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Blunt Trauma

What Is It, Diagnosis, Outcomes, and More

Author: Lily Guo

Editors: Ahaana Singh, Lisa Miklush, PhD, RN, CNS

Illustrator: Abbey Richard

What is blunt trauma?

Blunt trauma, also known as non-penetrating trauma or blunt force trauma, refers to injury of the body by forceful impact, falls, or physical attack with a dull object. Penetrating trauma, by contrast, involves an object or surface piercing the skin, causing an open wound. Blunt trauma can be caused by a combination of forces, including acceleration and deceleration (the increase and decrease in speed of a moving object), shearing (the slipping and stretching of organs and tissue in relation to each other), and crushing pressure.

Blunt trauma can generally be classified into four categories: contusion, abrasion, laceration, and fracture. Contusion—more commonly known as a bruise—is a region of skin where small veins and capillaries have ruptured. Abrasions occur when layers of the skin have been scraped away by a rough surface. Laceration refers to the tearing of the skin that causes an irregular or jagged-appearing wound. Lastly, fractures are complete or partial breaks in bone. Such injuries can often occur in motor vehicle crashes, sports injuries, physical assaults, and falls.

What is blunt trauma death?

Blunt trauma death refers to physical trauma to the body by way of fall, impact, or attack, that results in death. Head trauma and severe loss of blood are the most common causes of death due to blunt traumatic injury. Severity of the injury depends on the mechanism and extent of injury. Typically, a large force applied to a sizable area over several minutes will result in vast tissue damage, which increases the chance of death. Whereas a smaller force applied to a smaller area will result in less tissue damage. 

Severity of injury also depends on the underlying age and health of the individual. For example, elderly patients have been identified as having some of the highest injury-related mortality rates. This has been attributed to several factors including reduced cardiopulmonary reserve, which is a measure of heart and lung function, as well as poor nutritional status, and propensity for bleeding after fractures.

Which organs are most likely to be injured by blunt trauma?

The majority of blunt trauma cases are from motor vehicle crashes and pedestrian injuries often resulting in abdominal injuries. These injuries are typically attributed to collisions between the individual and the external environment, or to acceleration and deceleration forces acting on the individual’s internal organs. 

Within the abdomen, the spleen is the most commonly injured organ, followed by the liver. The kidneys, bladder, diaphragm, and the large and small intestines may also be affected. Injuries to the internal organs can lead to hemorrhage (release of blood from damaged blood vessels). This may result in hypotension, or a decrease in blood pressure, and more severely, hypovolemic shock. This occurs when the volume of blood in the body is too low, resulting in circulatory failure. Hypovolemic shock can be life-threatening and can lead to organ failure.

How is blunt trauma diagnosed?

When assessing possible abdominal trauma, physicians look for abdominal pain, tenderness, nausea, and vomiting. In cases of motor vehicle crashes, the presence of a positive ‘seatbelt sign’, appearing as bruising in a horizontal or diagonal band that corresponds to a seatbelt across the abdomen, chest, or neck, indicates an increased likelihood that the individual has an intra-abdominal injury. If serious trauma is suspected, imaging techniques, such as X-rays, CT scans, and ultrasound imaging, can also be used to detect fractures and internal injury.

If a hollow organ, such as the small or large intestine, ruptures upon injury, it is considered a medical emergency and requires immediate medical attention. In addition to diagnostic imaging, providers may use a diagnostic peritoneal lavage to determine if there is free floating fluid, such as blood, in the abdominal cavity. The procedure entails inserting a catheter into the peritoneal cavity, or the sac around the abdominal cavity. After insertion, any free floating blood or fluid is drawn out. If necessary, sterile saline is then infused to wash out the cavity.

Can blunt force trauma cause blood clots?

Blunt force trauma can often lead to bruising and blood clots. Bruising occurs when the blood vessels on the surface of the soft tissue of skin are broken, typically resulting in a temporary discoloration of the skin. Subsequently, the body forms clots, or semi-solid masses of blood, as a natural reaction to prevent an excess loss of blood from injured vessels or tissues. 

A specific type of blood clot that may be cause for larger concern is a deep vein thrombosis (DVT), which can occur after there has been damage to the inner lining of a vein. This damage can occur as a result of blunt trauma. Deep vein thrombosis typically forms deep in the legs, but can occur in other parts of the body, such as the arm. The most serious complication of DVT occurs when a part of the clot breaks off and travels through the bloodstream to the lungs, causing a blockage known as a pulmonary embolism. A pulmonary embolism is considered a medical emergency and requires immediate medical attention. Additionally, DVT can lead to long-term complications caused by the damage the clot does to the valves in the vein—this is known as post-thrombotic syndrome (PTS). Individuals with PTS often have symptoms such as swelling, pain, discoloration, and in severe cases, scaling or ulcers in the affected part of the body.

Can blunt force trauma cause aneurysms?

If there is blunt force trauma to the head and skull, there may be a risk for aneurysms, or enlarged and weakened arteries in the brain. For example, hitting one’s head against the steering wheel in a motor vehicle crash could cause blunt force trauma to the head. Brain aneurysms due to blunt and penetrating head injuries are rare, however, and make up less than 1% of all cases.

Can blunt force trauma cause miscarriages?

Blunt injury during pregnancy can cause miscarriages, especially if it occurs after the first trimester of the pregnancy. The most common mechanisms of injury are motor vehicle crashes, falls, and assaults. The effects of traumatic injuries on the pregnancy largely depends on the gestational age of the fetus, as well as the type and the severity of the trauma. In the beginning of pregnancy, the uterus is protected by the pelvis, so a miscarriage caused by blunt trauma to the abdomen is unlikely. If, however, the pregnancy is in its second or third trimester, the outcomes can be more severe. At this point, the uterus begins to expand above the pelvis, and the placenta has fully formed. If there is rapid deceleration, acceleration, or direct injury to the pregnant abdomen during this period, the placenta can detach from the uterus. Such placental abruption, or detachment of the placenta, is associated with complications, such as loss of blood from both the birth parent and fetus, uterine rupture, and miscarriage. Diagnostic ultrasound imaging and fetal heart rate monitoring may be used in emergency medical situations to determine the extent of injury.

What are the most important facts to know about blunt trauma?

Blunt trauma refers to injury of the body by forceful impact with a dull object. With blunt force trauma, there can be internal organ injuries that are not immediately visible. Common organs that are affected include the spleen, liver, and small intestine. Injuries to internal organs can lead to hemorrhage and sudden drop in blood pressure. If not diagnosed promptly, this can lead to hypovolemic shock. The formation of blood clots is a common occurrence with blunt trauma injuries, and, in most cases, is not cause for concern. If more severe blood clots, such as a deep vein thrombosis, forms, medical attention may be required. Aneurysms are a less common complication of blunt head trauma, but can occur in rare instances and prove to be fatal. If a pregnant person suffers a traumatic injury during pregnancy, there is a risk of miscarriage depending on the stage of pregnancy and severity of the trauma. Diagnosis for blunt trauma injuries primarily focuses on physical examination and imaging tests. If internal organ damage is suspected, additional tests may be required. 

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