Anesthesia is induced in a 50-year-old man; peak airway pressure rises after initial intubation. The most likely cause is?

Anesthesia is induced in a 50-year-old man; peak airway pressure rises after initial intubation. The most likely cause is?

• A. Mainstem intubation
• B. Thrombotic pulmonary embolism
• C. Tension pneumothorax
• D. Venous air embolism

Answer: (A)

Rising peak airway pressure after intubation points to an issue with the airway tube or how the lungs are being ventilated. The most likely cause here is that the endotracheal tube has been advanced too far and entered the right mainstem bronchus, causing single-lung ventilation. Ventilating mainly one lung increases the resistance the ventilator has to overcome and reduces the overall compliance of the system, so the peak inspiratory pressure goes up. You’d expect diminished breath sounds on the opposite side, and correcting by pulling the tube back so it sits about 2–3 cm above the carina should restore normal pressures and bilateral ventilation. The other options don’t fit as neatly: tension pneumothorax would present with acute distress and hemodynamic instability and abnormal chest findings; thrombotic pulmonary embolism and venous air embolism typically cause sudden changes in oxygenation and circulation rather than an isolated immediate rise in peak airway pressure after intubation.

Rising peak airway pressure after intubation points to an issue with the airway tube or how the lungs are being ventilated. The most likely cause here is that the endotracheal tube has been advanced too far and entered the right mainstem bronchus, causing single-lung ventilation. Ventilating mainly one lung increases the resistance the ventilator has to overcome and reduces the overall compliance of the system, so the peak inspiratory pressure goes up. You’d expect diminished breath sounds on the opposite side, and correcting by pulling the tube back so it sits about 2–3 cm above the carina should restore normal pressures and bilateral ventilation.

The other options don’t fit as neatly: tension pneumothorax would present with acute distress and hemodynamic instability and abnormal chest findings; thrombotic pulmonary embolism and venous air embolism typically cause sudden changes in oxygenation and circulation rather than an isolated immediate rise in peak airway pressure after intubation.