Avoid rough handling of the victim, and transport to a medical treatment facility.  If transportation to a definitive care facility will be lengthy or delayed, seek the radio or phone advice of a medical officer on whether to give fluids by mouth or to start an intravenous line. If this consultation is impossible, use your own judgment. In the case of cardiogenic shock, DO NOT start intravenous fluids since blood volume is sufficient and only function is impaired.  Constantly monitor the patient and record vital signs every 15 minutes so that you are able to keep track of the patient’s progress. PNEUMATIC COUNTER-PRESSURE DEVICES (MAST) Commonly known as Medical Anti-Shock Trousers or Military Anti-Shock Trousers (MAST), pneumatic counter-pressure devices are designed to correct or counteract certain internal bleeding conditions and hypovolemia. The garment does this by developing an encircling pressure up to 120 mm Hg around both lower extremities, the pelvis, and the abdomen. The pressure created  slows or stops venous and arterial bleeding in areas of the body enclosed by the pressurized garment;  forces available blood from the lower body to the heart, brain, and other vital organs;  prevents pooling of blood in the lower extremities; and  stabilizes fractures of the pelvis and lower extremities. Some indications for use of the pneumatic counter-pressure devices are when  systolic blood pressure is less than 80 mm Hg,  systolic blood pressure is less than 100 mm Hg and the patient exhibits the classic signs of shock, or  fracture of the pelvis or lower extremities is present. Although the only absolute contraindication in the use of these devices is in the case of pulmonary edema, other conditional contraindications include congestive heart failure, heart attack, stroke, pregnancy, abdominal evisceration, massive bleeding into the thoracic cavity, and penetrating wounds where the object is still impaled in the victim. Application of the anti-shock garment is a simple procedure, but it requires some important preliminary steps. When the garment is laid out flat, ensure that there are no wrinkles. If the patient is to remain clothed, remove all sharp and bulky objects from the patient’s pockets. Take vital signs before applying the MAST garment. When applying the garment, inflate sufficiently so the patient’s systolic blood pressure is brought to and maintained at 100 mm Hg. Once the garment is inflated, take the patient’s vital signs every 5 minutes. The garment should be removed only under the direct supervision of a physician. BREATHING AIDS LEARNING OBJECTIVE: Recognize breathing aids and their uses. As a Hospital Corpsman, you should become familiar with the breathing aids that may be available to help you maintain an open airway and to restore breathing in emergency situations. Breathing aids include oxygen, artificial airways, bag-valve mask ventilator, pocket face mask, and suction devices. USE OF OXYGEN (O₂) In an emergency situation, you will probably have a size E, 650-liter cylinder of oxygen available. The oxygen cylinder is usually fitted with a yoke-style pressure-reducing regulator, with gauges to show tank pressure and flow rate (adjustable from 0 to 15 liters per minute). A humidifier can be attached to the flowmeter nipple to help prevent tissue drying caused by the water-vapor-free oxygen. An oxygen line can be connected from the flowmeter nipple or humidifier to a number of oxygen delivery devices that will be discussed later. When available, oxygen should be administered, as described below, to cardiac arrest patients and to self-ventilating patients who are unable to inhale enough oxygen to prevent hypoxia (oxygen deficiency). Hypoxia is characterized by tachycardia, nervousness, irritability, and finally cyanosis. It develops in a wide range of situations, including p o i s o n i n g , s h o c k , c r u s h i n g c h e s t i n j u r i e s , cerebrospinal accidents, and heart attacks. 4-25