The purpose of this paper is to identify the medical literature that pertains to verification of endotracheal tube placement in the emergency department and out-of-hospital settings.

Discussion

1. Improper placement of endotracheal tubes into the esophagus ("esophageal intubation?, can remain undetected despite physical examination, chest radiography, and pulse oximetry methods that seem to confirm proper tube placement. For this reason, an additional method should be used to verify correct initial placement of the endotracheal tube.
   
   
2. No single technique used for confirmation of endotracheal tube placement has been proven to be 100% accurate. While visualization of the endotracheal tube passing through the vocal cords represents the primary method for assessing initial endotracheal tube placement, objective confirmation of proper placement is necessary.
   
   
3. Methods of endotracheal tube position assessment include repeat direct laryngoscopy, qualitative and quantitative end-tidal carbon dioxide detection, esophageal detector devices, and more recently, ultrasound utilization and transthoracic impedance.
   
   
4. End-tidal carbon dioxide detection, using either qualitative or quantitative methods, approaches 100% sensitivity and specificity in the patient with spontaneous circulation.
   
   
5. Assessment of endotracheal tube position by detection of exhaled carbon dioxide is less reliable in patients with poor circulatory perfusion conditions, particularly cardiac arrest patients. In these patients, delivery of carbon dioxide to the lungs may be insufficient to produce a reliable confirmation of tube placement. Essentially all reported false negative (endotracheal tube in the trachea with no detection of exhaled carbon dioxide) events of carbon dioxide detection in intubated patients have been observed in the setting of a low perfusion state, including cardiac arrest patients or those in extensive pulmonary edema. In these patients, an alternative method of confirming endotracheal tube placement may be required.
   
   
6. Esophageal detector devices have some utility as a technique for endotracheal tube position assessment. While these devices are often inexpensive and have generally demonstrated good utility in detecting esophageal intubations, inaccurate findings can result in obese patients, those with a large amount of air in the esophagus or stomach, and in patients with copious pulmonary secretions. In addition, esophageal detector devices do not provide the possibility for ongoing assessment of continued proper tube location.
   
7. Ultrasound imaging and transthoracic impedance methods offer potential as techniques that may prove to be helpful as adjuncts to detect and monitor the proper location of endotracheal tubes. The evidence is currently insufficient to endorse widespread implementation of these technologies for this purpose.
   
   
8. Endotracheal tubes that are initially placed into the trachea may be dislodged during patient movement or patient transport. Given the frequency of movements and transport, particularly in the emergency setting, tube position should be frequently reassessed. Continuous endotracheal tube monitoring is recommended to assure prompt detection of endotracheal tube dislodgement from the trachea. If equipment to continuously monitor endotracheal tube position is not available, at a minimum, endotracheal tube placement should be reconfirmed promptly if the patient's condition deteriorates.

Summary

Verification of proper endotracheal tube location should be performed for all patients at the time of the initial intubation effort(s). Chest and abdomen auscultation, pulse oximetry, chest radiography and esophageal detector devices are not comparable to end-tidal carbon dioxide assessment for the verification of endotracheal tube placement in patients who have adequate tissue perfusion. Endotracheal tube location re-assessment should be performed whenever patient movement, clinical interventions, or clinical conditions suggest the possibility of tracheal tube dislodgement.

Extracted from American College of Emergency Physicians