ICP changes following application of the MAST suit.

The MAST suit is used primarily in the field to raise arterial pressure in patients with hemorrhagic shock. By 'squeezing' blood back to the heart and compressing arteries, the suit acts to transfuse the patient as well as to compress bleeding sites. Because of the sudden increase in venous return with abdominal compression, its use has been questioned after closed head injury, cardiac tamponade, and/or tension pneumothorax. A study was devised to evaluate the MAST suit in dogs following hemorrhage and hemorrhage with the creation of a tension pneumothorax, cardiac tamponade, and mass intracranial lesion. Pulmonary artery, central venous, systemic arterial, and intracranial pressures were monitored in control dogs before and after hemorrhage and application of the MAST suit. Following hemorrhage, the inflated MAST suit raised systolic arterial pressure as well as central venous, pulmonary artery, and intracranial pressures. The rise in intracranial pressure mirrored the rise in venous pressure and never reached potentially harmful levels in the hemorrhaged animals and animals with a mass intracranial lesion. In the animals with cardiac tamponade and tension pneumothorax, inflation of the abdominal portion of the MAST suit produced a marked rise in central venous and intracranial pressures. This was altered by either relieving the lesion or reducing the pressure of the abdominal portion of the MAST suit.