Nitrous Oxide Induction Induces Amnesia in Pediatric Patients

The investigators are conducting a study to investigate the amnestic effects of 2 different concentrations of nitrous oxide in children before induction of anesthesia in a prospective double-blinded placebo controlled study.

Children of age group 6-12 will be randomly divided in 3 groups, First group will be Placebo , second group will be nitrous oxide end tidal 20-30% and third group will be nitrous oxide 60-70%. Each group will be divided into 2 subgroups randomly with either a flavored or unflavored mask for induction.

All children will be told a joke before the mask is applied, with the answer provided after the end-tidal nitrous oxide concentration reaches the randomized concentration (0, 30 or 60%) for at least one minute. At that point, the child will randomized to be either shown a picture of one of four animals (predetermined randomly) or a food will be stated aloud. For the animal, the child will be asked to name the animal aloud. The child's response (yes or no to a response and whether the item is correctly named) will be recorded. If the child does not respond, the name of the animal will be stated out loud. For the food, one of four foods will be named aloud and child will be asked to repeat the name. The child's response (named or not) will be recorded. Anesthesia will continue with the designated nitrous oxide concentration combined with 8% Sevoflurane.

When the child is ready for discharge from the recovery room and recovered from anesthesia, a nurse or doctor who is blinded to the treatment group assignment will ask the child to recall the joke and answer. The child will then be asked if they were shown any animals and if so, which animal? If the child cannot recall an animal, the child will be asked to name the first animal that comes to mind. The child will then be shown pictures of four animals and asked to identify one. The child will be asked if they heard any foods when they went to sleep? If the child cannot recall hearing any foods recited, the first letter of the food will be shown: B _ _ _ _ _ . If the child does not recall any foods, then the child will be given the names of four foods that begin with the letter B and asked to pick one. Finally, the child will be asked about any odors in the mask during anesthesia. If he/she does not recall, then four odors will be read out and the child asked to identify any one. Additionally, the children will be asked whether they recall any odors on the mask as they were anesthetized. The order of items questioned in the recovery period will follow the same order as in the OR.

Eligibility Criteria:
Inclusion Criteria:

1. Age: 6-12 years old,
2. ASA classification: 1 and 2
3. Elective surgery

Exclusion Criteria:

1. Uncooperative child needs sedation before induction of anesthesia
2. Developmental delay, ADHD, autism, Tourette's syndrome, schizophrenia, congenital and acquired brain disorder, Down syndrome.
3. Those who request for IV induction
4. Those taking sedative medications, anti-seizure medication
5. Those with malignant hyperthermia, muscular dystrophy; those with uncorrected cardiac defects and those with severe or active lung disease
6. Those with elective admissions to PICU with ongoing sedation and tracheal intubation