Pope Francis was in critical condition Saturday after he suffered a long asthmatic respiratory crisis that required high flows of oxygen, the Vatican said.

ROME (AP) — Pope Francis remained in critical condition Monday but showed slight improvement in laboratory tests and resumed some work, the Vatican said, including calling a parish in Gaza City that he has kept in touch with since the war there began.

Pope Francis, 88, is in critical condition due to double pneumonia and a severe lung infection. While receiving high oxygen flows and blood transfusions, doctors fear the onset of sepsis, which could further complicate his condition given his advanced age and respiratory issues.