The announcement on Saturday evening indicated that Francis’ medical condition had become more complicated since an update from his doctors on Friday.

Pope Francis was in critical condition on Saturday night after having a long “asthmatic respiratory crisis” earlier in the day that required “high flows of oxygen” as well as a blood transfusion, the Vatican said, adding to concerns about the health of the 88-year-old pontiff.

The announcement indicated that Francis’ medical condition had become more complicated since an update from his doctors on Friday evening, when he was also said to be in critical condition.

“The pope is not out of danger,” the Vatican said on Saturday evening.

As the pope’s hospital stay enters a second week, questions have grown about whether Francis — the spiritual leader of almost 1.4 billion Roman Catholics worldwide — will recover, pass away, or manage to fight his infection but emerge physically diminished.

The damage to his lungs was already chronic, and in recent days a few cardinals have openly spoken about the possibility of Francis resigning, as his predecessor Benedict XVI did in 2013.

A death or resignation would prompt a conclave of the church’s cardinals, who would elect a successor.

In an interview with Milan daily Corriere della Sera on Saturday, Pope Francis’ secretary of state, Cardinal Pietro Parolin, spoke of “useless speculation.” The only thing that mattered, he said, was “the Holy Father’s health, his recovery, his return to the Vatican.”