SAN DIEGO – In the clinical experience of Dr. Julia Grabowski, managing blunt abdominal trauma injuries in children can be tricky business because of the wide variation in development between infants and adolescents.
Such differences "affect both the care of the injured child and injury prevention efforts," she said at the University of California San Diego Critical Care Summer Session. Anatomic considerations in the management of pediatric abdominal trauma include the close proximity of multiple organs, "which can affect their overall injury patterns," said Dr. Grabowski, a pediatric surgeon at Rady Children’s Hospital in San Diego. "In addition, their solid organs are larger compared with the rest of their abdomen. They generally have less body fat, less connective tissue, and less muscle mass, and their bony skeleton is incompletely ossified."
Dr. Julia Grabowski
Compared with adults, the rib cage in children "is higher and much more pliable, so rib fractures are quite uncommon in the pediatric population," she said. "If you do see a child who has a rib fracture, that’s a trigger to think they had a much worse trauma than you originally expected."
Blunt injuries account for about 90% of all injuries and deaths in children, Dr. Grabowski said. In blunt abdominal trauma, the most common mechanism of action is a fall, followed by motor vehicle collisions, pedestrian versus auto accidents, bicycle accidents, and assaults. The most commonly injured organs are the spleen and liver, followed distantly by the kidney, small bowel, and pancreas.
Diagnostic evaluation of blunt abdominal trauma includes C-spine imaging for those in whom you suspect C-spine trauma, chest x-rays, anterior-posterior x-ray of the pelvis as necessary, and a computed tomography scan, "which is really the workhorse of evaluation for blunt abdominal trauma," she said. Lab studies may include CBC, liver function tests, amylase, lipase, and blood type and cross.
Another option is Focused Assessment With Sonography for Trauma (the FAST scan). According to Dr. Grabowski, recent research has demonstrated that FAST has a low sensitivity and is inappropriate for use in hemodynamically stable children, but that it may be useful in unstable patients.
For splenic and hepatic injuries, grade and clinical exam dictates the need for PICU admission, frequency of vital signs, hematocrit and hemoglobin testing, diet, and activity. The American Pediatric Surgical Association published guidelines for the management of hemodynamically stable children with isolated spleen or liver injury (J. Pediatr. Surg. 2000; 35:164-9).
"Most children are in the hospital 1 day longer than their grade of injury, and they’re out of any activity for 2 weeks longer than their grade of injury," said Dr. Grabowski. Splenic injuries from to sports competition "are quite common, especially around football and hockey seasons," as are those caused by motor vehicle accidents and accidents from all-terrain vehicles. Common complaints include abdominal pain/tenderness, shoulder pain, nausea and vomiting, and anemia. CT scan is 98% sensitive in identifying the injury.
"Over time we have found that splenic salvage can be achieved in greater than 90% of children with blunt splenic injury, even up to a grade IV or V injury," she said. "Management of splenic injury should be based on physiologic parameters, rather than on a grading of the spleen injury or the presence of ‘blush’ on a CT scan. When an operation is required it’s usually for hemodynamic stability or for ongoing transfusion requirements."
For patients who undergo splenectomy, incidence of overwhelming post-splenectomy sepsis is thought to be about 0.8%, and the risk is greatest in the first 2 years. "Even though it’s such a low incidence, overwhelming post-splenectomy sepsis has a very high mortality, up to 50%," she said. "It’s important to educate the patients and the parents that if they develop a fever, it’s important to come to the hospital as soon as possible for evaluation."
Next, Dr. Grabowski discussed hepatic injuries, which involve the right lobe of the liver in 60%-78% of cases. Children with hepatic injuries commonly present with abdominal pain/tenderness and 56%-100% have associated injuries, most commonly involving the brain. Shock occurs in fewer than 10% of patients who present with a liver injury, while an aspartate aminotransferase/alanine aminotransferase (AST/ALT) level of greater than 250 units/L suggests liver injury.
Nonoperative treatment is successful about 90% of the time. This requires hemodynamic stability and absence of peritoneal signs. "Head injury is not a contraindication for nonoperative management," she said. "We have less experience with, and less studies looking at, angioembolization for hepatic injuries, but since we’ve had such good success with splenic injuries, we think it’s going to be helpful for hepatic injuries as well."