Three-dimensional Craniofacial Phenotyping of Patients With Difficult Airway

Study Overview
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Brief Summary
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The purpose of this study is to identify differences in craniofacial morphology and tongue size between patients who have a history of difficult airway management and a control group of patients who had an uneventful airway management during induction of general anesthesia. In this study the investigators want to validate the hypothesis that there are craniofacial phenotypic differences between patients who have a history of difficult airway management and a control group of patients who have had an uneventful airway management during the induction of general anesthesia.

Detailed Description
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Difficult airway management is one of the most challenging tasks for anesthesiologists. Recent data from the American Society of Anesthesiologists (ASA) Management Closed Claims Project [1] show that the percentage of claims resulting from adverse respiratory events, though on the decline (42% in the 1980s to 32% in the 1990s), continue to constitute a large source of morbidity and mortality in anesthetized patients. In 2005, a closed claims analysis of trends in anesthesia-related death and brain damage between 1975 and 2000 showed that out of all respiratory events (n=503) responsible for death and brain damage, difficult endotracheal intubation (n=115), inadequate oxygenation (n=111) and inadvertent esophageal intubation (n=66) were the top three causes [2].

Official Title
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Three -Dimensional (3-D) Craniofacial Phenotyping of Patients With Difficult Airway

Conditions
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Failed or Difficult Intubation

Intervention / Treatment
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* Procedure: 3D Laser Scanning of the Head
* Procedure: Measurements and Digital Photo's of the head, neck and Mouth
* Procedure: Ultrasound Exam of the Tongue
* Procedure: 3D Laser Scanning of the Head
* Procedure: Measurements and Digital Photo's of the head, neck and Mouth
* Procedure: Ultrasound Exam of the Tongue


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients that had undergone or will undergo a surgery under general anesthesia . Exclusion Criteria: known history of syndromal craniofacial abnormalities (e.g. Down syndrome) previous craniofacial surgery excessive facial hair which significantly obscure facial landmarks cervical spine fractures tracheostomy tube patients who are unable to give consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Difficult intubation patients<br>patients who were difficult to intubate during previous anesthetics provided by the staff anesthesiologists. | Procedure: 3D Laser Scanning of the Head<br>* Five scans will be collected from different angles, each scan taking approximately 3 seconds. Each scan will consist of a thin beam of light flashing of your head.<br>* Other names: 3D digitizing Konica Minolta 3D laser scanner;Procedure: Measurements and Digital Photo's of the head, neck and Mouth<br>* Prior to the photographs, certain bone and soft tissue areas such as angle of the jaw, neck and chin will be gently touched and marked with self-adhesive paper stickers. Using the self-adhesive paper stickers and a measuring tape, we obtain measurements of your head and neck.Digital Photographs of your Mouth - You will be also asked to open your mouth and a digital photograph of the back of the mouth will be taken, as well as, pictures of the front and side of the head and neck.<br>* Other names: 3D digitizing konica minolta 3D laser scanner;Procedure: Ultrasound Exam of the Tongue<br>* The ultrasound study of the tongue will be performed after the series of laser scans. You will be examined in the sitting position. A small,handheld, curved ultrasound instrument will be placed under the chin to take images of the tongue. This exam should take less than a minute.<br>* Other names: General Electric Total Access ultrasound;|
| Placebo Comparator: Control<br>The control group will consist of patients with the easy laryngoscopy and intubation, recruited prospectively. | Procedure: 3D Laser Scanning of the Head<br>* Five scans will be collected from different angles, each scan taking approximately 3 seconds. Each scan will consist of a thin beam of light flashing of your head.<br>* Other names: Konica Minolta 3D Digitizing Konica Minolta 3D laser scanner;Procedure: Measurements and Digital Photo's of the head, neck and Mouth<br>* Prior to the photographs, certain bone and soft tissue areas such as angle of the jaw, neck and chin will be gently touched and marked with self-adhesive paper stickers. Using the self-adhesive paper stickers and a measuring tape, we obtain measurements of your head and neck. You will be also asked to open your mouth and a digital photograph of the back of the mouth will be taken, as well as, pictures of the front and side of the head and neck.<br>* Other names: General Electric Total access ultrasound;Procedure: Ultrasound Exam of the Tongue<br>* The ultrasound study of the tongue will be performed after the series of laser scans. You will be examined in the sitting position. A small,handheld, curved ultrasound instrument will be placed under the chin to take images of the tongue. This exam should take less than a minute<br>* Other names: General Electric Total access ultrasound;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Hyomental Distance Ratio | A curved low-frequency transducer and a Flex focul 400 ultrasound system were used to visualize the tongue and shadows of the hyoid bone and mandible. Midsagittal and coronal/transverse scans from the ultrasound were analyzed using ImageJ. The hyomental distances in the neutral and heal-extended positions were measured from the upper border of the hyoid bone to the lower border of the mentum. The ratio is defined as the ratio of the hyomental distance at the extreme of head extension to that in the neutral position. | end of study approximately one year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Tongue Volume | The midsagittal scans were used to measure the cross-sectional area of the tongue. Transverse scans obtained in the midsection of the tongue (at the glossal end of the genioglossus muscle) provided a measure of the tongue width, which was measured between the most distant points on its upper surface. The tongue volume was derived from the multiplication of the midsagittal cross-sectional area by the tongue width. | end of study approximately one year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Difficult airway management, anesthesia, difficult intubation