I'm ICU, not PACU or OR. We use Versed & Fentanyl gtts to maintain sedation in intubated pts.
That said, I have given up to 300mcg/hr of Fentanyl and, oh, around 33mg/hr of Versed. We dose Versed in mg/kg/hr, and we max out at 0.12mg/kg/hr. So a larger pt will get more Versed than a smaller one. I have hung both concurrently, at the max rate on the fentanyl and near max on the Versed. I have also hung max rate of Versed concurrently with max rate on Propofol, which for us is 50mcg/kg. This was on a large pt, and we were hanging new bags of Versed about q3h and new bottles of Propofol about once an hour (this was during the propofol shortage, and all we had were 50mL bottles).
As far as side effects of higher doses, I think the folks who are on Versed for a couple of weeks for a prolonged intubation, esp at higher doses, seem to take longer to wake up when we turn it off. JMO.