Nitrous Oxide

My child had some cavities filled. The dentist assistant started him on the nitrous oxide about 10 mins before the dentist came in to start. After being on it for 35 to 40 minutes while they were filling the teeth my child fell asleep and then began to vomit. He opened his eyes but did not seem to be responsive. Did not fuss or cry. No response even when we talked to him. I have NEVER seen my child like that and I felt very uncomfortable with my childs nonresponsiveness. Glazed eyes, blank stare,not there look and behavior. Is this normal with Nitrous? There is more dental work needed. Do I refuse the Nitrous? Please explain what could have happened.

Thank you

[Jerome Tsang, DDS]

Did the dentist provide any other medication along with the nitrous?  You may want to discuss with your dentist the situation to find out what was the cause to prevent it from happening again.