Comparison of Various Measures for Anticipating Difficult Laryngoscopy

Study Overview
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Brief Summary
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Demographic features and eight diagnostic variables were evaluated for difficult laryngoscopy (DL) predictivity. These were retrognathia, presence of buck teeth, modified Mallampati test (MMT), upper lip bite test (ULBT), sternomental distance (SMD), interincisor distance (IID), thyromental distance, and neck circumference. DL was identified by Grade III-IV view during laryngoscopy according to the Cormack-Lehane (CL) classification.

Detailed Description
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Creating a regression model among selected bedside tests for predicting difficult laryngoscopy )defined as Grade III or IV view during laryngoscopy according to Cormack-Lehane classification) is the primary objective. Recruiting of 145 ASA I-II adult patients who would have an elective surgery under general anesthesia were planned. Criteria for exclusion were: a history of craniofacial surgery or restriction of cervical mobility, edentulous patients, pregnant women, patients who did not have a proper mouth opening (< 3 cm), and those who might require awake intubation or rapid sequence induction, cancellation of the surgery or change in the anesthetic strategy. The selected tests and clinical situations were: The presence of retrognathia (reduced temporomandibular joint-incisor distance) Buck teeth Modified Mallampati test (MMT) in the sitting position without phonation. A scale ranging between 1 and 4 points is used and scores of 3 or 4 are considered as predictors of DL. Upper lip bite test (ULBT) performed in a neutral position. ULBT is graded as 1-3 according to the extension ability of lower incisors. Sternomental distance - The distance between the mentum and upper border of the manubrium sterni when the head is fully extended and the mouth is closed. Thyromental distance (TMD) - The distance between mentum and the thyroid notch when the head is fully extended. Interincisor distance (IID) - The distance between upper and lower incisors when the mouth is fully opened. Neck circumference (NC) - It was measured at the level of the cricoid cartilage, perpendicular to the cervical axis. The patients are premedicated with 0.03 mg/kg and oxygenated with the help of a bag-mask. Anesthesia is induced by consequent administration of 2 mcg/kg fentanyl, 1 mg/kg lidocaine, 2 mg/kg propofol, and 0.7 mg/kg rocuronium bromide thereafter. Two minutes after induction, the laryngoscopy is performed

Official Title
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Comparison of Various Measures for Anticipating Difficult Laryngoscopy in Turkish Population: An Observational Study

Conditions
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Difficult Laryngoscopy

Intervention / Treatment
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* Diagnostic Test: Laryngoscopy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA I-II Candidate for elective surgery under general anesthesia Exclusion Criteria: History of craniofacial surgery or restriction of cervical mobility, Edentulous patients Pregnancy Patients who do not have a proper mouth opening (< 3 cm) Patients who might require awake intubation or rapid sequence induction.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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 |
| --- | --- |
| Group DL (+)<br>Grade III or IV laryngeal view according to Cormack-Lehane classification | Diagnostic Test: Laryngoscopy<br>* The laryngoscopy is performed with the help of an appropriate size Macintosh blade. The patient's head is held in the sniffing position. External manipulation is not used for improving the view in this investigation.<br>|
| Group DL (-)<br>Grade I or II laryngeal view according to Cormack-Lehane classification | Diagnostic Test: Laryngoscopy<br>* The laryngoscopy is performed with the help of an appropriate size Macintosh blade. The patient's head is held in the sniffing position. External manipulation is not used for improving the view in this investigation.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difficult laryngoscopy | Grade III or IV laryngeal view before endotracheal intubation | Up to two weeks after preoperative examination | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cephalometry, Endotracheal intubation, Ethnicity, Laryngoscopy