
Hard Hits: Blunt Force Trauma
The above radiograph shows a displaced trimalleolar fracture resulting from a blunt force injury.
Trauma is the leading cause of morbidity and mortality in Americans aged 1-55 years, resulting in more than 100,000 deaths annually.[1] Blunt force trauma, also known as nonpenetrating trauma, accounts for a large proportion of morbidity and mortality. This type of trauma can be defined as physical injury caused by forceful impact to the body; it may result from motor vehicle accidents/collisions (MVAs/MVCs), falls, assaults, or sporting accidents.
Hard Hits: Blunt Force Trauma
Blunt Head Trauma
The above image shows a severe soft-tissue defect of the forehead resulting from blunt trauma.
Head injuries caused by blunt force trauma require specialized management that is focused on preventing secondary neurologic injury.[2] Initial assessment of the patient should include a thorough neurologic examination (eg, Glasgow Coma Scale [GCS] score,[2] pupillary examination, and evaluation for signs of skull fracture, such as periorbital ecchymosis [raccoon eyes], mastoid ecchymosis [Battle sign], and cerebrospinal fluid [CSF] drainage from the nose or ears[3]).
If the patient's evaluation indicates significant trauma, rapid-sequence intubation should be considered for airway protection.[4]
Hard Hits: Blunt Force Trauma
The above computed tomography (CT) scan shows a subdural hematoma resulting from trauma. The thin arrows denote the spread of the hematoma; the thick arrows mark the midline shift of the ventricles.
Intracranial hypertension
Traumatic brain injuries (TBIs) can cause swelling in the brain; because the skull is an enclosed space, volume expansion due to continued bleeding or edema may result in increased intracranial pressure (ICP). Ideally, ICP should be kept below 20 mmHg, with a cerebral perfusion pressure (CPP) of 60 mmHg.
Hard Hits: Blunt Force Trauma
Concussion
A concussion results from blunt trauma to the head and can cause a change in mental status with or without loss of consciousness (LOC).[5]
Images A and B (top left and right) denote computer modeling of shear stress forces within the brain following a strong blow to the head in helmet-to-helmet American football impacts.
Images C and D (bottom left and right) reveal core brain regions with significant volume reduction (yellow) and increase (blue) in patients with severe TBI, between 8 weeks and 12 months post injury.[6,7] Coronal (C) and sagittal (D) sections through the brain show severe tissue shrinkage (orange) in the core brain regions encompassing the basal ganglia and brainstem, respectively.
Hard Hits: Blunt Force Trauma
Postconcussion syndrome
Patients should be advised to be aware of symptoms of postconcussion syndrome, which can develop over the weeks following an event.
The above T1-weighted coronal magnetic resonance imaging (MRI) scans are from a male adolescent with TBI (left column) and an age-matched control subject (right column).
Top row, left: The upper left arrows point to a prominent interhemispheric fissure and prominent cortical sulci in the patient with TBI, indicating global brain-volume loss and generalized cerebral atrophy. The lower arrow indicates an atrophic hippocampus and dilated temporal horn, seen bilaterally.
Middle row: Dorsal view of a three-dimensional (3D) reconstruction of the ventricles (blue) superimposed on a 3D reconstruction of the surface of the two brains. The ventricle-to-brain ratio (VBR) in the TBI brain (left) is markedly deviant from that in the normal brain (right).
Bottom row: Frontal view of the 3D-reconstructed brains. In the TBI brain (left), as compared with that of the age-matched control subject (right), there is global frontal atrophy with visibly larger cortical sulci, representative of generalized cerebral atrophy. An increased VBR reflects this type of global brain-volume loss, ventricular enlargement, gyral shrinkage, and sulcal enlargement.
Hard Hits: Blunt Force Trauma
Cervical spine injuries
The above anteroposterior and lateral radiographs demonstrate bilateral C5-C6 dislocation in a patient after a fall and head injury.
More than 6% of patients who sustain blunt force trauma will have some form of cervical spine (C-spine) injury, with MVAs and higher injury severity scores being risk factors.[8] After a traumatic injury, many patients will meet the criteria for requirement of C-spine protection and imaging.
Hard Hits: Blunt Force Trauma
Blunt Thoracic Trauma
The above image depicts a 3D reconstruction, from a CT scan, of a flail chest.
Blunt trauma to the thorax can result in life-threatening injuries. Of particular concern are injuries to the airway as well as flail chest, pneumothorax, hemothorax, and tension pneumothorax.[9]
A flail chest is defined as fracture of three or more contiguous ribs in two or more locations (anterior, posterior, and lateral).[10] These fractures create a segment of chest wall that is not in sync, causing paradoxical movement, wherein the injured section of chest does not move in conjunction with the rest of the thoracic cage during respiration.[10]
Hard Hits: Blunt Force Trauma
Pulmonary contusion
The above images are from an 89-year-old woman on anticoagulation who presented to the ED after a ground-level fall. She sustained five rib fractures, pulmonary contusions, and a small hemothorax.
Pulmonary contusions are seen in blunt thoracic trauma and can be diagnosed on chest radiographs or CT scans.[11] Lung hemorrhage and edema cause impaired gas exchange and hypoxia and may progress to acute respiratory distress syndrome (ARDS).[12] Patients may demonstrate dyspnea, tachypnea, chest pain, or hemoptysis. Crackles or diminished breath sounds may be noted on chest auscultation.[11]
Hard Hits: Blunt Force Trauma
Pneumothorax, tension pneumothorax, and hemothorax
A tension pneumothorax is shown above.
Although more common following a penetrating chest injury, a pneumothorax can also result from blunt chest trauma.[13] A broken rib can lacerate the pleura or lung and allow air or blood to enter the pleural space.[14]
If the defect acts as a one-way valve so that air can escape into the pleural space but is then trapped there, a tension pneumothorax may result.[13]
A hemothorax occurs when the pleural space fills with blood from the lung, chest wall, heart, major vessels, or intercostal vessels.[15]
Hard Hits: Blunt Force Trauma
Acute respiratory distress syndrome
ARDS is a frequent complication of significant blunt thoracic trauma.[12]
The above images demonstrate a series of chest radiographs and CT scans obtained over a period of 18 hours in a patient who sustained blunt thoracic trauma. The initial chest radiographs (top row, first and second images) appeared normal. Pulmonary changes developed rapidly, first as a mild opacification at the right lung base and then as a lung parenchymal infiltrate associated with a small pleural effusion (top row, third and fourth images).
Axial CT scans (bottom) revealed that the opacity was in the peripheral lung, near the injured chest wall.
Hard Hits: Blunt Force Trauma
Blunt Cardiac Trauma
The above image is an admission electrocardiogram in a 47-year-old man who fell from a height of 19.7 feet (6 m), sustaining a cardiac contusion that manifested as cardiogenic shock. Note the 1-mm ST-segment elevation in the lateral leads, with an associated right bundle-branch block and ventricular beats in couplet.
Blunt cardiac trauma should be suspected whenever patients have significant trauma to the chest, including first or second rib fractures or sternal fractures, or have been injured via a severe mechanism such as an MVA with a broken steering wheel column.[9,16]
Hard Hits: Blunt Force Trauma
Thoracic aortic injury
The above CT scan shows the intimal flap seen in aortic dissection (red arrows). The presence of a pericardial effusion (blue arrow), a common sequela of aortic dissection, is apparent.
Blunt traumatic aortic injury is the second most common cause of death in trauma victims; the majority of persons with this injury die at the scene (80-85%).[17] Of those who survive transport to a hospital, half will die in the first 24 hours.[17]
Injuries to the aorta are normally the result of acceleration-deceleration forces, which cause tearing of the aortic wall.[18] CT angiography (CTA) is the definitive diagnostic test for evaluation of acute traumatic aortic injuries.[19]
Hard Hits: Blunt Force Trauma
Pericardial tamponade
The above ultrasonogram reveals pericardial effusion with tamponade.
Although more common in penetrating injuries, pericardial tamponade can also occur in blunt trauma. Signs of cardiac tamponade include the Beck triad, consisting of muffled heart sounds, hypotension, and jugular venous distention.[20] Patients may also show signs of obstructive shock, including tachycardia and cool extremities.[20]
Hard Hits: Blunt Force Trauma
Blunt Abdominal Trauma
The above images were obtained from a 6-year-old girl who sustained multiple traumatic injuries following blunt abdominal trauma. The patient had injuries to both kidneys (a), the liver and spleen (d), and the pancreatic body (e). In addition, she had bilateral hemothoraces (b, c) and bilateral acetabular fractures (f).
In patients who sustain blunt abdominal trauma, the spleen is the most commonly injured organ, followed by the liver, kidneys, and small and large intestines.[21]
Hard Hits: Blunt Force Trauma
Pelvic Fractures
Pelvic fractures result from high-velocity injuries.[22] The above pelvic radiograph reveals fractures of the superior and inferior right ramus in a pregnant patient with MVA multitrauma. The photograph (inset) shows the state of the involved vehicles at the scene of the crash. The patient also suffered extensive lacerations to the vaginal, perineal, and rectal areas and had additional fractures of the proximal right tibia and the shaft of the left fibula.
Pelvic fractures are commonly associated with vascular damage with significant bleeding; hemorrhagic shock may result.[22-24] Neurologic injuries to the lumbosacral plexus may also occur, typically involving L4-5 or S1.[22] Injuries to the urethra and bladder must be considered as well.[22]
Hard Hits: Blunt Force Trauma
Crush Injuries
Crush injuries are a type of blunt trauma that results from compression of a body part by direct force, usually for a prolonged period (>4 hours).[25] The injuries result from direct compression, which decreases perfusion to the region.
The above images are from a 44-year-old man who was crushed under a heavy vehicle and mechanical parts, sustaining traumatic asphyxia with severe thoracic injury and mild brain edema. The chest radiograph (left), obtained after placement of bilateral tube thoracostomies, shows multiple rib fractures and subcutaneous emphysema as well as multiple lung opacities; the opacities correspond to sites of lung contusion. Residual pneumothorax in the left lung is also demonstrated. The CT scan (right) reveals the presence of bilateral hemopneumothoraces and multiple lung contusions.
Hard Hits: Blunt Force Trauma
Compartment syndrome
Compartment syndrome is a complication of blunt trauma and may occur in the extremities over time after a fracture or crush injury or after reperfusion of ischemic tissue.[25-27] Brisk swelling in muscle compartments following the injury increases the compartment pressure on the arterial supply to a limb, resulting in vascular compromise, limb ischemia, and, potentially, loss of limb.[25-27]
The images in the slide were obtained from a middle-aged male patient who was struck by a car 1 day before presentation. Significant swelling of the left thigh was apparent (left). An anteroposterior left femur radiograph (center) showed no fractures. A small incision (top right) was made through the fascia to evaluate the viability of the quadriceps muscles. A partial fasciotomy (center right) was performed while the muscles were still under pressure. A complete anterolateral fasciotomy (bottom right) was performed, with the muscles escaping the high intracompartmental pressure.
Comments