Pediatric abdominal trauma





Pearls





  • In pediatric trauma, as with all trauma patients, the first priority remains the ABCs: airway, breathing, circulation.



  • Intubation in children can be challenging and is best done by experienced providers. Maintain airway control with bag-mask ventilation if able until experienced providers can assist.



  • The same principles of hemorrhage control in adults apply to children. Establishing intravenous or intraosseous access early and restoring lost volume with blood is lifesaving.



  • As in all trauma patients, there is no contraindication to tourniquet use in children.



  • Pediatric trauma patients can maintain relatively normal vital signs despite significant hypovolemia.



  • Nonoperative management of solid-organ injuries is the standard of care. However, if the patient is hemodynamically unstable despite volume restoration, consider operative intervention.



  • Child abuse is a significant source of pediatric morbidity and mortality.



Trauma is the leading cause of morbidity and mortality in the pediatric age group. An estimated 1.5 million pediatric injuries occur each year, resulting in 500,000 hospitalizations and 20,000 deaths. Thus, trauma exceeds all other causes of death combined. Abdominal injuries are a marker of severe trauma; evaluation of the child with an abdominal injury must include a thorough examination of the child’s entire body. Management of pediatric trauma requires a multidisciplinary approach with emergency department physicians, critical care specialists, anesthesiologists, and surgeons working as a team to provide prompt stabilization, assessment, and treatment. Performing the primary and secondary survey, ensuring a stable airway, instituting fluid resuscitation, and arriving at a decision as to the most appropriate management plan are the principal goals of the trauma team leader.


The majority of abdominal injuries in children are preventable. Healthcare providers must work with the broader community to identify and alleviate causes of pediatric trauma. Education, public safety measures, and legislation will prevent many cases of pediatric injury.


In the pediatric population, child physical abuse must be considered and, if suspected, must be reported to the appropriate agency. As part of disaster preparedness, clinicians providing trauma care for children should have an awareness of wartime and mass casualty injury management.


Mechanisms and patterns of injury


The severity and pattern of abdominal injury correlate with the mechanism of injury. Blunt injury accounts for 90% of abdominal trauma in children. Common mechanisms include motor vehicle collisions, automobile versus pedestrian crashes, falls, bicycle crashes, and nonaccidental trauma. In pediatric blunt abdominal trauma, solid viscus organs such as the liver, spleen, and kidney are more frequently injured than hollow viscus organs. Children suffering lap belt injury, handlebar injury, or kicks may suffer small-bowel perforation. Children struck by motor vehicles may have specific patterns of head injury, intraabdominal or intrathoracic injury, and femur fracture (Waddell triad). In addition, urban violence and the high prevalence of firearms result in penetrating abdominal injuries in children. Although the mechanism of injury may correlate with the extent of injury, ongoing clinical assessment is a more sensitive indicator of the extent of blood loss and hemodynamic instability, and it determines the resuscitation and management of the child with an abdominal injury.


Penetrating abdominal trauma


Penetrating abdominal injuries are most commonly caused by firearm use or stabbings but can result from a variety of mechanisms. In children, abdominal gunshot wounds result in more severe injuries than stab wounds because of the increased energy delivered by firearms, particularly shotguns and assault rifles. Significant intraperitoneal injuries are present in most children who sustain gunshot wounds, suggesting the need for abdominal exploration in all gunshot victims. There is a trend toward selective exploration of penetrating injuries in adults. For example, computed tomography (CT) has been used successfully to determine the application of selective laparotomy in penetrating torso trauma in adults. However, most trauma centers continue to perform laparotomy on most patients with gunshot wounds to the abdomen. Abdominal stab wounds that penetrate the transversalis fascia are at high risk of intraabdominal injury. Expectant observation of stab wounds in children is controversial.


Recreational and sports injury


Specific recreational activities commonly practiced by children—such as bicycling, all-terrain vehicle (ATV) use, skiing, snowboarding, and horseback riding—result in predictable injury patterns that guide evaluation. Snowboard injuries are increasing and include abdominal injuries in 25% of cases. At a level 1 pediatric trauma center in the United States, 213 cases of pediatric snowboarding injury were admitted over 7 years. Of these cases, 39 patients had an injury involving the thorax or abdomen, with almost half being abdominal. The spleen was the most commonly injured organ. Male gender and age 14 years or younger were associated with a significant increase in abdominal injury. Upper extremity trauma was significantly associated with abdominal or pelvic trauma. ATV crashes produce a particularly damaging pattern of injury as the ATV has the weight of a car and the lack of protection of a motorcycle. This results in a combination of an ejection and rollover mechanism of injury, with the worst of both. The majority of deaths involve head and spine injuries. Lack of helmet use is associated with a higher mortality. A retrospective study of trauma admissions to a level 1 pediatric trauma center of 163 pediatric ATV crashes showed that almost two-thirds of patients did not wear helmets. Of those who did, helmet use was significantly associated with a lower incidence of injury to the head and neck.


ATV abdominal injuries include crush injuries to liver, spleen, and kidney. Child drivers are more susceptible to crash. Even where laws restrict ATV use by children, they are frequently injured and have a high rate of missed injuries. Blunt impalement on a bicycle handlebar can result in a predictable pattern of injury to the bowel, mesentery, or pancreas.


Wartime trauma


Children can also be victims of wartime trauma causing abdominal and other injuries. Modern warfare is often conducted in urban areas with a civilian population present and the frequent involvement of children. Additionally, medical infrastructure is disrupted in a war zone, and many residents suffer malnutrition and infections, which makes them more debilitated in the face of a new injury. Military high-energy rifles cause penetrating wounds in which the pressure wave of the projectile results in a cone of tissue destruction. In abdominal injuries, this necessitates wide debridement of soft tissues; a second-look laparotomy is often required to detect evolving intestinal necrosis. It is common for children to suffer blast and fragmentation injuries from landmines, bombs, indirect-fire weapons (rockets and mortars), improvised explosive devices, and suicide bombings. Landmines and air-delivered cluster bomblets are particularly insidious because their interesting colors and shapes attract children’s curiosity. Wounds include pressure wave blunt injury, shrapnel penetration, and burns. These injuries in children often require a damage-control laparotomy, wide debridement of soft tissues, temporary abdominal closure, and multiple operations. Vacuum-assisted wound dressings are particularly useful.


Evaluation and resuscitation


Evaluation and resuscitation occur simultaneously when a child presents with an abdominal injury. The Advanced Trauma Life Support (ATLS) guidelines developed by the American College of Surgeons should be followed. The primary survey includes stabilization of the cervical spine while evaluating for airway patency, function of breathing, and adequacy of circulation (the ABCs). Prompt endotracheal intubation should occur in any patient in whom the stability of these functions is in doubt. Intravenous access in the small child can be particularly challenging—skilled personnel should be employed. If peripheral venous access is unsuccessful after two attempts in a hemodynamically unstable child, an intraosseous line should be attempted. Basic neurologic function is assessed. The patient must be completely exposed for examination and then covered with blankets to maintain body temperature. Children are more susceptible to heat loss and dehydration because of their greater surface area/mass ratio.


Physical examination


The vast majority of children who receive an intervention for blunt abdominal injury manifest abnormal physical examination findings. Abdominal examination includes observation of external signs, then palpation for tenderness, distension, or firmness. Children swallow a large amount of air when they cry—gastric distension may require orogastric tube or nasogastric tube decompression. Upper quadrant ecchymosis, tenderness, and associated rib fractures suggest the presence of liver or spleen injury. Midabdominal ecchymosis from a seatbelt suggests the possibility of a small-bowel injury. Stability of the pelvis is assessed with lateral and axial manual compression of the pelvic ring. Extraperitoneal bladder ruptures may cause localized suprapubic tenderness, whereas an intraperitoneal bladder rupture may present as generalized abdominal distension. Injuries near the abdomen may also be associated with intraabdominal injury. In a mixed adult/pediatric study of patients admitted to seven trauma centers in the United States over a 6-year period, patients with Chance fractures (horizontal fracture through the vertebra) of the thoracolumbar spine were reviewed. Of the 79 patients reviewed, one-third had an intraabdominal injury; hollow viscus injuries were the most common and were found in 22% of patients. Twenty-five percent of patients had a laparotomy; abdominal wall contusions were strongly associated with hollow viscus injury and need for laparotomy. Of 20 patients with abdominal wall contusion and Chance fractures, 85% had an intraabdominal injury and 70% required laparotomy.


Laboratory tests


Wide variability exists in the routine initial laboratory assessment of children following blunt abdominal trauma. Selective laboratory examination—including complete blood counts, serum chemistries, hepatic enzymes, pancreatic enzymes, coagulation parameters, and urinalysis—may be considered depending on the level of clinical suspicion. , Elevated transaminase levels suggest nonspecific parenchymal liver injury, whereas elevated amylase and lipase levels may suggest a pancreatic injury. Hematuria may be associated with intraabdominal injury and renal injury. ,


Radiographic assessment


Prompt plain radiographs of the chest and pelvis should be obtained during the initial assessment after blunt trauma as part of ATLS protocols. Patients who are hemodynamically stable may undergo further radiographic evaluation. In hemodynamically stable patients with a normal examination, forgoing the routine pelvic radiograph can also be considered.


Computed tomography


CT with intravenous contrast (oral contrast is not routinely needed) is the procedure of choice for definitive radiographic assessment after blunt abdominal trauma in children. CT can be used to identify hepatic, splenic, intestinal, pancreatic, renal, and bladder injuries in children and can even detect intestinal and mesenteric injury with sensitivities of 94% and 96%, respectively. Findings on CT suggestive of intestinal injury are unexplained free fluid without solid-organ disruption, abnormal distribution of bowel loops, contrast extravasation, and contrast enhancement of intestinal wall. The Organ Injury Scaling Committee of the American Association for the Surgery of Trauma has developed a grading system to estimate the extent of abdominal injury. , Short of operative exploration, CT is the most accurate method used to grade the extent of injury. Concern over the use of abdominal CT scan and radiation exposure in children has led centers to reexamine the use of CT scans to evaluate blunt abdominal trauma and to try to make prediction rules for when CT scanning will be most helpful. A retrospective study of 571 pediatric patients at two Canadian level I pediatric trauma centers admitted after blunt abdominal trauma sought to correlate clinical parameters such as mechanism of injury as well as radiologic and laboratory analysis variables that might predict injuries seen on CT scan. Injury results were classified as “notable” or “clinically important” if an injury was classified as a grade 3 or higher injury on the Abbreviated Injury Scale (AIS) or if the injury required surgery. A total of 441 (77%) of the children had an abdominal CT scan. Of the children, 37% had a notable injury and 18% had a clinically important injury. Most injuries were solid organ; only 2% were hollow viscous injuries. Factors significantly associated with notable abdominal injury included abdominal examination findings of pain or tenderness, hematuria, and elevated serum alanine aminotransferase. Factors that were significantly associated with clinically important injuries were low hematocrit and hematuria.


A retrospective study of trauma patients suspected of abdominal injury who had a laparotomy demonstrating intestinal injury or mesenteric injury showed that there were no false-negative studies using 64-slice CT. Free fluid was seen on all CT scans. A total of 88% of patients had one finding in addition to free fluid. Findings associated with bowel or mesenteric injury on CT scan were free fluid, bowel wall thickening, mesenteric or bowel wall hematoma, active mesenteric bleeding, mesenteric stranding, pneumoperitoneum, or contrast extravasation. The most common finding besides free fluid was bowel wall thickening.


Recent research has focused on identifying children at low risk for intraabdominal injury for whom a CT scan of the abdomen could be safely omitted. The Pediatric Emergency Care Applied Research Network developed and validated a clinical prediction rule using seven clinical patient history and physical examination findings to identify such a population. In this model, patients with no evidence of abdominal trauma, Glasgow Coma Scale score greater than 13, no abdominal tenderness, no thoracic wall trauma, no complains of abdominal pain, normal breath sounds, and no emesis had a 0.1% incidence of intraabdominal injury requiring intervention. This prediction rule had a negative predictive value of 99.9% and a sensitivity of 97%. A five-variable clinical prediction rule incorporating laboratory and plain radiograph information was developed by the Pediatric Surgical Research Collaborative. In this model, the absence of abdominal pain; abdominal wall trauma, tenderness, or distention; abnormal chest radiograph; aspartate transaminase level greater than 200 mg/dL; and abnormally elevated pancreatic enzymes generated a negative predictive value of 99.4% for intraabdominal injury and 100% for intraabdominal injury requiring intervention.


Sonography


The focused abdominal sonogram for trauma (FAST) is a rapid, noninvasive, and portable method to evaluate the abdomen. Various reports note that sonography for abdominal trauma has a sensitivity of 55% to 86% and a specificity of 95% to 98% in adults. Sonography accurately identifies intraperitoneal free fluid, but it does not accurately identify the source of that fluid. Sonography is comparable to diagnostic peritoneal lavage (DPL) as a method for detecting free peritoneal fluid, but it is noninvasive. However, it does not supplant CT in its ability to define the specific nature and extent of abdominal injury. In children, FAST has a low sensitivity and specificity for identifying clinically meaningful intraabdominal injury and has not been shown to improve clinical care in hemodynamically stable children. ,


Additional assessment tools


Diagnostic peritoneal lavage


Refinement of nonoperative management of pediatric abdominal trauma makes DPL unnecessary in stable patients because the presence of free intraperitoneal blood is not an absolute indication for surgery in children. In addition, performing DPL can be difficult in small children owing to the decreased domain of the smaller abdomen. However, DPL may be a useful triage tool for selectively applying laparotomy for blunt intestinal trauma in children. In the rare event that DPL is performed in a child, the procedure is the same as in adults except that the amount of warm crystalloid instilled into the abdominal cavity is less (10 mL/kg). In one series, the cell count, amylase activity, and particulate matter in the DPL specimen were able to identify small-bowel perforation with a sensitivity of 100%.


Diagnostic laparoscopy


Diagnostic laparoscopic evaluation has been suggested as a safe and effective modality for evaluating the abdomen in the stable patient after penetrating trauma. Diaphragmatic injuries can be diagnosed and repaired laparoscopically. Thoracoscopy in hemodynamically stable penetrating-trauma patients can be used to avoid nontherapeutic laparotomy by ruling out penetration of the abdominal cavity and can identify thoracic and diaphragmatic injuries.


Management of specific abdominal injuries


Children often demonstrate hemodynamic stability in the face of significant hemorrhagic loss until their capacity for compensatory vasoconstriction is surpassed. Although fluid resuscitation and blood transfusion are far and away the primary therapy, a select few children may require inotropic support after major trauma. Frequent serial abdominal examinations are performed to determine the need for surgical exploration for a missed hollow viscus injury. Operative intervention should not be delayed, because hypotension and decreased cerebral perfusion pressure worsen morbidity and mortality. Although abdominal compartment syndrome has a low trauma-reported incidence of 0.6% to 4.7% in critically injured children, it will be detected only through a high index of suspicion and frequent measurement.


Nonoperative management of solid-organ injuries


The standard of care in treating hemodynamically stable children with hepatic or splenic injury is nonoperative management. Management of these injuries varies widely between adult and pediatric facilities; splenectomy can be avoided if a child is taken to a facility that uses this nonoperative strategy. Previously, the American Pediatric Surgical Association (APSA) Trauma Committee proposed guidelines for care based on radiographic severity of injury ( Table 120.1 ). A recent systematic review published by the APSA Outcomes and Evidence-Based Practice Committee suggests that management, including hospital length of stay, should be driven by clinical and not imaging findings.



TABLE 120.1

Proposed Guidelines for Resource Utilization in Children With Isolated Spleen or Liver Injury

Data from Stylianos S, APSA Trauma Committee. Evidence-based guidelines for resource utilization in children with isolated spleen or liver injury. J Pediatr Surg. 2000;35:164–169.








































Computed Tomography Grade I II III IV
Intensive care unit stay (days) None None None 1
Hospital stay (days) 2 3 4 5
Predischarge imaging None None None None
Postdischarge imaging None None None None
Activity restriction (weeks) a 3 4 5 6

a Return to full contact, competitive sports (e.g., football, wrestling, hockey, lacrosse, mountain climbing) should be at the discretion of the individual pediatric trauma surgeon. The proposed guidelines for return to unrestricted activity include “normal” age-appropriate activities.



Embolization of solid-organ injuries


CT can identify active extravasation from splenic and hepatic injuries. Angiography is able to map out the specific site of hemorrhage, and embolization can be used to selectively occlude the bleeding vessel. This therapy may reduce the need for transfusion and avoids the need for laparotomy. Nonselective embolization of the main splenic artery may also be performed ( Fig. 120.1 ). Angiography should be reserved for children with active extravasation with ongoing bleeding who are hemodynamically stable. Unstable patients with solid-organ injury require laparotomy. There remains a wide variability in clinical practice across institutions; embolization is more commonly employed at adult trauma centers and for high-grade splenic injuries.


Jun 26, 2021 | Posted by in CRITICAL CARE | Comments Off on Pediatric abdominal trauma
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