What Neddy said....
Along w/ not eating 3-4 hrs prior to laying down, lift the head of the bed so that the stomach is always below the esophagus/mouth. No, sleeping on pillows will not do, the head of the bed has to be elevated no less than 6inches is usually recommended.
My doctor and I both have had the coming awake choking on acid incidents. It hasn't happened to me since I've been on Nexium, but it is horrible when it does happen. There's no question that acid has just been aspirated into the lungs and it is very painful, scary and burns to the point of blisters in the back of the throat. I think this condition is more known as bile-reflux as opposed to simple acid-reflux, especially if the fluid is vivid greenish-yellow.
-Noggin