Background and Need for Study

Difficult airway during anesthesia increases the risk of complications.

Traditional assessment methods like Mallampati score and thyromental distance are not very accurate.

Ultrasound provides a safe and real-time method to examine the airway.

There is a need to validate ultrasound-based measurements for predicting difficult laryngoscopy 

Objectives

Primary Objective

To assess the relationship between ultrasound measurements and difficult laryngoscopy based on Cormack Lehane grading 

Secondary Objectives

To compare each ultrasound parameter individually and in combination

To find the best cut off values for prediction

To compare ultrasound results with traditional clinical airway tests

Methodology

Study Type Prospective observational clinical study

Duration One year and six months from May 2025 to November 2026

Sample Size 526 adult patients aged 18 to 65 undergoing elective surgery under general anesthesia

Inclusion ASA Class I to III, normal mouth opening and neck mobility

Exclusion Facial deformity, neck pathology, morbid obesity, pregnancy, previous airway surgery

Preoperative ultrasound measurements include

Tongue thickness

Skin to epiglottis distance

Hyomental distance in neutral and extended positions

Laryngoscopy performed by a separate anesthesiologist who is unaware of the ultrasound findings

Analysis

Statistical tools include regression analysis and ROC curve

Main outcome is correlation of ultrasound findings with difficulty in laryngoscopy

Additional outcomes include accuracy of each parameter and comparison with clinical scores

Importance

If successful this method can help in better preparation for airway management and improve patient safety before anesthesia