Head Position for Laryngeal Mask Air Leak and Performance in Paediatric Patients (Neutral, Sniffing and Beyond Sniffing Position) (SNIFFLMA)

May 19, 2026 updated by: Petr Štourač, MD, Brno University Hospital

Head Position for Laryngeal Mask Air Leak and Performance in Paediatric Patients (Neutral, Sniffing and Beyond Sniffing Position): Prospective Randomized Trial

The correct head position for airway management is considered as a mainstay of good clinical practice. The recommended head position for all patients is the horizontal position of the head with in tragus-to- sternal notch in line alignment. This could be achieved in infant (under two years) supporting the shoulder, neutral head positioning in children between 2-8 (12) years and with so called "sniffing position" (SP) in patients over 12 year by supporting the head (i.e. with pillow) to reach the proper alignment (tragus to sternal notch). Although, this could be considered as gold standard, there are currently insufficient high quality evidence-based data to confirm the association between the better laryngeal view during the direct laryngoscopy and tragus-to-sternal notch position. Recently, "beyond sniffing" position was described as further head elevation (compared to sniffing position) in adult patients. Beyond sniffing position was associated with superior laryngeal inlet visualization compared to standard sniffing position in common elective adult airway management (patients with suspected or confirmed difficult airway was excluded). The hypothesis of SNIFF LM trial is that the sniffing position or even beyond sniffing position could be associated with superior laryngeal mask performance (lower incidence of air leak, LM easier introduction) compared neutral position in paediatric patients undergoing elective paediatric anaesthesia

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.

Detailed Description

Paediatric patients (between 2-18 years) undergoing elective airway management without predicted/confirmed difficult airway will be eligible for inclusion. The patients will be screened for eligibility during the preanaesthesia visit in anaesthesiology examination room. After informed consent the patients will be randomized into 3 groups (according to the induction head position) - neutral head position (without head elevation, head supported with the hollow foam circle to prevent side head movement), sniffing position (head support with inflatable pillow the reach the horizontal in-line alignment of tragus-to-sternal notch line) and beyond sniffing position (further 25% increase of head support compared to sniffing position). The randomization will be performed by the Institute of Biostatistics and Analysis in form of sealed envelopes. The group allocation will be 1:1:1. After fulfilling the inclusion criteria and obtaining the informed consent the patient will be randomized into 3 groups. Before anaesthesia induction the head of the patient will be positioned into the predefined position according to the results of randomization. The anaesthesia induction could be performer either inhalation or intravenous route. After anaesthesia induction, the laryngeal mask will be inserted in the selected position. After laryngeal mask insertion, stabilisation of vital signs and of anaesthesia depth, the measurement will be intiated within 5 minutes. After one minute of ventilation 3 leak volumes (inspiration - expiration tidal volume) together with the peak airway pressure (3 measurements) will be recorded (the mean volume and mean pressure will be analyzed). Patient´s head will be repositioned into the 2nd position and after one minute of ventilation leak volume and airway pressure will be recorded as previously described, after measurement, the head position will be repositioned into the 3rd positon and the measurement will be repeated. The incidence of 1st insertion attempt failure rate, incidence of laryngeal mask failure rate, incidence of the need for reposition will be recorded together with the incidence of airway related complications.

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.
205

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.

Study Contact Backup

Study Locations

  • Czechia
    • South Moravian
      • Brno, South Moravian, Czechia, 62500
        • Brno University 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

2 years to 19 years (Child, Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 2-19 years
  • Informed consent
  • Elective airway management
  • laryngeal mask for airway management

Exclusion Criteria:

  • Outside the age limits
  • Decline to participate
  • Predicted or confirmed difficult airway
  • Cervical spine injury
  • limited access to head of the patient after anaesthesia induction (for the measuement purposes)
  • Intubation

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: Single

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.
Active Comparator: Neutral head position
Laryngeal mask will be inserted after anaesthesia induction in neutral head position
Device: Laryngeal mask insertion
Laryngeal mask insertion in neutral position
Device: Laryngeal mask insertion
Laryngeal mask insertion in sniffing position
Device: Laryngeal mask insertion
Laryngeal mask insertion in beyond sniffing position
Active Comparator: Sniffing position
Laryngeal mask will be inserted after anaesthesia induction in sniffing head position
Device: Laryngeal mask insertion
Laryngeal mask insertion in neutral position
Device: Laryngeal mask insertion
Laryngeal mask insertion in sniffing position
Device: Laryngeal mask insertion
Laryngeal mask insertion in beyond sniffing position
Experimental: Beyond sniffing position
Laryngeal mask will be inserted after anaesthesia induction in sniffing head position
Device: Laryngeal mask insertion
Laryngeal mask insertion in neutral position
Device: Laryngeal mask insertion
Laryngeal mask insertion in sniffing position
Device: Laryngeal mask insertion
Laryngeal mask insertion in beyond sniffing position

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
leak volume in 3 different head position in every patient (1st position will be randomized)
Time Frame: 1 minute mechanical ventilation in predefined head position
leak volume in 3 different head position in every patient (1st position will be randomized) defined by the average leak obtained from 3 measurements in selected position
1 minute mechanical ventilation in predefined head position

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
Leak pressure in 3 different head position in every patient (1st position will be randomized)
Time Frame: 1 minute mechanical ventilation in predefined head position
Leak pressure in 3 different head position in every patient (1st position will be randomized) defined by the first audible leak during stepwise increasing inspiratory pressure
1 minute mechanical ventilation in predefined head position
incidence of failed 1st attempt insertion rate
Time Frame: anaesthesia induction
incidence of failed 1st attempt insertion rate
anaesthesia induction
incidence of overall laryngeal mask failure
Time Frame: anaesthesia induction
incidence of overall laryngeal mask failure
anaesthesia induction
incidence of the need for head reposition to obtain better airway seal in the 3 randomized head positions.
Time Frame: Intraoperatively
incidence of the need for head reposition to obtain better airway seal in the 3 randomized head positions
Intraoperatively
Incidence of airway related complication
Time Frame: From anaesthesia induction until dismission from postanaesthesia care unit
Incidence of airway related complication -regurgitation/aspiration, desaturation, oesophageal intubation, laryngeal/airway injury incidence
From anaesthesia induction until dismission from postanaesthesia care unit

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.
Brno University Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Masaryk 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.
  • Study Chair: Petr Stourac, prof. MD., Ph.D., Department of paediatric anaesthesia and intensive care 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.
February 1, 2022

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.
December 31, 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.
December 31, 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).
August 30, 2021

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.
August 30, 2021

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.
September 5, 2021

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.
May 20, 2026

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.
May 19, 2026

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.
May 1, 2026

More Information

Terms related to this study

Keywords

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.
  • KDAR SNIFF LMA

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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