Pope Francis stabilized enough Tuesday after two respiratory crises to resume using a nasal tube for oxygen, rather than a ventilation mask, as he continued to fight pneumonia, the Vatican said.

The 88-year-old pope, who has chronic lung disease and had part of one lung removed as a young man, woke up after sleeping through the night, the Vatican said. The fact that Francis no longer needed the mask by Tuesday morning was a sign of some improvement after crises that required doctors to extract "copious" amounts of mucus from his lungs.