Emergency physicians spend years evaluating patients and honing the craft of history and physical exam. Every patient we see is another data set that we add to our clinical brain that factors into our future decision making. We do it every day. We find the pieces, put together the puzzle, and risk stratify the potential outcomes. But there are always a lot of gray areas. And those gray areas are often the areas of biggest struggle. One of those gray areas is CT imaging in the setting of pediatric blunt abdominal trauma. Who needs it? Who doesn’t?

The goal of this discussion is to briefly explore some topics about pediatric blunt trauma regarding the use of abdominal CT imaging with IV contrast. Of note, we all recognize that each individual case has variables that cannot be predicted by every study.

To begin, let’s assume that we are evaluating an 8-year-old trauma patient who was involved in a 40-mph motor vehicle crash. He was restrained properly and is hemodynamically stable and well-appearing. He is breathing well and has a soft abdomen on your exam.

Are there physical exam findings—or maybe the absence of certain physical exam findings—that can help guide our decision making regarding abdominal CT imaging in the setting of pediatric blunt trauma?

Avoiding Imaging With Bedside Evaluation Only

A 2013 Pediatric Emergency Care Applied Research Network (PECARN) network study by Holmes et al. prospectively evaluated 12,044 pediatric patients with blunt torso trauma at 20 emergency departments (EDs) that regularly evaluate pediatric trauma patients.¹ The primary outcome was intra-abdominal injury undergoing acute intervention defined as death, therapeutic laparotomy, angiographic embolism, blood transfusion for abdominal hemorrhage, or IV fluid for ≥ 2 nights for pancreatic/gastrointestinal injuries. So, these were clinically significant intra-abdominal injuries.

They also kept tabs on intra-abdominal injuries that did not warrant interventions. The exclusion criteria for this observational cohort study were: ED presentation more than 24 hours since injury, penetrating trauma, pre-existing neurologic disorders impeding reliable exam, known pregnancy, and transfer from another hospital with prior abdominal CT imaging or diagnostic peritoneal lavage.

The study sought to identify cases where history and physical exam might identify those children who didn’t require an abdominal CT scan in the setting of significant abdominal trauma. In this study of 12,044 patients, the median age was 11.1 years (interquartile range, 5.8-15.1 years). Abdominal CT scans were performed in 46 percent of all patients (5,514 patients). Any intra-abdominal injury was identified in 761 patients (6.3 percent), while intra-abdominal injuries requiring acute intervention (i.e., the primary outcome) were identified in 204 patients (1.7 percent). Among the patients who had abdominal CT imaging (5,514 of 12,044 total patients), the acute intervention group accounted for 3.7 percent of that group.