Original ContributionPredicting need for additional CT scan in children with a non-diagnostic ultrasound for appendicitis in the emergency department☆
Introduction
Acute appendicitis is the most common abdominal emergency in children [1], and early diagnosis is critical in preventing perforation, abscess formation and postoperative complications [2]. History and physical examination alone has a low sensitivity and specificity [3], so imaging may play a key role in the accurate and prompt diagnosis of suspected appendicitis. Computerized tomography (CT) has high sensitivity for diagnosis of appendicitis, and has been used more frequently in the pediatric population in recent years [4]. However, due to radiation exposure [5], providers in the emergency department (ED) are preferring ultrasound (US) as imaging modality [6], [7]. Point of care ultrasound for appendicitis performed in ED has high effectiveness in clinical decision making of ED physicians [8]. Although the specificity of US is high, the sensitivity is variable (50–100%) depending on the operator [9]. It is unclear which children should have advanced imaging after US is considered non-diagnostic when performed by the ED physician [10]. Performing selective CT only for children with non-diagnostic US [11], [12] may reduce CT utilization, but a significant proportion of these children may still have a negative test for appendicitis on CT [11]. The purpose of this study was to determine a method for identification of children who will benefit from a CT scan after a non-diagnostic US.
Section snippets
Methods
We conducted a retrospective study at an urban, tertiary-care hospital in Japan with about 40,000 ED visits per year. Our hospital ethics committees approved the research protocol. We obtained data from the electronic medical record (EMR) system and the hospital electronic administrative system for the period January 1, 2011 through December 31, 2015 in order to identify patients who presented to the ED with complaints of abdominal pain and while in the hospital had both an US exam and
Results
A total of 473 patients with complaints of abdominal pain had both US and CT during the study period. We excluded 129 patients who had [1] imaging studies due to trauma (34, 7.2%), [2] history of appendicitis (11, 2.3%), [3] US or CT documented before presenting to our ED (63, 13.3%), [4] CT performed before US (10, 2.1%), [5] US findings not found in the EMR (11, 2.3%) and [6] suspected other diagnoses than appendicitis based on physical examination, clinical history and US (16, 3.4%). Thus, a
Limitations
Our study has several limitations. This is a retrospective, single-center non-randomized study, where decisions on type of imaging modality were left to the clinician, and practice variation may play a role in our findings. However, we included results from over 50 physicians and findings represent practice in many other EDs. Also, it is possible that some children were discharged after an US and went to another facility where they were diagnosed with appendicitis. Patients who presented with
Discussion
We found that for children with suspected appendicitis and a non-diagnostic US exam by an emergency physician, CT is likely needed only when children have at least two of the following; RLQ tenderness, peritoneal signs or WBC > 10,000 in mm3. If we had applied this decision rule to our study group, we could have avoided about 65% of CT scans that were negative for appendicitis with a much lower false negative rate of 4% (Fig. 3).
Acute appendicitis is the most common cause of abdominal surgical
Author contribution
TN, SM, RG and HH conceived the study, designed the trial. SM, RG and HH supervised the conduct of the trial and data collection. TN, SM, RG, and HH undertook recruitment of patients and managed the data, including quality control. RG provided statistical advice on study design and analyzed the data; SM, RG and HH chaired the data oversight committee. TN drafted the manuscript, and all authors contributed substantially to its revision. TN takes responsibility for the paper as a whole.
Conflicts of interest
Nothing.
Acknowledgement
We would like to thank Mr. Boris Kuzeljevic for his dedicated work on the statistical portion of this work.
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Cited by (7)
Bedside ultrasonography for acute appendicitis: An updated diagnostic meta-analysis
2019, International Journal of SurgeryCitation Excerpt :The diagnosis of this emergency can be challenging due to atypical symptoms, variable clinical presentation and shared clinical features with other disease status [3]. Recently, modern diagnostic imaging techniques, such as CT scan and ultrasonography are regarded as pivotal diagnostic approaches in acute appendicitis which are shown to improve diagnostic accuracy and patient prognosis [4–7]. Since the application of those imaging modalities, the rate of negative appendectomy and other complications such as appendiceal perforation has considerably decreased.
Utility of applying white blood cell cutoffs to non-diagnostic MRI and ultrasound studies for suspected pediatric appendicitis
2019, American Journal of Emergency MedicineCitation Excerpt :A study analyzing this approach provides evidence that it is more cost-effective for ultrasound to be the first-line imaging test despite its shortcomings [11]. Several investigations have combined laboratory test results or other clinical parameters with non-diagnostic ultrasound studies to improve their negative predictive values (NPVs) and thereby avoid the need for additional imaging or admission for observation [6,7,12,13]. No one has investigated whether combining laboratory test results with non-diagnostic MRI studies improves their NPVs.
Reliability of standardized reporting system of acute appendicitis in adults at low-dose 320-rows CT
2019, European Journal of Radiology OpenCitation Excerpt :Ultrasound is favored by some physicians but it has lower sensitivity and limited by operator dependence, patient body habitus [9]. Many researchers have also tried to use color Doppler imaging to detect blood flow in the wall of the appendix, but this has shown only a marginal increase in the sensitivity to 87 % for detecting acute appendicitis [10]. Elastography is recently applied to assess appendicitis but it is in early stages [11].
Magnetic Resonance Imaging Provides Useful Diagnostic Information Following Equivocal Ultrasound in Children With Suspected Appendicitis
2021, Canadian Association of Radiologists JournalProper pre-operative observation time reduces the incidence of unnecessary appendectomy in managing suspected acute appendicitis in children
2020, Pakistan Journal of Medical and Health Sciences
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