Macintosh Blade Size for Endotracheal Intubation in Operative Rooms (MacSize_OR)

January 29, 2026 updated by: University Hospital, Clermont-Ferrand

Macintosh Blade Size During Laryngoscopy for Endotracheal Intubation in Operative Rooms. A Nationwide Prospective Observational Study.

Endotracheal intubation is a frequent procedure in the operating room but optimal Macintosh blade size remains unknown to date.

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

Endotracheal intubation is an extremely frequent procedure in the operating room, in intensive care units and in emergency medicine (in- or out-of-hospital). Apart from special cases of foreseen difficult programmed intubation, direct laryngoscopy remains the most frequently used technique. It requires the use of a handle (short or long), which serves as a light source on which is adapted a Macintosh curved blade, metallic or plastic, single or multiple use. The choice of blade size is based on the experience of the physician. Most often, in adult settings, size 3 or 4 blades are used. The very spartan literature on the subject and the current recommendations do not provide any information on the choice of blade size. Our team (and others) recently concluded that intubation first attempt rates in intensive care units or emergency settings were improved when using shorter Macintosh blade size No3 vs 4 (Godet et al. Intensive Care Medicine 2022 and Landefeld et al. Critical Care Explorations 2023). We therefore wish to evaluate these practices in terms of success of the first laryngoscopy, Cormack-Lehane and POGO (percentage of glottic opening visualized) scores, the need to use an alternative technique or a second operator in operative rooms. The results will be analyzed with regard as a function and experience of the person performing the laryngoscopy, as well as the setting (urgent or scheduled). These data are usually collected during the performance of an endotracheal intubation in a nationwide fashion in French operative rooms.

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.
Observational

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.
3058

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

  • France
      • Clermont-Ferrand, France, 63000
        • CHU clermont-ferrand

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Any patient requiring orotracheal intubation with direct laryngoscopy in first place

Description

Inclusion Criteria:

  • Patients must be admitted in a participating operative room and require mechanical ventilation through an orotracheal tube.
  • Adult (age ≥ 18 years)
  • Subjects must be covered by public health insurance
  • Written informed consent from the patient or proxy (if present) before inclusion or once possible when patient has been included in a context of emergency.

Exclusion Criteria:

  • Anticipated difficult intubation requiring videolaryngoscopy or other technic in first place
  • Nasotracheal intubation
  • Refusal of study participation or to pursue the study by the patient
  • Absence of coverage by the French statutory healthcare insurance system
  • Protected person

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

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
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.
Macintosh blade size 3
Patients intubated using Macintosh blade size 3
Device: Direct laryngoscopy using Macintosh blade
Patients in operative room requiring direct laryngoscopy for endotracheal intubation
Macintosh blade size 4
Patients intubated using Macintosh blade size 4
Device: Direct laryngoscopy using Macintosh blade
Patients in operative room requiring direct laryngoscopy for endotracheal intubation

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
Number of patients with successful first-pass orotracheal intubation
Time Frame: At intubation
The proportion of patients with successful first-pass orotracheal intubation
At intubation

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
Moderate complications related to intubation_difficult intubation
Time Frame: At intubation
Rate of difficult intubation
At intubation
Moderate complications related to intubation_arrythmia
Time Frame: At intubation
Rate of severe ventricular or supraventricular arrhythmia requiring intervention
At intubation
Moderate complications related to intubation_oesophageal intubation
Time Frame: At intubation
Rate of oesophageal intubation
At intubation
Moderate complications related to intubation_agitation
Time Frame: At intubation
Rate of agitation
At intubation
Moderate complications related to intubation_aspiration
Time Frame: At intubation
Rate of pulmonary aspiration
At intubation
Moderate complications related to intubation_dental injuries
Time Frame: At intubation
Rate of dental injuries
At intubation
Difficulty of intubation
Time Frame: During intubation
Rate of operator-assessed difficulty of intubation
During intubation
Additional airway equipment
Time Frame: During intubation
Rate of need for additional airway equipment (video laryngoscope, bougie, stylet, fibroscope, cricothyrotomy)
During intubation
Additional second operator
Time Frame: During intubation
Rate of need for a second operator
During intubation
Severe complications related to intubation_hypoxemia
Time Frame: At intubation
Rate of severe hypoxemia defined by lowest oxygen saturation (SpO2) < 90 %
At intubation
Severe complications related to intubation_severe collapse
Time Frame: At intubation
Rate of cardiovascular collapse, defined as systolic blood pressure less than 80 mmHg systolic blood pressure less than 50 mmHg recorded at least once
At intubation
Severe complications related to intubation_cardiac arrest
Time Frame: At intubation
Rate of cardiac arrest related to intubation
At intubation
Severe complications related to intubation_death
Time Frame: At intubation
Rate of death related to intubation
At intubation
Cormack Lehane
Time Frame: During laryngoscopy
Cormack-Lehane grade of glottic view
During laryngoscopy
Percentage of Glottic Opening
Time Frame: During laryngoscopy
Percentage of Glottic Opening (POGO) grade of glottic view
During laryngoscopy

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.
University Hospital, Clermont-Ferrand

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.
Société Française d'Anesthésie-Réanimation (SFAR)

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: Thomas Godet, MD, PhD, Clermont-Ferrand University Hospitals

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)

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.
January 22, 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.
September 20, 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.
September 20, 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).
January 10, 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.
January 22, 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.
January 31, 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.
February 2, 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.
January 29, 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.
November 1, 2025

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.
  • IRB 00010254-2023-081

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data available upon reasonable request and satisfactory presented analysis plan. Authorship will include principal investigator (last author).

IPD Sharing Time Frame

Data available after study completion and publication

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

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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