More of your patients may be getting oxygen from Apria. Lake Forest, Calif.-based giant Apria Healthcare plans to buy Praxair's Danbury, Conn.- based U.S. oxygen business, the companies say in press releases. Praxair has 85 branch locations in 27 states and employs about 1,100 people. Apria will integrate the Praxair acquisition into its existing business, which operates more than 500 locations nationwide.