Pope Francis suffered two acute respiratory crises on Monday, prompting doctors to put him back on a non-invasive mechanical ventilator. The 88-year-old pontiff, who had been battling a complicated respiratory infection for more than two weeks, underwent a bronchoscopy to remove a large amount of mucus from his lungs. The Vatican confirmed that the mucus was a reaction to his pneumonia and not a new infection.

Despite the dangers, the pope remains alert and responsive to medical officials. His doctors have not yet declared him stable, and the prognosis remains cautious. The use of non-invasive ventilation is intended to avoid more invasive procedures such as intubation.

This is the latest in a series of health challenges for the pope, who suffers from chronic lung disease and has had part of a lung removed. His prolonged hospitalization is the longest absence of his papacy, and no recent photos or videos have been released. Archbishop Vincenzo Paglia urged Francis to speak out, saying the world needs his voice amid the ongoing health crisis.