Macintosh Blade Size During Laryngoscopy for Endotracheal Intubation. A Prospective Observational Study. (MacSize)

Endotracheal intubation is a frequent procedure in the operating room, in intensive care units and in emergency medicine (in- or out-of-hospital) but optimal Macintosh blade size remains unknown to date.

Study Overview

• Status: Recruiting
• Conditions: Endotracheal Intubation
• Intervention / Treatment: Device: Direct laryngoscopy for endotracheal intubation

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. 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. 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 whatever the circumstances: operating room, intensive care unit and emergency department (in-hospital) and in the SAMU-SMUR (pre-hospiatl medical service) at Clermont-Ferrand University Hospital.

• Study Type: Observational
• Enrollment (Anticipated): 1500

Contacts and Locations

Study Locations

• France
  • Clermont-Ferrand, France
    • Recruiting
    • CHU

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 15 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Any patient requiring orotracheal intubation with direct laryngoscopy

Description

Inclusion Criteria:

• Patients must be admitted in an operative room, an intensive care unit (ICU) or an emergency department 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
• 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

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Macintosh blade size 3; Patients intubated using Macintosh blade size 3	Device: Direct laryngoscopy for endotracheal intubation; Patients in operative room, intensive care unit and emergency department requiring direct laryngoscopy for endotracheal intubation
Macintosh blade size 4; Patients intubated using Macintosh blade size 4	Device: Direct laryngoscopy for endotracheal intubation; Patients in operative room, intensive care unit and emergency department requiring direct laryngoscopy for endotracheal intubation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of patients with successful first-pass orotracheal intubation	The proportion of patients with successful first-pass orotracheal intubation	At intubation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Severe complications related to intubation_hypoxemia	Rate of severe hypoxemia defined by lowest oxygen saturation (SpO2) < 80 %	At intubation
Severe complications related to intubation_severe collapse	Rate of cardiovascular collapse, defined as systolic blood pressure less than 65 mm Hg recorded at least once or less than 90 mm Hg lasting 30 minutes despite 500-1,000 ml of fluid loading (crystalloids solutions) or requiring introduction or increasing doses by more than 30% of vasoactive support	At intubation
Severe complications related to intubation_cardiac arrest	Rate of cardiac arrest	At intubation
Severe complications related to intubation_death	Rate of death during intubation	At intubation
Moderate complications related to intubation_difficult intubation	Rate of difficult intubation	At intubation
Moderate complications related to intubation_arrythmia	Rate of severe ventricular or supraventricular arrhythmia requiring intervention	At intubation
Moderate complications related to intubation_oesophageal intubation	Rate of oesophageal intubation	At intubation
Moderate complications related to intubation_agitation	Rate of agitation	At intubation
Moderate complications related to intubation_aspiration	Rate of pulmonary aspiration	At intubation
Moderate complications related to intubation_dental injuries	Rate of dental injuries	At intubation
Cormack Lehane	Rate of Cormack-Lehane grade of glottic view	During intubation
Difficulty of intubation	Rate of operator-assessed difficulty of intubation	During intubation
Additional airway equipment	Rate of need for additional airway equipment (video laryngoscope, bougie, stylet, fibroscope, cricothyrotomy)	During intubation
Additional second operator	Rate of need for a second operator	During intubation
POGO (percentage of glottic opening)	Rate of POGO grade of glottic view	During intubation

Collaborators and Investigators

• Sponsor: University Hospital, Clermont-Ferrand

Study record dates

Study Major Dates

• Study Start (Actual): June 15, 2021
• Primary Completion (Anticipated): December 1, 2021
• Study Completion (Anticipated): January 1, 2022

Study Registration Dates

• First Submitted: June 15, 2021
• First Submitted That Met QC Criteria: September 16, 2021
• First Posted (Actual): September 28, 2021

Study Record Updates

• Last Update Posted (Actual): October 5, 2021
• Last Update Submitted That Met QC Criteria: September 28, 2021
• Last Verified: June 1, 2021

More Information

Terms related to this study

• Keywords: Intensive Care Unit; Intubation; Emergency department; Macintosh blade; Laryngoscopie; Operative room
• Other Study ID Numbers: IRB 00010254-2021-016

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No