Prevalence of Difficult endotracheal intubation with clinical screening tests and ultrasonographic measurement of anterior neck soft tissue and to assess the Correlation between two modalities for prediction of difficult endotracheal intubation.

Prediction of difficult intubation through evaluation of the airway is very important in the practice of anaesthesia. There are several clinical predictors for assessing difficult airways. However due to the low reliability of traditional protocols, algorithms and combinations of screening tools, the rate of difficult laryngoscopy and tracheal intubation remains at 1.5–13 per cent for the identification of potentially difficult airways. An unexpectedly difficult airway is even a terrible nightmare for an experienced anaesthesiologist, as it can cause morbidity and mortality associated with anaesthesia that threaten life. The aetiology of difficult airways is multifaceted and should require detailed clinical history and physical examination. However, most clinical predictors have low sensitivity and moderate specificity. The prevalence of difficult/invalid intubations in the general population is low, and the positive prediction value (PPV) is therefore also low. Although there are several multivariate scoring systems that increase the PPV compared to single tests, prediction scores remain low and many failures are not expected to occur as all airway management techniques can fail. Thus, any tool that improves airway assessment will be extremely valuable for the safe practice of anaesthesia. Though X-ray, Computerised tomography (CT) scan and Magnetic Resonance Imaging (MRI) have been used to study airway and predict difficult intubation, their size, radiation risk and cost limits their routine use. With the improvement of the visualization of airways structures, more studies have focused on airway structure and function. the Ultrasonography (US) can reliably visualize all structures visualized by CT and that  the parameters of the infra-hyoid airway structure measured by ultrasound are well compatible with the parameters measured by CT. The present study aimed to assess the utility of ultrasonographic measurements of anterior soft tissue neck thickness at the level of vocal cords, thyroid isthmus, and sternal notch in determining difficult endotracheal intubation. We will examine the correlation of clinical screening tests, ultrasonic measurements, and laryngoscopic view (Cormack Lehane grade) to distinguish between easy and difficult endotracheal intubation. With this study  i would like to estimate the Prevalence of difficult endotracheal intubation and Is there any correlation between clinical screening tests for airway and ultrasonographic measurement of anterior neck soft tissue for prediction of difficult endotracheal intubation. My primary hypothesis is there is no difference between clinical screening tests and ultrasonographic measurements to establish the Prevalence of difficult endotracheal  intubation.