Endotracheal Intubation

Endotracheal Intubation

Jan Kasal

Chakradhar Venkata

1. A 46-year-old man is admitted to the Emergency Department after a high-speed motor vehicle collision. He has suspected bilateral rib fractures and develops respiratory distress and hypoxemia. The decision is made to intubate. After intubation, his SpO2 remains 82% on 100% FiO2, and there is resistance to delivering breaths. His BP is 130/60 mm Hg, and HR is 110 bpm. An ultrasound image of the right chest during ventilation is performed and shown in Figure 78.1.

Which of the following statements is most likely to be correct?

A. There is a right-sided pneumothorax

B. There is a left mainstem intubation

C. There is no esophageal intubation

D. There is no issue related to intubation

View Answer

1. Correct Answer: B. There is a left mainstem intubation

Rationale: The M-mode ultrasound in Figure 78.1 shows vertical movement extending from the pleura to the bottom of the screen at regular intervals, representing brief movements of lung tissue. These movements correlate with heartbeats, and this ultrasound pattern is called the lung pulse. The lung pulse confirms the presence of both layers of pleura and excludes pneumothorax at that location. Air between the pleural layers (pneumothorax) would reflect the ultrasound waves, and no cardiac movement could be seen. Normal ventilation should produce a “beach sign” on M-mode. Since this pattern is not seen during ventilation, one should consider the possibility of pneumothorax, or lack of lung movement for other reasons. Because the presence of lung pulse rules out pneumothorax, a lack of ventilation to the right lung is most likely, from esophageal intubation, left-mainstem intubation, or another process obstructing ventilation to the right lung.

Selected Reference

1. Lichtenstein D. Lung Ultrasound in the Critically Ill. Springer; 2016, Chapter 31 and 34.

2. A 47-year-old woman with acute respiratory distress syndrome (ARDS) from COVID-19 infection is in the intensive care unit (ICU) on venovenous extracorporeal membrane oxygenation (VV ECMO). She becomes agitated and pulls at her endotracheal tube (ETT) and nasogastric (NG) tube. Because she is oxygenated and ventilated with ECMO, the team decides to perform a neck ultrasound to evaluate tube positioning (image Video 78.1 and Figure 78.2).

These findings are most consistent with which of the following?

A. The ETT is in the esophagus.

B. The ETT is in the trachea.

C. The venous ECMO cannula is in the internal jugular vein.

D. The NG tube has been displaced.

View Answer

2. Correct Answer: B. The ETT is in the trachea

Rationale: Ultrasound can be a useful adjunct for examination of the upper airway. The ultrasound shown demonstrates a 2D view of the trachea in the long axis (sagittal view), with the left side of the image cephalad, and the right caudad, using a linear transducer. In Figure 78.4, the cricoid cartilage (CC, on the left side) and tracheal cartilages (TC, on the right side of the screen) are visible. Cartilage has an oval hypoechoic appearance. The bright line just below the cartilages represents the air-mucosa (A-M) interface. Reverberations (R, below A-M) represent comet tail artifacts. The ETT is seen as a double line structure, better seen on the right of the screen. Because air does not conduct ultrasound waves well, to make the ETT visible, the cuff was filled here with normal saline. This examination is consistent with endotracheal intubation (choice B is correct). The esophagus and internal jugular veins are not visible in the image (choices A, C are incorrect).

An esophageal intubation will appear lateral to the anterior trachea on a transverse image taken approximately 1 inch above the suprasternal notch (the “double-tract” sign, white arrows, Figure 78.5). The tube diameter visible on the ultrasound is too large for a misplaced NG tube (choice D is incorrect). Also, the well-visible tube segment is due to the cuff filled with saline surrounding the tube, something that would not be possible with an NG tube. In a study by Arya et al., ultrasound identified 100% of tracheal intubations and 83% of esophageal intubations.