Most transport programs & hospitals have a "max dose" for pressors. When we think of a maximum dose for medications, typically, one of two things will happen when you approach that dose.
No further benefit
There is another reason max doses are put in place, and it may have nothing to do with ceiling effects or harmful doses. As Dan mentions, sometimes max doses are used to build in clinical stop points to encourage clinicians to avoid falling into monotherapy tunnel vision.
"If the blood pressure isn't increasing with levophed, it must just not be a high enough dose."
While this certainly can be the case, the patient could also have tamponade, adrenal insufficiency, hypovolemia, etc.
In this episode, we discuss whether having a "max dose" of your pressor has any evidence or physiological backing. Joining me in this discussion are Dan Rauh, Shane O'Donnell, and Shad Ruby.