This medical exhibit describes the circulatory system impaired by a positive end expiratory pressure (PEEP) value over 15. The illustration consists of five images. The first image is a schematic diagram of the respiratory system and vascular network. The second image is a schematic of a PEEP reading. The third image is a transverse section through the thorax. The fourth image is a microscopic view of alveoli. The fifth image is a microscopic view of a blood vessel.