NREMT Study Guide: Trauma

This section of our NREMT Study Guide covers trauma, which accounts for 14%–18% of the EMT exam. Our overview includes causes of traumatic injuries, mechanisms of injury and multisystem trauma, categories of traumatic injuries, bleeding control, spinal immobilization, and how to identify and treat shock.

After you have reviewed this section of our study guide, you will be given ten practice questions to test your knowledge and retention of the material you have read.

Causes of Traumatic Injuries     

Patients requiring EMS assistance are classified as medical or trauma patients. With proper prehospital assessment and treatment, you can help reduce patient pain and suffering, long-term disability, and death from traumatic injuries.

Traumatic injuries occur when physical forces are applied to the body. By learning how the body responds and what type of injuries to expect from different mechanisms of injury (MOI), you can quickly identify potential problems and react with the appropriate treatment.

When you evaluate the MOI in a trauma patient, it will provide you with an index of suspicion, which is “awareness and concern for potentially serious and underlying and unseen injuries.” There are many reasons why someone experiences a traumatic injury, including vehicle and motorcycle accidents, assaults, workplace injuries, falls, animal attacks, gunshot wounds, explosions, sports injuries, and stabbings.

In every situation, remain calm and in control, correct life-threatening injuries, complete a thorough, rapid assessment, and do not hesitate to call for ALS backup or medical control for guidance when needed.

Mechanism of Injury

The MOI refers to the energy (force or forces) that cause bodily injury or how an injury occurred. For example, a motorcycle traveling 100 mph crashes into a tree, ejecting the rider from the bike, or a person falls ten feet off their roof onto a concrete walkway while cleaning gutters.

There are three concepts of energy associated with traumatic injuries: potential energy, kinetic energy, and the energy of work. It is essential to have a basic understanding of how these types of energy affect the human body.

Potential energy is mainly associated with the energy of falling objects and is the product of mass (weight), the force of gravity, and height. Anyone who is some height above the ground has potential energy. If they fall, the potential energy is converted into kinetic energy. As they hit the ground, the kinetic energy is converted into the energy of work, which is the work of bringing the body to a stop and thereby damaging tissues and fracturing bones.

Kinetic energy is the energy of a moving object, reflecting the relationship between its weight and the speed at which it travels. For example, in a vehicle accident, the vehicle’s kinetic energy is converted into the work of stopping the vehicle, usually by damaging the automobile. Simultaneously, the vehicle’s passengers have kinetic energy that converts to the work of bringing their bodies to a stop, resulting in injuries.

When arriving at the scene of an accident, maintain a high index of suspicion of severe injuries and multisystem trauma. Multisystem trauma is a term that describes a person who has been subjected to multiple traumatic injuries involving more than one body system, such as chest and multiple extremity trauma, head and spinal trauma, or chest and abdominal trauma.

You must quickly recognize patients who fit into this classification, provide rapid treatment and transportation, and alert medical control of the patient’s injuries so the trauma center is prepared prior to your arrival. Multisystem trauma patients have a high level of morbidity and mortality; therefore, they require multidisciplinary teams of physicians and surgeons to treat their injuries.

Categories of Traumatic Injuries

There are two categories of traumatic injuries: blunt trauma and penetrating trauma. Blunt trauma is a force to the body, or the transfer of energy, that causes injury without an object penetrating the internal organs or soft tissues. Penetrating trauma is an injury sustained by something that pierces and penetrates the skin, internal organs, and the body’s soft tissues. Both types of trauma can occur from a variety of MOIs and can be accidental or intentional.

Blunt trauma is caused by an object making contact with the body, such as a baseball bat to the head or another part of the body. The two most seen MOIs for blunt trauma are motor vehicle accidents and falls. When assessing your patient, look for signs of discoloration to the skin, swelling, deformity, or complaints of pain, because often those may be the only signs and symptoms of blunt trauma.

Many different objects can cause penetrating trauma, such as firearms, knives, hand tools, and ice picks. Some unusual calls involving penetrating trauma can include an object falling off a truck and penetrating a person’s windshield and then their body. Another example is climbing over a metal fence and falling onto the steel pickets.

If someone has something impaled in them, always leave the object in place, unless it is in the cheek and interfering with the patient’s airway, or in the chest and interfering with chest compressions. Call medical control for direction in these situations before removing the object.

Bleeding Control

When performing a rapid exam of the patient, look for signs of external bleeding and treat immediately. Remember, quickly control the bleeding first, before airway and breathing, then assess the ABCs and provide further treatment. If the bleeding is in an extremity and direct pressure is ineffective, a tourniquet will need to be applied.

Direct Pressure

If available, place a sterile dressing over the injury and apply direct pressure with a gloved hand. Direct pressure can control most cases of external bleeding by stopping the flow of blood and permitting normal clotting to occur.

Apply pressure with a gloved hand over the top of the sterile dressing. If a dressing is not readily available, use your gloved hand. If the patient has an impaled object, put bulky dressings around the object to stabilize it and apply pressure as best you can for at least five minutes without interruption.

Do not remove a bandage over a wound, as it will interfere with the clotting process. Apply additional dressings over the original one if the bleeding continues. Once the bleeding is controlled, apply a pressure dressing over the wound by firmly wrapping a roll of gauze or roller bandage over the site. Be sure the dressing is snug but not too tight that the distal circulation is cut off. Reassess the patient’s distal pulses after applying the dressing and adjust if needed.


A tourniquet is a device that closes off arterial blood flow to and from an extremity and is generally a last-resort effort. Direct pressure and pressure bandages should be utilized first and will nearly always control bleeding. However, arteries are under a lot of pressure, and it may be difficult to stop with direct pressure only.

There are many types of tourniquets available. If your agency and protocols allow you to apply a tourniquet, familiarize yourself with the manufacturer’s instructions for use.  

Spinal Immobilization

Spinal immobilization is defined as the use of adjuncts being applied to minimize the movement of the spine. A cervical collar (c-collar), backboards, straps, and blocks are adjuncts used to help alleviate further damage being done in the event of a spinal injury.

The need for spinal immobilization is determined when assessing the scene and patient.

Patients who need spinal immobilization include those with:

  • Spinal pain or tenderness
  • Blunt trauma
  • An altered level of consciousness
  • Neurological deficits
  • Obvious anatomic deformity of the spine
  • High-energy trauma (i.e., vehicle accidents, motorcycle accidents, ejection from a vehicle)
  • Falls
  • Diving accidents

Cervical Collars

Cervical collars are rigid immobilization devices that provide preliminary, partial support. Keep in mind that cervical collars do not fully immobilize the cervical spine. Therefore, you must maintain manual support until the patient has been completely secured to a backboard.


The backboard, also called a spinal board, provides rigid support while moving patients with a suspected spinal injury. They are also used for patients with leg injuries and for extrication purposes.

In the prehospital setting, full spinal precautions describe a patient who has a c-collar applied, is placed on a backboard with straps to hold the body, and whose head is secured to the board in line with the spine.

In the field, you may hear EMS personnel use the term “C-spine precautions” or just “C-spine” when referring to their patient. However, it does not refer only to the c-collar; it relates to full spinal precautions. For example, an EMS provider may report to the hospital that their patient is in “C-spine.” Each agency uses different terminology, so use what is appropriate for the provider you work for.


Straps are used to secure a patient to a backboard. There are a variety of different strapping techniques, so it is important to be familiar with what your EMS provider carries. Some backboards come with permanently applied straps, while others have different locations on the board where you can apply a removable strap based on the patient’s size. Some straps go directly across the body, while others are placed in a crisscross method.

The Log Roll

After placing a c-collar on your patient, you need to move them onto the backboard while maintaining manual stabilization of the head in line with the body. The best procedure for doing this is called the four-person log roll.

If you do not have four responders at the scene, you may need to recruit bystanders and instruct them on the technique before moving the patient. The EMT who is manually stabilizing the head is the team leader for this procedure. If you are the team leader, your job is to ensure the head, torso, and pelvis move as one unit.


There are many different types of shock. As it relates to trauma, we will be referring to hypovolemic shock, which is due to blood or fluid loss. When caused by uncontrollable bleeding, or hemorrhage, it can be called hemorrhagic shock.

Shock is defined as inadequate perfusion of the body’s cells and tissues caused by insufficient blood flow through the capillaries. These are the typical signs and symptoms of hypovolemic shock:

Altered mental status: Occurs because the brain is not receiving enough oxygen.

Pale, cool, clammy skin: Occurs when blood is being directed away from the skin to vital organs such as the brain and heart.

Nausea and vomiting: While the body continues to keep perfusing vital organs, blood is diverted from the digestive system.

Changes in vital signs: The first changes you will see are in the patient’s pulse and respirations. The pulse will increase to pump more blood. As the pulse increases, it becomes weak and thready. Respirations will also increase in an attempt to increase the amount of oxygen in the blood. Respirations will become shallower and more labored as shock progresses. Blood pressure is one of the last signs to change. The patient is clearly in a life-threatening state when their blood pressure drops.

Other signs: Increased thirst, dilated pupils, and cyanosis around the lips and nail beds.

How to Treat Shock

As soon as you identify possible shock, you must begin immediate treatment. As with any type of patient care, you should begin by following standard precautions. Control all obvious external bleeding. Place dry, sterile dressings over the bleeding sites and secure them with bandages. If direct pressure is not rapidly successful in the control of bleeding from an extremity, apply a tourniquet proximal to the bleeding site. Make sure the patient has an open airway and apply high-flow oxygen or artificial ventilation if needed. Keep the patient warm to prevent heat loss and transport to the most appropriate medical facility following local protocols.

Trauma Review Test

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