Pediatric Abdominal Trauma Workup

Updated: Jun 22, 2022
  • Author: Amulya K Saxena, MD, PhD, DSc, FRCS(Glasg); Chief Editor: Harsh Grewal, MD, FACS, FAAP  more...
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Approach Considerations

Workup of the pediatric trauma patient includes selected laboratory tests and computed tomography (CT). Ultrasonography (US), in the form of focused assessment with sonography in trauma (FAST), may also be considered, though definition of the role of FAST in the pediatric population has lagged behind that in the adult population. Diagnostic peritoneal lavage (DPL) is not used as frequently as it once was.

In all children with suspected inflicted injury, the abdomen must be thoroughly evaluated. This investigation may include laboratory assessment (eg, liver function tests [LFTs], amylase level, lipase level, complete blood count [CBC], and urinalysis), diagnostic imaging (eg, CT), or both to help detect abdominal injury. In the obtunded patient with inflicted injury, CT should be performed to exclude concomitant abdominal injury. [19]


Laboratory Studies

Laboratory testing is a routine component of the trauma evaluation. The baseline tests performed are typically determined according to the suspected severity of injury and individual institutional guidelines. CBC and urinalysis are the only initial tests routinely performed in most children with suspected intra-abdominal injuries.

The CBC provides a baseline blood count. Overall, CBCs should be performed only as often as is necessary for adequate assessment of the patient’s clinical condition; the usual frequency is every 12 hours for the first 36 hours and daily thereafter. Urinalysis has proven useful in screening for injury to the urinary tract. Detection of blood should prompt further evaluation because even microscopic hematuria can be associated with significant renal trauma.

LFTs and pancreatic enzyme tests have variable sensitivity and specificity for abdominal organ injuries and should not be relied on as screening tools. However, trends in findings from LFTs or pancreatic enzyme tests may be useful for monitoring the course of a liver or pancreatic injury. In all cases in which significant abdominal injury is suspected or present, a blood specimen for typing and cross-matching should be obtained.

A prospective observational study by Kuas et al (N = 323) assessed the diagnostic value of laboratory tests for detection of solid-viscus injuries after blunt abdominal trauma in pediatric patients. [20]  They found that abnormal values for alanine aminotransferase (ALT), aspartate aminotransferase (AST), amylase, and lipase were statistically significant predictors of injuries to solid organs but that none of these tests were sufficiently sensitive or specific. They did not find hemoglobin, hematocrit, lactate, and base excess values to be statistically significant predictors.


Computed Tomography

CT with double contrast (intravenous [IV] and oral) is the criterion standard for the assessment of the abdominal cavity in a hemodynamically stable child. [21] Increasingly rapid scan acquisition times and better quality images make this modality ideal for trauma evaluation. [22]

IV contrast is essential for the evaluation and accurate grading of solid-organ injuries; oral contrast should be given to increase the sensitivity of CT scans for the diagnosis of pancreatic, duodenal, and proximal bowel injuries (see the images below). [23]

Computed tomography (CT) image of grade IV splenic Computed tomography (CT) image of grade IV splenic laceration from auto-pedestrian accident.
Computed tomography (CT) image of grade IV renal l Computed tomography (CT) image of grade IV renal laceration from handlebar injury. Reprinted with permission from Pryor JP, Stafford PW, Nance ML. Severe blunt hepatic trauma in children. J Pediatr Surg, 36:7, 2001, Elsevier Science.
Computed tomography (CT) image of grade V liver la Computed tomography (CT) image of grade V liver laceration in unrestrained passenger in motor vehicle accident.
Computed tomography (CT) image of duodenal hematom Computed tomography (CT) image of duodenal hematoma from blow to abdomen. (Large arrow, hematoma; small arrow, lumen of duodenum.)

The use of oral contrast in the immediate radiologic assessment of abdominal trauma has been questioned. [24, 25] Administration of oral contrast may delay the scheduling of the scan and, because it may induce vomiting, poses an aspiration risk. Thus, the use of oral contrast in the immediate assessment of abdominal trauma should be selective and based on institutional best practice guidelines.

Some reports have described the acute extravasation of contrast (blush) as a sign of acute hemorrhage. [26] Although such a sign has been associated with the need for surgical intervention in adults, its clinical significance is still under evaluation in children.

Some studies have suggested that in low-risk patients, it is safe to forgo CT and thereby avoid the attendant radiation exposure. [27, 28]  Streck et al described a prediction rule that used history and physical examination, chest radiography, and laboratory evaluation at the time of presentation after blunt abdominal trauma to identify children who are at very low risk for intra-abdominal injury and in whom CT can therefore be avoided. [29]



The FAST examination has become a standard part of the initial evaluation of bluntly injured abdomens in adult trauma centers. [30, 31, 32, 33, 34] It allows rapid assessment of the peritoneal cavity and can detect free fluid.

In the pediatric population, studies have been slower to define the role of FAST. Despite its high sensitivity for the detection of free intraperitoneal fluid, there have been concerns that FAST is operator-dependent, lacks specificity, and does not provide detailed information regarding the grade of organ injury.

Another concern is that FAST produces a significant number of false-negative results (eg, solid-organ injury without free intraperitoneal fluid), which may lead to inappropriate triage and management. It has been widely held that because management protocols for solid-organ injury in the pediatric population are highly dependent on accurate grading of the organ injury, FAST cannot yet replace CT. Accordingly, evaluation of FAST in pediatric trauma centers is ongoing with the aim of validating and specifying its utility. [35]

In a study of 543 injured children (mean age, 8.2 years) who underwent FAST examination, Ben-Ishay et al found that whereas a positive FAST result was not necessarily correlated with the presence of intra-abdominal injury, a negative result was strongly suggestive of the absence of such injury (high negative predictive value). [36]

Holmes et et al performed a randomized clinical trial that evaluated a standard trauma evaluation with FAST in the emergency department (ED) against a standard trauma evaluation alone in 925 hemodynamically stable children and adolescents (< 18 y) with blunt torso trauma; the aim was to determine whether FAST during initial evaluation improved clinical care. [37]  They concluded that the addition of FAST did not improve care as compared with standard evaluation alone and that their findings did not support routine use of FAST in this setting.

Calder et al, in a multi-institutional study that included 2188 children younger than 16 years who were treated for blunt abdominal trauma, found that FAST had a low sensitivity for intra-abdominal injury, often missed intra-abdominal injuries necessitating acute intervention, and rarely had a significant effect on management in this setting. [38]  They also found that FAST was not more accurate in centers that performed it more frequently.

In March 2022, an international group comprising 26 experts on pediatric emergency point-of-care US published consensus definitions of complete, high-quality, and accurate FAST and extended FAST (eFAST) studies in children after injury. [39]  The panelists rated five anatomic views as important and appropriate for a complete FAST: (1) right-upper-quadrant abdominal view, (2) left-upper-quadrant abdominal view, (3) transverse suprapubic view, (4) sagittal suprapubic view, and (5) subxiphoid cardiac view. For eFAST, the panelists considered the same five views to be appropriate and important, with the addition of the lung or pneumothorax view. 


Diagnostic Peritoneal Lavage

Before the advent of CT and FAST, DPL was the modality of choice for the assessment of the injured abdomen. [40] In current management algorithms, its use is significantly diminished. DPL may still be indicated when CT is unavailable or when a hemodynamically unstable child has suspected bleeding from an intra-abdominal injury. [41] In the intensive care unit (ICU), DPL may also be useful in the assessment of the critically ill and traumatized child in whom an evolving intraperitoneal process is present.

Although DPL is very sensitive for the detection of intra-abdominal blood and hollow-viscus injuries, it is nonspecific and invasive and has associated morbidity.


Diagnostic Laparoscopy

Laparoscopy has been used for assessment of both blunt and penetrating abdominal injuries. It also has therapeutic applications. The introduction of laparoscopy in the diagnosis of abdominal injuries has reduced the incidence of exploratory laparotomies and the morbidity associated with them. [42] Laparoscopy is useful in the management of the hemodynamically stable pediatric patient [43] but may be of less value in cases with a delayed presentation. [44] The laparoscopic approach can be used to repair many types of intra-abdominal injuries. The use of laparoscopy avoided the need for laparotomy more often in patients with penetrating trauma than in those with blunt abdominal trauma.