Pope Francis, 88, rested during a peaceful ninth night at Rome's Gemelli Hospital after a respiratory crisis and blood transfusions, the Vatican said Sunday.

ROME — Pope Francis remained in critical condition Sunday and blood tests showed early kidney failure but he remains alert, responsive and attended Mass, the Vatican said, as the 88-year-old pontiff battles pneumonia and a complex lung infection.

Pope Francis showed slight improvement in laboratory tests Monday and resumed some work activities, the Vatican said.

Francis, 88, remains in critical condition but hasn't experienced any further respiratory crises since Saturday.

The 88-year-old Francis, suffering from pneumonia in both lungs, hadn’t had any more respiratory crises, officials said.