Pope Francis, battling double pneumonia, remains in a critical condition for a second day running and has shown an ¡°initial, slight insufficiency¡± in his kidney function, the Vatican said on Sunday.

The prognosis for the 88-year-old pope, who required a transfusion of two units of blood on Saturday after experiencing a ¡°prolonged asthma-like respiratory crisis,¡± remains ¡°guarded,¡± according to the latest medical update.

Francis was admitted to Rome¡¯s Gemelli hospital on Feb. 14. The Vatican first described his condition as critical on Saturday.