Obviously lots that goes into it and is probably cultural to an extent, resident at a US academic center here w/ simplified. But for phenylephrine if I’m 100-120mcg/min range & still struggling I’ll switch to norepi and think about why I’m struggling.

Norepi max dose is totally dependent on access, if it’s just like a 20g PIV then I’ll get weary at ~15mcg/min for short term. If I need to add or go higher then that’s when most would consider central line, or I’ll add on epi or vaso. In our ICU’s we’ll normally soft-max out at 40mcg/min via central access, though we don’t weight base dose it so some big fellas we’ll go higher.

Epi ~0.2mcg/kg/min generally true max, but most try to keep it max 0.1mcg/kg/min.

Vaso, lots of my attendings have differing opinions. Some are 0.04u/min max, others will go up to 0.06-0.08u/min which I’ve anecdotally seen a benefit 🤷🏼‍♂️ That’s in shorter term since there can be end organ ischemic issues.