Chocolate or Sevoflurane: Use of Parosmia to Facilitate More Cooperative Inhalation Inductions in Children

August 7, 2025 updated by: Johns Hopkins University

Children undergoing surgery and anesthesia are often negatively impacted by anxiety and fear in the preoperative period. Routine inhalational anesthetic induction is a unique aspect of pediatric anesthesia. Inhalation inductions are usually initiated with sevoflurane with or without nitrous oxide. While less pungent than other volatile agents, sevoflurane at high concentrations and flows used for inhalation inductions still causes children to often repel from the smell. This can lead to an unpleasant interaction and cause heightened anxiety for any subsequent procedures.

Olfactory senses are processed in the hippocampus and amygdala and tied to emotion and memory. Parosmia is the distortion of smell perception which can utilized to the pediatric anesthesiologists advantage. It has been demonstrated that using this phenomenon, the anesthesiologist can induce a better smell for the child leading to improved cooperation during an inhalation induction. However, limitations of this study include lack of randomization, small sample size, and use of a nominal scale of yes or no for face mask acceptance. The investigators identified no other studies to validate this potentially powerful tool to optimize anesthetic induction for pediatric patients.

The overall objective of this pilot randomized trial is to determine the feasibility of parosmia during inhalation inductions to decrease perioperative stress for children and provide key pilot data to power a larger study to determine effectiveness of parosmia during inhalation inductions to decrease perioperative stress for children and provide key pilot data to power a larger study to determine effectiveness of parosmia.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
50

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Pooja O'Neil, MD
  • Phone Number: 4109556412
  • Email: poneil3@jh.edu

Study Contact Backup

Study Locations

  • United States
    • Maryland
      • Baltimore, Maryland, United States, 21287
        • Johns Hopkins Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Ages of 5-12 years old
  • American Society of Anesthesiologist physical status classification system (ASA) I and II
  • Patients coming from home

Exclusion Criteria:

  • Patients undergoing emergent surgery
  • Patients who have not adequately maintained preoperative nothing per mouth/os (NPO) status
  • Patients with inability to communicate verbally
  • Tracheostomy patients
  • ASA III , IV, V patients

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Inhalation induction with parosmia
The experimental group will be told about a magical machine that can change the smell of the mask to any flavor the patient desires. The participant will be asked to take a deep breath thinking about that smell and then sevoflurane will be introduced. The patient will be asked if the the chosen flavor is smelled and the response will be noted.
Other: Inhalation induction with parosmia
The experimental group will then be told that the patient's favorite smell will be put into the face mask via the "magical machine". The patient will be asked to take a deep breath thinking about that smell and then introduce sevoflurane. The patient will be asked if the chosen flavor is smelled and their response will be noted.
No Intervention: Standard inhalation induction
Standard inhalation induction.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Perioperative anxiety as assessed by the Modified Yale Preoperative Anxiety Scale-Short Form (mYPAS-SF)
Time Frame: perioperatively
The modified Yale Preoperative Anxiety Scale-Short Form (mYPAS-SF) will be used to evaluate perioperative anxiety. Patients are evaluated in 4 domains: activity (score 1,2,3, or 4), vocalizations (score 1,2,3,4,5 or 6), emotional expressivity (1,2,3 or 4), and state of apparent arousal (1,2,3, or 4), with higher numbers indicating the highest severity within that item. Each score is calculated by dividing each item rating by the highest possible rating (i.e., 6 for the "vocalizations" item and 4 for all other items), adding all the produced values, dividing by 5, and multiplying by 100. This calculation produces a score ranging from 23.33 to 100, with higher values indicating higher anxiety.
perioperatively

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Number of antiemetic mediations administered post-operatively
Time Frame: immediately after the surgery
Measuring statistical difference in 1) number of antiemetic medications administered
immediately after the surgery
Type and total dose of opioids administered post-operatively
Time Frame: immediately after the surgery
Type and total dose of opioids administered
immediately after the surgery
Length of time (minutes) to post-anesthesia care unit (PACU) discharge
Time Frame: admission to the PACU through discharge from the PACU (<2 hours post-operatively)
Length of time from admission to PACU discharge between the control group and the intervention group
admission to the PACU through discharge from the PACU (<2 hours post-operatively)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Johns Hopkins University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Pooja O'Neil, MD, Johns Hopkins School of Medicine

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 10, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 7, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 7, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 31, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 6, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 7, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 11, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 7, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB00434506

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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