To compare upper airway ultrasonography concerning end-tidal capnography in the rapid confirmation of endotracheal tube placement in patients requiring intubation for elective surgeries under general anesthesia and to determine the sensitivity, specificity, positive predictive value and negative predictive value of upper airway ultrasonography - Merlin, J. bridgit; Kammukutti, S. (International Archives of Integrated Medicine, 2021)