Intubation Confirmation
Endotracheal intubation is an important procedure for managing the airway of a patient who is suffering respiratory failure or who requires airway protection due to altered mental status. In properly trained hands the procedure is relatively simple in the majority of patients, but it can be extremely difficult in a small percentage of patients with anatomic anomalies. Furthermore, if intubation is either unsuccessful or if the endotracheal tube is placed in the esophagus and not detected in a timely fashion, the procedure can result in permanent brain damage or death.
Clinical judgment is routinely employed to detect these misplaced tubes, but it is well established in the literature that clinical judgment is flawed. For this reason, secondary methods (to supplement clinical judgment) to establish proper endotracheal tube (ETT) placement are the established standard of care. The most used method is end tidal carbon dioxide detection (ETCO2). ETCO2 relies on the exhalation of CO2 from the lung to determine ETT location: If the endotracheal tube is properly placed in the trachea CO2 levels are detected by the device; If the ETT is improperly placed into the esophagus, no CO2 will be measured. However, the technology is not perfect. In some situations such as extreme hypoperfusion and cardiac arrest there is insufficient exhalation of CO2 and the ETCO2 detector may fail to measure CO2 even if the ETT is in the trachea.
Another complementary method of detecting ETT location is the esophageal detector device – which relies on anatomic differences between the esophagus and the trachea rather than physiologic CO2 detection. By applying suction to the endotracheal tube the esophageal detector device determines the ETT location. If the ETT is in the trachea, the device fills with air that is aspirated from the trachea. If the ETT is in the esophagus, the device will not aspirate any air. This anatomic difference is maintained even in low perfusion and cardiac arrest situations.
By carefully combining clinical judgment with ETCO2 and esophageal detector device technology well trained clinicians should always be able to distinguish an esophageal intubation from a tracheal intubation, increasing safety of this procedure and reducing potential liability that results from a missed esophageal intubation.