Quote from calling
Levo is a great first line pressor fora septic patient who has already been volume resuccitated. It worksby vaso constricting the extremeties to adequately profuse coreorgans. The problem with neo is a) it is a weak pressor (nice forpushing in the OR if the patient gets too much prop!) and b) it worksin the same way as levophed, so many intensivists don't use it as asecond pressor because it really doesn't make sense. If 20 or 30 oflevo doesn't work, than adding neo probably won't help. Vaso is agood second-line pressor for sepsis. After that, you're desperateanyway, so neo won't hurt. I don't think I've seen anyone survive whohas needed more than three pressors. No wait, there was one!
Levo has mostly alpha adrenergic activity with some beta adrenergic activity. Neo has exclusive alpha adrenergic activity. So both pressors are not the same. On very tachycardic patients adding neo to the balance might work better than adding more levo orr starting epi. In children levo has been known to cause reflective bradycardia where neo does not.
It all depend on the type of shock you have and the situations surrounding it. I've seen cardiogenic shocks survive on 4 pressors and three intotropes and methylene blue on top of all that. There are some notorious septic shocks that have profound hypotension requiring massive amounts of vasopressors but once you make it through this acute phase some of these patients recover very well.
I agree with you that in the statistical sense adding more/different vasopressors doesn't make a difference because the majority of these patients will die. And only levo has been of scientifically proven value in terms of survival.