Sure, you should pay more attention and not get yourself in a next turn = death situation, but this is not always avoidable and no one (presumably) is so meticulously patient. ALWAYS carry get away items – Phase Door, Teleport, Recall, Teleport Level, etc. When you can, stockpile those that work NOW. If a unique starts chasing you, you don’t want to be waiting for Recall to kick in.
You should seriously consider a quick escape if dealing with a situation in which monsters are breeding explosively. Some classes, such as mages, are more easily able to handle these though the use of spells that affect multiple monsters simultaneously, but even they should consider leaving if it becomes apparent that the monsters are breeding more quickly than the player can kill them.