Just curious how you quantify having a propofol bolus "light hand" in mcg/kg numbers on a 60 yo with heart disease getting a scope. 100? 300? 500? 1000? Plus Fentanyl? Plus Versed? I usually go with 500 mcg/kg (3 mL bolus on a 60 kg pt to start) but I'm just curious about your technique.
I haven't done outpatient GI for the last few months, so this is all from long-term memory. Also, all my patients are non-intubated and in left lateral decubitus.
I mostly titrate propofol to effect. If the patient has low cardiac or respiratory reserve, the "effect" is the minimal level of sedation which keeps the patient comfortable while still being safe (I aim for vitals within 10-15% of what the patient had in admitting, before meeting me).
I don't have a magic number (I don't really think in mg/kg for GI or any MAC induction). In healthy young and middle-aged patients I go directly for ~100 mg to start with (around 1.5 mg/kg). But if I think the patient might be really sensitive to propofol, I can push as little as 1-2 cc's at a time, then wait for the effect; the older the patient, the more I wait (you know how it goes: half the dose, double the interval). I might push 1 cc while the patient is still being adjusted, just to get an idea of the patient's response. Once I see how the patient tolerates propofol, it's much easier; I might just leave them on an infusion pump.
If I am really concerned, I tell the patient pre-procedure that I cannot promise they will be completely asleep, that they might remember things, and that it's done for their safety. I also reassure them that the procedure is not really painful (for colonoscopies), but if they are uncomfortable at any time we will just stop (never happened, and 95+% of the time they still won't remember anything.)
I cycle that BP cuff every 3 minutes or more frequently, and watch the patient like a hawk. I involve the GI doc, explaining my concerns (and why), telling him/her that it might take a bit longer to induce and the patient might be lighter than usual, asking him/her to go slowly and gently, use local anesthetic for the pharynx etc.
The only patients I might give some Fentanyl and/or Versed to are the patients who are having painful procedures, such as dilation, or RFA (Halo). I also used more of those when we had a propofol shortage. For a relatively healthy patient who is having a double endoscopy, 50-100 mcg of Fentanyl + 1-2 mg of Versed can cut down nicely on the propofol requirements, without affecting wake-up.