Nitrous Oxide

We recently found out that the hospital we are delivering at has nitrous oxide (laughing gas) available to moms for pain relief during labor. I am open to trying it if I reach my breaking point while attempting natural labor. The pamphlet I received recommends you start inhaling the gas about 30 seconds before a contraction so that it has its strongest effects during the peak of the contraction and then removing the mask at the end of the contraction. I am curious if anyone has ever tried it and can give any feedback about when and how they used it and what the results were. Thanks!