SEALion: Study on Supplemental Oxygenation Via Nasal Cannula for Young Children During Intubation (SEALION)

August 24, 2026 updated by: Vinícius C Quintão, MD, MSc, PhD

SEALion: a Study on the Effectiveness of Additional Oxygenation in Little Children During Intubation Using Oxygenation Delivered by Nasal Cannula

Tracheal intubation in neonates can be technically challenging, even for experienced pediatric anesthesiologists, with a high first-attempt success rate crucial to ensure safety. Intubation, while life-saving for children with circulatory shock or respiratory failure, carries risks of severe desaturation that can lead to hypoxic encephalopathy, cardiac arrest, or death. Neonates, especially, are prone to hypoxemia due to high oxygen consumption, low functional residual capacity, small closing capacity, and increased risk of airway collapse, which is exacerbated under anesthesia and neuromuscular paralysis. Rapid desaturation occurs after cessation of ventilation, with neonates facing shorter apnea times before desaturation. Studies show that about two-thirds of neonates undergoing non-emergency nasotracheal intubation experience desaturation (SpO₂ <80% for over 60 seconds), although low-flow oxygen supplementation (0.2 L/kg/min) can extend safe apnea time.

This study aims to investigate apneic oxygenation with VL (using Miller or Macintosh blades size 0 or 1) in operating rooms or intensive care units. We hypothesize that supplemental oxygen and standardized VL use will improve first-pass success rates and reduce adverse events.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Eligible children will undergo preparation for intubation following the local Standard Operating Procedures (SOPs) of the pediatric anesthesia departments. Mandatory monitoring includes pulse oximetry (SpO2), heart rate (HR), and non-invasive blood pressure (NIBP).

Anesthesia Induction:

Where feasible, all children enrolled in this protocol will be pre-oxygenated for one minute prior to induction of anesthesia using a face mask with FiO2 1.0 and a flow rate of 6-10 L/min. Anesthesia induction for tracheal intubation will involve a combination of sedative or hypnotic drugs, opioids, and a non-depolarizing muscle relaxant.

Required Medications (per protocol):

Neuromuscular Blocking Agent (NMBA): One of the following-Rocuronium 0.5-1 mg/kg, Cis-Atracurium 0.2-0.5 mg/kg, Atracurium 0.5 mg/kg, Vecuronium 0.1 mg/kg, Mivacurium 0.2-0.3 mg/kg, or Succinylcholine 2 mg/kg.

Hypnotic Agent: One or more of the following-Thiopentone 4-7 mg/kg, Ketamine 0.5-2 mg/kg, Propofol 1-4 mg/kg, Midazolam 0.5-1 mg/kg, or Sevoflurane up to 8%.

Optional Medications: An opioid and/or anticholinergic may be administered at the anesthetist's discretion.

Pre-Intubation Preparation:

Following induction of anesthesia and administration of an NMBA, bag-mask ventilation with FiO2 1.0 (flow rate of 6-10 L/min) will be performed for 60 seconds until apnea occurs. To facilitate airway management, complete neuromuscular blockade will be confirmed using train-of-four (TOF) monitoring. Oxygen administration, laryngoscopy, and tracheal intubation will follow.

Intubation Procedure:

Oxygen administration during intubation is mandatory for all participants and will be randomized as follows:

Apneic Oxygenation: Oxygen will be administered at 1 L/kg/min via a conventional nasal cannula. Laryngoscopy and tracheal intubation will proceed following apneic oxygenation.

Standard Care: No apneic oxygenation will be administered. After induction, laryngoscopy and tracheal intubation will proceed without additional oxygen support.

Tube Selection:

For premature neonates under 1 kg, an uncuffed tube with an internal diameter (ID) of 2.5 will be used.

For premature neonates and newborns between 1 kg and 3.0 kg, an uncuffed tube with ID 3.0 will be used.

For babies over 3.0 kg up to 8 months, a cuffed tube with ID 3.0 or an uncuffed tube with ID 3.5 will be used.

For infants aged 8 to 12 months, a cuffed tube with ID 3.5 or an uncuffed tube with ID 4.0 will be used.

Oxygen delivery will follow the assigned randomization group, either via conventional nasal cannula (apneic oxygenation) or standard care.

Laryngoscope Blade Selection:

For children weighing less than 1 kg, a Miller or Macintosh blade, size No. 0, will be used. In cases of unexpected difficult intubation, the difficult airway algorithm will be applied. After an unsuccessful first intubation attempt with the assigned flow rate, clinical judgment will guide the intubating physician on whether to repeat the attempt with the same flow rate or to modify the flow rate, blade size, or type of laryngoscope. A maximum of four intubation attempts will be allowed, with the final attempt performed by the most experienced physician present. Additional tools, such as a stylet or bougie, may be used at any stage. If intubation remains unsuccessful, the difficult airway algorithm will be applied, and a supraglottic airway (SGA) device will be inserted.

Study Type

Interventional

Enrollment (Estimated)

240

Phase

  • 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 Locations

  • Australia
    • Western Australia
      • Perth, Western Australia, Australia, 6009
  • Brazil
    • São Paulo
      • São Paulo, São Paulo, Brazil, 05403000
        • Recruiting
        • Hospital das Clinicas HCFMUSP
        • Contact:
  • Canada
    • British Columbia
      • Vancouver, British Columbia, Canada
        • Recruiting
        • British Columbia Children's Hospital
        • Contact:
  • Sweden
      • Uppsala, Sweden

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

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Pediatric patients requiring oral or nasal tracheal intubation for elective, semi-elective, or urgent surgical and non-surgical procedures.
  • Neonates and infants up to 52 weeks post-conceptual age.
  • Written informed consent provided by legal guardians prior to the intervention.

Exclusion Criteria:

  • Prediction of difficult intubation based on physical examination or a history of previous difficult intubation.
  • Requirement for an alternative technique to direct laryngoscopy to secure the airway.
  • Specific conditions, such as congenital heart disease requiring FiO₂ < 1.0, or cardiopulmonary collapse necessitating advanced life support and intubation for emergency surgical or non-surgical interventions.

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: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Standard of care
Tracheal intubation performed with a video laryngoscope with Miller-blade or Macintosh-blade size No. 0 or No. 1 without apneic oxygenation.
Experimental: Apneic oxygenation
1 L/kg/min FiO2 1.0 low-flow nasal supplemental oxygen with conventional nasal cannula during tracheal intubation performed with a video laryngoscope with Miller-blade or Macintosh-blade size No. 0 or No. 1.
Procedure: Apneic oxygenation
1 L/kg/min FiO2 1.0 low-flow nasal supplemental oxygen with conventional nasal cannula during tracheal intubation performed with a video laryngoscope with Miller-blade or Macintosh-blade size No. 0 or No. 1.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
First-attempt success rate
Time Frame: From randomization until up to 15 minutes
The primary study outcome is to evaluate the first attempt success rate of oral tracheal intubation without desaturation (< 90%) and/or bradycardia (< 100 bpm) with video laryngoscope with supplemental oxygen (apneic oxygenation) vs without supplemental oxygen in infants up to 52 weeks postconceptual age. A successful tracheal intubation (ETI) attempt is defined as successful placement of a tracheal tube in the trachea, confirmed by visualization of the tube passing the vocal cords, a waveform capnography suggesting correct ETT placement and auscultation of breath sounds in the lungs
From randomization until up to 15 minutes

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Desaturation rate
Time Frame: From randomization until up to 15 minutes
Occurrence and duration of moderate and severe desaturation (SpO2 < 90% and SpO2 < 80%), with or without bradycardia, during intubation.
From randomization until up to 15 minutes
Overall number of intubation attempts
Time Frame: From randomization until up to 15 minutes
The overall number of intubation attempts.
From randomization until up to 15 minutes
Time to intubation
Time Frame: From randomization until up to 5 minutes
Time required for intubation (in seconds, defined from the first introduction of laryngoscope between the lips till successful lung ventilation defined as positive capnography).
From randomization until up to 5 minutes
Respiratory complications rate
Time Frame: From randomization until up to 24 hours
Respiratory complications and complications of airway management within the first 24 hours, such as airway injury, cardiopulmonary resuscitation, bleeding, aspiration of gastric contents, post-extubation stridor, laryngospasm, bronchospasm, need for High Flow Nasal Oxygen (if not preoperatively on oxygen), need for low flow nasal oxygen (if not preoperatively on oxygen) or need for re-intubation will be recorded. Respiratory complications are defined as the need for re-intubation after being extubated, persistent stridor (even if oxygen is not required), respiratory failure, the occurrence of pneumothorax, or the need for any additional diagnostic examination following respiratory problems (i.e., bronchoscopy, radiology).
From randomization until up to 24 hours
First EtCO2 after successful intubation
Time Frame: From randomization until up to 10 minutes
Value in mmHg or kPa of the first reliable etCO2 reading after successful intubation
From randomization until up to 10 minutes
Cormack-Lehane score
Time Frame: From randomization until up to 5 minutes
The Cormack-Lehane score, classified as 1, 2a, 2b, 3, or 4, recorded at each laryngoscopy attempt
From randomization until up to 5 minutes
The need for additional devices
Time Frame: From randomization until up to 5 minutes
The need for additional devices used at any step of intubation
From randomization until up to 5 minutes
Duration of severe desaturation
Time Frame: From randomization until up to 15 minutes
Duration of moderate and severe desaturation (SpO2 < 80%), with or without bradycardia, during intubation
From randomization until up to 15 minutes
Percentage of Glottic Opening (POGO) score
Time Frame: From randomization until up to 5 minutes
Percentage of Glottic Opening (POGO) score recorded at each laryngoscopy attempt, ranging from 0% to 100%, with 100% indicating the best possible glottic view
From randomization until up to 5 minutes

Collaborators and Investigators

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

Sponsor

Vinícius C Quintão, MD, MSc, PhD

Collaborators

University of Bern
The University of Western Australia

Investigators

  • Principal Investigator: Vinicius C Quintao, MD, MSc, PhD, Hospital das Clinicas, Faculdade de Medicina, Universidade de Sao Paulo

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

December 10, 2024

Primary Completion (Estimated)

June 1, 2027

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

November 5, 2024

First Submitted That Met QC Criteria

November 8, 2024

First Posted (Actual)

November 12, 2024

Study Record Updates

Last Update Posted (Actual)

August 25, 2026

Last Update Submitted That Met QC Criteria

August 24, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • SEALION

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

product manufactured in and exported from the U.S.

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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