The U.S. Conference of Bishops and Apostolic Nunciature announced last week that Most Rev. Pietro Sambi has been placed on assisted ventilation.
It says he is suffering complications after delicate lung surgery two weeks earlier. Sister Mary Ann Walsh said Tuesday that Sambi had been readmitted to the Baltimore hospital but declined to comment on his condition.
Sambi is one of Pope Benedict XVI's first major appointees. He has served as the papal representative to the U.S. since 2006.