Summary
Blunt force trauma (BFT) is any nonpenetrating injury resulting from the impact of a blunt object against the body (e.g., a vehicle-pedestrian collision) or impact of the body against a blunt object or surface (e.g., a fall from height). Common causes include motor vehicle crashes, falls, and being struck by an object (e.g., sports injuries). Low-impact BFT can result in dermal contusions and/or abrasions that only require supportive treatment, whereas high-impact BFT, especially of the head, thorax, and abdomen can cause severe internal organ injury in addition to skin injury and represents a major cause of morbidity and mortality in all age groups. First response in severe BFT focuses on stabilizing vital signs, airway and circulation management. FAST and CT imaging are used to detect intraabdominal bleeding and organ damage, while chest x-ray is the most important initial diagnostic tool in the assessment of blunt force chest and abdominal trauma. Treatment depends on the hemodynamic status of the patient as well as the type of injury, which may require emergency surgery. Conservative management with close monitoring is indicated for hemodynamically stable patients.
For information on prehospital care and general principles of trauma management, see “Prehospital trauma care.” Penetrating trauma is discussed in a separate article.
General
Epidemiology [1]
- Unintentional injuries are the fourth leading cause of death overall and the leading cause of death in individuals under 35 years of age. [2]
- Most serious unintentional injuries are caused by BFT, mainly from motor vehicle crashes and vehicle-pedestrian collisions.
Classification [1]
- Four main BFT categories:
- Abrasion: a superficial skin injury due to rubbing, scraping, or irritation
- Contusion: an injury associated with localized ischemia, edema, and/or mass effect due to the rupture of blood vessels, usually as a result of direct trauma
- Laceration: a deep cut or tear in the skin and/or underlying tissue, typically caused by blunt or shearing forces.
- Fracture: a partial or complete interruption in the continuity of a bone
Blunt trauma injury mechanisms [1]
BFT typically results from the impact of a blunt object against the body or impact of the body against a blunt object or surface. The most common causes of BFT are motor vehicle crashes, vehicle-pedestrian collisions, falls from height, and bicycling injuries. [3]
-
Motor vehicle crashes
- Injury by type of collision
- Head-on collision: facial, aortic, and lower extremity injuries
- Rear-end collision: central cord syndrome, cervical spine fractures, spinal hyperextension injuries (see “Vertebral fractures”)
- Lateral collision: clavicle fractures, humerus fractures, rib fractures, and thoracic, abdominal, and pelvic injuries
- Specific types of injuries
- Windshield-related injuries: facial fractures, skull fractures, cervical spine fractures, head injuries, coup contrecoup injuries
- Seatbelt-related injuries: rib fractures and sternal fractures, injuries and fractures of the head, face, and cervical spine, pulmonary contusions
- Airbag-related injuries: injuries and fractures of the upper and lower extremities, corneal abrasions, cervical spine injuries, burns
- Injury by type of collision
-
Vehicle-pedestrian collisions
- Low speed: knee injuries, fractures of the lower extremities (e.g., tibial fracture, femoral shaft fracture)
- High speed: Waddell triad, multisystem trauma
-
Falls from a height
- Vertical impact: head injuries, cervical spine fractures, lower extremity fractures, pelvic fractures, renal injuries
- Horizontal impact: facial fractures, thoracic and abdominal injuries, hand and wrist fractures, aortic injuries
- Bicycling injuries: head injuries, handlebar injuries, upper and lower extremity injuries (e.g., clavicle fractures, distal radius fractures)
- Assault: head injuries, facial fractures (e.g., zygomatic bone fractures, mandibular fractures)
Blunt abdominal trauma
Commonly affected systems [4]
The most commonly injured organs in blunt force abdominal trauma are the spleen (e.g., splenic rupture, laceration) and liver (e.g., liver hematoma, laceration).
-
Genitourinary tract
- Renal injuries (e.g., renal laceration, renal hematoma)
- Bladder injuries (extraperitoneal and/or intraperitoneal injuries)
- See “Genitourinary trauma”
-
Gastrointestinal tract
- Small bowel injuries: duodenal rupture, duodenal hematoma (more common in children)
- Pancreas: pancreatic contusion, laceration, or rupture (through direct impact, e.g., handlebar injury)
- Large bowel injuries
- Stomach injuries
- See “Gastrointestinal perforation”
- Diaphragm: diaphragmatic rupture
- Other
Clinical features of abdominal bleeding [4]
- Abdominal pain and/or tenderness
- Abdominal distention
- Abdominal guarding
- Decreased bowel sounds (due to peritoneal irritation)
- Abdominal bruising (e.g., seatbelt sign)
- Hemodynamic instability and/or shock (hypotension, tachycardia, cyanosis)
- Periumbilical ecchymosis and discoloration (Cullen sign)
- Flank ecchymosis (Grey Turner sign)
Clinical features of commonly affected organs [4]
-
Splenic injury
- Pain over the left costal margin (often due to fractured ribs 9–11)
- Referred pain in the left shoulder (Kehr sign)
-
Liver hematoma
- Referred pain in the right shoulder (due to diaphragmatic irritation)
- Ecchymoses over the lower right chest or RUQ
- Duodenal hematoma
-
Renal hematoma
- Flank tenderness and/or pain
- Ecchymosis and/or flank discoloration
- Hematuria (microscopic or gross hematuria)
Management [4]
-
Imaging
- Portable x-ray of the chest and pelvis
- Detects fractures, free intraabdominal air (e.g., due to diaphragmatic rupture), and large collections of blood
- Lower sensitivity than CT or FAST
-
Focused Assessment with Sonography for Trauma (FAST) exam
- Detects hemoperitoneum (collection of blood in the peritoneal cavity)
- Indicated for all hemodynamically unstable blunt abdominal trauma patients
-
CT scan
- Detects free abdominal fluid, solid organ injuries, retroperitoneal injuries (e.g., upper retroperitoneal hematomas)
- Abdominal and pelvic CT arteriograms may also be performed to detect vascular injuries or active arterial bleeding
- Portable x-ray of the chest and pelvis
-
Diagnostic peritoneal lavage (DPL)
- Performed by placing a catheter into the abdomen, aspirating, then instilling a warm saline.
- This highly sensitive but invasive procedure is gradually being replaced by the rapid, noninvasive FAST exam.
- Indications
- Hemodynamically unstable patients if FAST is inconclusive
- Hemodynamically unstable patients if FAST or CT cannot be performed
-
Laparotomy
- Performed in patients with severe injuries due to abdominal BFT
- Indications
- Hemodynamically unstable patients with a positive FAST exam and/or positive CT scan
- High suspicion of intraabdominal injury (e.g., large volume of intraperitoneal fluid on CT scan, unstable patient with unexplained hypotension)
- Signs of peritonitis
- Diaphragmatic rupture or injury
- Hollow organ injury (e.g., duodenal injury)
- Fecal matter or significant amounts of blood detected during DPL
- Hemodynamically stable patients with an inconclusive FAST scan
-
Laboratory studies
- CBC
- Blood glucose
- Liver function studies
- Prothrombin time
- Urinalysis
- Lactate
- Urine pregnancy test (on all individuals of child-bearing age)
Approach to blunt abdominal trauma
Initial management of abdominal BFT is focused on stabilizing, identifying potential intraabdominal bleeding, and treating life-threatening injuries.
-
Prehospital trauma care
- Resuscitation and stabilization (e.g., rapid transfusions, CPR)
- See “Primary survey.”
-
Initial assessment and examination
- See “Clinical features of abdominal bleeding” above.
- The absence of abdominal pain or tenderness does not exclude the presence of intraabdominal injuries.
-
Hemodynamically stable patients: initial risk assessment according to the mechanism of injury, physical examination (e.g., GCS, evidence of intoxication), and initial laboratory studies
- If the patient is alert:
-
FAST scan
- Negative findings of injury: serial examinations and additional tests (e.g., CT scan) if there is suspicion of injury
- Positive findings of injury: abdominal CT scan
- Inconclusive findings: laparotomy or DPL
-
Abdominal CT scan
- Negative findings of injury: close monitoring
- Positive findings of injury: close monitoring of vital signs or laparotomy
-
FAST scan
-
If the patient is not alert: perform abdominal CT scan and serial examinations
- Positive findings of injury in abdominal CT scan: close monitoring of vital signs or laparotomy
- Negative findings of injury in abdominal CT scan: serial examinations until the patient is alert
- If the patient is alert:
-
Hemodynamically unstable patients
-
FAST scan
-
Negative findings of injury: assess for additional signs of extraabdominal hemorrhage.
- If negative signs of extraabdominal hemorrhage: resuscitate with fluids, stabilize, and perform abdominal CT scans.
- If positive signs of extraabdominal hemorrhage: stabilize, resuscitate with fluids, and manage accordingly.
- Positive findings of injury: laparotomy
-
Negative findings of injury: assess for additional signs of extraabdominal hemorrhage.
- DPL
-
FAST scan
-
According to specific injuries
-
Splenic injury
- Hemodynamically stable patients: observation and supportive care
- Hemodynamically unstable patients: laparotomy
-
Liver injury
-
Hemodynamically stable patients
- Observation and supportive care
- Arteriography and hepatic embolization (according to liver injury grading)
- Hemodynamically unstable patients: laparotomy
-
Hemodynamically stable patients
-
Duodenal injury
- Hemodynamically stable patients: nasogastric suction and parenteral nutrition to promote healing
- Hemodynamically unstable patients: laparotomy and duodenal repair
-
Pancreatic injury
- Hemodynamically stable patients without other indications for laparotomy: nasogastric suction and enteral nutrition
- Hemodynamically unstable patients or if there is a high suspicion of pancreatic injury: repair, debridement, and percutaneous drainage (with culture) to prevent complications (e.g., fistulas, pseudocysts, abscesses)
- Retroperitoneal hematomas and hemorrhage: therapeutic angiography with embolization to control bleeding
-
Splenic injury
If significant intraabdominal injury is suspected, imaging should be performed even in the absence of pain.
Blunt chest trauma
Common associated injuries
- Aortic injury (highest lethality rate)
- Pneumothorax (e.g., tension pneumothorax)
- Blunt cardiac injury (e.g., cardiac contusion)
- Pericardial effusion and cardiac tamponade
-
Chest wall injuries
- Flail chest
- Sternal fracture
- Rib fracture
- Pulmonary contusion
- Hemothorax
- Tracheobronchial injury
- Diaphragmatic rupture
- Esophageal rupture
Clinical features
- Chest pain or tenderness
- Hemodynamic instability
- Dyspnea
- Abnormal breath sounds (e.g., diminished in pneumothorax)
- Jugular venous distention
Approach to blunt chest trauma
-
Primary survey
- Resuscitation procedures and stabilization (e.g., rapid transfusions, CPR)
- See “Prehospital trauma care.”
- Initial assessment and examination: : performed in hemodynamically unstable patients to rule out life-threatening conditions
-
Imaging
- Chest x-ray (initial test for all blunt chest trauma patients)
- Ultrasound (extended FAST)
- ECG (performed in all patients with anterior blunt chest trauma)
- Chest CT
- Other
-
Management
- Close monitoring of vital signs
- Appropriate surgical repair after stabilization of vitals
- Unstable patient: immediate surgery or emergency thoracotomy
Chest wall injury
Rib fracture
- Etiology
-
Clinical features
-
Pain on inspiration
- Respiratory distress
- Tachypnea
- Shallow breaths
- Crepitus
-
Flail chest
- Three or more adjacent ribs fractured in two or more places
- Paradoxical movement: the floating segment moves inward during inspiration and outward during expiration
- Focal chest wall tenderness
- Chest wall deformity
-
Pain on inspiration
- Diagnostics
-
Treatment
- Usually no surgery is necessary
-
Analgesia
- NSAIDs
- Opiates
- Local nerve block or epidural catheter
- Intubation with positive pressure ventilation in severe flail chest (bridge to surgery)
- In case of pneumothorax or hemothorax: thoracic drainage and thoracic surgical intervention
- Indications for surgery
- Significant chest wall deformity
- Severe flail chest
- Nonunion
-
Complications
- Pneumothorax
- Hemothorax
- Atelectasis/pneumonia: especially in the elderly individuals, caused by splinting and hypoventilation
- Pulmonary contusion
- Respiratory failure
- Fracture of the lower ribs → abdominal organ injury
Phrenic nerve paralysis
-
Anatomical course of the nerve
- Originates as a branch from the cervical plexus of C3–C5
- Passes ventrally on the anterior scalene muscle before descending into the chest wall
- Runs between pleura and pericardium accompanied by pericardiacophrenic artery and vein
- Supplies motor innervation of the diaphragm and sensory innervation of the pericardium, parietal pleura (mediastinal and diaphragmatic part), and peritoneum
-
Etiology
- Unilateral
- Trauma
- Iatrogenic (e.g., cardiac surgery)
- Compression (e.g., malignancy)
- Bilateral
- Motor neuron diseases (e.g., amyotrophic lateral sclerosis)
- Neuropathies (e.g., Guillain-Barré syndrome, post-polio syndrome)
- Cervical spine surgery
- Trauma
- Tumor
- Unilateral
-
Clinical features
-
Unilateral paralysis
- Often asymptomatic
- Exertional dyspnea possible
- Bilateral paralysis: severe dyspnea
-
Unilateral paralysis
-
Diagnostics
-
Unilateral phrenic nerve paralysis
-
Auscultation
- Decreased respiratory movement
- Dull on percussion
-
Chest x-ray
- Ipsilateral diaphragmatic elevation
- Possibly mediastinal shift
- Compression atelectasis
- Fluoroscopy: paradoxical elevation of the paralyzed hemidiaphragm on respiration or on asking the patient to sniff (sniff test)
-
Auscultation
- Bilateral phrenic nerve paralysis
- Spirometry: decreased vital capacity
- Diaphragmatic electromyography
-
Unilateral phrenic nerve paralysis
-
Treatment
- Ventilation may be required.
- Possible implantation of a diaphragmatic pacemaker
Cardiovascular injury
Blunt cardiac injury (BCI) [5][6]
- Definition: any type of injury to the heart resulting from blunt force trauma
-
Mechanisms of injury [7]
- Rib and sternal fractures
- Crush injuries
- Thoracic traumas, such as pneumothorax, hemothorax, and pulmonary contusion
- See “Mechanism of injury” in “General” above.
-
Possible injuries
- Cardiac contusion: a cardiac injury secondary to blunt force thoracic trauma, which causes myocardial dysfunction with a wide range of clinical effects, including chest pain, hypotension, arrhythmias, elevated cardiac biomarkers, and cardiogenic shock
- Arrhythmias (e.g., new bundle branch block, AV block, extrasystoles)
- Atrial and ventricular wall injuries
- Septal and valvular injuries
- Acute coronary syndrome, myocardial infarction
- Pericardial effusion and cardiac tamponade
- Myocardial rupture
- Sudden cardiac arrest
-
Clinical features
- Asymptomatic
- Chest ecchymosis
- Chest pain or tenderness
- Hypotension
- Tachypnea, shortness of breath
- Tachycardia, arrhythmias
- New cardiac murmur, muffled heart sounds
- Jugular venous distention
- Dizziness, syncope
- Cardiogenic shock
-
Management [5][8]
-
Primary survey
- Initial resuscitation and stabilization according to ATLS protocol
- Cardiac contusion should be suspected if tachycardia persists despite fluid resuscitation.
- Concomitant injuries and ongoing hemorrhage should be suspected in individuals with persistent hypotension.
-
Electrocardiogram
- Best initial test
- Indicated in stable patients with suspected BCI, patients with a history of cardiovascular disease, or in patients with clinical findings consistent with chest trauma or acute heart disease (e.g., chest pain, shortness of breath)
- Screen for arrhythmias (e.g., sinus tachycardia, dysrhythmia) and ST-segment changes
- A normal ECG does not exclude BCI.
- Imaging
- Ultrasound (FAST) (e.g., screen for hemopericardium, pericardial effusion, cardiac tamponade, pneumothorax)
-
Echocardiography (transesophageal echocardiography, transthoracic echocardiography)
- Indicated in patients with unexplained, persistent shock or tachycardia that is out of proportion to injuries or does not respond to aggressive resuscitation
- Assesses cardiac contractility and function and identifies cardiac wall motion abnormalities
- TEE: indicated in patients with suspected BCI, hemodynamic instability, ECG changes, elevated troponin levels
- TTE: indicated in patients with additional noncardiac injuries or if TEE provides insufficient information
- Chest x-rays (e.g., to screen for rib fractures, pneumothorax)
- Chest CT with or without IV contrast or CT angiography (usually part of the initial trauma workup) [9]
- Indicated in stable patients with suspected BCI
- Screen for valvular injury, septal rupture, hemopericardium, or pneumopericardium
- Cardiac biomarkers: indicated in stable patients > 60 years of age with suspected BCI, ECG changes, or clinical findings suggestive of myocardial infarction
-
Primary survey
-
Treatment
- Cardiac monitoring
- IV fluid resuscitation
- Medications: inotropic drugs, amiodarone (e.g., to treat arrhythmias)
- Surgical intervention: (e.g., to treat myocardial infarction, cardiac tamponade, valvular, septal, ventricular wall rupture)
Commotio cordis [10][11]
- Definition: ventricular fibrillation and sudden cardiac death caused by a relatively mild nonpenetrating blunt force trauma to the precordial area
- Etiology: blow to the precordial area at a perpendicular angle, most commonly by a hard, spherical object (e.g., baseball, golf ball), during a brief electrically vulnerable period of T-wave upstroke
- Pathophysiology: BFT leads to myocardial stretch→ activation of ion channels because of mechano-electric coupling → augmentation of repolarization and premature ventricular depolarization → ventricular fibrillation
-
Diagnosis: must meet the following criteria
- Blunt force trauma to the chest followed by collapse
- Absence of structural myocardial injury (on imaging studies and/or autopsy)
- ECG showing ventricular fibrillation (if obtained)
-
Management
- Immediate: cardiopulmonary resuscitation
- Long-term: cardiac work-up (ECG, echocardiogram, cardiac MRI, stress testing)
-
Prevention
- Avoidance of sports that involve chest wall impact (e.g., baseball, hockey, football)
- Use of chest protectors and/or safety balls may reduce risk.
- Underlying cardiac disease: implantable cardioverter defibrillator (ICD)
- No underlying cardiac disease: no ICD necessary
Blunt thoracic aortic injury [12]
- Definition: an injury of the aorta, most commonly at the aortic isthmus, distal to the exit of the left subclavian artery resulting from blunt force trauma
- Etiology: typically rapid deceleration (see “Blunt trauma injury mechanisms”)
-
Clinical features
- Initially, often asymptomatic or unspecific findings (e.g., chest pain, dyspnea, dysphagia)
- Chest wall instability and/or ecchymoses, new interscapular murmur
- Severity ranges from intimal lesions (e.g., aortic pseudocoarctation) to thoracic aortic rupture
- In case of aortic rupture: signs of hemorrhagic shock (tachycardia, hypotension) and tearing pain
-
Diagnostics
- History and physical examination
-
Initial test: chest x-ray
- Mediastinal widening
- Aortic knob obscuration
- Left pleural effusion (hemothorax)
- Apical pleural cap
- Tracheal deviation
- Left main bronchus depression
- Further tests
- In hemodynamically stable patients: CT scan and contrast-enhanced CT angiography (high sensitivity and specificity)
- In hemodynamically unstable patients: transesophageal echocardiography (TEE) in the operating room
-
Treatment
- IV fluids
- BP monitoring
-
Medications [12]
- Antihypertensive therapy with beta-blockers (e.g., esmolol, labetalol)
- Vasodilator therapy (e.g., nitroprusside, nicardipine), if needed
- Definitive treatment
- Endovascular repair (TEVAR)
- Open surgical repair
- Prognosis: very poor (∼ 80% of patients die before reaching the hospital) [12]
Pulmonary injury
Pulmonary contusion
- Definition: edema and blood collecting in the alveolar spaces as a result of blunt chest trauma, usually developing within the first 24 hours
-
Clinical features
- Hypoxia and hypoxemia (may worsen after fluid administration as it increases interstitial fluid accumulation)
- Dyspnea, tachypnea
- Tachycardia
- Chest pain
-
Diagnostics
-
Chest x-ray
- Patchy alveolar infiltrates
- White out or diffuse opacity
- CT: if x-ray is inconclusive
-
Chest x-ray
- Differential diagnosis: pneumothorax (ipsilateral reduced or absent breath sounds)
-
Treatment
- Arterial blood gas monitoring
- Intubation: only necessary if respiratory distress with severe hypoxia develops
- Complications
Tracheobronchial injury (TBI)
- Definition: a tear in the tracheobronchial tree as a result of a high-energy impact, decelerating forces, or a penetrating chest wall injury
-
Clinical features
- Dyspnea
- Sternal tenderness
- Subcutaneous emphysema
- Treatment-resistant pneumothorax: In contrast to a tension-pneumothorax, TBI usually does not feature midline shift and distended neck veins.
- Hoarseness
- Dysphonia
- Bloody tracheal secretions
-
Diagnostics
- Chest x-ray: air in surrounding soft tissue
- Bronchoscopy: visualization of the lesion (the most common site of the tear is within 2 cm of the carina)
- Treatment: mostly surgical repair
-
Complications
- Chylothorax
- Chylopericardium
- Chylomediastinum
Pneumomediastinum [13]
- Definition: presence of gas (usually air) in the mediastinum
-
Etiology
-
Primary (spontaneous)
- Rupture of pulmonary blebs
- Predisposing factor: smoking
- Secondary
- Traumatic: penetrating injuries of chest and/or abdomen
- Non-traumatic
-
Iatrogenic
- Endoscopy
- Intubation
- Central line placement
-
Primary (spontaneous)
- Pathophysiology: ↑ intra-alveolar pressure → rupture of alveoli → air travel along the peribronchial and perivascular sheaths to enter the mediastinum
-
Clinical features
-
Chest pain
- Sudden in onset
- Retrosternal
- Radiates to the neck or back
- Dyspnea
- Subcutaneous emphysema
- Cough
-
Voice change
- Rhinolalia
- Nasal quality of voice
- Occurs due to the presence of air within the soft palate
- Hoarseness
- Rhinolalia
- Hamman sign: precordial crepitation that is audible synchronous to the heartbeat
-
Chest pain
-
Diagnostics
-
Chest X-ray
- Air outlining the mediastinal structures (e.g. aorta, trachea)
- Visible mediastinal pleura
- CT scan: performed if chest x-ray findings are inconclusive
-
Chest X-ray
-
Management: usually self-limited when associated with barotrauma
- Clinical and radiographic monitoring
- Ventilation pressure reduction
Diaphragmatic rupture
- Definition: a complication of blunt trauma or penetrating trauma in which abdominal contents herniate through the diaphragmatic defect into the thorax
-
Clinical features
- Often initially asymptomatic
- Chest/abdominal wall bruises
- In case of herniation of abdominal organs into the chest
- Decreased breath sounds, bowel sounds in the thorax, respiratory distress
- Signs of bowel obstruction
For more information on diagnosis and management, see “Diaphragmatic rupture” in “Penetrating trauma.”
Tracheal injury
- Definition: potentially life-threatening damage to the tracheobronchial tree caused by medical procedures, caustic inhalation, blunt or penetrating trauma
-
Etiology
- Blunt trauma (e.g., strangulation, endotracheal intubation, increased intrathoracic pressure)
- Penetrating trauma (e.g., stab wounds)
-
Types of injury
- Laryngotracheal contusions and or lacerations
- Tracheal rupture: the partial or complete puncture or laceration of the trachea or the main bronchi
- Fracture and/ dislocations of the tracheal cartilages
-
Clinical features
- Hoarseness
- Dyspnea
- Hemoptysis
- Palpable fracture crepitus
- Hamman sign
- Dysphagia
- Cyanosis
- Irritating cough
-
Diagnostics
- Clinical assessment (for further information, see “ABCDE approach”)
- Imaging
- Chest x-ray (showing tracheal rupture and/or pneumothorax)
- Chest CT
- Bronchoscopy (in inconclusive x-ray and CT)
-
Management
- In stable patients: conservative management
- Neck immobilization
- Administration of O2
- Administration of antibiotic prophylaxis
- In hemodynamically unstable patients: emergency management (for further information see “Advanced cardiac life support”)
- In case of vascular injury, tracheal rupture: surgical management
- In stable patients: conservative management
- Complications