Dean had stood up to reassure Mary that there was nothing wrong with her falling asleep on the bed, it wasn't like he was an invalid. He didn't need a hospital bed for a broken and battered hand. He heard Peggy calling out instead. And since his voice wasn't exactly up to raising more than a gruff scratchy version of his regular speaking voice he stepped out into the hall instead. Smacking his good hand against the wall to get her attention.