MAST Pants - (Military Anti-Shock Trousers) are used on a patient that has major blunt trauma (They were hit with something really hard), if they have a blood pressure of under 60 systalic, and if show signs of inadequate perfusion (shock) AND if they are still awake. <- which barely ever happens (usually patients with under 60 systalic BP are unconscious). They are usually used for patients with a pelvic fracture, systalic BP of under 90 and have inadequate perfusion. (One of those conditions may be met unless they have a pulmonary edema).