Vapp/clb
Single engine app is VREF45+10 using F22°
in case of go-around single engine, fly VAPP/CLB speed for F22° (ice or w/o ice speed accordingly).
F22 is used to permit faster acceleration meeting minimum climb gradient.
now if you approach all engine F45, vref will be VREF45 plus additive for wind.
if engine fail during go-around, use VREF 45 speed w/o additive.
the same principle apply if using F22 landing,VREF22 plus additive, and go-around use VREF22 w/o additive.
yes I know that's looking complicated, It's the way EMB designed it, and all malfunctions speed correction are related to VREF45.
It's little more complicated if you land single engine in CAT3 condition.
hope this help