Back to he original question. Tourniquet pain is time dependent mostly. Te block density can extend the time and the pts tolerance of discomfort can as well. It's never a good idea to tell a pt that will have a 90-120 min thigh tourniquet that you will not need to put them to sleep. But that being said, with a good block you should be able to skip PACU, which means the pt meets all criteria. I do this very frequently. And the. Using staff loves it because they can get the pt out of the facility sooner as well. With a good block you need very little anesthetic. The problem I see with many anesthesiologist ( I don't work with midlevels) is that they run the gas of propofol too deep for someone that has no surgical pain, just tourniquet pain. With a good block, my Des is usually around ET 4.0, depending on age of the pt. Also, I prefer Des for these cases (as I do for all cases). I believe it has greater analgesic properties than Sevo. It allows me to get away with less.
If I were doing the case you describe, an ankle fx with a 90min tourniquet, I would do a popliteal and saphenous block with an LMA general. I'd give 50mcg of fentanyl at induction and probably nothing more. I'd run my Des at 5.0 for incision and then start to trend down to mid 3's for the last 20 min unless the tourniquet was breaking through. In that case I'd turn up the gas. No narcs for this. As soon as the tourniquet comes down I turn off the gas and leave the flows at 1 lpm. As the splint is going on I crank the flows to burn off the gas and I give 2-3cc of propofol. If resp rate is greater than 12 I might give a small dose of fentanyl. This will not slow wake up of discharge. I can usually skip PACU with this approach. The key to all of this is a good surgical block.
