Pope Francis experienced a severe asthmatic respiratory crisis on Saturday morning, requiring oxygen support, the Vatican confirmed. His condition remains critical as doctors closely monitor his health.

A Vatican statement revealed that blood tests showed plateletopenia, a condition associated with anemia, prompting the need for blood transfusions. “The Holy Father continues to be alert and spent the day in an armchair, though in more pain than yesterday,” the statement added.

Medical experts say an asthmatic respiratory crisis indicates difficulty in maintaining adequate oxygen levels, while plateletopenia, or low platelet count, can result from infections, medication side effects, or impaired platelet production.

Pope Francis, 87, has been hospitalized since February 14 following a bronchitis diagnosis, which later developed into pneumonia. Despite ongoing health challenges, he was previously described as being in “good spirits” earlier this week.

Due to his condition, the Vatican confirmed that the pope will not preside over Sunday mass as he continues his recovery.