EMT-Basic Exam: The Basics of Trauma - Bleeding and Shock

Trauma calls are some of the most difficult situations that EMT-Basics must deal with on the job. Trauma-related injuries often involve bleeding, shock, soft tissue damage, musculoskeletal damage, and injuries to the head and spine. Although every case is different, it is important for EMT-Basics to understand what they might encounter on a trauma call.
About 16 percent of the questions that you encounter on the EMT-Basic exam will test your knowledge of trauma-related injuries and quiz you on how best to handle these situations. Remember, this guide does not cover everything that you will see on the exam, so it’s important to review what you’ve already learned about trauma-related situations. 

Bleeding and Shock
Bleeding and shock are two of the most common trauma-related injuries you will encounter as an EMT-Basic. In most cases, your initial assessment of the patient will help you determine where the patient is injured and how he or she must be treated. However, internal bleeding can be difficult to recognize, and symptoms of shock are not always clear. Because such injuries can quickly lead to death, it is vital that EMT-Basics understand how to identify and treat these cases.

1. The Cardiovascular System
Before discussing the treatment of blood loss and shock, it is important for you to have a good understanding of the cardiovascular system. As you already know, the cardiovascular system supplies the body’s organs with blood and nutrients using a complex network of veins, capillaries, and arteries powered by the heart. Most adults have about 5 to 7 liters of blood in their bodies. Blood performs a task known as perfusion. Perfusion is the process by which blood transports oxygen to and removes waste products from bodily organs. Some organs, particularly the brain, require a constant stream of oxygen and nutrients. When the brain’s blood supply is impaired, even for a short period of time, changes in mental status may occur.
Blood is pumped through the entire body of an average adult heart at a rate of 60 to 100 beats per minute. At this rate, the body’s entire blood volume can be circulated through the whole system in under a minute. When a patient experiences stress or a medical emergency, the heart rate can increase significantly.
One important factor in perfusion is blood pressure. There are two forms of blood pressure. Diastolic blood pressure is the pressure present in the blood vessels when the heart is at rest. Systolic blood pressure refers to the intermittent rise in pressure that occurs when the heart contracts and blood is forced out into the arteries. Healthy blood pressure is a key element of proper perfusion.

2. Shock
An interruption in blood flow can result in cell and organ damage. Severe bleeding depletes the cardiovascular system’s blood supply, leading to a decrease in perfusion. A decrease in perfusion causes a condition known as hypoperfusion. When hypoperfusion starts to affect the entire body, the patient enters into shock. Shock occurs when vital organs are no longer being properly perfused by the cardiovascular system. In cases of shock, organ tissues are damaged by the accumulation of waste products and the lack of oxygen. As damage to the organs progresses, organ failure and death may occur.
Although there are many types of shock, the most common form of shock EMT-Basics will be required to treat in the field is hypovolemic shock. This type of shock results from inadequate blood volume and can be caused by problems with the heart, blood, or blood vessels. Other causes include dehydration, vomiting, diarrhea, or severe blood loss.
Your most important responsibilities are to determine what stage of shock the patient is in and the best course of treatment. Recognizing the signs of early shock allows you to transport and treat the patient before the onset of late shock. Most of the signs and symptoms of shock are connected with the body’s struggle to maintain perfusion in the event of blood loss. As hypoperfusion sets in, blood flow to the skin is reduced because of blood vessel constriction. This may cause your patient’s skin to become pale, cool, and clammy. Vessel constriction also leads to a decrease in peripheral perfusion, which causes weak peripheral pulses.
Elevated heart rate is a critical sign of shock, as the heart rate will rise as the heart attempts to pump the remainder of the body’s blood volume faster. In early shock, elevated heart rate and the constriction of blood vessels allow for the maintenance of normal blood pressure. As the blood volume decreases, blood pressure will fall to abnormally low levels. This is a sign of late shock. A patient at this stage is near death. The patient’s breathing rate may increase as he or she tries to oxygenate the remaining blood in the cardiovascular system. When shock worsens, the patient may exhibit shallow, labored, or irregular breathing.
In some cases, a change in mental status due to impaired blood flow to the brain may be a later symptom of shock. Patients may become anxious, restless, or combative. Recognizing changes in mental status is particularly important for patients experiencing shock related to internal bleeding, as these, along with changes in vital signs, may be the only apparent symptoms of this potentially fatal condition.

Tip: Other possible signs of shock may include excessive thirst, nausea, vomiting, sluggishly reactive pupils, or cyanosis of lips, nail beds, and mucous membranes.
The first task in treating a patient in shock is to ensure a patent airway. This is particularly important for trauma patients, who may have various airway obstructions. Once the airway is cleared, you should give the patient high-flow oxygen and ensure adequate ventilation. Then, you should attempt to control any serious bleeding. If there are no injuries that would inhibit moving the patient, you should elevate the legs in order to maximize blood flow to the brain. Also, keep the patient warm to prevent shivering, which would waste energy and oxygen. Next, you must quickly transport the patient to a medical facility where more advanced treatments are available.

3. External Bleeding
The volume of blood loss a patient can withstand before shock develops depends on the patient’s size. Smaller patients and children have a naturally lower blood volume and will most likely develop shock quickly if left untreated. Elderly patients are also at risk of an earlier onset of shock because their hearts may not be capable of meeting an increased demand. The severity of blood loss can be measured based on the patient’s signs and symptoms.
When an injury causes blood loss, the body tries to stop the blood flow with vessel constriction and blood clotting. Some injuries may cause excessively forceful bleeding that the body can’t stop on its own. This uncontrolled bleeding can lead to shock.

There are three type of bleeding:
- Arterial bleeding occurs after damage to an artery. Highly pressurized blood may spurt out of a wound. Blood loss from this type of injury is rapid and shock may begin very quickly. External arterial bleeding will produce bright red, oxygen-rich blood. The high pressure of arterial blood makes this type of bleeding the most difficult to control.
- Venous bleeding originates from a vein and produces dark red blood that flows steadily from the wound. The lower pressure of venous blood makes this type of bleeding easier to control.
- Capillary bleeding results from scrapes and abrasions and will produce dark red, oozing blood. This type of bleeding is easily treatable and usually clots on its own.
All forms of bleeding require the same basic treatments. Because most bleeding is localized to one main artery or vein, the best way to control blood loss is with concentrated direct pressure. Use your fingertip to press directly on the bleeding point with sterile gauze. Try not to remove the gauze frequently, as this may break up clots that have started to form.
For large injuries or situations where bleeding is occurring at more than one location, diffuse direct pressure may be applied. When using this method, place sterile gauze pads on the injury and apply pressure using the entire hand. This decreases blood flow to the injury site. In the event that blood starts seeping though the gauze, add more layers on top. Don’t remove the initial layer of gauze at any time.
In cases where the patient shows no signs of swelling, pain, or deformity, you may raise the affected extremity above the level of the heart. This helps to reduce blood flow to the injury site.
You can also slow bleeding by utilizing pressure points. A pressure point is a place in an extremity where a major artery lies close to the bone. Applying pressure on these areas can reduce blood flow to that extremity. These are the same locations where you are able to palpate the patient’s pulse.
Splints may be used to help control bleeding caused by skeletal injuries. When you immobilize a bone injury with a splint, you decrease the movement of broken bone ends that can cause damage to blood vessels and tissues. Immobilization of the lower extremities can be accomplished with the use of pneumatic antishock garments. These devices are placed on the lower extremities and inflated with air. This diffuse pressure immobilizes limbs and helps control bleeding.
Tourniquets have traditionally been used as a last-resort option for controlling bleeding because of the risk of permanent damage to muscles, nerves, and blood vessels. Extensive damage to an extremity can lead to the need for amputation, so tourniquets should only be used in situations where there is clearly a life threat. However, if the patient is already in shock and you are unable to control hemorrhage from an extremity with direct pressure, a tourniquet should be immediately applied to prevent the patient from further deterioration.
Blood loss from certain areas of the body may require different forms of treatment. Bleeding from the ears or nose may indicate a skull fracture. In this instance, the ears and nose should be lightly covered with sterile gauze. Facial bleeding caused by trauma can usually be treated with direct pressure. A bloody nose, or epistaxis, can be caused by blunt force to the nose or digital trauma, such as finger insertion. As long as no spinal injuries are present, you can treat a nosebleed by placing the patient in a seated, forward-leaning position and pinching the fleshy part of the nostrils together.

4. Internal Bleeding
Compared to external bleeding, internal bleeding can be more difficult to recognize and harder to control. Internal bleeding is bleeding inside the body. Internal blood loss can result in a rapid onset of shock and cannot be treated in the field. The goal of an EMT-Basic is to recognize the signs of internal bleeding and transport the patient to a medical facility capable of surgical intervention as quickly as possible.
When internal organs are damaged, they may bleed into the thoracic and abdominal cavities. Skeletal trauma may cause damage to blood vessels and blood loss into the extremity. Because there may not be any apparent signs of internal bleeding, this diagnosis is generally based on the mechanism of injury and the patient’s other symptoms. In many cases, the only sign of internal bleeding is the onset of shock.
One important possible indication of internal bleeding is bleeding from the mouth, rectum, or genitals. Even when these types of external blood loss appear minor, the internal bleeding causing it may be severe. Additional signs and symptoms of internal bleeding may include swelling, discoloration of the skin, and pain.
In some cases, internal bleeding may occur inside the gastrointestinal tract. The specific characterizations of blood that exits the gastrointestinal tract can indicate the exact location of the bleeding and when it started. Blood in the stomach is very irritating to its lining and frequently causes vomiting. This may produce vomit tinged with bright red blood. If vomiting is delayed for a period of time, it can become mixed with digestive fluids, and, when regurgitated, appears dark brown in color with a consistency similar to coffee grounds.
Blood in the intestinal tract that is partially digested usually results in dark, tarry stool. Undigested blood that originates in the lower intestinal tract usually results in stool with bright red blood.
Damaged abdominal cavity blood vessels can cause massive, hard-to-control internal bleeding. Blood that is trapped in the abdominal cavity can cause distention, rigidity, and tenderness.
On-scene treatment of internal bleeding is generally limited to maintaining a patent airway, supplemental oxygen, and rapid transport. When internal bleeding is caused by an injury to an extremity, you can reduce bleeding with direct pressure and splinting. The use of a pneumatic antishock garment may be necessary when a patient shows signs of shock, has abdominal tenderness, or has a pelvic injury.

Related Topics You Should Review:
- Cardiovascular anatomy and physiology
- Specific types of shock