Blunt trauma

A blunt trauma, also known as a blunt force trauma or non-penetrating trauma, is a physical trauma due to a forceful impact without penetration of the body's surface. Blunt trauma stands in contrast with penetrating trauma, which occurs when an object pierces the skin, enters body tissue, and creates an open wound. Blunt trauma occurs due to direct physical trauma or impactful force to a body part. Such incidents often occur with road traffic collisions, assaults, and sports-related injuries, and are common among the elderly who experience falls.

Blunt trauma can lead to a wide range of injuries including contusions, concussions, abrasions, lacerations, internal or external hemorrhages, and bone fractures. The severity of these injuries depends on factors such as the force of the impact, the area of the body affected, and the underlying comorbidities of the affected individual. In some cases, blunt force trauma can be life-threatening and may require immediate medical attention. Blunt trauma to the head and/or severe blood loss are the most likely causes of death due to blunt force traumatic injury.

Blunt abdominal trauma (BAT) represents 75% of all blunt trauma and is the most common example of this injury. Seventy-five percent of BAT occurs in motor vehicle crashes, in which rapid deceleration may propel the driver into the steering wheel, dashboard, or seatbelt, causing contusions in less serious cases, or rupture of internal organs from briefly increased intraluminal pressure in the more serious, depending on the force applied. Initially, there may be few indications that serious internal abdominal injury has occurred, making assessment more challenging and requiring a high degree of clinical suspicion.

There are two basic physical mechanisms at play with the potential of injury to intra-abdominal organs: compression and deceleration. The former occurs from a direct blow, such as a punch, or compression against a non-yielding object such as a seat belt or steering column. This force may deform a hollow organ, increasing its intraluminal or internal pressure and possibly leading to rupture.

Deceleration, on the other hand, causes stretching and shearing at the points where mobile contents in the abdomen, like the bowel, are anchored. This can cause tearing of the mesentery of the bowel and injury to the blood vessels that travel within the mesentery. Classic examples of these mechanisms are a hepatic tear along the ligamentum teres and injuries to the renal arteries.

When blunt abdominal trauma is complicated by 'internal injury,' the liver and spleen (see blunt splenic trauma) are most frequently involved, followed by the small intestine.

In rare cases, this injury has been attributed to medical techniques such as the Heimlich maneuver, attempts at CPR and manual thrusts to clear an airway. Although these are rare examples, it has been suggested that they are caused by applying excessive pressure when performing these life-saving techniques. Finally, the occurrence of splenic rupture with mild blunt abdominal trauma in those recovering from infectious mononucleosis or 'mono' (also known as 'glandular fever' in non-U.S. countries, specifically the UK) is well reported.

The supervised environment in which most sports injuries occur allows for mild deviations from the traditional trauma treatment algorithms, such as ATLS, due to the greater precision in identifying the mechanism of injury. The priority in assessing blunt trauma in sports injuries is separating contusions and musculo-tendinous injuries from injuries to solid organs and the gut. It is also crucial to recognize the potential for developing blood loss and to react accordingly. Blunt injuries to the kidney from helmets, shoulder pads, and knees are described in American football, association football, martial arts, and all-terrain vehicle crashes.