Role of Airwayultrasound in Predicting Difficult Endotracheal Intubation in Patients Undergoing General Anesthesia

Study Overview
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Brief Summary
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Unpredictable difficult endotracheal intubation remains a challenge especially if difficult ventilation occurs. Difficult intubation is associated with many severe fatal complications including air way trauma, laryngospasm, hypoxemia, arrhythmias and potential cardiac arrest. Therefore, preoperative evaluation and prediction of potential difficult airway is very important. Several screening tests are used in clinical practice to identify patients at the risk of difficult airway. Despite their accuracy and beneﬁt, a small number of patients classiﬁed to an easy airway may still present an unexpected difficulty. Predicting a difficult airway is not at all an easy task for all patients . Incidence of difficult airway and difficult intubation varies from 5% to 22% with important implications for clinical practice and patients' outcomes . There are multiple scores used for airway assesment ,the commonest one is LEMON score. LEMON is an airway assessment score that measures factors associated with difficult intubation such as obesity, head and neck movement, jaw movement , receding mandible, long upper incisors, Mallampatti scores, maxillary incisor characteristics, decreased mouth opening ,shorten thyromental distance and short neck . Diagnostic criteria for LEMON scoring system : L- Look. E- Evaluation using the 3-3-2 rule. M- Mallampati. O- Obstruction. N- Neck mobility. Ultrasound (US) imaging technique is simple, portable, noninvasive tool helpful for airway assessment and management. In the last few years, there have been some reports that described various roles of US imaging in airway management. It helps in rapid assessment of the airway anatomy, not only in operation theatre but also in the intensive care unit and emergency department. Various clinical applications of US imaging of the upper airway include identification of endotracheal tube (ETT) placement, guidance of percutaneous tracheostomy and cricothyroidotomy, detection of subglottic stenosis, prediction of difficult intubation and post-extubation stridor, prediction of paediatric ETT and double-lumen tube (DLT) size. Recently there are researches about airway assesment by ultrasound. Several airway assesment indicies are used to help in prediction of difficult endotracheal intubation. The most commonly used indices are distance from skin to epiglottis, distance from skin to vocal cord level, and distance from skin to hyoid bone.

Official Title
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Role of Airwayultrasound in Predicting Difficult Endotracheal Intubation in Patients Undergoing General Anesthesia

Conditions
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Predict Diificult Endotracheal Intubation

Intervention / Treatment
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* Device: assesment of difficult endotracheal intubation by airway ultrasound


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients from 18- 50 yrs old Patients who require endotracheal intubation for surgery under general anesthesia. Exclusion Criteria: Patients with history of previous difficult intubation. Neck deformity such as swelling , scar ,etc.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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

| Intervention/Treatment |
| --- |
|Device: assesment of difficult endotracheal intubation by airway ultrasound|preoperative assesment of airway by ultrasound to predict difficult endotracheal intubation in patients undergoing general anesthsia|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ultasound airway assesment index ..distance from skin to epiglottis | to measure distance from skin to epiglottis | 6 months | 
| ultasound airway assesment index ..distance from skin to hyoid bone | to measure distance from skin to hyoid bone | 6 months | 
| ultasound airway assesment index ..distance from skin to vocal cord | to measure distance from skin to vocal cord | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| airway ultrasound and LEMON score | compare between LEMON score and airway ultrasound in predicting difficult airway. | 6 months |