Computed tomography in the assessment of pediatric abdominal trauma

Clinical significance of isolated intraperitoneal fluid on computed tomography in pediatric blunt abdominal trauma

PURPOSE

The finding of isolated free intraperitoneal fluid (FIPF) on computed tomography of the abdomen (CTA) in children after blunt trauma is of unclear clinical significance and raises suspicion for a solid or hollow viscus injury. In our institution, pediatric blunt trauma patients presenting with isolated FIPF on CTA who are hemodynamically stable and have no peritoneal signs on initial physical examination (iPE) have been historically approached nonoperatively. We reviewed our level 1 trauma center experience with this subset of the trauma population and sought to (1) justify an initial nonoperative approach and (2) identify early predictors of the eventual need for surgical exploration.

METHODS

Data on all trauma patients less than 14 years of age admitted to our hospital from 2001 to 2006 after Blunt Abdominal Trauma (BAT) whose screening CTA showed FIPF and no other radiographic signs of solid or hollow viscus injury were retrieved from the local trauma registry. Clinical progress, operative findings, and follow-up were obtained by hospital and office chart review, as well as telephone contact. Mechanism of injury (MOI); Injury Severity Score (ISS); Revised Trauma Score; Pediatric Trauma Score (PTS); the presence of abdominal tenderness or external signs of injury on iPE; and quantity, location, and density of the FIPF were statistically analyzed as possible early predictors of the eventual need for surgical exploration.

RESULTS

A total of 670 children admitted to our institution after blunt trauma were evaluated with CTA during the time of enrollment. Isolated FIPF was found in 94 individuals (14%). Mean age was 9.7 (+/-SD 3.2) years; 52% were males. Motor vehicle crash was the most common MOI. Mean PTS was 10.6 (+/-SD 1.8). Mean ISS was 10.2 (+/-SD 7.2). Free intraperitoneal fluid was most commonly found in only one intraperitoneal region (93%). Most patients (97%) were discharged home without undergoing a surgical procedure. Three other patients developed peritonitis on serial physical examination and were surgically explored. Hollow viscus injuries were found in 2 of these individuals and treated with primary repair or segmental bowel resection. All surgical patients enjoyed a full recovery, with no postoperative complications. The presence of abdominal tenderness on iPE and the quantity of FIPF on initial CTA were the only studied variables to reach statistical significance as predictors of the eventual need for operative intervention. Follow-up after hospital discharge was obtained in 46.8% (44/94) and averaged 124.9 weeks.

CONCLUSION

To the best of our knowledge, this is the largest series of pediatric blunt trauma patients with isolated FIPF on CTA ever reported. Our findings justify an initial nonoperative approach for the management of these individuals. Abdominal tenderness on iPE and the quantity of FIPF on initial CTA were predictors of the eventual need for operative intervention.

Abdominal Computed Tomography Scan in Pediatric Blunt Abdominal Trauma

The purpose of this study was to evaluate the role of abdominal CT scans in pediatric patients and correlate the findings with the clinical examination. A 2-year retrospective review of 88 patients with an abdominal CT scan after blunt trauma was performed. Seventy-two patients were identified with complete clinical examination data available. In its ability to predict the need for surgery, the CT scan had a sensitivity of 67 per cent and a negative predictive value of 98.7 per cent. The combination of the clinical examination and the CT scan findings did not miss any significant injuries. No patient with a soft, nontender abdomen and a negative CT scan required an abdominal operation. We conclude that the CT scan alone may miss clinically significant injuries. In blunt abdominal trauma in the pediatric population, the CT scan findings should be coupled with the clinical examination to ensure that no significant abdominal injuries are missed.

Ultrasound is an effective triage tool to evaluate blunt abdominal trauma in the pediatric population

BACKGROUND

Although computed tomography has been considered the diagnostic modality of choice for pediatric patients with blunt abdominal trauma (BAT), it is costly, time-consuming, requires sedation, and may be associated with complications in young children. Abdominal ultrasonography (US) is a promising modality in the evaluation of BAT that is quick, noninvasive, repeatable, and cost-effective. We hypothesized that emergency department US, performed by trauma surgeons, is a useful triage tool for pediatric BAT that reduces the need for computed tomography.

METHODS

The 230 children (<18 years old) with suspected BAT were initially evaluated with US in the emergency department by surgeons. Subsequent computed tomographic scan or exploratory laparotomy was performed as indicated by the key clinical pathway.

RESULTS

Twelve children (5.2%) had documented intra-abdominal injuries. All five injured children with significant intraperitoneal fluid were identified by US. Of the seven patients who had intra-abdominal injury not detected by US, six sustained solid organ injuries that were managed nonoperatively. Extrapolated reductions in hospital charges due to the decreased number of computed tomographic scans total $130,000.

CONCLUSIONS

Using US as a triage tool may dramatically reduce the cost of pediatric BAT evaluation while being able to quickly identify significant intraperitoneal fluid that requires further evaluation and possible laparotomy.

Validation of surgeon-performed emergency abdominal ultrasonography in pediatric trauma patients

BACKGROUND/PURPOSE

The focused assessment for the sonographic evaluation of trauma patients (FAST) in adults is effective in detecting intraperitoneal and intrapericardial fluid and can be performed quickly by surgeons in the emergency department (ED). The authors sought to validate the accuracy of FAST performed by surgeons during ED resuscitation of pediatric trauma patients.

METHODS

Patients were assigned to one of three groups based on standard clinical criteria: immediate surgery, abdominal computed tomography (CT), or observation alone. FAST was then performed in the ED by a surgery resident (postgraduate year 3 or higher) or an attending trauma surgeon. Four views were used to assess the possible presence of fluid in the pericardial, subphrenic, subhepatic, and pelvic spaces. Time needed to conduct FAST was noted. Presence of peritoneal or pericardial fluid by FAST was compared with that determined by CT or surgery. Sensitivity, specificity, and predictive values were calculated. For those who did not undergo CT or surgery, FAST findings were compared with the clinical course.

RESULTS

Technically adequate studies could be performed on 192 of 196 eligible children. Their ages ranged from 3 months to 14 years (mean, 6.9 years); 119 were boys (62%), and 188 (98%) had sustained a blunt injury. FAST was performed in a mean time of 3.9 minutes (range, 1-17 minutes). All FAST examinations were reviewed by our senior surgeon-sonographer (GSR). Interrater agreement between the performing and reviewing surgeon-sonographer was 100%. Sixty (31%) patients underwent either abdominal CT (n = 56; mean Injury Severity Score (ISS), 9.6) or immediate operation (n = 4; mean ISS, 18.8). Of the 10 patients with verified presence of intraperitoneal fluid, eight had positive and two had false-negative FAST examination results. Of the 50 patients with verified absence of intraperitoneal fluid, none had a positive FAST (ie, no false-positives); sensitivity was 80%; specificity, 100%; predictive value positive, 100%; predictive value negative, 96%. None of the 132 patients followed up clinically without CT or surgery (mean ISS, 4.5) had fluid documented by FAST, and all did well.

CONCLUSIONS

The focused assessment for the sonographic evaluation of pediatric blunt trauma patients performed by surgical residents and attendings in the ED rapidly and accurately predicted the presence or absence of intraperitoneal fluid. The FAST is a potentially valuable tool to rapidly prioritize the need for laparotomy in the child with multiple injuries and extraabdominal sources of bleeding.

Computed tomography in the evaluation of children with blunt abdominal trauma

OBJECTIVE

This study determined the sensitivity, specificity, and accuracy of CT in pediatric patients with blunt trauma. Correlation of the CT-identified injuries and intraoperative findings with comparison to the results of DPL was performed.

SUMMARY BACKGROUND DATA

Clinical evaluation frequently is unreliable in determining the presence of intra-abdominal injury in children with blunt trauma. Peritoneal lavage has been used to establish the need for operative intervention and has been found to be safe, efficient, and reliable (98%). In many institutions, abdominal CT scans are used to evaluate these children. Because most reports involve nonoperative management, operative confirmation of CT-identified injuries is available only for those children in whom nonoperative treatment is unsuccessful.

METHODS

Sixty children sustaining blunt abdominal trauma were included in the study. CT scans with both oral and IV contrast were performed before open lavage, and positive results were confirmed by operation in 18 patients.

RESULTS

CT had a sensitivity of 67%, however, only 60% of the actual organ injuries were identified by the scan. In contrast, DPL has a sensitivity of 94%. Both studies were equally specific (100%). DPL was also more accurate, 98% as compared with 89% for CT.

CONCLUSIONS

Although the abdominal CT scan is useful in evaluating children with blunt abdominal trauma, a number of significant injuries were missed. Based on the low sensitivity of the CT, the authors suggest diagnostic peritoneal lavage may offer advantages over CT as the initial study in the evaluation of children with blunt abdominal trauma.

Initial evaluation of the patient with blunt abdominal trauma

Unrecognized abdominal injury remains a distressingly frequent cause of preventable death following blunt trauma. Peritoneal signs are often subtle, overshadowed by pain from associated injury, and masked by head trauma or intoxicants. The initial management of the patient with blunt abdominal trauma should parallel the primary survey of airway, breathing, and circulation. Diagnostic peritoneal lavage remains the cornerstone of triage in patients with life-threatening blunt abdominal trauma. The only absolute contraindication to the procedure is an existing indication for laparotomy. Computed tomography is useful as a complementary diagnostic tool in selected patients, and it is the critical test for guiding nonoperative management of known intraperitoneal trauma. Routine ancillary tests for potentially occult injuries include nasogastric-tube placement for ruptures of the left diaphragm, Gastrografin contrast study for duodenum perforation, and pyelography for urologic injury. Ultrasonography may become a valuable tool in the initial assessment of the injured abdomen. Ultimately, the most important principle in the management of blunt abdominal trauma is repeat physical examination by an experienced surgeon.

Abdominal CT scanning in pediatric blunt trauma

The use of the emergency IV contrast-enhanced abdominal computed tomography (CT) scanning was evaluated in 90 pediatric patients sustaining blunt abdominal trauma. Medical records, CT scans, and operative and postmortem reports, when applicable, were reviewed retrospectively. By identifying the organs of injury, CT scans of the abdomen, with IV contrast, proved to be useful to the surgeon in deciding whether to operate in the setting of blunt abdominal trauma. The failure rate for conservative, non-operative management (four of 33) in "positive" scans was low, and represented progression of known injuries, not the appearance of unexpected injuries. Similarly, the (unplanned) surgery rate in the "negative" scan cases was low (one of 57). Abdominal CT scans cannot be relied on to consistently diagnose gastrointestinal perforation or pancreatic injury.