They are often used to mean the same thing, but they could also have a different intention. "Check his pulse" could mean see how fast/strong it is; "check for his pulse" only means to see if he HAS a pulse (otherwise, he's dead). Someone speaking quickly could say, "check his pulse" to (1) see if he has one, and then (2) to see if he is weak by monitoring the pulse for a few seconds. But "check for" always means, "does he have one"?