Nitrous Oxide Induction Induces Amnesia in Pediatric Patients

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Dose Response Effect of Nitrous Oxide on Amnesia in Healthy Children

Conditions
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Amnesia

Intervention / Treatment
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* Behavioral: Explicit and Implicit memory
* Drug: 0% nitrous oxide, 30% nitrous oxide and 60% nitrous oxide


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 6-12 years old, ASA classification: 1 and 2 Elective surgery Exclusion Criteria: Uncooperative child needs sedation before induction of anesthesia Developmental delay, ADHD, autism, Tourette's syndrome, schizophrenia, congenital and acquired brain disorder, Down syndrome. Those who request for IV induction Those taking sedative medications, anti-seizure medication Those with malignant hyperthermia, muscular dystrophy; those with uncorrected cardiac defects and those with severe or active lung disease Those with elective admissions to PICU with ongoing sedation and tracheal intubation

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: 0% nitrous oxide<br>Explicit and implicit memory will be tested in 0% nitrous oxide | Behavioral: Explicit and Implicit memory<br>* Explicit and implicit memory will be tested visually (showing an animal) and auditory (telling a joke, stating a food type that starts with the letter B) and smell recall (bad smell of anesthesia)<br>Drug: 0% nitrous oxide, 30% nitrous oxide and 60% nitrous oxide<br> <br> |
| Active Comparator: 30% nitrous oxide<br>Explicit and Implicit memory in 30% nitrous oxide | Behavioral: Explicit and Implicit memory<br>* Explicit and implicit memory will be tested visually (showing an animal) and auditory (telling a joke, stating a food type that starts with the letter B) and smell recall (bad smell of anesthesia)<br>Drug: 0% nitrous oxide, 30% nitrous oxide and 60% nitrous oxide<br> <br> |
| Active Comparator: 60% nitrous oxide<br>Explicit and Implicit memory with 60% nitrous oxide | Behavioral: Explicit and Implicit memory<br>* Explicit and implicit memory will be tested visually (showing an animal) and auditory (telling a joke, stating a food type that starts with the letter B) and smell recall (bad smell of anesthesia)<br>Drug: 0% nitrous oxide, 30% nitrous oxide and 60% nitrous oxide<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Nitrous Oxide effects on explicit memory | Explicit and implicit memory will be tested during the recovery period (once the child has fully recovered from anesthesia but before discharge from hospital) by a blinded observer who will ask the child to recall the joke they were told, the animal picture they were shown, the name of the food they heard and any odor they noticed as they fell asleep | After full recovery from anesthesia (generally by 2 hours after termination of anesthesia), but before discharge from hospital all variables will be assessed | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Nitrous oxide effect on Implicit memory | Implicit memory will be tested if the child fails to identify any of the explicit tests by showing the child four animal pictures and picking an animal or by reciting four foods and asking the child to pick one. | After recovery from anesthesia (in recovery room or before discharge from hospital) within 4 hours of anesthesia completion | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Amnesia, Memory, Implicit, Explicit, Nitrous Oxide