D.D.
You can try distraction when they wake up the first time. I use to get air freshner (different scent than I always used in the house,)wrapped the can in paper and had my kids cover the paper with stickers. When they woke up during the night with bad dreams I would wake them totally up (usually they are still half asleep which is why they fall back into the nightmare stage) and we'd make a big deal about filling the room with 'happiness air'. The happiness air would smell great and they would fall asleep knowing that all the bad things were gone.