Pediatric Trauma

Published on 22/03/2015 by admin

Last modified 22/03/2015

Print this page

This article have been viewed 1565 times

210 Pediatric Trauma

Injury is the leading cause of medical expenditure for children aged 5 to 14 years. In addition, traumatic injury accounts for approximately 300,000 childhood hospitalizations per year and, in the year 2000, was responsible for more deaths in the 1- to 14-year age group than all natural causes combined. This chapter focuses on trauma-related topics from the viewpoint of a pediatric critical care physician.

Trauma Systems and Trauma Centers

Many studies support the concept that trauma systems and trauma centers improve outcome and that pediatric trauma centers improve outcome for children, especially for those with severe traumatic brain injury. The “Guidelines for the Acute Medical Management of Severe Traumatic Brain Injury in Infants and Children and Adolescents,” published in 2003, found sufficient evidence to set seven guidelines for pediatric management. One of the guidelines states, “In a metropolitan area pediatric patients with severe traumatic brain injury (TBI) should be transported directly to a pediatric trauma center if available.” An accompanying option states, “Pediatric patients with severe TBI should be treated in a pediatric trauma center or in an adult trauma center with added qualifications for pediatric treatment.” These guidelines have been endorsed by six medical societies, including the American Association for the Surgery of Trauma and the Society of Critical Care. Over the last 3 decades, thanks to heroic efforts by the American College of Surgery (ACS), many trauma systems with designated adult and pediatric trauma centers have been developed. A recent paper concluded that pediatric trauma center “mortality rates are lower among children admitted directly from the injury scene compared with those admitted by interhospital transfer.”¹ Even after allowing for injury severity, Glasgow Coma Scale (GCS) scores, elapsed time between injury and hospital admission, and age, this finding held true. The ACS program provides verification of trauma centers by an excellent outside review process. To date, the ACS has verified 29 level I pediatric trauma centers² (increased from 13 in 2007). The ACS delineates recommended equipment, staffing, policies, and procedures. Important to the trauma center is a designated trauma director and an active morbidity and mortality conference that is attended by all physician members of the trauma team.

Trauma Teams

Trauma teams are essential to the trauma center. A trauma team refers to all who care for the trauma patient from resuscitation through discharge. Members of the trauma team include the trauma surgeons, emergency department physicians and nurses, critical care physicians and nurses, respiratory therapists, subspecialty surgeons, radiologists, rehabilitation team, social workers, and clergy. A trauma team requires strong hospital commitment and support. To function optimally, multiple policies and procedures that are understood and respected by all members have to be in place. The resuscitation team is usually led by a surgeon and performs best when led by an attending trauma surgeon. The prepared trauma team improves performance in resuscitation as well as outcome of the patient.³

Role of Pediatric Critical Care Physicians

The role of the intensivist in the care of trauma patients has been debated for decades. In 1986, Meyer and Trunkey argued that in most instances, optimal care of seriously injured patients requires “participation between trauma surgeons and critical care specialists, as well as trauma and critical care services. With proper leadership and systems to ensure effective communication between such services, these goals can be achieved. Important secondary goals, in education and research, can also be achieved by such methods.”³ Such attitudes of collaboration and inclusiveness were not always apparent in the 1990s. An editorial in the Journal of Trauma stated, “The American Association for the Surgery of Trauma ratifies the position of the American College of Surgeons Committee on Trauma that the trauma surgeon is and must be responsible for the comprehensive management of the injured patient in the critical care unit, including hemodynamic monitoring, ventilator management, nutrition, and posttraumatic complications.”⁴ A letter to the editor responding to the editorial stated, “Except for a nod to a team effort, the tenor of your editorial would imply that the trauma surgeon and only the trauma surgeon has all the necessary skills in all areas to care for the multiply injured patient to the exclusion of all others.”⁵ A reply to the letter stated that the intent of the editorial was not meant to be exclusive and that collaborative participation with all specialties was important. Such debates led to feelings of noncollaboration and exclusion among critical care physicians.

In 1991, the American College of Surgeons Committee on Trauma recommended that an “inclusive” trauma system be developed.⁶ Atweh advocated that the concept of the inclusive trauma system be broadened to include all phases of injury as well as all the disciplines involved with injuries.⁷ In 1999, the president of the American Association for the Surgery of Trauma stated, “It is interesting to note who actually provides much of the minute-to-minute and day-to-day care of patients in many trauma centers. The busier the trauma center, the more likely the care is provided by nonsurgeons: anesthesiologists, emergency physicians, critical care doctors of various stripes…. Clearly these workers are needed to manage patients.”⁸ Cooper wrote, “What we do know, however, is that trauma systems and trauma centers that make special provision for the needs of children achieve better outcomes than those that don’t.”⁹ He went on to say that the reason for this is more likely to be the specialized system than the surgeon per se and to recommend the development of a fully inclusive trauma system. In October 2002, the Trauma System Agenda for the Future, coordinated through the American Trauma Society, stated that trauma requires a multidisciplinary approach, hospital physicians of all specialties should be included, and appropriate use of all members of the trauma team must be planned.¹⁰ The most recent version of “Resources for Optimal Care of the Injured Patient” states, “Appropriately trained surgical and medical trained specialists may staff the pediatric critical care unit.”¹¹

An inclusive system is the right system for pediatric trauma patients, and the pediatric critical care physician should have a significant role. The pediatric critical care physician has the most training and experience in life-support therapies for children, including mechanical ventilation, hemodynamic support, renal replacement therapies, and prevention and treatment of secondary brain injury. As an example, data from San Diego Children’s Hospital (unpublished) show that during an 18-month period, 80 trauma patients required mechanical ventilation. During the same period, 904 nontrauma patients required mechanical ventilation. The critical care physician is also in the critical care unit on a minute-to-minute basis. Studies have shown better outcomes for children in critical care units directed and attended by critical care physicians.¹² In our system, the critical care physician and the trauma surgeon conduct daily rounds together, including all trauma patients in the pediatric ICU. All patients are discussed on a daily basis with a neurosurgeon as well. This has built mutual respect, contributed to better patient care, and promoted a good working environment. Inclusive attitudes, teamwork, leadership, standard protocols and policies, an ongoing review of the system, and monthly morbidity and mortality conferences all contribute to the quality of the pediatric trauma center and better patient outcomes.

Initial Resuscitation

Resuscitation of the pediatric trauma patient follows the ABCs (airway, breathing, circulation) of Advanced Trauma Life Support (ATLS) and Pediatric Advanced Life Support (PALS) guidelines. Additional discussion of pediatric resuscitation is provided in Chapter 42 on pediatric neurointensive care. Resuscitation begins in the field with emergency medical service personnel and continues at the trauma center with the designated trauma team.

Upon arrival, the airway is assessed for patency and maintainability. The airway may need to be secured if the patient has experienced head, thoracic, abdominal, or airway trauma. Adequate airway control must be obtained while maintaining cervical spine immobilization. These patients are at risk for aspiration secondary to absent or diminished laryngeal reflexes and delayed gastric emptying. Most trauma patients should be orally intubated with direct cricoid pressure.

Many pharmacologic agents are available for rapid-sequence intubation, similar to adult resuscitation. Doses are adjusted for patient weight. The reason for intubation as well as the type of injuries present dictate the medications used. Tracheal tube placement should be confirmed by auscultation of the abdomen and both sides of the chest, checking the position at the lips, and palpation of the cuff in the suprasternal notch. Placement should also be confirmed by end-tidal carbon dioxide monitoring and radiography. The patient’s heart rate, blood pressure, oxygen saturation, color, and perfusion should be continuously monitored. Once the airway is secure, ventilation should be evaluated. If unequal breath sounds are noted and the tracheal tube is in the correct position, a hemothorax, pneumothorax, or plugging of a large bronchus may be present. Tracheal deviation, though rare, may help with the diagnosis of tension pneumo- or hemothorax. Breath sounds are transmitted easily in children, and a simple pneumothorax is often not apparent until a chest radiograph is obtained. Tube thoracostomies are placed as needed. Flail chest is rare in pediatrics owing to the flexibility of the rib cage. Ventilation should be maintained with 100% oxygen during resuscitation.

After successful airway establishment and ventilation, circulation must be assessed. Direct pressure should be applied to any site of active hemorrhage. Pulses, perfusion, capillary refill, heart rate and rhythm, and blood pressure should be evaluated. Intravenous (IV) access, preferably two large-bore catheters, must be obtained rapidly for volume resuscitation. Subgaleal, intraabdominal, intrathoracic, or fracture-related hemorrhage may be life threatening. Heart rate is the most sensitive indicator of hypovolemia in pediatric trauma patients. Young children preserve blood pressure despite losing as much as 25% of their intravascular blood volume.^13,¹⁴ Thready pulses and altered mental status are evident with loss of 30% to 45% of blood volume. Volume resuscitation begins with crystalloid at 20 mL/kg, with further volume boluses based on the patient’s status. Blood products may be necessary to stabilize patients with hemorrhagic shock. Damage control resuscitation (DCR), or early and aggressive prevention and treatment of traumatic hemorrhagic shock, is advocated by a majority of recent trauma transfusion papers. Basic tenets of DCR include hypotensive resuscitation, rapid surgical control, hemostatic resuscitation with red blood cells, plasma, and platelets in a ratio of 1 : 1 : 1 along with appropriate use of coagulation factors such as rFVII and cryoprecipitate. Fresh whole blood can be used if available. Some refer to hemostatic resuscitation as damage control hematology.¹⁵^–¹⁷ Hemostatic resuscitation can be monitored and fine-tuned with thromboelastography. Hypertonic (3%) saline has been shown to effectively restore intravascular volume while also decreasing cerebral edema and may be used as a bolus of 5 to 10 mL/kg. Blood products should be warmed, because pediatric patients are at high risk for hypothermia.

Hypotension contributes to secondary injury to the brain and other vital organs and must be treated aggressively. In rare cases, vasoactive agents may be necessary in the resuscitation room. Trauma victims who are pulseless at the scene have an almost uniformly fatal outcome.^14,¹⁸ Prolonged, heroic resuscitative efforts should be avoided in these patients. Patients who have a pulse at the scene but arrest on route or in the emergency department have a slightly better prognosis, and resuscitation should be attempted. Most cardiac arrest associated with blunt trauma is a result of multisystem injuries, including severe brain injury.¹⁹ Open chest resuscitation should be considered only in the rare case of penetrating chest trauma, as it has been shown to be of no benefit in blunt trauma.

The neurologic examination should focus on the level of alertness, GCS score, pupillary response, focal signs of spinal cord injury, and signs of increased intracranial pressure (ICP). Subjects with a GCS score of 8 or less or with a waning mental status should be intubated using rapid-sequence intubation. Noncontrast head computed tomography (CT) should be performed immediately. Cooling the head-injured patient remains an interesting and controversial therapy.

All trauma patients are undressed and exposed for a full examination. Children rapidly lose heat and should be warmed with lights and blankets.

A secondary survey with full physical examination and radiographs as needed should follow the primary survey and stabilization. Once the patient is stabilized and resuscitation is complete, the team decides on a disposition.

Specific Injuries and Critical Care Management

Neck Injuries

Injuries to the airway in children can be rapidly life threatening. Small airway diameter combined with penetrating or blunt injury to the neck can produce rapid airway obstruction. Children are at greater risk than adults for spinal and major vascular injury from neck trauma. Death from airway injury may occur secondary to disruption of the airway at any level.

Clinically, the neck is divided into three anatomic zones, and management of traumatic airway injuries largely depends on which zone contains the injury. Zone 1 extends from the level of the clavicles up to the cricoid cartilage. Injuries to this area may involve the apex of the lung; trachea; subclavian, carotid, and jugular vessels; thoracic duct; esophagus; vagus nerve; and thyroid gland. Patients suffering zone 1 injuries typically exhibit hypotension, because the great vessels are often injured. Zone 2 encompasses the area from the cricoid to the mandible. Injuries to this area are the easiest to detect. Active bleeding can be reduced by direct pressure. The previous approach of mandatory operative management for zone 2 penetrating injury has been replaced by one of selective surgical exploration of wounds after clinical, endoscopic, and radiographic evaluation. Zone 3 extends from the angle of the mandible to the base of the skull. The oropharynx, jaw, and teeth are located within this area. Mandibular fractures in children manifest as malocclusion of the biting surfaces of the teeth and are usually associated with dental injuries. Injury to the chin associated with tympanic membrane perforation or hemotympanum is associated with an occult fracture of the mandible. Orotracheal intubation is not usually problematic in children with mandibular fractures unless there is copious oral hemorrhage. The neck is further divided into anterior and posterior regions. The anterior region contains the oropharynx, trachea, esophagus, and major vascular structures. The posterior neck contains the spine, spinal cord, and large neck muscles.

Penetrating neck and airway injuries occur less frequently in children than in adults. The majority of penetrating airway injuries in children occur in adolescent males.²⁰ Because major structures of the airway, central nervous system, and digestive and vascular systems are contained within the neck, penetrating injuries can be lethal owing to the anatomic structures injured. Wounds from sharp objects or bullets may injure the major vascular structures in the neck, trachea, or esophagus. As a result, penetrating wounds to the face and neck are more likely to require surgical intervention than blunt injuries are. Extensive damage to deep tissues may not be apparent on examination of the wound site. Stab wounds typically produce linear tissue injury that follows a predictable path from the entrance wound into the deeper tissue. Bullet injuries may produce unpredictable tissue damage as the result of deflection and shattering of the projectile throughout the neck. Penetrating injury to any of the major systems usually results in rapid airway compromise and shock.

Penetrating injury to the esophagus may not be immediately apparent but can produce delayed morbidity due to mediastinitis. Investigation of anterior neck injuries that involve the trachea should always include evaluation of the esophagus for perforation. Esophageal perforation should be suspected if fever, elevated white blood cell count, and subcutaneous air in the neck occur in the days following a traumatic neck injury. Management of the perforation requires prompt surgical repair of the esophagus, drainage of the surrounding soft-tissue infection, and IV antibiotics.

Although less common than penetrating injuries, blunt neck injuries can be associated with life-threatening airway disruption.^21,²² This injury is frequently missed in the presence of concurrent head, face, and thoracic injuries. Also associated with blunt neck trauma are injuries to the cervical spine, esophagus, lungs, and great vessels. Mortality rates of up to 30% are reported for children with these injuries, and half these children die of tracheobronchial rupture within 1 hour of the injury.²³

Blunt laryngeal trauma in children is uncommon and frequently unrecognized. The pediatric larynx is characterized by features related to immaturity. Its small diameter, funnel shape, and elastic structure result in significantly greater respiratory problems after trauma compared with adults. Due to its high anterior position in the neck, the larynx of a child is relatively sheltered by the mandible.²⁴ Greater cricothyroid pliability decreases the incidence of fractures, but surrounding tissue edema or blood in the lumen may rapidly produce respiratory difficulties because of the smaller diameter of the airway. The clinical presentation of laryngeal injury in children includes frank respiratory distress with hoarseness, stridor, and palpable subcutaneous emphysema.²¹ Radiographs of the chest and neck may show subcutaneous emphysema as well. The diagnosis of blunt laryngeal trauma in children is based on history, physical examination, and radiographic studies, followed by flexible or rigid bronchoscopy. CT of the neck adds little to the diagnosis of laryngeal injury. Once a laryngeal injury is suspected, rigid endoscopy in the operating suite should be used to secure the airway as well as delineate and repair the injury. Although adult patients with laryngeal injury frequently undergo an awake tracheostomy under local anesthesia, this is not routine in children. Careful placement of a tracheal tube below the level of injury provides an airway, but this may be difficult to accomplish. Difficulties in securing the airway usually reflect a lack of appreciation of the injury. Typical problems include hematoma and airway distortion, bleeding into the airway, or passage of the tracheal tube into the mediastinum.²⁵

Thoracic Injuries

Thoracic trauma, though rare in children, accounts for 5% to 10% of admissions to trauma centers. In isolation, it carries a 5% mortality rate. This increases fivefold when there is concomitant head or abdominal injury and can exceed 40% when a combination of head, chest, and abdominal injuries is present.²⁶ Potentially life-threatening injuries such as airway obstruction, tension pneumothorax, massive hemothorax, open pneumothorax, flail chest, and cardiac tamponade must be corrected immediately. The last three injuries are relatively uncommon in the pediatric population. Young children have a significantly more flexible thoracic cage than adults do. As a result, compression of intrathoracic organs with blunt trauma may lead to significant parenchymal injuries in the absence of rib fractures. Thus, pulmonary contusions, rather than broken ribs, are far more common in children. In isolation, a broken rib is rarely associated with increased morbidity or mortality.²⁷ An isolated first rib fracture, however, is a potential sign of child abuse²⁸ or may be associated with significant thoracic injury. Isolated cervical rib fracture is very rare but has been associated with backpack usage.²⁹ Multiple rib fractures should alert the clinician to look for underlying injuries in the thoracic cavity. Further radiographic evaluation, such as CT angiography, may be warranted to complete the diagnostic evaluation. Numerous studies have demonstrated that the presence of multiple rib fractures has an approximate 40% mortality rate, often due to the presence of associated multisystem injury.³⁰ Supportive care is the mainstay of rib fracture management. Appropriate analgesia is necessary to promote deep inspiratory effort and prevent atelectasis. Intercostal nerve blocks or epidural analgesia may be helpful when there is respiratory insufficiency but are rarely necessary.

Trauma to the intrathoracic trachea and bronchi is fortunately rare, as 50% of pediatric patients die within 1 hour of tracheobronchial disruption.³¹ Pneumothorax and subcutaneous emphysema are common findings, but rib fractures are not common. Failure of tube thoracostomy to reexpand the lung and the continued presence of a large air leak denote a tracheal or bronchial disruption. If the site of tracheal or bronchial disruption is within the chest cavity, the endotracheal tube tip should be placed distal to the disruption. This may require bronchoscopy. Selective intubation of the undisrupted mainstem bronchus, followed by one-lung ventilation until the proper resources can be obtained for control of the damaged bronchus, may be required. This must be done rapidly and with great care to avoid extending the tracheal injury. Once the injury is repaired, the patient may benefit from a low-tidal-volume ventilation strategy.

Complete bilateral tracheobronchial disruption in a child with blunt chest trauma has been reported. The child survived after median sternotomy, intubation of both left and right mainstem bronchus, and subsequent cardiopulmonary bypass with subsequent reanastomosis of both left and right mainstem bronchi to the trachea.³²

Pulmonary contusion may occur with or without the presence of overlying rib fractures or chest wall injury. Symptoms include tachypnea, dyspnea, cyanosis, hemoptysis, and respiratory failure. The initial chest radiograph may not demonstrate this injury, and repeat x-rays may be necessary to reveal the infiltrates. Excessive fluid administration should be avoided. Mechanical ventilation may be necessary. Acute respiratory distress syndrome (ARDS) is uncommonly associated with pulmonary contusion, but it may develop. In rare cases, there may be severe pulmonary hypertension.

In children, the mediastinum is less fixed than in adults, and the physiologic consequences of tension pneumothoraces may become evident rapidly. Each hemithorax can hold 40% of a child’s blood volume. A chest tube large enough to drain the entire hemithorax without clotting or occluding is necessary. Surgical exploration for hemostasis may be required if the initial chest tube output is 20 mL/kg or greater than 3 to 4 mL/kg/h.³³ Inadequate evacuation leads to lung entrapment from a fibrothorax and predisposes the patient to chronic atelectasis. Penetrating injuries may require thoracotomy in the operating room. Anterior penetrating injuries below the nipple line and posterior penetrating injuries below the tip of the scapula warrant exclusion of intraabdominal injuries.

Other thoracic injuries include traumatic asphyxia, chylothorax, and esophageal tears. Esophageal tears occur in less than 1% of children with blunt thoracic injuries. Esophageal lacerations can be diagnosed with flexible esophagoscopy. Lacerations almost always need repair. Mediastinitis can occur and causes with it a risk of mortality.³⁴ Traumatic asphyxia is caused by sudden, severe compression of the chest and upper abdomen and is characterized by craniofacial and cervical cyanosis, edema, and petechiae. Subconjunctival and thoracic wall petechiae also occur. There may be associated respiratory distress, cardiac arrest, and cerebral edema with raised ICP. Retinal hemorrhage, blindness, and orbital compartment syndrome have also been reported.³⁵ Traumatic chylothorax is rare in children but has been reported with blunt and penetrating injury and with child abuse.

Cardiac and Aortic Injuries

Traumatic injury to the heart and great vessels is significantly less common in pediatric patients than in adults. Most injuries are the result of blunt trauma; penetrating injuries are rare and carry a higher mortality rate.

Myocardial contusion results from blunt force injury to the chest. The vast majority of pediatric patients with myocardial contusions have multisystem trauma; pulmonary contusion is the most common coexisting injury, found in 50% of patients.³⁶ Hemodynamically significant myocardial contusion is relatively rare in pediatric patients and may present with arrhythmia or ventricular dysfunction. The majority of arrhythmias occur within 24 hours. In a study of 184 pediatric patients with blunt cardiac injury, no hemodynamically stable patient who presented with normal sinus rhythm subsequently developed an arrhythmia or cardiac failure.³⁶ However, there have been case reports of delayed arrhythmia occurring up to 6 days later.

Diagnostic evaluation of myocardial contusion is controversial and is usually based on a series of tests in the appropriate clinical setting. In pediatrics, testing may include a combination of cardiac enzyme determinations, electrocardiography, and echocardiography. Creatine kinase-MB and cardiac troponin-I elevation following blunt trauma has been used to diagnose contusion. Cardiac troponin-I is highly specific for the myocardium, but creatine kinase-MB may be elevated with injury to skeletal muscle. Elevation of troponin-I occurs within 4 hours of injury and peaks within 24 hours. The significance of elevation in a hemodynamically stable patient is unclear, and determination may not be necessary in these patients.^37,³⁸ An admission 12-lead electrocardiogram (ECG) is recommended in all patients. Echocardiography may show wall motion abnormalities or ventricular dysfunction. In a small pediatric study, echocardiography was diagnostic of cardiac injury in patients with hemodynamic instability or abnormal chest radiographs who had nondiagnostic ECG and creatine kinase-MB.³⁹

In addition to myocardial contusion, structural damage such as traumatic ventriculoseptal defect, valve injury, ventricular rupture, or aneurysm may occur with blunt chest trauma. The management of all blunt cardiac injury is largely supportive, with operative intervention as needed for significant structural damage. Continuous ECG monitoring is recommended.

Commotio cordis is an unusual event but is much more common in pediatric patients, with 80% of victims younger than 18 years and 50% younger than 14 years. Blunt trauma to the chest with the impact centered over the heart results in immediate cardiac arrest. It is thought that the narrow anteroposterior diameter of the chest, in conjunction with the increased compliance of the chest wall in pediatric patients, allows a chest-wall blow to be transmitted to the underlying heart. Many but not all cases occur during sports-related activity.⁴⁰ Blunt chest trauma leads to cardiovascular collapse, with ventricular tachyarrhythmia being the most common arrhythmia. Unlike myocardial contusion, there is no evidence of myocardial injury on autopsy. The survival rate is low, even with prompt resuscitation.^40,⁴¹

Blunt aortic injury is an extremely uncommon pediatric injury; however, as in adults, it is potentially lethal. The aortic arch is relatively fixed, and the descending aorta is more mobile, making it susceptible to shearing forces during horizontal and vertical deceleration. Three reasons for the rarity of blunt aortic injury in pediatric patients have been proposed. First, most adult thoracic aortic injuries are the result of the driver of a vehicle impacting the steering wheel, with a large force being imparted over a small area. This mechanism does not occur in pediatric patients. Second, blunt trauma in children is often the result of pedestrian-automobile accidents, allowing the force of impact to be widely distributed over the body surface area.⁴² Third, the breaking stress of the thoracic aorta is inversely related to age⁴³ but is decreased in connective tissue diseases such as Ehlers-Danlos and Marfan syndromes. One of our rare cases of blunt aortic injury occurred in a young child with a connective tissue disorder.

Diagnosis of thoracic aortic injury is similar in children and adults. The pattern of chest x-ray findings is similar, although one study found that depression of the left mainstem bronchus is not as common in pediatric patients. Angiography has been the gold standard for the diagnosis of thoracic aortic injury.⁴⁴ Helical CT is fast becoming an important diagnostic tool and, when performed properly, has a sensitivity and specificity similar to that of angiography.^45,⁴⁶ Transesophageal echocardiography may also have a role in diagnosis, although its place is less clear. As in adults, successful management of these potentially lethal injuries depends on prompt recognition and treatment.

Abdominal Injuries

More than 90% of abdominal trauma in pediatrics is the result of blunt trauma; penetrating trauma accounts for only 5% to 10% of injuries. After initial resuscitation, evaluation of specific injuries begins. It is important to know the mechanism of trauma to appreciate the potential abdominal injuries. A nasogastric or orogastric tube as well as a Foley catheter should be placed during abdominal evaluation, because dilatation of the stomach and bladder can cause significant pain, interfering with the examination. Inspection of the abdomen may reveal external evidence of trauma suggestive of an underlying injury. Evaluation of abdominal tenderness is important but may be an unreliable finding in a child with lower rib fractures, contusion or soft-tissue injury to the abdominal wall, or pelvic fracture. Auscultation with absent bowel sounds indicates ileus and may suggest underlying gastrointestinal (GI) injury. The pelvis should be examined by compression. Rectal examination should always be performed. If there is blood at the urethral meatus, perineal hematoma, or pelvic instability, a serious pelvic injury should be suspected. Hematuria is indicative of genitourinary injury.

The initial evaluation of children with abdominal trauma may include radiographs of the chest, abdomen, and pelvis. At the present time, focused abdominal sonography for trauma is an excellent initial study of the peritoneum and pericardium. Its use is more widespread in adults than pediatrics.⁴⁷^–⁴⁹ The gold standard for evaluation of children with blunt abdominal trauma is CT with IV contrast. It gives reliable information about solid-organ injuries, the presence of abnormal fluid, the presence of pneumoperitoneum indicating hollow viscus injury, and the retroperitoneal space. Further, organ blood flow and contrast extravasation can be observed. Diagnostic peritoneal lavage is a sensitive test to detect bleeding and a perforated hollow viscus in blunt abdominal trauma; however, its use in pediatrics is limited owing to the success of nonoperative management of solid-organ injuries and rapid CT scanning. Diagnostic peritoneal lavage may be indicated in children who have an emergent operative neurologic injury and require immediate assessment of the abdominal cavity.

Penetrating injury is rare in pediatrics. Virtually all gunshot wounds to the abdomen and lower chest should be treated by mandatory laparotomy. Stab wounds below the nipple line and above the inguinal ligament can be managed selectively by local wound exploration, peritoneal lavage, CT scan, and frequent serial physical examinations to determine the need for laparotomy. A recent paper supports selective nonoperative management of penetrating abdominal injuries in children.⁵⁰

Liver

Signs and symptoms of hepatic injury include pain and tenderness, abrasions, and contusion of the abdominal wall. Signs of peritonitis due to hemoperitoneum are frequently present. Most isolated liver injuries can be managed nonoperatively. Selective angiography and embolization may control bleeding without the need for operative repair. Operation, however, may be required for hemodynamic instability, continued transfusion requirement, or other associated injuries. The decision to operate is based on the child’s physiologic status and not the graded classification of injury.⁴⁷ Complications of hepatic injury include hemobilia, abscess, biliary fistula, and bile peritonitis. The potential for delayed bleeding is higher in hepatic than in splenic injury.

Spleen

The spleen is the organ most frequently injured in blunt abdominal trauma. Ecchymosis, pain, and tenderness over the left upper quadrant are suggestive of splenic injury. Left shoulder pain may be present as a result of diaphragmatic irritation. Abdominal CT is recommended to determine the extent of injury as well as the presence of hemoperitoneum and other associated injuries.

Nonoperative management is preferable and is similar to the nonoperative management of liver injuries. Angiography and selective embolization should be considered in patients with active bleeding seen on CT.⁵¹ Pediatric experience with AE is limited. However, a recent paper reports successful AE in 7 pediatric patients, two spleen (grades IV and V), two liver (grades III and IV), and three grade IV renal injuries.⁵² Surgical management may be necessary in patients who are hemodynamically unstable, require continued transfusions, or have other associated abdominal injuries. A variety of surgical techniques are available to control bleeding, often without a total splenectomy. The incidence of total splenectomy in pediatric trauma centers is 3%. In patients requiring total splenectomy, there is a risk of post-splenectomy sepsis. In patients splenectomized for trauma, sepsis develops in 1.5%, with a mortality rate of 50%. Postsplenectomy sepsis may occur at any time, but the risk is greatest in the first 5 years of life. All postsplenectomy patients must be immunized.

Duodenum and Pancreas

The duodenum and pancreas are considered as a unit because they share a blood supply and are connected in the retroperitoneum. For these reasons, managing pancreaticoduodenal injuries is complicated. The most common cause of injury is blunt midepigastrium trauma from a blow, automobile crash, or bicycle handlebar. The diagnosis of pancreaticoduodenal injuries can be achieved using chemical markers and imaging studies. Serum amylase and lipase are indicators of pancreatic injury, but amylase levels may be elevated due to injuries to other organs, including the salivary glands. Ultrasonography and CT are the preferred imaging studies to delineate the pancreas. Duodenal perforations can be diagnosed using upper GI studies with water-soluble contrast or CT scan with oral contrast, in which free air or extravasation may be seen.

Most pancreatic injuries are mild.⁵³ They can be managed nonoperatively with nasogastric decompression and parenteral nutrition. When the patient’s condition improves, nasogastric drainage can be discontinued and oral intake begun. Serial enzyme levels and ultrasonography should be performed to identify complications. Patients with severe pancreatic injury may require surgical repair or endoscopic placement of pancreatic duct stents.

Several complications may occur after pancreatic injury, including pleural effusion, bile duct obstruction, and pancreatic pseudocyst. Pancreatic pseudocyst occurs in one-third of patients.

Most duodenal injuries are lacerations that can be treated by simple débridement and primary repair. For extensive duodenal injuries in which more than 50% of the circumference is affected, the blood supply is compromised, or bile duct/pancreatic injury is present, an aggressive surgical approach may be necessary. Duodenal hematoma results from blunt abdominal trauma associated with rapid deceleration or from a direct blow to the upper abdomen. It may present a day or more after injury as vomiting or a large amount of nasogastric drainage. It is easily diagnosed by ultrasonography or upper GI studies. The resultant intestinal occlusion should be treated by nasogastric decompression and parenteral nutrition until the obstruction resolves. If it fails to resolve within 3 weeks, an operation should be considered.

Small Intestine

Hollow viscus injuries are far less common than solid-organ injuries in pediatric abdominal trauma patients. Nevertheless, bowel injury may result from even mild abdominal trauma. The mechanism of injury is either compression or shear forces resulting from rapid deceleration. There are two points of fixation to the retroperitoneum that frequently lead to transections: the ligament of Treitz and the cecum. Handlebar blows or direct blows to the abdomen compress the bowel against the vertebral column, resulting in intestinal perforation. In the lapbelt complex, contusions or abrasions of the abdominal wall and lumbar spine injury are associated with bowel perforation. Lapbelt loading generates significant intraabdominal injuries in children. Upper lapbelt loading is associated with liver, spleen, rib, stomach, small-bowel, and large-bowel injuries. Lower lapbelt loading is associated with ribs, small bowel, large bowel, bladder, kidney, and stomach injury. Greater than 40% of Abbreviated Injury Severity Score (AISS) 2+ injuries have small-bowel and large-bowel injuries.⁵⁴

Identification of patients with a bowel injury may be challenging. Obtaining a detailed history of the mechanism of injury may prevent a delay in diagnosis and late complications. Detection of peritoneal signs may be difficult owing to distracting pain from the abdominal wall and back injury. If there is also a solid-organ injury, peritoneal signs and symptoms may be interpreted as solely from the associated hemoperitoneum. There is no completely reliable imaging study available to detect intestinal injury. CT may show nonspecific findings suggestive of bowel injury. Serial clinical examinations and repeat CT scanning are important to diagnose injury in a timely fashion. Diagnostic peritoneal lavage may also play a role. Patients should receive nothing by mouth until a bowel injury is no longer suspected.

Diaphragm

Diaphragmatic rupture is the consequence of direct blunt trauma over the lower thorax and abdomen. The injury is most frequent on the left side. Contusion or abrasions of the upper abdomen, bowel sounds in the chest, and respiratory distress are the classic findings of a traumatic diaphragmatic rupture. A chest radiograph may show bowel and the nasogastric tube in the thorax. The diagnosis may be confirmed by upper GI studies, ultrasonography, CT, and/or thoracostomy/laparoscopy. Laparotomy allows proper repair of the diaphragmatic defect and assessment of other organs.

Damage Control and Abdominal Compartment Syndrome

If the child is hemodynamically unstable despite aggressive resuscitation, a laparotomy for damage control may be required.⁵⁵ In the presence of the lethal triad of hypothermia, acidosis, and coagulopathy, an immediate definitive surgical repair is unnecessary.^56,⁵⁷ The damage control approach has three stages.⁵⁸ The first stage is the initial laparotomy, the goal being to prevent ongoing damage by controlling hemorrhage and fecal contamination. Abdominal packing and temporary closure of the wounds with loose retention sutures may be required.⁵⁹ Definitive surgical repair is postponed until the patient is stabilized. The second stage is carried out in the ICU, with the goals of rewarming, correcting the coagulopathy, and restoring acid-base balance. An abdominal compartment syndrome may develop during the second phase.⁶⁰ Intraabdominal pressure may be increased by edema, tissue swelling, ascites, and ongoing bleeding. The high pressure may cause cardiorespiratory and renal deterioration. Elevation of the diaphragm produces basilar atelectasis and restriction of lung inflation, which makes ventilation difficult. Increased abdominal pressure can also cause hypoperfusion of the abdominal contents, leading to renal failure and ischemic bowel injury with resultant bacterial translocation. Increased abdominal pressure also may decrease venous return and therefore cardiac output. Treatment of abdominal compartment syndrome is urgent and may require a peritoneal drain or opening of the abdominal wound and placement of a prosthetic silo.⁶¹ The third stage involves definitive surgery once the patient is stabilized. Packs are removed, tissues are débrided, bowel anastomoses are performed, and fractures are reduced. Most injured patients are not candidates for damage control surgery. Unstable pediatric patients with severe abdominal injury benefit from this staged approach, which is designed to allow medical resuscitation and avoid continued hypothermia, acidosis, and coagulopathy.