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

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: Completed
• Conditions: Anesthesia; Pediatrics
• Intervention / Treatment: Other: Inhalation induction with parosmia

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Perioperative anxiety as assessed by the Modified Yale Preoperative Anxiety Scale-Short Form (mYPAS-SF)	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

Outcome Measure	Measure Description	Time Frame
Number of antiemetic mediations administered post-operatively	Measuring statistical difference in 1) number of antiemetic medications administered	immediately after the surgery
Type and total dose of opioids administered post-operatively	Type and total dose of opioids administered	immediately after the surgery
Length of time (minutes) to post-anesthesia care unit (PACU) discharge	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

• Sponsor: Johns Hopkins University
• Investigators: Principal Investigator: Pooja O'Neil, MD, Johns Hopkins School of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): October 10, 2024
• Primary Completion (Actual): August 7, 2025
• Study Completion (Actual): August 7, 2025

Study Registration Dates

• First Submitted: May 31, 2024
• First Submitted That Met QC Criteria: June 6, 2024
• First Posted (Actual): June 7, 2024

Study Record Updates

• Last Update Posted (Actual): August 11, 2025
• Last Update Submitted That Met QC Criteria: August 7, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Sensation Disorders; Olfaction Disorders
• Other Study ID 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