Archived case 177 · April 1-April 8, 2015
Middle-aged patient transferred from an outside facility following a pulseless electrical activity arrest
What are the most pertinent radiographic findings if any? What is your leading diagnosis?
Radiologic Findings AP portable chest (Figure 1) shows a transcutaneous pacer pad overlying the cardiomediastinal silhouette and epigastric region, a gastroenteric tube extending into the stomach, and an endotracheal tube. An endovascular stent is present in the left axillary-subclavian venous system. The cardiac silhouette is enlarged, as are the pulmonary arteries. The latter is consistent with underlying pulmonary hypertension. There is also marked gaseous distention of the stomach. On closer inspection, the endotracheal follows an oblique rather than vertical course and parallels the indwelling gastroenteric tube. Because of the clinical concern of massive pulmonary embolism causing the PEA arrest, the patient underwent emergent CT Pulmonary Angiography. Contrast-enhanced mediastinal windows (not illustrated) revealed no evidence of pulmonary embolism. Selected axial (Figure 2A-C) (lung windows) demonstrate the esophageal lumen residing directly behind the tracheal air column. The gastroenteric tube appropriately courses down the esophageal lumen. Paralleling the gastroenteric tube is the endotracheal tube with an overinflated balloon cuff. Similar findings are confirmed on the accompanying coronal (Figure 3A) and sagittal (Figure 3B) multiplanar reconstructions. Answer Diagnosis: Esophageal Intubation
Esophageal Intubation
Answer
Diagnosis: Esophageal Intubation
Differential Diagnosis
None
Discussion
Esophageal intubation is a relatively common complication occurring in about 5 out of every 100 intubations (incidence ~5.4%). Early recognition and correction is clinically important to avoid serious patient morbidity and potential mortality. Physical exam and auscultation of breath sounds is often unreliable to confirm airway intubation as air flowing through the esophagus may mimic respiratory airflow. Capnometry is being used with increasing frequency to assess appropriate airway intubation and is fairly reliable but still fails to detect about 3% of esophageal intubations. Capnometry may give a false positive reading (ET tube reportedly in the trachea but actually resides in the esophagus) when expired alveolar gas enters the stomach during ambu-bag-valve-mask ventilation. Alternatively, capnometry may give a false positive reading (ET tube reportedly in the esophagus but resides in the trachea). This most often occurs in the setting of low cardiac output states (e.g., cardiac arrest, hypotension) and or with severe pulmonary disease or acute pulmonary embolism.
Imaging Findings
· Endotracheal tube courses lateral to the tracheal air column or follows an oblique course
· Endotracheal parallels the course of an indwelling enteric tube
· Over-inflated balloon cuff (easier to overinflate and distend the compliant esophagus as opposed to the more rigid trachea)
· Endotracheal tube course below the carina
· Marked gaseous distention of the stomach
· Lateral or oblique radiography is often helpful in problematic cases
Caveat
Although gaseous distention of the stomach may occur following bag-valve mask ventilation and or inadvertent esophageal intubation that was recognized and subsequently corrected, the presence of such should raise the specter of potential esophageal intubation until proven otherwise.
Selected Readings
1. Dittrich KC. Delayed Recognition of Esophageal Intubation. CJEM 2002; 4(1): 41-44.
2. Li J. Capnography Alone is Imperfect for Endotracheal Tube Placement Confirmation During Emergency Intubation. J Emerg Med 2001; 20:223-229.
3. Smith GM, Reed JC, Choplin RH. Radiographic Detection of Esophageal Malposition of Endotracheal Tubes. AJR 1990; 154:23-6.
4. Sakles JC, Laurin EG, Rantapaa AA, et al. Airway Management in the Emergency Department: A One-Year Study of 610 Tracheal Intubations. Ann Emerg Med 1998; 31:325-332.
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Original case written by its authors at Virginia Commonwealth University and published at this address as part of a weekly teaching collection. Reproduced here as an archive.