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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Macintosh Blade Size During Laryngoscopy for Endotracheal Intubation. A Prospective Observational Study.

Conditions
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Endotracheal Intubation

Intervention / Treatment
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* Device: Direct laryngoscopy for endotracheal intubation


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 15 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Macintosh blade size 3<br>Patients intubated using Macintosh blade size 3 | Device: Direct laryngoscopy for endotracheal intubation<br>* Patients in operative room, intensive care unit and emergency department requiring direct laryngoscopy for endotracheal intubation<br>|
| Macintosh blade size 4<br>Patients intubated using Macintosh blade size 4 | Device: Direct laryngoscopy for endotracheal intubation<br>* Patients in operative room, intensive care unit and emergency department requiring direct laryngoscopy for endotracheal intubation<br>|

What is the study measuring?
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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 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Intubation, Macintosh blade, Laryngoscopie, Operative room, Intensive Care Unit, Emergency department