I have recently had a few bariatric patients that have required PC/SIMV mode settings. I went back to the old school and we had better success weaning straight to CPAP compared to going to volume mode then CPAP.
I am looking for back-up litreature and studies on the subject for one of my Pulmonologists.
I cannot remeber who or where studies were done in the U.S. in support of this.

Bill C,
I am not sure you will find much on SIMV (PC) to CPAP vs SIMV(PC) to VC to CPAP as far as weaning effectiveness. Most of the stuff out their states that a SBT is the most effective way to wean, which it sounds like you are doing. Going from SIMV(PC) to VC or SIMV(VC) before you start weaning does not make anysense. If you are using low levels of PC to achieve your desired VT and your patient meets all other weaning parameters (ie reversal of original pathology, no signs of pulmonary infection, VT >5-6 ml/kg of IBW, VC>10 ml/kg, RSBI<100) then why would you want to go to a volume mode where the patient is doing even less of the work than in PC. All to often therapist and Doc's hear PC and think the patient must be sick, but PC is just another mode of ventilation that uses pressures and time's vs volumes and flows to achieve ventilation. PC waveforms and mechanics are actually more patient comfortable than VC, so I personally do not see a reason for the switch.

If you would like the articles on weaning techniques that I have I will give them to you, but none discuss the situation that you mentioned.