Towards evidence based emergency medicine: best BETs from the Manchester Royal Infirmary.(Best evidence topic)

Best evidence topic reports (BETs) summarise the evidence pertaining to particular clinical questions. They are not systematic reviews, but rather contain the best (highest level) evidence that can be practically obtained by busy practising clinicians. The search strategies used to find the best evidence are reported in detail in order to allow clinicians to update searches whenever necessary.

The BETs published below were first reported at the Critical Appraisal Journal Club at the Manchester Royal Infirmary. [1] Each BET has been constructed in the four stages that have been described elsewhere. [2] The BETs shown here together with those published previously and those currently under construction can be seen at http://www.bestbets.org [3] Six topics are covered in this issue of the journal.

(1.) Carley SD, Mackway-Jones K, Jones A, et al. Moving towards evidence based emergency medicine: use of a structured critical appraisal journal club. J Accid Emerg Med 1 1998;15:220-2.

(2.) Mackway-Jones K, Carley SD, Morton RJ. et al. The best evidence topic report: a modified CAT for summarising the available evidence in emergency medicine. J Accid Emerg Med 1998;15:222-6.

(3.) Mackway-Jones K, Carley SD. bestbets.org: Odds on favourite for evidence in emergency medicine reaches the worldwide web. J Accid Emerg Med 2000;17:235-6.

The accuracy of abdominal ultrasound in paediatric trauma

Report by Ross Murphy, Senior Clinical Fellow Search checked by Angaj Ghosh, Senior Clinical Fellow

Clinical scenario

An 8 year old boy is taken to the emergency department after falling out of a tree. He has no signs of injury apart from abrasions and tenderness across his upper abdomen; he is haemodynamically stable. He undergoes an abdominal ultrasound that is normal but you wonder how accurate this is at identifying intra-abdominal injury compared with the current gold standard, abdominal computed tomography.

Three part question

In [a paediatric patient with blunt abdominal trauma] how [accurate is an ultrasound scan] at [identifying intra-abdominal injury]?

Search strategy

Medline 1966-12/00 using the OVID interface. {[(exp child OR children.mp OR exp pediatrics OR pediatric.mp OR paediatric.mp) AND (exp abdominal iniuries OR abdominal trauma.mp) AND (exp tomography, x-ray computed OR CT.mp OR computerised tomography.mp OR exp ultrasonography OR ultrasonography.mp OR exp ultrasonics OR ultrasonics.mp OR ultrasound.mp)} LIMIT to human AND english.

Search outcome

Altogether 511 papers found of which 505 were irrelevant or of insufficient quality. The remaining six papers are shown in table 1.

Comments

The evidence indicates a variability in the accuracy of ultrasound at identifying intra-abdominal injury in children. This is probably related to the skill of the ultrasonographer. Ultrasound can have a high diagnostic specificity and it may be useful as part of a rule in strategy in these situations. Focused abdominal sonography for trauma (FAST) seems to be neither sensitive nor specific enough.

Clinical bottom line

Abdominal ultrasound can be used to rule in intra-abdominal fluid or organ damage in children. Negative ultrasound does not rule out intra-abdominal injury and, if clinical suspicion persists, abdominal compted tomography with contrast should be performed.

(1.) Krupnick AS, Teitelbaum DH, Geiger JD, et al. Use of abdominal ultrasonography to assess paediatric splenic trauma. Potential pitfalls in the diagnosis. Ann Surg 1997;225:408-14.

(2.) Richardson MC, Hollman AS, Davis CF. Comparison of computed tomography and ultrasonographic imaging in the assessment of blunt abdominal trauma in children. Br J Surg 1997;84:1144-6.

(3.) Partrick DA, Bensard DD, Moore EE, et al. Ultrasound is an effective triage tool to evaluate blunt abdominal trauma in the pediatric population. Trauma 1998;45:57-63.

(4.) Mutabagani KH, Coley BD, Zumberge N, et a!. Preliminary experience with focussed abdominal sonography for trauma (FAST) in children: Is it useful? J Paediatr Surg 1999;34:48-52.

(5.) Benya EC, Lim-Dunham JE, Landrum O, et a!. Abdominal sonography in examination of children with blunt abdominal trauma. Am J Roenterol 2000; 174:1613-6.

(6.) Coley BD, Mutabagani RH, Martin LC, et al. Focused abdominal sonography for trauma (FAST) in children with blunt abdominal trauma. J Trauma 2000;48:902-6.

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