Nitrous Oxide Induction Induces Amnesia in Pediatric Patients

Dose Response Effect of Nitrous Oxide on Amnesia in Healthy Children

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.

Study Overview

• Status: Completed
• Conditions: Amnesia
• Intervention / Treatment: Drug: Nitrous Oxide 0%; Drug: Nitrous oxide 33%; Drug: Nitrous oxide 66%

Detailed Description

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 33% and third group will be nitrous oxide 66%. 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, 33 or 66%) 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.

• Study Type: Interventional
• Enrollment (Actual): 90
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • New York
    • Buffalo, New York, United States, 14222-2006
      • Women and Children's Hospital of Buffalo

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 6 years to 12 years (Child)
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Nitrous oxide 0%; Nitrous oxide 0% by mask for 2 minutes while showing pictures and telling jokes.	Drug: Nitrous Oxide 0%; Behavior: recall at discharge from hospital will be tested for the content of photos and a joke told while breathing a mask; Other Names: Placebo
Active Comparator: Nitrous oxide 33%; Nitrous oxide 33% for 2 minutes while showing pictures and telling jokes.	Drug: Nitrous oxide 33%; Behavior: recall at discharge from hospital will be tested for the content of photos and a joke told while breathing a mask; Other Names: low concentration Nitrous oxide
Active Comparator: Nitrous oxide 66%; Nitrous oxide 66% for 2 minutes while showing pictures and telling jokes.	Drug: Nitrous oxide 66%; Behavior: recall at discharge from hospital will be tested for the content of photos and a joke told while breathing a mask; Other Names: high concentration Nitrous oxide

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Explicit Memory	Explicit 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 whether they smelled za bad odor while they breathed through the mask.	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
Explicit Memory	Explicit memory will be tested for the child recalling the riddle and answer after the study	After recovery from anesthesia (in recovery room or before discharge from hospital) within 4 hours of anesthesia completion
Explicit Memory if the Child Remembered Being Shown an Animal in a Photo	The child will be shown the photo of an animal while they were breathing through the mask and then asked to recall which animal they were shown in the photo during the mask induction	2 hours after anesthesia
Explicit Memory of the Name of a Food That Begins With the Letter "b"	The child will be asked if they recall hearing the name of a good that began with the letter "b" while breathing the mask	2 hours after anesthesia

Collaborators and Investigators

• Sponsor: State University of New York at Buffalo
• Investigators: Principal Investigator: Jerrold Lerman, MD, FRCPC, Professor

Study record dates

Study Major Dates

• Study Start: May 1, 2013
• Primary Completion (Actual): October 1, 2013
• Study Completion (Actual): October 1, 2013

Study Registration Dates

• First Submitted: March 22, 2013
• First Submitted That Met QC Criteria: January 28, 2014
• First Posted (Estimated): January 30, 2014

Study Record Updates

• Last Update Posted (Actual): June 30, 2026
• Last Update Submitted That Met QC Criteria: June 24, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Memory; Nitrous Oxide; Amnesia; Implicit; Explicit
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Neurobehavioral Manifestations; Neurocognitive Disorders; Memory Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Amnesia; Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Anesthetics, General; Anesthetics; Analgesics, Non-Narcotic; Anesthetics, Inhalation; Nitrous Oxide
• Other Study ID Numbers: Nitrous Oxide Amnesia Children

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO