One tip from my play throughs...
In Chapter 4-2, after you fight the two El Gigantes there's that vast cave with all the Novistadors. On professional, this can be a deceptively difficult area. The Novistadors on pro here are quick- and smart. When you go into the two small caves to push the light buttons, it activates a whole swarm of Novistadors to come rushing at you. DO NOT, and I really mean DO NOT, stay against the back wall of the cave when this happens. If you do, you will quickly be surrounded by five or six Novistadors and they will hit and grab and spit acid on you so quickly that you won't even have time to heal yourself. You'll be dead VERY quickly. The key there is to go back to the narrow entrance of the small caves and fight them there- so that they can't surround you. Use the narrow entrance as a choke point and you should be okay. Keep in mind though, that some of them will be attacking via the ground while others will fly in and try and grab you and then burn your face off- at the same time.
The moment you're surrounded, you're dead basically!
I have only ever died in that part of the game on pro- they just aren't anywhere near as lethal on normal. But I died there on pro four or five times before I realised what I was doing wrong...