Multiple Trauma
M. Michele Mariscalco
As therapeutic measures for patients with congenital anomalies and serious infections have become increasingly successful, trauma has become the leading cause of death and disability during childhood and adolescence. In 2001, 22,000 children and adolescents (age 1 to 21 years) died from traumatic injury. Traumatic injury accounts for 57% of all deaths in children aged 1 to 4 years and 81% of all deaths in children aged 5 to 21. In infants, deaths from injury are due to child abuse, suffocation, choking, motor vehicle accidents, and fires. For the preschool-age group, fires, drowning, and motor vehicle accidents are the leading causes, whereas cycling and pedestrian injuries become more common among school-aged children. Motor vehicle injuries, suicide, and homicide become the leading causes of death during the adolescent years. Each year, an estimated 300,000 children are hospitalized for the treatment of injuries in the United States, and 16 million are treated in emergency departments.
Because the causes of injury in children differ from those in adults, reflecting the differences in activities, size, and intellectual maturity, the patterns of injury in children also differ from those in adults. Head trauma occurs in 80% or more of severely injured children. Abdominal injuries occur more frequently because poorly developed abdominal muscles offer little protection to the viscera. Both the spleen and the duodenum are more likely to be injured. Elasticity of the chest wall renders rib and sternal fractures rare events but also permits severe crush injuries of the heart and lungs without apparent deformation of the chest wall.
PHYSIOLOGY OF TRAUMA
Restoring and preserving adequate tissue perfusion and oxygenation is the highest priority in the care of the injured patient. Although, as in all cases of hypoperfusion, the restoration of blood pressure, urine output, and heart rate are adequate end-points, as many as 85% of patients may have continued evidence of poor tissue perfusion. However, in the era of nonoperative management of solid organ injuries, concerns regarding the “overexpansion” of circulating volume, which could lead to excessive bleeding and “blowing the clot,” render resuscitation end-points even more critical. No perfect end-point exists; however, many clinicians use base deficits and serum lactate levels as indicators of ongoing tissue perfusion deficits. Clinicians familiar with the injured, multiple-trauma victim recognize that the combination of a cool patient, bleeding from multiple sites, and metabolic acidosis represents the “triad of death.”
Blunt trauma accounts for 80% to 90% of pediatric trauma. It differs from other forms of injury in that multiple organ injuries are common findings, as is occult head injury. Progressive organ damage occurs frequently in blunt trauma because of continuing hemorrhage or the formation of edema. Often, acidosis and hypoxia are more prominent than is the dysfunction from the primary injury.
Children’s physiologic responses also differ from those of adults. The vascular system can compensate for a greater loss of blood volume (20% to 25%) before hypotension occurs, but tachycardia presents earlier than in adults. The maintenance of normal blood pressure masks impaired tissue perfusion and may lead to a delay in providing treatment. Young children become hypothermic easily, which greatly increases the difficulty of resuscitation. Because children are growing organisms, uncorrected injury may lead to progressive deformity and disability.
PREHOSPITAL CARE
The treatment of multiple trauma begins at the scene, rendered by prehospital attendants. A fundamental difference between the medical delivery and surgical delivery of prehospital emergency care exists. In medical prehospital care, in which the vast majority of patients are adults with cardiac dysfunction, the working premise is to take time to stabilize affected patients and to achieve a stable rhythm, then slowly transport the patient to the hospital. For trauma patients, the definitive management is available only in the hospital. Once the airway is stabilized, such patients are ventilated adequately; patients should be transported to the hospital as soon as possible after bony injuries are stabilized.
In children, the concept of stabilization should be confined to airway control and immobilization of the cervical spine and long bones. Control of hemorrhage can be obtained by primary pressure. Peripheral intravenous access is the preferred route but may be technically difficult in children. Intraosseous infusion is technically easy and safe to perform and is recommended in children younger than 8 years old, although it may be used in older children and adults. Once vascular access is established, care must be taken to avoid the overtransfusion of crystalloid. Transport must not be delayed while vascular access is established in pediatric trauma patients. Notable is the paradigm shift from treatment with intravenous fluids before control of hemorrhage to treatment only after hemorrhage has been managed. A large clinical trial of hypotensive patients with penetrating trauma demonstrated that delayed resuscitation (i.e., only on arrival to the operating room) improved outcome, when compared to immediate resuscitation preoperatively. Importantly, these studies involved adult patients with penetrating injuries. The role for this scheme in blunt trauma patients is not as clear. Because children predominantly have blunt traumatic injuries, the relevance of these paradigms to children with trauma remains unproven.
PRIMARY SURVEY
The successful initial management of critically injured, multiple-trauma pediatric patients depends on the expertise of a well-coordinated team consisting of physicians—often headed by surgeons familiar with pediatric trauma—and emergency medical personnel. The primary survey systematically evaluates the essential components of ABCDE (airway,
breathing, circulation, neurologic disability, and exposure) for life-threatening injuries. Within the first 20 to 30 minutes at the hospital, affected patients should receive a primary survey with initial resuscitation, a secondary survey consisting of a complete examination from head to toe, and a plan for definitive care.
breathing, circulation, neurologic disability, and exposure) for life-threatening injuries. Within the first 20 to 30 minutes at the hospital, affected patients should receive a primary survey with initial resuscitation, a secondary survey consisting of a complete examination from head to toe, and a plan for definitive care.
The initial focus of the primary survey is the airway. The goals are to relieve anatomic obstruction, to prevent the aspiration of gastric contents, and to promote adequate gas exchange with protection of the cervical spine. Any child with significant trauma is assumed to have cervical spine injury. These goals may be met by maneuvers as simple as a chin lift or a jaw thrust, with careful attention given to avoiding hyperextension of the cervical spine. Use of a rigid collar, sandbags, and tape or use of manual immobilization with the head in a neutral position prevents those manipulations of the cervical spine that may result in spinal cord injury with quadriplegia. The mouth may be suctioned for retained secretions, but care must be taken to avoid precipitating vomiting and regurgitation. Artificial nasopharyngeal and oropharyngeal airways are tolerated poorly and often induce gagging. Usually, children who tolerate them have compromised protective reflexes and require definitive airway management using an endotracheal tube.
The second goal of the primary survey is to maintain breathing. Affected patients should receive 100% inspired oxygen. If ventilation is inadequate or absent, if arterial hypoxemia unresponsive to increased inspired oxygen is present, if the face and neck are burned, or if such patients are hemodynamically unstable, the airway should be secured. Oral tracheal intubation is the preferred route. Such patients are at high risk for vomiting and aspirating. Also, their airways may be rendered more inaccessible by traumatic injury to the bones and soft tissue. Intubation is performed by the most experienced personnel and under controlled conditions using rapid sequence and cricoid pressure to prevent passive regurgitation. Manual, cervical in-line immobilization is performed to counter the flexion and extension caused during intubation if cervical injury is suspected.
Once the patient is intubated, ventilation is begun using 100% inspired oxygen at rates of 10 to 20 breaths per minute. If head injury is suspected, the minute ventilation rate should be increased to lower the arterial carbon dioxide pressure. If ventilation is impaired, malposition of the endotracheal tube or tube plugging with secretions is suspected. If inadequate ventilation continues, a pneumothorax, hemothorax, or other thoracic injury is suspected, evaluation is completed, and treatment is given. Usually, treatment entails the use of needle thoracentesis or tube thoracostomies.
The third goal of the primary survey is to ensure effective circulation. Initially, it may be accomplished by artificial support with chest compressions. At the same time, basic steps for hemorrhagic shock, including control of active hemorrhage, placement of intravenous lines, and aggressive crystalloid and blood replacement, are undertaken. The control of obvious hemorrhage is most important. In most situations, direct pressure is adequate. Fractures of the pelvis or long bones produce hidden blood loss that can be massive in both adults and children.
In patients with hemorrhage and shock, no substitute for volume and blood replacement exists. The debate about the use of crystalloid versus colloid for volume replacement continues. In the few studies of young-adult, previously healthy trauma patients, no differences in the development of pulmonary edema and pulmonary dysfunction were noted when either crystalloid or colloid was used. Some physicians prefer the use of lactated Ringer’s solution over the use of normal saline because the chloride concentration more closely approximates that found in normal plasma and the lactate serves as a source of buffering base. The volume infused should be 20 to 30 mL/kg initially, with an observation for improvement in circulatory status; if no improvement is noted, another 20 to 30 mL/kg is given. Balanced salt solution is not intended as a substitute for blood. A loss in excess of 30% of total circulating blood volume must be replaced with red blood cells in addition to fluid. Blood volume is 60 to 80 mL/kg of optimal body weight. In the emergent phase of resuscitation, time may not allow for a full type and crossmatch to be obtained. When uncrossmatched blood is used, obtaining at least an ABO-Rh type and a partial crossmatch is best. This combination is preferable to the use of type O, Rh-negative uncrossmatched blood, although it may be used if type-specific uncrossmatched blood is unavailable. If large amounts of crystalloid and red blood cells are required, hemostatic defects occur. Fresh-frozen plasma should be given to replete circulating coagulation factors and platelets when 100% to 200% of the circulating blood volume has been replaced.
If children with blunt trauma are in cardiorespiratory arrest despite having an adequate airway and ventilation, immediate insertion of bilateral thoracostomy tubes and a large fluid bolus are indicated. This step is followed by pericardiocentesis if improvement does not result. Failure to respond indicates irreversible shock, traumatic myocardial injury with pump failure, or severe central nervous system failure.
An assessment of the patient’s disability necessitates performing a rapid neurologic examination to evaluate the level of consciousness and presence of abnormal pupillary findings. The neurologic examination may be carried out using the AVPU system (alert, responds to verbal stimuli, responds to painful stimuli, unresponsive). Alternatively, the Glasgow Coma Scale and its modification for infants can be used (Table 460.1). The final component of the primary survey involves fully undressing an affected patient and examining under cervical collars and bandages. Because of the increased surface area–to–mass ratios in children, increased minute ventilation with accompanying heat of vaporization loss, and (usually) resuscitation in a cold environment, affected children may become fairly hypothermic, thus further complicating resuscitation. Temperature can be supported by warming administered fluid and blood, by using external heating elements, and by wrapping all exposed areas in plastic once the full evaluation is accomplished.