help the physician get these patients of the ventilators as quickly and effectively as possible, than lets do what works best. The remaining 15% of the patients will appreciate our efforts.

Several fairly recent studies have shown that Simv is a fairly useless mode. Initially the thought was to allow the patient to do some of the work of breathing with intermittent ventilator breaths. Emg's have shown that the wob on Simv is equivalent to that of Cpap/psv, hence the trend to A/c with Psv intervals as tolerated.

If the evidence shows that full support with SBT's daily is the current best practice (and it does) then why would one hold onto their own biased methods of weaning? Just because something "works" doesn't mean it is the best option for the patient. We are moving into an age of Evidence Based Medicine and as RT's we need to be on that band wagon. I have pulmonologists who prefer to use a PB 7200 over an LTV 1000. What sense does that make? They have a biased opinion based on what they are comfortable with and they have an aversion to trying something new. Just because the patient doesn't die and eventually weans off the 7200 doesn't mean the 7200 is the best ventilator for the patient. Those same pulmonoligst use SIMV extensively and do not try SBT's daily.