Pope Francis suffered two episodes of "acute respiratory insufficiency" on Monday, the Vatican said, a setback for the 88-year-old pontiff as he battles double pneumonia, APA reports citing Reuters.
Francis, who has been in Rome's Gemelli Hospital since February 14, is again receiving "non-invasive, mechanical ventilation" to help with his breathing.
"Today, the Holy Father experienced two episodes of acute respiratory insufficiency, caused by a significant accumulation of endobronchial mucus," the latest detailed medical update said.
The pope also suffered a bronchospasm, akin to an asthma attack, which required doctors to perform two bronchoscopies, or procedures to inspect his air passages.
The pope's prognosis remained "guarded", the statement said, which means Francis is not out of danger.
A Vatican official, who did not wish to be named because he was not authorised to discuss the pope's health, said the pontiff's blood tests on Monday had remained stable.