All correct.
Basically you put the first trocar in (if all goes well, 10-15 min), burn for 15 min. While burning, you put the next one in. Ideally you always finish placing before the previous level is done burning, so the 15 min burns are rate limiting.
2 level: 15 min place 1, 15 burn 1, 15 burn 2 = 45 min, and every additional is 15 per.
They usually go this way but a number of things can make a placement go sideways and > 15 min. If multilevel and multi tough placements, can get long.
Given potential to go long, I prefer GA on multilevel, fat, old, comorbities. Plus don't have to waste time numbing, adjusting MAC if patient pt squirmy.
On a 2 level, thin healthy pt, MAC is fine. Some have done CS but I don't have experience. Want to try but if they start screaming during the 15 min burn, it'd be a nightmare since you can't grit through like a 90 sec RFA.
Medicare pro fee sucks. Commercial is hit or miss. I make more doing regular injections and E&M from opportunity cost perspective, so I do these on my off-day. Also can be seen as a loss leader. Gotten tons of word of mouth referrals from happy patients, some willing to self-pay. One self payer makes up for a lot.
ASC margins are tight but still profitable if you run an efficient ASC, unless you do multilevel or run long and eat into OR time.