The line between "so sedated you don't feel your guts being cut open" and "so sedated you stop breathing" is frighteningly thin and requires a constant, careful

The line between "so sedated you don't feel your guts being cut open" and "so sedated you stop breathing" is frighteningly thin and requires a constant, careful, measured supply of anesthetic. In modern surgeries, there is one guy who goes to school for years to do nothing but monitor the patient's vitals and adjust the flow accordingly. In al Quff's day, I imagine such reliable precision was difficult or impossible, and you'd rather err on the side of pain than death. Which is to say, there's a very real chance of your patient waking up mid-surgery and freaking the fuck out, and you want to be prepared for that.