Review Question - QID 217721

This patient who is intubated for ARDS remains hypoxic following intubation, with radiography demonstrating left lung collapse. The most likely cause of this presentation is right mainstem intubation.

To confirm endotracheal tube placement following intubation, auscultation of the chest and stomach should be performed to verify bilateral breath sounds and to ensure that the endotracheal tube has not been inadvertently placed in the esophagus. Measurement of end-tidal carbon dioxide (EtCO2) levels should also be completed. Lastly, the presence of bilateral chest rise during mechanical ventilation also helps confirm correct endotracheal tube placement. Several complications can occur immediately following intubation. Esophageal intubation may occur, leading to desaturation. Additionally, because the right bronchus has a more vertical orientation than the left, over-advancement of the endotracheal tube can lead to ventilation of only 1 lung and right mainstem intubation. This can be diagnosed by the absence of breath sounds in the left lung and a chest radiograph demonstrating de-aeration of the left lung, as it is not being ventilated or oxygenated. If identified, right mainstem intubation should be immediately corrected by pulling back the endotracheal tube and obtaining a repeat chest radiograph. Complications of right mainstem intubation include barotrauma (due to a single lung receiving the entire tidal volume), worsening hypoxia, and pneumothorax.

Ramsingh et al. discuss bronchial intubation and report that the assessment of endotracheal tube location via point-of-care ultrasound is superior to the determination of location by auscultation.

Incorrect Answers:
Answer 1: Esophageal intubation is a common complication of endotracheal tube placement; however, it would present with absent bilateral breath sounds. Other findings include worsening hypoxia, inability to oxygenate or ventilate, and auscultation of air filling the stomach.

Answer 2: Mucus plugging is a complication of mechanical ventilation that typically occurs after hours to days of ventilation. Mucus plugging can cause complete white-out of a lung field and respiratory compromise. Acute hypoxia in a newly intubated patient is unlikely to be due to mucus plugging.

Answer 3: Pneumothorax can occur following intubation due to positive pressure ventilation. However, pneumothorax would not present with diffuse atelectasis on chest radiograph but would instead cause a distinct pleural line due to the delineation of air in the pleural space and the lung parenchyma. Other signs of pneumothorax, such as distended neck veins or tracheal shift, may also be present.

Answer 5: Worsening ARDS is a cause of hypoxia in intubated patients, as sepsis and ARDS can cause decreased lung compliance and impair gas exchange. However, worsening ARDS typically causes hypoxia over the course of days. This patient's acute hypoxia following intubation coupled with chest radiograph findings suggest an alternate cause of hypoxia.

Bullet Summary:
Inadvertent placement of an endotracheal tube in the right mainstem bronchus can occur during intubation due to its vertical orientation compared to the left main bronchus.