Approach to the Traumatized Child
David B. Burbulys, MD
A 6-year-old boy is brought to the emergency department after being struck by an automobile while crossing the street. He was found unconscious at the scene. Initial evaluation shows that he has an altered level of consciousness, shallow respirations, ecchymosis across the upper abdomen, and a deformed, swollen left thigh. The pediatric emergency physician is called in to discuss an initial assessment and management plan for the injured child with the trauma surgeon.
1. What are the most common mechanisms of injury responsible for trauma in children?
2. What are some of the physiologic differences between adults and children that make children more susceptible to certain types of injury?
3. Which areas of the body are most likely to be injured in a typical automobile versus pedestrian collision?
4. What are the components of a primary survey in pediatric trauma patients?
5. What radiologic and laboratory studies should be performed in children with multiple injuries?
Trauma is often referred to as the neglected disease of modern society. Childhood trauma, in particular, is poorly understood and studied. Death from trauma is higher in pediatric patients than in adult patients. Mechanisms of injury may be similar in adults and children, but children have particular anatomic differences and physiologic responses to injury. Health professionals should realize that children have unique anatomic and physiologic features compared with adults (Box 75.1). Evaluation and management of traumatized children requires specialized knowledge, training, and equipment. Recognition of such facts, coupled with expertise in the performance of emergency procedures, has improved the outcomes of children who sustain major injuries.
Traumatic injuries are the most common cause of death in children aged 1 to 21 years (and in adults aged 21–44 years) in the United States. In many of these age groups, murder and suicide are the second and third leading cause of death, respectively. Approximately 7 to 8 million pediatric injuries result in 250,000 to 500,000 hospitalizations and 15,000 to 25,000 deaths each year. Medical costs associated with these injuries exceed $50 billion annually. Infants are most likely to die from suffocation, young children from drowning, school-age children from motor vehicle collisions or after being struck by an automobile, and adolescents from motor vehicle crashes. Boys are twice as likely as girls to be injured and die. The magnitude of pediatric trauma becomes even more evident when morbidity is considered. Between 50,000 and 100,000 children per year become permanently disabled as a result of their injuries. Such disabilities have an enormous effect on society; they result in financial and emotional losses for families and years of lost productivity for the injured individuals themselves.
Box 75.1. Characteristics of Children That Result in Increased Susceptibility to Injury
•Smaller body size allows for the greater distribution of force with trauma, so multisystem injury is common.
•A prominent occiput, exaggerated head-to-body ratio, weak neck muscles, and higher center of gravity predispose younger children to head injury.
•Cranial bones are thinner, and the brain is less myelinated, resulting in more serious head injury.
•Skeletal and ligamentous structures have increased flexibility, which results in greater transmission of force to internal organs.
•Less protective muscle and subcutaneous tissue over internal organs expose them to injury.
•Growth plates are not yet fused, which results in Salter-Harris-type fractures and possible bone growth abnormalities with healing.
•High body surface area-to-weight ratio predisposes children to hypothermia, which may complicate shock and worsen acidosis and coagulopathy if it is not corrected.
•Hypoxia and respiratory failure are more likely in children.
•Hemorrhagic shock is initially well tolerated by increasing heart rate and peripheral vascular resistance without significant changes in systolic blood pressure.
Blunt trauma, which is more common than penetrating injury in children, represents approximately 87% of all childhood injuries. Head injuries, followed by thoracoabdominal injuries, are the leading causes of death in this group. In adolescents and young adults, however, penetrating injury (ie, homicide, suicide) accounts for a higher percentage of total trauma, especially among minority populations in urban areas. Causes of nonpenetrating trauma are motor vehicle crashes (>40%), falls (25%–30%), drowning (10%–15%), and burns (5%–10%). Included in the remainder are bicycle-related and automobile versus pedestrian injuries. These numbers vary significantly by locale and age. In some centers, a high percentage of trauma deaths are related to child abuse.
Children who sustain severe trauma present with multiorgan system injury manifested by shock, respiratory failure, or altered mental status, either alone or in combination. Those with mild to moderate injury may present in this way or may simply present with localized signs and symptoms in the injured area.
It is important to identify patterns of injury to develop strategies for injury prevention as well as anticipate injuries during treatment. One common pattern is the Waddell triad, that is, the triad of injuries that results from an automobile versus pedestrian collision (Figure 75.1).
Multisystem injury is the rule rather than the exception in children. Internal injury must always be suspected when the mechanism of injury warrants such injury, even in the absence of apparent evidence suggestive of external trauma. Because children are anatomically and physiologically different from adults, they are more susceptible to diverse types of injury (see Box 75.1). The most striking physiologic differences between adults and children concern responses to acute blood loss. Children have a tremendous capacity to maintain systolic blood pressure despite 25% to 30% acute blood loss.
Hypovolemic shock secondary to acute blood loss is the most common cause of shock in pediatric trauma patients. Hemorrhagic shock is a clinical state in which cardiac output is unable to meet the metabolic demands of tissues for oxygen and nutrients; it is not defined by any absolute blood pressure value.
Acute blood loss stimulates peripheral and central receptors and results in increased production of catecholamines and corticosteroids. The body responds by increasing peripheral vascular resistance, stroke volume, and heart rate. Children have the capacity to dramatically increase heart rate and peripheral vascular resistance, and they often may exhibit normal blood pressure in the presence of hypovolemic shock. By the time their blood pressure falls, they commonly have lost 20% to 25% of their circulating blood volume. In adults, blood pressure tends to decline after a less significant blood loss, resulting in earlier recognition of the extent of blood loss (Figure 75.2). Subtle changes in heart rate, blood pressure, pulse pressure, and capillary refill may indicate impending cardiovascular collapse in children who have sustained traumatic injury and should not be overlooked. Indicators of end-organ perfusion, such as lactic acid levels or calculated base deficit, may also be helpful and predictive.
Figure 75.1. The Waddell triad, that is, femur, abdominal, and contralateral head injuries, should be expected to result from automobile versus pedestrian collisions in the United States. For example, a child crossing the street is struck on the left side of the body by an automobile traveling on the right side of the road. The left femur is likely to be injured by the bumper, and the abdomen or chest strikes the grille as the child is lifted into the air and lands on the opposite side of the head, sustaining blunt head trauma. The Waddell triad illustrates the necessity of having a high degree of suspicion for predictable injuries based on a well-known mechanism.
Figure 75.2. Cardiovascular response to hypovolemia in children. Blood pressure does not begin to decline until the volume deficit is more than 25% because of the compensatory increase in vascular resistance. Cardiac output drops earlier and is manifested clinically as delayed capillary refill; cool, clammy skin; and tachycardia.
Another obstacle to the recognition of shock in children is the lack of knowledge on the part of many health professionals of age-appropriate vital signs, particularly blood pressure. Table 75.1 gives the normal blood pressure ranges for children of different ages.
Three stages of shock correspond to the progression of volume loss. In the first stage, compensated shock, mechanisms for preserving blood pressure remain effective. Decreased capillary refill, diminished pulses, cool extremities, and tachypnea may be apparent, but blood pressure is normal (although accompanied by tachycardia). Unrecognized, untreated compensated shock rapidly progresses to uncompensated shock. Examination reveals decreased level of consciousness, pallor, reduced urine output, and lower blood pressure with weak, thready pulses and marked tachycardia. With inadequate therapy, uncompensated shock becomes irreversible shock, resulting in irreparable organ damage and often unpreventable death. (See Chapter 74 for a more extensive discussion.)
Shock has several causes, and it is important to emphasize that in trauma patients, it should always be initially attributed to hemorrhage. Shock resulting from obstructive cardiac output causes, such as tension pneumothorax or cardiac tamponade, is much less common. Shock resulting from spinal cord injury is exceedingly rare. Shock should never be attributed solely to head trauma. The pathways resulting in decreased blood pressure in patients with head trauma are present only at the terminal stages. Therefore, the possibility of blood loss from internal organs should be pursued promptly and aggressively. The most common site of hemorrhage resulting in preventable mortality is intra-abdominal. Other sources of hemorrhage are external, thoracic, pelvic, and retroperitoneal.
Evaluation and Management
Because of the high potential for serious morbidity and mortality in trauma patients, evaluation and management are performed simultaneously. This care is best managed using an organized, multidisciplinary team approach, with preestablished criteria for activation of the trauma team. History of the event provides important information when implementing these criteria. For example, the entire team responds for all pedestrians struck by an automobile. The types of subspecialists that make up a trauma team are decided by individual institutions and commonly include pediatric emergency and critical care specialists, anesthesiologists, trauma surgeons, surgical subspecialists, emergency nurses, respiratory therapists, social workers, and radiology technicians.
Several approaches to the assessment of trauma patients have been developed by professional organizations. The Advanced Trauma Life Support (ATLS) course of the American College of Surgeons and the International Trauma Life Support (ITLS) course (formerly Basic Trauma Life Support, which was initially funded by the American College of Emergency Physicians) are 2 such approaches. The ATLS and ITLS methods stress the importance of a primary evaluation, or primary survey, to identify and manage immediate life-threatening injuries followed by a more detailed regional examination, or secondary survey, after stabilization, to identify and manage all other injuries. Additionally, both protocols adhere to the principles of serial examination and reassessment after each intervention. The primary survey and initial resuscitation efforts must occur simultaneously and within the first several minutes of the evaluation. The secondary survey is meant to enhance the primary survey. Vital signs should be reassessed frequently during the primary and secondary survey until the trauma team feels the patient has been adequately stabilized. The physician should understand the rationale for the trauma examination and its parts. This topic is beyond the scope of this chapter, but articles that explain the rationale for trauma examination and provide detailed descriptions of evaluation and management techniques are listed in the Selected References section.
The primary survey begins with an assessment of level of consciousness, patency of the airway (Box 75.2), and quality of breathing (Box 75.3). When evaluating injured patients, physicians should always assume that the cervical spine has been injured and should use in-line immobilization to secure it. Basic airway maneuvers for positioning should be performed, the safest of which is the jaw thrust to avoid moving the cervical spine (Figure 75.3). The oral cavity should be examined for foreign bodies, blood, or secretions. The most common form of airway obstruction in children is a posteriorly displaced tongue, which is relieved by good airway positioning. Advanced airway maneuvers (ie, bag-valve-mask ventilation, endotracheal tube intubation) are performed during the primary survey if the child has apnea, significant respiratory distress, severe head trauma, or an airway that cannot be maintained with basic techniques. All trauma patients are initially given supplemental oxygen by non-rebreathing mask at a concentration of 100%. The adequacy of ventilation is assessed by a general evaluation of the respiratory rate, depth, chest movement and symmetry, and tracheal deviation.
Box 75.2. Airway Assessment and Treatment
•Airway patency and ability to protect it.
•Level of consciousness.
•Jaw thrust and suctioning.
•100% oxygen by non-rebreathing mask.
•Intubate for Glasgow Coma Scale score <9, or absence of an intact gag reflex.