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

In a late update, the Vatican said Francis hadn’t had any more respiratory crises since Saturday night but was still receiving high flows of supplemental oxygen. He was admitted to the hospital Feb. 14.

Some blood tests showed “initial, mild, kidney failure,” but doctors said it was under control. The decreased platelet count, necessary for clotting, that was first detected Saturday was stable.

“The complexity of the clinical picture, and the necessary wait for drug therapies to provide some feedback, dictate that the prognosis remains guarded,” Francis’ doctors concluded.

Prayers for him poured in from around the world, from his native Argentina to the seat of Sunni Islam in Cairo to schoolchildren in Rome.

In New York, Cardinal Timothy Dolan admitted what church leaders in Rome weren’t saying publicly: that the Catholic faithful were united “at the bedside of a dying father.”

“As our Holy Father Pope Francis is in very, very fragile health, and probably close to death,” Dolan said at St. Patrick’s Cathedral, without saying whether he had independent information about the pope’s condition.

Doctors have said Francis’ condition is touch-and-go, given his age, fragility and pre-existing lung disease.

His condition has revived speculation about what might happen if he becomes unconscious or otherwise incapacitated, and whether he might resign.

Francis was supposed to have celebrated Mass on Sunday morning in St. Peter’s Basilica and ordained deacons as part of the Holy Year commemoration.

The organizer of the Holy Year, Archbishop Rino Fisichella, presided in his place and offered a special prayer for Francis from the altar before delivering the homily that the pope had prepared.

“Even though he is in a hospital bed, we feel Pope Francis close to us. We feel him present among us,” Fisichella told the hundreds of white-robed deacons.

A message that had been prepared for Francis to read Sunday but not delivered said he was “confidently continuing my hospitalization at the Gemelli Hospital, carrying on with the necessary treatment; and rest is also part of the therapy!”

The message asked for prayers for him — as he always asks — and noted Monday’s third anniversary of Russia’s invasion of Ukraine, “a painful and shameful occasion for the whole of humanity.”

In Cairo, the grand imam of Al-Azhar, the seat of Sunni learning who forged a close bond with Francis, wished him well.

“I pray to Allah to grant my dear brother, Pope Francis, a swift recovery and to bless him with good health and well-being so that he may continue his journey in serving humanity,” Sheikh Ahmed al-Tayeb wrote in a Facebook post.