PMC6733966_01
Placement of a Philips L12-4 vascular probe on the lateral neck allows for visualization of the esophagus.
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Using the probe position shown in Fig. 1, the esophagus was identified.
Images obtained during bag mask ventilation. (A) The dotted line outlines the air signal seen in the esophagus during a bag-delivered breath. (B) The dotted line outlines the esophagus between breaths. There is no air signal. (C) The dotted line outlines the esophagus with a small air signal during cricoid pressure. (D) The dotted line outlines the narrow air signal seen in the esophagus during ultrasound probe pressure.
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During bag-mask ventilation, an air signal was visualized in the esophagus with each bag-delivered breath (Fig. 2A). The air signal disappeared between breaths (Fig. 2B). During cricoid pressure, the air signal in the esophagus became attenuated, but not eliminated (Fig. 2C). This maneuver virtually eliminated esophageal air (Fig. 2D).