Esophageal Intubation

Description

Esophageal intubation may occur during attempted tracheal intubation due to the anatomical proximity of the two structures. Possible consequences of inadvertent tube placement or dislodgement into the esophagus during repositioning include:
- Injury to the esophagus
- Gastric insufflation and aspiration
- Hypoxia
- Cardiovascular collapse
Intended "esophageal intubations" with orogastric tubes, nasogastric tubes, and esophageal temperature probes can also cause esophageal injury and contribute to injury claims in anesthesiology.

Epidemiology

Incidence

In non-operative emergency settings, esophageal intubation has been reported at rates from 1.3% to more than 5%, varying by study location.
Actual incidence may be higher as many esophageal intubations are recognized immediately and corrected without report.

Morbidity/Mortality

Data from the American Society of Anesthesiologists (ASA) Closed Claims Project Database indicated esophageal intubation as the cause of 13% of claims originating from a respiratory damaging event and resulting in death or permanent brain damage.
Previous analysis reported esophageal perforation as the result in 90% of all esophageal injury claims.
Esophageal perforation may result in infection, pneumomediastinum, pleuritis, or abscess formation. Symptoms may progress to shock or death if untreated. Treatment is usually surgical. If treated within 24 hours, complete recovery is expected. If treatment is delayed, mortality up to 50% can be expected.

Etiology/Risk Factors

Setting:
- First responders to trauma scene outside hospital
- Emergency rooms
- Hospital setting outside the OR (floor codes/emergency airway)
Difficult airway
Head repositioning
Transport
Age >60 years
Female gender
Anatomical anomalies (tracheoesophageal fistula, laryngeal mass)

Physiology/Pathophysiology

Esophageal damage: The normal trachea with its cartilaginous rings is held open for the passage of endotracheal tubes (ETT). The esophagus collapses on itself, and passage of the ETT (even without a stylette) can tear mucosa causing a perforation.
Risk of aspiration increases. Attempts at ventilating after esophageal intubation will insufflate the stomach. The increase in intragastric pressures significantly increases the possibility of aspiration into the pulmonary tree.
Hypoxemia resulting from ineffective oxygenation causes vasodilation, with increases in heart rate and cardiac output as compensatory mechanisms to maximize perfusion.
Cardiovascular collapse can result. Maximal vasodilation will cause hypotension with resultant reductions in perfusion, precipitating shock, and cardiovascular collapse.

Prevantative Measures

Patient positioning: Obtain optimal sniffing position or other appropriate positioning as indicated by body habitus and comorbidities.
Appropriate monitors: Ensure that the pulse oximetry is on the patient prior to intubation. Always have CO₂ detection device available.
Visualization of glottis at intubation: Try to visualize the ET tube passing through the vocal cords.
Have a video or optical intubating device available if a challenging airway is suspected.
Follow the ASA Difficult Airway Algorithm in cases where a difficult airway is encountered, rather than force a blind intubation.

Diagnosis ⬆ ⬇

Lung auscultation lacks recognizable breath sounds bilaterally and in all fields.
Stomach auscultation can reveal gurgling sounds while bag ventilation is attempted.
Fiberoptic bronchoscopy remains the definitive gold standard to confirm tube placement. Insertion through the ETT should demonstrate visible tracheal rings and muscular bands.
Real-time ultrasound: The transverse view at the level of the thyroid may be used to detect intubation of the esophagus. The limiting factor may be the experience of the sonograph operator as this technique is not widely used yet.
Esophageal detection devices (EDD) are attached to the ETT after intubation and apply vacuum to the tube. Resistance indicates a collapsed lumen around the ETT, suggesting esophageal intubation.
CXR: Because the proximal airway overlies the esophagus, esophageal intubation may not be distinguished from tracheal intubation. In addition to not necessarily being conclusive, results are also slow to obtain. Thus, it is not recommended as a first choice to confirm tracheal intubation. It is, however, useful for determining endotracheal position of the ETT (distance from the carina) after confirmed tracheal intubation by other means.
Chest and/or abdominal pain may be seen postoperatively secondary to injury from esophageal intubation from ETT, orogastric tubes, nasogastric tubes, and temperature probes.

Monitors

End-tidal CO₂ tracing: May show no tracing or a reduced tracing that diminishes over time. Bag-mask ventilation prior to intubation may result in stomach insufflation with a gas mixture containing exhaled CO₂. Also may be confounding in the setting of dead space ventilation (cardiac arrest, pulmonary embolism).
Pulse oximetry: After esophageal intubation normal oximetric values may be displayed if pre-intubation oxygenation was sufficient. However, without pulmonary ventilation, residual oxygen is taken up by pulmonary capillary blood flow and over time will be exhausted. As the PaO₂ begins to fall, the saturation, and thus the pulse oximeter, will begin to decrease. The time to decrease depends on the residual capacity of the patient and effectiveness of pre-oxygenation. Pulse oximetry may also be less reliable in states of low cardiac output or cardiac arrest.
Colorimetric end-tidal CO₂ detectors are devices commonly used in settings outside of the OR (e.g., emergency response teams, floor codes/emergency airways, etc.). They allow for inline rapid detection of CO₂ while ventilating the patient. They can give false-negatives in the setting of cardiac collapse (code situation with reduced cardiac output) or false-positives (gastric insufflation with mask ventilation).

Differential Diagnosis

It is critical to immediately recognize ETT misplacement in the esophagus. Esophageal intubation often needs to be distinguished from other ETT malpositioning or the inability to ventilate the lungs after intubation. The differential diagnosis includes:

Pharyngeal intubation with the tip of the ETT at level of arytenoid cartilages or above
Selective endobronchial intubation
Herniation of the ETT cuff occluding the tip of the tube and preventing ventilation
Severe bronchospasm causing inability to ventilate and decreased CO₂ return
Low cardiac output states and pulmonary embolism (conditions that may present with very low ETCO₂ readings)

Treatment ⬆ ⬇

Prompt diagnosis of the situation is critical.
Suctioning through the ETT while it is still in the esophagus has been suggested.
Removal of the ETT and replacement in the appropriate position must be performed promptly. A change in airway management technique and/or provider is possibly indicated at this time.
Supportive measures for ventilation (bag-mask ventilation) and perfusion (pressors if needed) must be provided prior to reintubation as needed. Consider administration of additional anesthetic agents, as appropriate.
Esophageal perforation requires surgical consultation and possible repair.

Follow-Up ⬆ ⬇

Any repositioning or airway manipulation after tracheal intubation requires re-examination and assessment of vital signs and monitors to ensure ETT is still in the trachea and not displaced into the esophagus.
After recognized intubation of the esophagus, patient must be monitored for chest or abdominal pain as those are the first presenting symptoms of esophageal perforation. Fever, tachycardia, dyspnea, and tachypnea are symptoms of progression after esophageal perforation. Surgical consult should be obtained immediately if injury is suspected.

Closed Claims Data

As mentioned above, an analysis of data from the ASA Closed Claims Project (years 1986–2000) reported esophageal intubation to be responsible for 13% of events associated with death or permanent brain damage.
Analysis of previous claims (1961–1996) showed esophageal injuries to account for 18% of airway injuries during anesthesia, with the highest mortality (19%) and the largest monetary settlement (median payment $138,975) when compared to all other airway injuries of the same claims period.

References ⬆ ⬇

Cheny FW , Posner KL , Lee LA , et al. Trends in anesthesia-related death and brain damage. Anesthesiology. 2006;105:1081–1086.
Domino KB , Posner KL , Caplan RA , et al. Airway injury during anesthesia. Anesthesiology. 1999;91:1703–1711.
Martin LD , Mhyre JM , Shanks AM , et al. 3,423 Emergency tracheal intubations at a university hospital: Airway outcomes and complications. Anesthesiology. 2011;114:42–48.

Additional Reading ⬆ ⬇

See Also (Topic, Algorithm, Electronic Media Element)

Laryngoscopy Positioning
End-Tidal Carbon Dioxide

Clinical Pearls ⬆ ⬇

Confirmation of ETT placement should include physical exam as well as monitors; reliance on only one method may delay diagnosis.
Maintain a high index of suspicion if the airway was difficult with a poor view. Consider visual confirmation (fiberoptic bronchoscope, video-assisted laryngoscopy) as quickly as possible if you are unsure or the patient shows clinical signs of inappropriate ventilation and oxygenation. DON’T wait for oxygen desaturation to verify.
Notify the surgical team of any suspected complications and watch for possible esophageal perforation.
Be aware of other situations that may involve "esophageal intubations" in the perioperative period and their associated risks. Positioning of the following devices may result in injury or perforation, particularly in patients with esophageal hernias or diverticulitis:
- Esophageal temperature probe
- Orogastric or nasogastric tubes
- Transesophageal Doppler and transesophageal echocardiographic probes
Although a rare occurrence, esophageal intubation while accessing the trachea for intubation through a tracheostomy opening or a stoma has been described. It is a possibility to consider in the case of an undiagnosed tracheoesophageal fistula through which the ETT, even though correctly inserted through the tracheal opening, may proceed into the esophagus.

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Basics ⬇