When no means of CO₂ detection is available or CO₂ detection is unreliable (ie, cardiac arrest), the esophageal bulb detector device can provide a means to ascertain whether the ETT is in the airway or in the esophagus for patients older than 1 year of age (Fig. 6-3A, B). As the trachea (and bronchi) possesses cartilaginous walls and contains a column of air, a collapsed bulb device attached to the proximal end of an ETT that is in the airway should suction air and be rapidly reinflated. On the other hand, if an ETT is placed in the esophagus, the deflated bulb device remains collapsed because the negative pressure generated by the device apposes the esophageal walls.⁴

Physical examination should always be performed in conjunction with the above methods for the confirmation of an ETT placement (Figs. 6-4 and 6-5). These include auscultation of chest (which is best carried out in the bilateral axillae) (<A onclick="if (window.scroll_to_id) { scroll_to_id(event,'F5-6'); return false; }" onmouseover="window.status=this.title; returnccur.² Even with correct ETT placement, exhaled CO₂ will be near 0 in patients with severe bronchospasm, cardiac arrest, or markedly diminished pulmonary blood flow despite correct placement of the ETT. Other confirmation methods are preferred in these situations. It should be noted that, during esophageal intubation, CO₂ can be detected from gases present in the stomach or esophagus. Detection of such CO₂ usually rapidly diminishes over four to five attempts at ventilation. If end-tidal CO) { scroll_to_id(event,’R5-6′); return false; }” xpath=”/CT{06b9ee1beed59419a70a2b44a923a9a919e6aa0a05fb19eaab5f1460e4f23815bb89cb78eb97be4173394fa239e8b930}/ID(R5-6)” title=”5″ onmouseover=”window.status=this.title; return true;” onmouseout=”window.status=”; return true;”>⁵ None of these methods is entirely reliable, but in combination with CO₂ detection (or the esophageal bulb detector, if CO₂