Pope Francis was back on "noninvasive mechanical ventilation" after two episodes of acute respiratory failure Monday, the Vatican said. It was the latest setback in the pope's 18-day battle against double pneumonia at a Roman hospital.

The pope may have turned a corner as the Vatican said he had no new respiratory crisis on Tuesday and that he remains stable. The Associated Press reported that Pope Francis will sleep with a ventilation mask. He is breathing with the help of high-flow supplemental oxygen via nasal cannula after two respiratory crises on Monday.