Indirect Laryngoscopy and Ultrasonography in Prediction of Difficult Airway

Study Overview
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Brief Summary
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This study was designed to assess the success of indirect laryngoscopy and ultrasonographic measurements in the prediction of difficult airway. All patients were examined by indirect laryngoscopy and ultrasonography preoperatively and the predictive values for difficult airway of these methods were compared.

Detailed Description
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Difficult airway is a condition that increases the patient's vital risk and leaves the anesthesia and surgical team in a difficult position. Failure to perform an adequate preoperative evaluation may result in the team being unprepared. Therefore, various methods have been investigated in the prediction of difficult airway from past to present. With the development of technology, imaging methods have become routine applications in clinical use. Ultrasonography and indirect laryngoscopy have been shown to be used in predicting difficult airway in the literature, but there is no study showing which is a better predictor.

Official Title
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The Role of Indirect Laryngoscopy, Clinical and Ultrasonographic Assessment in Prediction of Difficult Airway

Conditions
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Difficult Intubation

Intervention / Treatment
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* Diagnostic Test: Ultrasonographic upper airway measurements


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject is operated in ear, nose and throat department. Subject over the age of 18. Subject giving consent to participate in the study. Exclusion Criteria: Subject under the age of 18 Subject with a history of radiotherapy in the head and neck region, Subject with facial deformity, Subject whose neck movements have been restricted by previous trauma or surgery, Subject has laryngeal disease Previously operated subject with known airway assessment Morbidly obese subject with BMI> 40

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Study group<br>Patients over the age of 18 who underwent surgery in the ear, nose and throat department. | Diagnostic Test: Ultrasonographic upper airway measurements<br>* Ultrasonographic upper airway measurements: Epiglottis-skin distance, Hyoid bone-skin distance, Anterior commissure-skin distance and Thickness of tounge root. Indirect Laryngoscopy: Grading of laryngoscopic view (I=Visible anterior commissure and vocal cords, II= visible posterior part of vocal cords and posterior commissure, III= Visible posterior commissure and epiglottis, IV= Visible only epiglottis tip and posterior pharyngeal wall)<br>* Other names: Indirect Laryngoscopy;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cormack-Lehane Classification | The anesthesiologist, who is blind about indirect laryngoscopy findings and ultrasonographic airway measurements, performs intubation and evaluates the laryngeal view. | Three minutes after induction of anesthesia. | 
| Epiglottis skin distance in centimeters. | The anesthesiologist, who is blind about indirect laryngoscopy findings and is experienced user of ultrasonography, measures epiglottis to skin distance. | Five minutes before induction of anesthesia. | 
| Hyoid bone-skin distance in centimeters. | The anesthesiologist, who is blind about indirect laryngoscopy findings and is experienced user of ultrasonography, measures hyoid bone to skin distance. | Five minutes before induction of anesthesia. | 
| Anterior commissure-skin distance in centimeters. | The anesthesiologist, who is blind about indirect laryngoscopy findings and is experienced user of ultrasonography, measures anterior commissure to skin distance. | Five minutes before induction of anesthesia. | 
| Thickness of tongue root in centimeters. | The anesthesiologist, who is blind about indirect laryngoscopy findings and is experienced user of ultrasonography, measures thickness of tongue root. | Five minutes before induction of anesthesia. | 
| Indirect Laryngoscopic Grade | The otolaryngologist,who is blind about ultrasonographic airway measurements of patients, performs indirect laryngoscopy and evaluates the laryngeal view. | The day before surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body mass index (BMI) | Weight and height will be combined to report BMI in kg/m^2.Evaluated by the anesthesiologist who performs intubation. | The day before surgery | 
| Thyromental distance in centimeters | The distance between thyroid notch and mentum. Evaluated by the anesthesiologist who performs intubation. | The day before surgery | 
| Sternomental distance in centimeters. | The distance between sternal notch and mentum. Evaluated by the anesthesiologist who performs intubation. | The day before surgery | 
| Neck circumference in centimeters. | Evaluated by the anesthesiologist who performs intubation. | The day before surgery | 
| Mallampati classification | Evaluated by the anesthesiologist who performs intubation. | The day before surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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airway, laryngoscopy, ultrasonography