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Three Part Question

In [stable pediatric patients who have sustained blunt abdominal trauma] is [Computed tomography] sufficient to rule out [Significant Intra-abdominal injury]?

Clinical Scenario

A 12 year old male involved in a motor vehicle crash is brought in by EMS. His vitals are within normal limits, however on exam you do note moderate left upper quadrant tenderness. Before sending the patient to the CT scanner you wonder if a negative read will be sensitive enough to rule out significant intra-abdominal injury (IAI).

Search Strategy

Medline 1990-05/11 using OVID interface, Cochraine Library (2011), PubMed clinical queries
[(exp abdominal injuries/diagnosis, radiography) AND (exp wound, nonpenetrating/radiography) AND (exp tomography, x-ray computed)]. Limit to English language and all children (0-18 years).

Search Outcome

245 papers were identified, six were relevant to the the clinical question

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Awasthi S. et al Oct 2008 USA	Patients less than 18 years of age with blunt abdominal trauma who underwent an abdominal CT scan in the ED over a 3 year period; 1085 of the total 1295 had negative CT scans.	Prospective Observational Cohort Study	Outcome of admitted patients with negative CT scans.	Of the 1085 patients that had negative CTs, 737 patients were admitted. Only 2 of the admitted patients were later found to have a IAI; neither required specific therapy.	All scans were read by a pediatric radiologist which may not be available at other hospitals. Some patients were discharged home from the ED after a normal CT scan; even though there were no reported complictions in these individuals there is potential that some may have returned to a different hospital with complications.
			Outcome of patients witch negative CT scans that were sent home.	The remaining 348 patients were sent home. None of these patients returned with an IAI.
			Negative Predictive Value of a Negative CT scan.	NPV 99.8% with 95%CI = 99.3-100%
Ruess L. et al October 1996 USA	Abdominal CT scans were performed on 1500 consecutive stable patients less than 18 years of age who had sustained blunt abdominal trauma over a 10 year period. Scan results were noted and the decision was made whether the patient needed to have operative management.	Prospective clinical study	Outcome of patients who had negative CT scans.	Of 1500 total patients evaluated, 1112 had normal CT scans of the abdomen. Fifteen of these subsequently died form non-abdominal injuries. One of the 1097 surviving children required operative intervention for a bowel rupture. The remainder were managed non-operatively.	This study did not use the newer technology helical CT scanners now commonly used in most EDs. They did not report the data analysis. Also, the main outcome measured in this study was not to determine the NPV of normal scans; instead, it was to determine the PPV of an abnormal scan.
Sievers E. et al October 1999 USA	Three hundred and sixty pediatric patients, 14 years old and less, who had sustained blunt abdominal trauma were evaluated at two major trauma centers over a 2 year period. Each patient was admitted for serial exams and potential CT scans.	Retrospective Review	Outcome of patients who received a CT scan.	Ninety six patients had CT scans performed however results were available for only 88 of these patients; 11 patients had positive scans for IAI, 2 of which required laprotomy; 77 patients had CT scans negative for IAI, however 1 of these patients subsequently was found to have a duodenal injury via laprotomy.	Retrospective review with a small number of patients. Over 8 percent of the patients scanned were excluded from the study for incomplete data. The study does not outline what criteria clinicians used to determine which patients needed a CT scan. Only approximately 1 in 4 patients received a scan, however the study does not report outcomes of patients not scanned, potentially missing important injuries and changing the PPV and NPV of the study. Finally even though this study used a helical scanner, the slices were obtained at 1cm intervals.
			Sensitivity	Sensitivity at finding surgically significant injuries of 66%.
			Negative Predictive Value	NPV to rule out significant IAI injury of 98.7%.
Shankar K. et al Aug 1999 England	The charts of 101 children less than 17 years of age who had been evaluated by CT scan for blunt abdominal trauma over a 5 year period were reviewed.	Retrospective Chart Review Study	Outcome of patients with a positive CT scan.	Thirty four scans were read as having significant IAI; of these, 3 required laparotomy.	This is a relatively small retrospective chart review. The type of CT scanner used was not reported. The main goal of this study was to see if oral contrast improves sensitivity for finding significant injuries in children, and not necessarily to evaluate the overall utility of CT scanners at evaluated blunt pediatric abdominal trauma.
			Outcome of patients with a negative CT scan.	Sixty seven patients had negative scans; 66 did not require surgical intervention. The remaining patient who had 2 negative CT scans was subsequently found to have rupture of the splenic flexture of the colon which was surgically repaired.
Kane N. et al July 1988 USA	One hundred consecutive pediatric patients who had sustained blunt abdominal trauma and had CT scans of the abdomen over a 2 year period were reviewed.	Retrospective review study	Outcome of patients with a negative CT scan.	Seventy three patients had normal abdominal CTs; none of these required further operative management of the abdomen. However 3 subsequently died from non-abdominal injuries.	Small retrospective review study. This study used older technology non-helical CT scanners. Also data analyis was not reported.
			Outcome of patients with a positive CT scan.	Twenty seven patients were found to have IAI; only 3 of these required operative management.
Haftel A. et al July 1988 USA	The records of 90 consecutive pediatric patients who underwent emergent CT scans of the abdomen after blunt abdomen trauma over a 3 year period were reviewed.	Retrospective Review Study	Outcome of patients with a positive CT scan.	Thirty three patients had positive scans. Five of these underwent emergent laparotomy. Four of the remaining patients subsequently developed anticipated abdominal complications and required surgical intervention. One of the remaining 24 patients eventually died from non-abdominal injuries.	This is a small retrospective study. Also, older non-helical CT scanners were used.
			Outcome of patients with a negative CT scan.	Fifty six patients had normal abdominal CT scans. One of these subsequently deteriorated and was found to a perforated jejunum; he did well after surgical management. The remainder of the patients were subsequently discharged without any significant complication.

Comment(s)

Computed tomography has been found to be an excellent screening tool for the evaluation of stable children who have sustained blunt abdominal trauma. However, most older studies reported sensitivities less than 100% with intestinal injury remaining the most difficult significant IAI to diagnose. New literature suggests that newer CT scanners may be appropriate to diagnose these injuries, however it is still recommended to use physical exam and other contributing information in addition to the CT scanner until these results can be confirmed by future studies.

Clinical Bottom Line

Current literature suggests that coupling physical exam with computed tomography, preferably newer generation helical thin slice scanners, is sufficient to exclude significant IAI.

References

1. Awasthi S, et al. Is hospital admission and observation required after a normal abdominal computed tomograpy scan in children with blunt abdominal trauma? Acad Emerg Med 2008 Oct; 15(10):895-9
2. Ruess L. et al Blunt Abdominal Trauma in Children: Impract of CT on Operative and Nonoperative Management AJR Am J Roentgenol 1997 Oct;169(4):1011-4
3. Sievers E. et al Abdominal Computed Tomograpy Scan in Pediatric Blunt Abdominal Trauma Am Surg 1999 Oct;65(10):968-71
4. Shankar K, et al Oral contrast with computed tomography in the evaluation of blunt abdominal trauma in children British Journal of Surgery 1999 Aug;86(8):1073-7.
5. Kane N. et al Pediatric Abdominal Trauma: Evaluation by Computed Tomography Pediatrics 1988 Jul;82:11-5.
6. Haftel A. et al Abdominal CT Scanning in Pediatric Blunt Trauma Annals of Emergency Medicine 1988 Jul;17(7):684-9