dependent atelectasis lung
Quick Answer. Atelectasis is the complete or partial collapse of a lung or lobe of a lung, according to Mayo Clinic. The term does not specify how much of the lung has collapsed. Mild dependent atelectasis refers to small areas of the lung near the spine that do not fully expand when a person is lying down, states NetWellness. This condition usually does not require treatment, as the lung inflates normally when the person is sitting or standing up.