Hemorrhage Control: Direct Pressure
Direct pressure remains the first-line intervention for controlling external bleeding. Apply firm, continuous pressure directly over the wound using a sterile gauze pad or clean cloth. Maintain pressure for a minimum of 10 minutes without lifting to check the wound, as this disrupts clot formation. If blood soaks through the initial dressing, apply additional dressings on top without removing the first layer. For extremity wounds, elevate the limb above the heart if possible while maintaining direct pressure. Pressure points over proximal arteries (brachial for upper extremity, femoral for lower extremity) can supplement direct pressure for severe arterial bleeding.
Tourniquet Application
Tourniquets are indicated for life-threatening extremity hemorrhage that cannot be controlled with direct pressure. Apply the tourniquet 2 to 3 inches proximal to the wound, never over a joint. Tighten until bleeding stops and distal pulses are absent. Note and document the time of application. A properly applied tourniquet is painful, and this is expected. Do not loosen or remove a tourniquet in the field once applied. If the first tourniquet does not control bleeding, apply a second tourniquet proximal to the first. Commercial tourniquets such as the CAT (Combat Application Tourniquet) and SOF-T are preferred over improvised devices.
Hemostatic Agents
Hemostatic agents such as QuikClot Combat Gauze and Celox are treated gauze products that promote rapid clot formation. They are indicated for junctional hemorrhage (groin, axilla, neck) and wounds where tourniquets cannot be applied. Pack the wound tightly with the hemostatic gauze, making sure the agent contacts the bleeding source directly. Apply direct pressure for a minimum of 3 minutes after packing. These agents work through different mechanisms: kaolin-based products activate the clotting cascade, while chitosan-based products directly form a mucoadhesive seal.
Wound Packing
Wound packing is used for deep, penetrating wounds to extremities, junctional areas, or truncal wounds where internal bleeding sources must be compressed. Using hemostatic or plain gauze, pack the wound firmly starting at the deepest point of the wound and working outward. The goal is to fill the entire wound cavity with tightly packed gauze to create pressure against the bleeding vessel. Apply direct pressure over the packed wound for at least 3 minutes. Wound packing is a critical skill for managing hemorrhage from wounds that are not amenable to tourniquet placement.
Hypovolemic Shock
Hypovolemic shock results from inadequate circulating blood volume, most commonly due to hemorrhage. It can also result from severe dehydration, burns, or third-spacing of fluids. Signs and symptoms progress through four classes based on estimated blood loss. Early signs include tachycardia, anxiety, and cool/pale skin. As shock progresses, blood pressure drops, mental status deteriorates, and urine output decreases. The patient may become confused, then unresponsive. Treatment includes controlling the source of bleeding, keeping the patient warm, positioning supine with legs elevated (if no spinal injury suspected), IV fluid resuscitation, and rapid transport to a trauma center. Permissive hypotension (targeting a systolic BP of 80 to 90 mmHg) may be appropriate for penetrating trauma to avoid disrupting clots.
Cardiogenic Shock
Cardiogenic shock occurs when the heart fails to pump effectively, most commonly following acute myocardial infarction, severe heart failure, or cardiac tamponade. The heart cannot generate adequate cardiac output to perfuse the organs. Signs include hypotension, tachycardia (or bradycardia), jugular venous distension (JVD), pulmonary edema with crackles/rales, cool and clammy skin, and altered mental status. Treatment differs from hypovolemic shock because fluid administration can worsen pulmonary edema. Management includes positioning the patient upright if tolerated, administering oxygen, and rapid transport. Avoid large-volume IV boluses. Medications such as dopamine or norepinephrine may be used per protocol to support blood pressure.
Distributive Shock
Distributive shock involves widespread vasodilation causing relative hypovolemia. There are three major subtypes. Neurogenic shock results from spinal cord injury (typically above T6) causing loss of sympathetic tone. Presentation includes hypotension with bradycardia (unlike other forms of shock), warm and dry skin below the injury, and possible priapism. Treatment includes IV fluids and vasopressors. Anaphylactic shock is a severe allergic reaction causing massive vasodilation, bronchoconstriction, and increased capillary permeability. Signs include urticaria, angioedema, wheezing, stridor, and rapid cardiovascular collapse. Treatment is epinephrine 0.3 mg IM in the lateral thigh (auto-injector), repeated every 5 to 15 minutes as needed, plus IV fluids, antihistamines, and airway management. Septic shock results from overwhelming infection causing systemic vasodilation and increased capillary permeability. Early signs include fever, tachycardia, and warm/flushed skin (warm shock), progressing to cool/mottled skin, hypotension, and organ failure (cold shock). Treatment includes IV fluid boluses (30 mL/kg crystalloid) and rapid transport for antibiotics and vasopressors.
Obstructive Shock
Obstructive shock occurs when blood flow is mechanically impeded, preventing adequate cardiac output. The two primary causes in the prehospital setting are tension pneumothorax and cardiac tamponade. Tension pneumothorax results from air trapped in the pleural space, causing mediastinal shift and compression of the heart and great vessels. Signs include severe respiratory distress, absent breath sounds on the affected side, JVD, tracheal deviation (late finding), and hypotension. Treatment is needle decompression at the second intercostal space, midclavicular line (or fourth/fifth intercostal space, anterior axillary line per protocol). Cardiac tamponade occurs when fluid accumulates in the pericardial sac, compressing the heart. Classic findings (Beck triad) include JVD, muffled heart sounds, and hypotension. Prehospital treatment is rapid transport for pericardiocentesis, with IV fluids to increase preload.