Medical anti-shock trousers can be applied to a casualty showing signs and symptoms of hypovolemic shock when the casualty is not responding to treatment for shock or when the cause of shock is not known.

The MAST can also be used to help control internal bleeding in the abdomen or legs and to stabilize a fracture of the pelvis. Some general rules for deciding if the MAST should be applied are given below.

a. The MAST can be used if the casualty has one of the following conditions and no contraindications exist.

(1) Systolic blood pressure reading is less than 60 mmHg and other signs and symptoms of hypovolemic shock are present. (The systolic is the higher number of a blood pressure reading.)

(2) Closed abdominal injury with signs and symptoms of hypovolemic shock present with systolic is less than 90 mmHg.

(3) Pelvic fracture(s) with signs and symptoms of hypovolemic shock present and with systolic less than 90 mmHg.

b. Do not apply the MAST if one of the following conditions (contraindications) exist.

(1) The casualty has psychogenic, anaphylactic, cardiogenic, or septic shock. (The MAST is used only with hypovolemic shock.)

(2) The casualty has an injury that will be aggravated by applying the MAST. (For example, you should not apply the MAST to a casualty with an impaled object protruding from a wound in the leg or intestine protruding from an open abdominal wound unless you are ordered to do so by a physician.)

(3) The casualty has congestive heart failure.

c. Do not apply the MAST to a casualty with one of the following conditions unless you are directed to do so by a physician.

(1) The casualty has a severe head injury.

(2) The casualty has an open chest wound or bleeding into the chest cavity.

(3) The casualty has other trauma above the level of the MAST application.

(4) The casualty is in heart failure with pulmonary edema.

(5) The casualty may have an aortic aneurysm.