Demand-Driven Method for Gas Delivery in a Dental Setting

NCT ID: NCT04305990

Last Updated: 2020-03-12

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

UNKNOWN

Clinical Phase

NA

Total Enrollment

100 participants

Study Classification

INTERVENTIONAL

Study Start Date

2020-03-31

Study Completion Date

2020-10-31

Brief Summary

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This study compares two methods of gas delivery in a dental setting: 1) demand-driven (DD) and 2) free-flow (FF).

Nitrous oxide and oxygen sedation (NOS) is a common form of minimal sedation for adult and paediatric patients undergoing dental procedures. In order for NOS devices to be utilized during dental treatment, dentists must be able to provide gas flow to the patient, and subsequently scavenge used and unused gasses. Gas delivery is via a nasal mask, since the oral cavity must be accessible to the dentist throughout treatment.

Current devices for NOS in the dental setting utilize a free-flow gas method, where nitrous oxide and oxygen are released continuously from their tanks. The flow rate is set by the dentist according to the patient's minute ventilation needs, and unused and exhaled gasses are scavenged via the nasal mask. The demand-driven gas flow method, where inspiration triggers gas flow, has been used successfully in other medical settings, such as in obstetrics, medical emergencies, and for patients with chronic obstructive pulmonary disease. However, in these settings the mask used covers both the nose and mouth, and patients can trigger the demand-driven method through inspiration of the nose or mouth. The demand-driven gas flow method has a significant gas-sparing advantage over the free-flow method. With a demand-driven method, the patient dictates the flow rate and gas is only delivered when they are inspiring, compared to the free-flow method which provide gas flow throughout inspiration and expiration. However, the demand-driven method have not been studied in a dental setting where flow can only be triggered through the nose. It is therefore unknown whether it is feasible or comfortable for patients to trigger a demand-driven method nasally when their mouth is open during dental treatment.

This study will aim to assess the feasibility and comfort of a nasal demand-driven gas delivery method utilizing 100% oxygen in healthy, adult participants in a simulated dental setting. If the device is feasible and comfortable with 100% oxygen in a simulated dental setting, future research can be conducted to assess its use for NOS for dental treatment.

Detailed Description

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The study design is a within-subjects, single-blinded, randomized control trial. Participants will be randomzied to inspire 100% oxygen through their nose utilizing a demand-driven (DD) gas delivery method and a free-flow (FF) gas delivery method for 2 minutes each in a simulated dental setting.

The study will take place at the University of Toronto's Faculty of Dentistry Children's Clinic. Participants will be positioned supine in the dental chair. A child size, rubber bite block will be inserted with an attached capnography device to measure end-tidal carbon dioxide at the mouth. A double-mask nasal hood with disposable insert will be placed on the participant's nose. The participant will be instructed to breathe through their mouth for 1 minute. Baseline respiratory rate and presence/absence of end tidal carbon dioxide at the mouth will be obtained through the capnograph and recorded. The presence of carbon dioxide at baseline during mouth breathing will confirm that the capnograph is able to measure end-tidal carbon dioxide at the mouth.

The researcher will then open the envelope with the randomization plan for the participant and will indicate whether they will receive the FF or DD gas delivery method first. The gas delivery device will be attached to the nasal hood, and set to either DD or FF gas delivery method. Once the device is connected, the participant will be instructed to breathe through their nose for 2 minutes. During this time, respiratory rate, presence/absence of end tidal carbon dioxide at the mouth, and oxygen flow rate per minute will be observed and recorded. The absence of end-tidal carbon dioxide at the mouth during this testing phase will provide a verifiable measure that patients are breathing through their nose. After 2 minutes, the flow will be stopped and the bite block removed. The participant will be instructed to breathe through their mouth. The participant will then complete the VAS on comfort of breathing through their nose during the first gas flow delivery method. The bite block will then be reinserted, and the flow resumed using the second gas flow delivery method for 2 minutes. During this time, respiratory rate, presence/absence of end tidal carbon dioxide at the mouth, and oxygen flow rate per minute will be observed and recorded. After 2 minutes, the gas flow will once again be stopped and the bite block removed. The participant will be instructed to complete the VAS on comfort of breathing through their nose. The nasal hood will be removed. The participant will be debriefed to the order of gas flow received (DD or FF first) and the participant will then be dismissed.

Conditions

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Nitrous Oxide Dentistry Drug Delivery System Comfort Feasibility Drug Administration, Inhalation

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

The study design is a within-subjects, single-blinded, randomized controlled trial. Each participant will receive both the free-flow (FF) and demand-driven (DD) gas delivery methods in a randomized sequence.
Primary Study Purpose

OTHER

Blinding Strategy

SINGLE

Participants
Participants will not be told the order the gas flow delivery method (DD or FF) they will be receive. To assist with masking participants, the same device and nasal hood will be used throughout, they will be told to face forward away from the device and device display, which indicates the setting of the gas flow. It will not be feasible to blind the researcher as the researcher will need to change the device setting (FF or DD).

Study Groups

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Demand-driven delivery followed by free-flow delivery

Participants will inspire 100% oxygen through their nose with the gas delivery device set to a demand-driven delivery setting through a nasal hood for 2 minutes followed by inspiration of 100% oxygen through their nose with the gas delivery device set to a free-flow delivery setting through a nasal hood for 2 minutes.

Group Type EXPERIMENTAL

Demand-driven delivery method

Intervention Type DEVICE

The gas delivery device is set to the demand-driven setting. Patients must inspire through their nose to trigger the flow of gas.

Free-flow delivery method

Intervention Type DEVICE

The gas delivery device is set to a free-flow setting. Gas flows through the system at a rate determined by the operator. Standard flow rate is 6 liters per minute. Patients do not need to inspire through their nose to trigger the flow of gas.

Free-flow delivery followed by demand-driven delivery

Participants will inspire 100% oxygen through their nose with the gas delivery device set to a free-flow delivery setting through a nasal hood for 2 minutes followed by inspiration of 100% oxygen through their nose with the gas delivery device set to a free-flow delivery setting through a nasal hood for 2 minutes.

Group Type EXPERIMENTAL

Demand-driven delivery method

Intervention Type DEVICE

The gas delivery device is set to the demand-driven setting. Patients must inspire through their nose to trigger the flow of gas.

Free-flow delivery method

Intervention Type DEVICE

The gas delivery device is set to a free-flow setting. Gas flows through the system at a rate determined by the operator. Standard flow rate is 6 liters per minute. Patients do not need to inspire through their nose to trigger the flow of gas.

Interventions

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Demand-driven delivery method

The gas delivery device is set to the demand-driven setting. Patients must inspire through their nose to trigger the flow of gas.

Intervention Type DEVICE

Free-flow delivery method

The gas delivery device is set to a free-flow setting. Gas flows through the system at a rate determined by the operator. Standard flow rate is 6 liters per minute. Patients do not need to inspire through their nose to trigger the flow of gas.

Intervention Type DEVICE

Eligibility Criteria

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Inclusion Criteria

1. Participants must be adults, 18 years of age or older.
2. Participants must be ASA I (a normal, healthy patient) or ASA II (a patient with mild systemic disease).

Exclusion Criteria

1. Participants who are ASA III (a patient with a severe systemic disease that is not life-threatening) or higher.
2. Participants who indicate they are claustrophobic.
3. Participants with nasal obstruction of both nostrils.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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O-Two Medical Technologies

UNKNOWN

Sponsor Role collaborator

University of Toronto

OTHER

Sponsor Role lead

Responsible Party

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Carilynne Yarascavitch

Assistant Professor, Specialty Program Director, Dental Anaesthesia, Faculty of Dentistry

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Carilynne Yarascavitch, BSc DDS MSc

Role: PRINCIPAL_INVESTIGATOR

University of Toronto

Locations

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University of Toronto, Faculty of Dentistry

Toronto, Ontario, Canada

Site Status

Countries

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Canada

Central Contacts

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Ayala Y Rubin, BA DDS

Role: CONTACT

(1)-647-988-5202

Facility Contacts

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Ayala Y Rubin, BA DDS

Role: primary

6479885202

Carilynne Yarascavitch, BSc DDS MSc

Role: backup

416-864-8252

References

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Wilson S, Gosnell ES. Survey of American Academy of Pediatric Dentistry on Nitrous Oxide and Sedation: 20 Years Later. Pediatr Dent. 2016 Oct 15;38(5):385-392.

Reference Type BACKGROUND
PMID: 28206894 (View on PubMed)

Malamed SF, Clark MS. Nitrous oxide-oxygen: a new look at a very old technique. J Calif Dent Assoc. 2003 May;31(5):397-403.

Reference Type BACKGROUND
PMID: 12839232 (View on PubMed)

Becker DE, Rosenberg M. Nitrous oxide and the inhalation anesthetics. Anesth Prog. 2008 Winter;55(4):124-30; quiz 131-2. doi: 10.2344/0003-3006-55.4.124.

Reference Type BACKGROUND
PMID: 19108597 (View on PubMed)

Clark MS, Brunick A. Handbook of Nitrous Oxide and Oxygen Sedation. 5th Edition ed: Elsevier Health Sciences; 2019.

Reference Type BACKGROUND

Tiep BL, Nicotra MB, Carter R, Phillips R, Otsap B. Low-concentration oxygen therapy via a demand oxygen delivery system. Chest. 1985 May;87(5):636-8. doi: 10.1378/chest.87.5.636.

Reference Type BACKGROUND
PMID: 3921316 (View on PubMed)

van der Kooy J, De Graaf JP, Kolder ZM, Witters KD, Fitzpatrick E, Duvekot JJ, Dons-Sinke IJ, Steegers EA, Bonsel GJ. A newly developed scavenging system for administration of nitrous oxide during labour: safe occupational use. Acta Anaesthesiol Scand. 2012 Aug;56(7):920-5. doi: 10.1111/j.1399-6576.2012.02668.x. Epub 2012 Mar 7.

Reference Type BACKGROUND
PMID: 22404276 (View on PubMed)

Dallal GD. Randomization.com [updated July 15, 2008. Available from: ⟨http://www.randomization.com/⟩.

Reference Type BACKGROUND

Doig GS, Simpson F. Randomization and allocation concealment: a practical guide for researchers. J Crit Care. 2005 Jun;20(2):187-91; discussion 191-3. doi: 10.1016/j.jcrc.2005.04.005.

Reference Type BACKGROUND
PMID: 16139163 (View on PubMed)

Humphris GM, Morrison T, Lindsay SJ. The Modified Dental Anxiety Scale: validation and United Kingdom norms. Community Dent Health. 1995 Sep;12(3):143-50.

Reference Type BACKGROUND
PMID: 7584581 (View on PubMed)

Humphris GM, Dyer TA, Robinson PG. The modified dental anxiety scale: UK general public population norms in 2008 with further psychometrics and effects of age. BMC Oral Health. 2009 Aug 26;9:20. doi: 10.1186/1472-6831-9-20.

Reference Type BACKGROUND
PMID: 19709436 (View on PubMed)

Humphris G, Crawford JR, Hill K, Gilbert A, Freeman R. UK population norms for the modified dental anxiety scale with percentile calculator: adult dental health survey 2009 results. BMC Oral Health. 2013 Jun 24;13:29. doi: 10.1186/1472-6831-13-29.

Reference Type BACKGROUND
PMID: 23799962 (View on PubMed)

King K, Humphris G. Evidence to confirm the cut-off for screening dental phobia using the Modified Dental Anxiety Scale. Soc sci dent. 2010;1(1):21-8.

Reference Type BACKGROUND

Hendrix JM, Garmon EH. American Society of Anesthesiologists Physical Status Classification System. 2025 Feb 11. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from http://www.ncbi.nlm.nih.gov/books/NBK441940/

Reference Type BACKGROUND
PMID: 28722969 (View on PubMed)

Other Identifiers

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00038876

Identifier Type: -

Identifier Source: org_study_id

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