Accuracy of Bedside Upper Airway Ultrasonography versus Standard Auscultation for assuring the location of Endotracheal Tube after tracheal intubation

INTERVENTION: Group I,tracheal intubation: controlled by Quantitative Waveform Capnography Group II tracheal intubation by bedside upper airway ultrasonography Group III tracheal intubation by standard auscultation CONDITION: ; tracheal intubation tracheal intubation PRIMARY OUTCOME: 1. The diagnosis of ETT position; tracheal or esophageal 2. The accuracy of diagnosis using either SA standard auscultatory method or UA‐US in comparison to WC. 3. time consumed till approaching the diagnosis SECONDARY OUTCOME: time consumed till approaching the diagnosis and recording blood pressure and heart rate readings and O2 saturation immediately, 5‐min and 15‐min after intubation. INCLUSION CRITERIA: adult patients of ASA grade I and II and were assigned for general anesthesia with endotracheal intubation