Obstructive Atelectasis Caused by Total Obstruction of the Left Main Bronchus by Mucous Plug

A 66-year-old male presented to the emergency department after suffering a major trauma. Endotracheal intubation and ventilator care were initiated on day 6 after hospitalization due to severe dyspnea. Open tracheostomy was performed on the 14th day of intubation. On the 20th day of tracheostomy, no atelectasis was observed in the AP chest radiography (Fig. 1A) and ABGA revealed the pH of 7.37, pCO2 of 36, pO2 of 121, HCO3 of 20.8, and O2 sat of 98.1. However, the total atelectasis in the left lung was observed in the AP chest radiography performed on the following day (Fig. 1B) and ABGA deteriorated to pH of 7.30, pCO2 of 42, pO2 of 54, HCO3 of 20.7, and O2 sat of 86.9. Fiberoptic bronchoscopy was performed to flush a very large amount of thick purulent secretion that totally obstructed the left main bronchus (Fig. 2). Atelectasis disappeared in the follow-up AP chest radiography (Fig. 3) and ABGA improved to pH of 7.32, pCO2 of 42, pO2 of 113, HCO3 of 21.6, and O2 sat of 99.2.