Comparison of diagnostic accuracy of ultrasonography against capnography for the confirmation of endotracheal tube placement using saline versus air forcuff inflation in adult patients undergoing surgery under general anaesthesia : A randomised controlled study

Patients will be kept nil per oral in accordance with standard ASA guidelines.The USG

linear probe (6-13 MHz, SonoSite Edge II) will be placed over the suprasternal notch in a

transverse orientation to acquire sono-anatomy of the airway before endotracheal tube

placement. Another qualified anaesthesiologist will perform endotracheal intubation with an

appropriately sized ETT. In group A endotracheal tube cuff will be inflated with air and this

will be observed as a hyperechoic air-mucosal interface with reverberation artifacts (comet

tail) posteriorly and snowstorm sign in ultrasound. In group B ETT cuff will be inflated

with saline and identified as a hypoechoic, oval-shaped structure in ultrasound. Thereafter

the probe will be moved to the left lateral side of trachea to see the “double track sign” for

esophageal intubation . In case of oesophageal intubation, ETT will be removed and

trachea will be reintubated .Following the confirmation of endotracheal tube placement

through ultrasound, the capnography waveform will be observed for seven waveforms to

re-verify the successful endotracheal intubation. Bilateral air entry will be confirmed by

auscultation of the chest before securing the endotracheal tube.

Stopwatch will be used to record the time elapsed between the insertion of the endotracheal

tube (ETT) and the confirmation of correct endotracheal intubation by either ultrasound

(USG).