Comparison of Skin to Epiglottis Distance (DSE) in Obese and Non-Obese Patients Using Ultrasonography as A Predictor for Difficult Intubation.

Abstract

Introduction: Airway ultrasound is simple, non-invasive technique that can show us the structure of upper airway from uvula to glottis. Obesity is considered as risk of difficult intubation.
Aim: To find a correlation between ultrasonography measured distance from skin to epiglottis at the level of vocal cords with Cormack Lehane grading in obese and non obese patients.
Objective: Use of skin to epiglottis as predictor of difficult intubation in patients with Body mass index (BMI>25).
Material and Methods: The study was analytical, prospective and cross-sectional study done for 6 months. Institute ethics committee and CTRI registration was done before starting the study. As per convenient sampling sample size 30 patients were allocated in each group. Ultrasonographic measurements was obtained using ultrasound system with linear transducer. Ultrasonographic distance was measured from skin to epiglottis. The patient was then induced and intubated by senior anesthesiologists using Macintosh blade. Cormack Lehane grade noted. Other parameters like number of attempts at intubation, use of alternative approach for difficult intubation or inability to secure the airway were noted.
Result: Ultrasonographic measurement of skin to epiglottis distance at the level of vocal cords ranged from 1.7 to 2.3 cm in non obese patients with mean of 2.02 cm. Distance ranged from 2.3 to2.9 cm in obese patient with mean of 2.68cm. The incidence of difficult laryngoscopy was 10% in non obese patients and 43.3% in obese group. Conclusion: Our study concludes that skin to epiglottis distance of >2.6cm is a risk factor for difficult intubation. This study also proves that this distance has significance only in obese patients.