Outcomes of Children With Suspected Appendicitis and Incompletely Visualized Appendix on Ultrasound

Abstract

Objectives: The objective was to review the clinical outcomes of children with suspected appendicitis after an ultrasound (US) examination fails to fully visualize the appendix, the diagnostic characteristics of US in children with suspected appendicitis, and the predictive value of secondary signs of appendicitis when the appendix is not fully visualized.Methods: This was a retrospective health record review of children aged 3 to 17 years presenting to a tertiary pediatric emergency department (ED) with suspected appendicitis. Descriptive statistics and diagnostic test characteristics are reported.Results: Overall, 968 children had US. The appendix was fully visualized in 442 cases (45.7%), and 526 (54.3%) children had incompletely visualized appendices. The disposition of those with incompletely visualized appendices were as follows: 59.1% were discharged home, 10.5% went directly to the operating room, and 30.4% were admitted to the hospital for further observation. Of those discharged home based on clinical findings after incompletely visualized appendices, fewer than 0.3% ended up having appendicitis. Ultimately 15.6% of children with incompletely visualized appendices had pathologyconfirmed appendicitis. The sensitivity and specificity of US for children with fully visualized appendices were 99.5% (95% confidence interval [CI] = 96.7% to 100%) and 81.3% (95% CI = 75.2% to 86.2%), respectively. The sensitivity and specificity for the presence of any secondary sign in diagnosing appendicitis were 40.2% (95% CI = 29.6% to 51.7%) and 90.6% (95% CI = 87.5% to 93.2%), respectively. Conclusions:Children with incompletely visualized appendices on US can be safely discharged home based on clinical findings with an acceptable rate of missed appendicitis. Children with nonreassuring clinical examinations following incompletely visualized appendices on US may benefit from further imaging studies prior to appendectomy, to reduce the rate of negative appendectomy. While the presence of secondary signs of inflammation can be used to rule in appendicitis, statistical strength to rule out appendicitis in the absence of secondary signs is insufficient.ACADEMIC EMERGENCY MEDICINE 2014;21:538-542

Ultrasound of paediatric appendicitis and its secondary sonographic signs: providing a more meaningful finding

“…Reliance on secondary signs however has also been associated with a high number of false positives 4. Estey et al53 and more recently Ross et al54 confirmed the PPV of secondary signs, yet their absence did not permit reliable exclusion of appendicitis. These contradictory findings warrant further investigation to determine the diagnostic potential of individual or certain combinations of secondary signs to obtain the most comprehensive and meaningful sonographic conclusion.…”

The Effect of a Full Bladder on Proportions of Diagnostic Ultrasound Studies in Children with Suspected Appendicitis

“…We performed a retrospective health record review, combining data that were available from a study previously reported by our team 9 with US images to calculate bladder size. This study was approved by the Conjoint Health Research Ethics Board of the University of Calgary.…”

“…Baseline demographic and clinical data were available from our previously published health record review, 9 in which we collected demographic data, ED visit details, results of laboratory investigations, surgical considerations, frequency of return visits to the ED, and imaging reports. These data were used in a previous study 9 to examine the outcomes of children with suspected appendicitis after US examination failed to identify the appendix.…”

“…These data were used in a previous study 9 to examine the outcomes of children with suspected appendicitis after US examination failed to identify the appendix. In particular, we studied children's outcomes, including their disposition, the proportion returning for care, the proportion undergoing surgical intervention, and the number of "missed" appendicitis cases, as well as the test characteristics of secondary signs of inflammation in this population.…”

“…8 The diagnostic accuracy of ultrasonography is subject to visualization of the structures to be assessed, which in the case of appendicitis is often limited. 9 In an attempt to optimize visualization of pelvic and intraabdominal structures, some institutions require bladder filling prior to pelvic US examination for suspected appendicitis. This can be uncomfortable for patients and leads to delays in test acquisition and subsequent diagnosis.…”