The pope has been given non-invasive mechanical ventilation and high-flow oxygen therapy. He does not have a fever and does not have a high white blood cell count, the Vatican said.
Pope Francis has not had any other episodes of bronchospasm since the isolated attack on Friday, the Vatican said.
He remains alert and oriented, receiving Eucharist then dedicating himself to prayer, the Vatican said.
"The night passed peacefully, the Pope is resting," the Vatican said Saturday morning. On Friday the Vatican said he suffered an "isolated attack of bronchospasm" which caused "vomiting with inhalation."
The pope underwent broncho aspiration and was put on non-invasive mechanical ventilation, the Vatican said.
The pontiff has been hospitalized in Rome since Feb. 14.
His prognosis, though, "remains uncertain," the Vatican said, and it will take 24 to 48 hours to understand the impact of the coughing attack and whether it has negatively affected his general condition.
The pontiff, who has led the Catholic Church since 2013, was diagnosed with pneumonia last week, according to the Vatican.