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Injury is the number one cause of death for people aged 1 to 44. In the US, there were 175,000 trauma deaths in 2006, about two thirds being accidental. Of intentional injury deaths, about 60% were due to self-harm. In addition to deaths, injury results in about 40 million emergency department visits annually.
Patients whose injuries are serious but not immediately fatal benefit the most from treatment in designated trauma centers, hospitals that have special staffing and protocols to provide immediate care to critically injured patients. Criteria for such designation (and for the necessity of transport to them) vary by state but usually follow guidelines of the American College of Surgeons' Committee on Trauma.
Many traumatic injuries (eg, burns, fractures, dislocations, sprains) are discussed elsewhere in The Manual.
Etiology
Of the myriad ways people are injured, most can be categorized as blunt or penetrating. Blunt injury involves a forceful impact (eg, blow, kick, strike with object, fall, motor vehicle collision, blast). Penetrating injury involves breach of the skin by an object (eg, knife, broken glass) or projectile (eg, bullet, shrapnel from explosion).
Other injury types include thermal and chemical burns, toxic inhalations or ingestions, and radiation injury. These injuries and other specific injuries (eg, bone and joint injuries—see Fractures, Dislocations, and Sprains: Introduction, spinal cord injury—see Spinal Trauma: Introduction, head injury—see Traumatic Brain Injury (TBI): Traumatic Brain Injury, facial injury—see Facial Trauma: Introduction, eye injury—see Eye Injuries: Introduction, genitourinary injury—see Genitourinary Tract Trauma: Introduction, lacerations—see Lacerations) are discussed elsewhere in The Manual.
Pathophysiology
All injuries, by definition, cause direct tissue damage, the nature and extent depending on the anatomic site, mechanism, and intensity of trauma. Severe direct tissue damage to critical organs (eg, to the heart, brain, spinal cord) is responsible for most immediate trauma deaths.
Additionally, patients surviving the initial insult may develop indirect injury effects. Disruption of blood vessels causes hemorrhage, which may be external (and hence visible) or internal, either confined within an organ as a contusion or hematoma, or as free hemorrhage into a body compartment (eg, peritoneal cavity, thorax). Small amounts of hemorrhage (ie, < 10% of blood volume) are tolerated well by most patients. Larger amounts cause progressive declines in BP and organ perfusion (shock—see Shock and Fluid Resuscitation: Shock), leading to cellular dysfunction, organ failure, and eventually death. Hemorrhagic shock causes most short-term (ie, within hours) deaths, and multiple organ failure from prolonged shock causes many of the near-term (ie, first 14 days) deaths. Additional near-term deaths result from infection because of disruption of normal anatomic barriers and immune system dysfunction.
Evaluation
and Treatment
Care in the emergency department rather than emergency care delivered at the accident site is discussed here. Evaluation and treatment are done simultaneously, beginning with systems that pose the most immediate threat to life if damaged. Attending to dramatic but not deadly
injuries (eg, open lower extremity fracture, finger amputations)
before evaluating immediate life threats can be a fatal mistake. A helpful mnemonic is A, B, C, D, E. Systems are rapidly examined for serious abnormalities (primary survey); a more detailed examination (secondary survey) is done after the patient is stable.
Airway:
Airway patency is threatened by blood clots, teeth, or foreign bodies in the oropharynx; soft-tissue laxity and posterior retraction of the tongue caused by obtundation (eg, from head injury, shock, intoxication); and edema or hematoma due to direct neck trauma. These obstructions are readily visible on direct inspection of the mouth or neck; having the patient speak can rapidly confirm that the airway is not likely in immediate danger.
Blood and foreign material are removed by suction or manually. Obtunded patients whose airway patency is in doubt and patients with significant oropharyngeal injury require endotracheal intubation; usually drugs are given for paralysis and sedation before intubation is done (see Respiratory and Cardiac Arrest: Endotracheal intubation). If patients require an artificial airway and endotracheal intubation is not possible (eg, due to edema of the airway caused by a thermal burn) or contraindicated (eg, due to severe maxillofacial injury), surgical cricothyroidotomy is indicated (see Respiratory and Cardiac Arrest: Surgical airway). Note: When evaluating or manipulating a patient's airway, cervical spine immobilization should be maintained (eg, by rigid collar, inline immobilization techniques) until cervical spine injury has been excluded by examination, imaging, or both.
Breathing:
Adequate ventilation is threatened by decreased central respiratory drive (usually from head injury, intoxication, or nearly fatal shock) or by chest injury (eg, hemo- or pneumothorax, multiple rib fractures, pulmonary contusion).
Adequacy of air exchange is usually apparent on auscultation. Tension pneumothorax (see Mediastinal and Pleural Disorders: Etiology) may cause the trachea to deviate to the side opposite the injury, as well as decreased breath sounds and sometimes distended neck veins. The chest wall is fully exposed to look for ample chest wall expansion and is palpated for obvious rib fractures and presence of subcutaneous air (sometimes the only finding with pneumothorax).
Pneumothorax is decompressed by chest tube (see Mediastinal and Pleural Disorders: Treatment) and must be excluded before initiating positive-pressure ventilation (which may markedly enlarge a pneumothorax and convert it to a tension pneumothorax). Suspected tension pneumothorax can be decompressed with needle thoracostomy (eg, a 14-gauge needle inserted in the midclavicular line, 2nd intercostal space) to stabilize the patient if a chest tube cannot be inserted immediately. Inadequate ventilation is treated with endotracheal intubation and mechanical ventilation.
Circulation:
Significant external hemorrhage can occur from any major vessel but is always apparent. Life-threatening internal hemorrhage is often less obvious. However, this volume of hemorrhage can occur in only a few body compartments: the chest, abdomen, and soft tissues of the pelvis or thigh (eg, from pelvis or femur fracture).
Pulse and BP are assessed, and signs of shock are noted (eg, tachypnea, dusky color, diaphoresis, altered mental status). Abdominal distention and tenderness, pelvis instability, and thigh deformity and instability are often present when internal hemorrhage in those areas is large enough to be life threatening.
External hemorrhage is controlled by direct pressure. Two large-bore (eg, 14- or 16-gauge) IVs are started with 0.9% saline or Ringer's lactate; rapid infusion of 1 to 2 L (20 mL/kg for children) is given for signs of shock and hypovolemia. Subsequently, additional fluids and, if necessary, blood component therapy is given as indicated (see Shock and Fluid Resuscitation: Prognosis and Treatment). Patients in whom there is strong clinical suspicion of serious intra-abdominal hemorrhage may require immediate laparotomy. Patients with massive intrathoracic hemorrhage may require immediate thoracotomy and possibly autotransfusion of blood recovered via tube thoracostomy.
Disability:
Neurologic function is evaluated for serious deficits involving the brain and spinal cord. The Glasgow Coma Scale (GCS—see Table 2: Traumatic Brain Injury (TBI): Glasgow Coma Scale* and, for infants and children, see Table 3: Traumatic Brain Injury (TBI): Modified Glasgow Coma Scale for Infants and Children) and pupillary response to light screen for serious intracranial injury. Gross motor movement and sensation in each extremity screen for serious spinal cord injury. The cervical spine is palpated for tenderness and deformity and stabilized in a rigid collar until cervical spine injury is excluded. With careful manual stabilization of the head and neck, the patient is “log rolled” onto a side to allow palpation of the thoracic and lumbar spine, inspection of the back, and rectal examination to check tone (decreased tone indicates possible spinal cord injury), the prostate (a high-riding prostate suggests urethral injury), and presence of blood. In the US, most patients arriving by ambulance are immobilized on a long, rigid board for ease of transport and to stabilize possible spinal fractures. If examination reveals no sign of spinal injury, patients are taken off the board because it is quite uncomfortable and pressure ulcers may occur within a few hours.
Patients with severe traumatic brain injury (GCS < 9) require endotracheal intubation, neurosurgical evaluation, and therapy to prevent secondary brain injury (eg, osmotic diuresis, sometimes hyperventilation for patients with signs of impending brain herniation—see Traumatic Brain Injury (TBI): Traumatic Brain Injury and see Fig. 1: Coma and Impaired Consciousness: Brain herniation. ).
Exposure/environmental
control:
To ensure injuries are not missed, patients are completely undressed (by cutting off garments) and the entire body surface is examined for signs of occult trauma. The patient is kept warm (eg, with heated blankets and by using only warmed IV fluids) to prevent hypothermia.
Secondary survey:
After immediate life threats are assessed and the patient is stable, a more thorough evaluation is done, and a focused history is obtained. If only limited conversation is possible, an “AMPLE” history covers essential information:
After the patient is completely undressed, the examination generally proceeds from head to toe; it includes all orifices and a more detailed look at areas examined in the initial survey. All soft tissues are inspected for lesions and swelling, all bones are palpated for tenderness, and range of motion is assessed in joints (unless there is obvious fracture or deformity).
A urinary catheter is usually placed in seriously injured and obtunded patients provided there is no evidence of urethral injury (eg, blood at the meatus, ecchymosis of the perineum, high-riding prostate). Seriously injured patients often also have a nasogastric tube placed, provided there is no serious midface trauma (rare reports exist of intracranial tube insertion through a cribriform plate fracture).
Open wounds are covered with sterile dressings, but cleansing and repair are deferred until completion of evaluation and treatment of more serious injuries. Serious clinically apparent dislocations with marked deformity or neurovascular compromise are imaged and reduced as soon as immediate life threats have been addressed. Obvious or suspected fractures are splinted pending full assessment of serious injuries and appropriate imaging studies.
Testing:
Imaging tests are the cornerstone; laboratory tests are generally ancillary. Patients with penetrating trauma typically have focal injuries that can limit necessary imaging to the obviously involved region or regions. Blunt trauma, particularly when significant deceleration is involved (eg, serious fall, motor vehicle crash), can affect any part of the body, and imaging is used more liberally. Such patients traditionally have x-rays of the chest, cervical spine, and pelvis unless they are awake and alert, completely lacking in symptoms or findings suggesting injury to those areas, and have no distracting injuries (eg, femur fracture) that might keep them from complaining about injuries elsewhere. These imaging tests are directed at life threats that may not be clinically obvious. Chest x-ray can identify airway disruption, lung injury, and pneumothorax and can suggest thoracic aorta tears (eg, by mediastinal widening).
CT of the chest, abdomen and pelvis, spine, head, or, particularly, combinations of these is increasingly being used instead of plain x-rays for patients who require imaging after severe multiple blunt trauma.
Identification of intra-abdominal injury is essential. Bedside ultrasonography (FAST examination: focused assessment with sonography in trauma) is being used increasingly, particularly for unstable patients; it is sensitive for significant volumes of intraperitoneal blood and thus the need for immediate laparotomy. If patients are stable, CT has the advantages of high accuracy, imaging of the retroperitoneal structures and bones, and showing the volume and sometimes the origin of hemorrhage. For unstable patients in whom bedside ultrasonography is not feasible, diagnostic peritoneal aspiration can be used, in which a peritoneal dialysis catheter is inserted through the abdominal wall into the peritoneal cavity. If > 10 mL of blood is aspirated, immediate laparotomy is indicated.
Head CT is typically done in patients with altered mental status or focal neurologic abnormalities and in patients who sustained loss of consciousness (some clinicians feel that patients with a brief loss of consciousness who are completely alert and neurologically intact do not require CT). Imaging is obtained more liberally in children < 2 yr with scalp hematoma, the elderly, patients taking anticoagulants, and patients who are alcoholics.
Aortic injury should be considered in patients with severe deceleration chest injury or suggestive signs (eg, pulse deficits or asymmetric BP measurements, end-organ ischemia, suggestive findings on chest x-ray); these patients may require CT angiography or other aortic imaging. All patients suspected of having significant blunt chest injury have an ECG to diagnose myocardial injury and cardiac monitoring for subsequent arrhythmias. Patients with abnormalities on ECG usually have blood levels of cardiac markers measured and sometimes echocardiography (see Cardiovascular Tests and Procedures: Echocardiography).
Plain x-rays are obtained of any suspected fractures and dislocations. Other imaging tests are obtained for specific indications (eg, angiography to diagnose and sometimes embolize vascular injury; CT to better delineate spinal, pelvic, or complex joint fractures).
Laboratory tests that may be useful include ABGs for Po2, Pco2, and base deficit; urine examination for blood; CBC to establish a baseline to monitor ongoing hemorrhage; glucose to evaluate for hypoglycemia; and type and crossmatch for possible blood transfusion. Measures of perfusion (serum lactate, base deficit on ABG measurement, and, in patients with a catheterized central vein, central venous O2 saturation) may help identify early or partially treated shock. Other reflexively obtained tests (eg, electrolytes and other chemistries, coagulation studies) are unlikely to be helpful unless suggested by relevant medical history (eg, renal insufficiency, diuretic use). Toxicology screening (eg, blood alcohol, urine drug screen) is often done; results of this testing rarely change immediate management but can help identify substance abuse causative of injury, allowing intervention to prevent subsequent trauma.
Last full review/revision September 2009 by Noelle Rotondo, DO
Content last modified September 2009
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