Ultrasound for Diagnosis of Appendicitis in a Community Hospital Emergency Department has a High Rate of Nondiagnostic Studies

Exploring diagnostic stewardship in the emergency department evaluation of pediatric abdominal pain in a statewide quality collaborative

BACKGROUND

Diagnostic stewardship is the effort to optimize diagnostic testing to reduce errors while avoiding overtesting and overtreatment. Abdominal pain and appendicitis in children are essential use cases. Delayed diagnosis of appendicitis can be dangerous and even life-threatening, but overtesting is harmful.

METHODS

We conducted a retrospective cohort study of children aged 5-17 years presenting with abdominal pain to 26 EDs within the Michigan Emergency Department Improvement Collaborative (MEDIC) from May 1, 2016, to February 29, 2024. We defined two outcome measures summarized by ED. First, we describe the cross-sectional imaging:appendicitis visits ratio, defined as the count of ED visits resulting in any cross-sectional imaging (CT or MRI) divided by the count of ED visits with a diagnosis of appendicitis. Second, we describe the delayed diagnosis rate, defined by an ED visit for abdominal pain resulting in a discharge and subsequent return visit with a diagnosis of appendicitis within 7 days.

RESULTS

The sample included 120,112 pediatric visits for abdominal pain at 26 EDs; 4967 (4.1%) were diagnosed with appendicitis. The cross-sectional imaging:appendicitis visits ratio varied by site, from as low as 0.2 (95% confidence interval [CI] 0.1-0.2) at a pediatric site to as high as 7.9 (95% CI 4.8-16.4) at an urban ED. The proportion of pediatric ED visits for abdominal pain that resulted in an identified delayed diagnosis of appendicitis was 0.1% (141/120,112). All but four sites had fewer than 10 cases of delayed diagnosis across the study period.

CONCLUSIONS

In this retrospective cohort study of 120,000+ ED visits for pediatric abdominal pain, we found that the ratio of visits with cross-sectional imaging to diagnosed cases of appendicitis varied widely across EDs. Delayed diagnosis of appendicitis was uncommon. Adherence to best practices and improved imaging quality may hold promise to improve diagnostic stewardship for children with abdominal pain across EDs.

Optimizing the Use of Computed Tomography for Appendicitis Diagnosis in the Pediatric Emergency Department Through the Quality Improvement Methodology

BACKGROUND

Acute appendicitis is one of the most common causes of an acute abdomen among pediatric patients. The diagnosis of appendicitis is challenging due to the nonspecific presentation. Diagnosis is based on historical, physical, and serologic information as well as right lower quadrant ultrasound (RLQ US). In equivocal patients, or those with a high degree of suspicion, computed tomography (CT) of the abdomen and pelvis with intravenous (IV) contrast can be utilized to rule in appendicitis. However, optimizing diagnostic protocols to minimize ionizing radiation exposure while maintaining diagnostic accuracy is important.

METHODS

We performed a monthly retrospective analysis of CT usage among pediatric patients with suspected acute appendicitis presenting to the pediatric emergency department (ED) from June 2023 to December 2023. We used quality improvement methodology to decrease CT use with monthly Plan-Do-Study-Act (PDSA) cycles with an aim to decrease CT use by 50%. The main intervention was coordination between the ED and surgical providers to require surgical consult before ordering a CT. We quantified the number of patients who received a surgical consult before CT, the number of RLQ US performed, the number of CTs performed, and the number of appendectomies, specifically the number with perforation.

RESULTS

A total of 249 patients under 18 years of age presented to the pediatric ED with symptoms of acute appendicitis during the study period. All 249 patients underwent an initial RLQ US. The number of CTs performed decreased from a baseline of 14 in June to a nadir of four in September (71% decrease, p=0.029). There was a decrease in the percentage of patients who underwent a CT scan after an RLQ US from 36.5% in June to 11.8% in September after our intervention. In June, a total of 38 RLQ US were performed and 14 patients underwent additional CT (36.5%) and in September a total of 34 US were performed and 14 patients underwent additional CT (11.8%). There was an increase in the surgical consults rate from a baseline of seven surgical consults with 14 total CTs in June 2023 (50%) to seven consults with a total of seven CTs performed (100%) in December 2023. There was no increase in appendiceal perforation rates.

CONCLUSION

Multidisciplinary discussions between pediatric ED physicians and pediatric surgeons reduced CT usage, and corresponding radiation exposure and cost, in the evaluation of appendicitis.

Negative Appendectomies: Evaluating Diagnostic Imaging Techniques at General versus Pediatric Emergency Departments

BACKGROUND

Although appendicitis is the most common pediatric surgical emergency, the path to diagnosis remains equivocal, with utilization of imaging modalities largely institution dependent.

OBJECTIVES

Our objective was to compare imaging practices and negative appendectomy rates between patients transferred from nonpediatric hospitals to our pediatric hospital and primary patients presenting directly to our institution.

METHODS

We retrospectively reviewed all laparoscopic appendectomy cases performed at our pediatric hospital in 2017 for imaging and histopathologic results. Two-sample z-test was used to examine negative appendectomy rates between transfer and primary patients. The negative appendectomy rates of patients who received different imaging modalities were analyzed using the Fisher's exact test.

RESULTS

Of 626 patients, 321 (51%) were transferred from nonpediatric hospitals. The negative appendectomy rate for transfer patients was 6.5% and 6.6% for primary patients (p = 0.99). Ultrasound (US) was the only imaging obtained in 31% of transfer and 82% of primary patients. The negative appendectomy rate of US performed at transfer hospitals compared with our pediatric institution was not significantly different (11% vs. 5%, p = 0.06). Computed tomography (CT) was the only imaging obtained in 34% of transfer and 5% of primary patients. Both US and CT were completed for 17% of transfer and 19% of primary patients.

CONCLUSION

The negative appendectomy rates of transfer and primary patients were not significantly different despite more frequent CT use at nonpediatric facilities. It may be valuable to encourage US utilization at adult facilities given the potential to safely reduce CT use in the evaluation of suspected pediatric appendicitis.

Factors affecting utilization of CT scan following ultrasound evaluation of suspected appendicitis

CONTEXT

When evaluating a pediatric patient in the emergency department for suspected appendicitis, a provider is often faced with the dilemma of deciding if a computed tomography (CT) scan is warranted when-as is most often the case-ultrasound results do not yield a definitive diagnosis. The potential risks of radiation must be weighed against numerous aspects of a patient's background, physical exam, and already-obtained workup.

OBJECTIVES

This study aims to aid in future decision making of providers in their evaluation of patients with suspected appendicitis, to help facilitate a more comprehensive answer to the "next-steps" in the question of equivocal ultrasound, and to create a pathway utilizing lab results, physical exam findings, and pertinent positives and negatives in patient history to facilitate a more objective decision-making process for ordering a CT scan.

METHODS

A retrospective chart review was performed for patients who were evaluated for possible appendicitis at our institution between October 2016 and October 2017 and whose ultrasound results were equivocal. We determined what factors led to increased frequency of obtaining CT scans.

RESULTS

Statistical analysis showed that several factors were independently associated with the increased likelihood of having a CT scan performed. When considered in combination with the other parameters, it was found that older children, males, report of right lower quadrant (RLQ) pain, and presence of RLQ tenderness on physical exam were all associated with a significantly higher likelihood of having a CT scan performed.

CONCLUSIONS

When combined with present algorithms and protocols already in use, this information can assist the provider in making prudent decisions for their patients with the potential for reduced provider bias.

Effect of Alvarado Score on the Negative Predictive Value of Nondiagnostic Ultrasound for Acute Appendicitis

Background:

The purposes of this study were to calculate the negative predictive value (NPV) of nondiagnostic ultrasound (US) in patients with suspected appendicitis and to identify the clinical factors that were associated with the nondiagnostic US.

Methods:

We conducted a retrospective review of 412 patients who had graded-compression appendiceal US performed during January 2017 and December 2017. The NPV of the nondiagnostic US in combination with clinical parameters was calculated. Multivariate regression analysis was used to determine the independent predictors for the nondiagnostic US.

Results:

The US exam was nondiagnostic in 64.8% of the patients, giving an NPV of 70.8%. The NPV of nondiagnostic US increased to 96.2% in patients who had an Alvarado score of <5. The patients who did not have migratory pain, did not have leukocytosis, and had a pain score of <7 were more likely to have a nondiagnostic US study (P < 0.001).

Conclusion:

Alvarado score had an inverse effect on the NPV of nondiagnostic appendiceal US. Patients who had nondiagnostic US and Alvarado score of <5 were very unlikely to have appendicitis. Active clinical observation or re-evaluation rather than immediate computed tomography may be a safe alternative approach in these low-risk patients. However, the Alvarado score itself was not a predictive factor of nondiagnostic US. The absence of migratory pain, absence of leukocytosis, and low pain score were the independent predictors of nondiagnostic appendiceal US.

Magnetic Resonance Imaging Provides Useful Diagnostic Information Following Equivocal Ultrasound in Children With Suspected Appendicitis

PURPOSE

In Canada, ultrasonography is the primary imaging modality for children with suspected appendicitis, yet equivocal studies are common. Magnetic resonance imaging provides promise as an adjunct imaging strategy. The primary objective of this study was to determine the proportion of children with suspected appendicitis and equivocal ultrasound where magnetic resonance imaging determined a diagnosis.

METHODS

A prospective consecutive cohort of children aged 5-17 years presenting to a tertiary pediatric Emergency Department with suspected appendicitis were enrolled. Participants underwent diagnostic and management strategies according to our local suspected appendicitis pathway, followed by magnetic resonance (Siemens Avanto 1.5 Tesla) imaging. Sub-specialty pediatric radiologists reported all images.

RESULTS

Magnetic resonance imaging was performed in 101 children with suspected appendicitis. The mean age was 11.9 (SD 3.4) years and median Pediatric Appendicitis Score was 6 [IQR 4,8]. Ultrasonography was completed in 98/101 (97.0%). Of 53/98 (54.1%) with equivocal ultrasound, magnetic resonance imaging provided further diagnostic information in 41 (77.4%; 10 positive, 31 negative; 12 remained equivocal). Secondary findings of appendicitis on magnetic resonance imaging in children with equivocal ultrasound included abdominal free fluid (24, 45.3%), peri-appendiceal fluid (12, 22.6%), intraluminal appendiceal fluid (9, 17.0%), fat stranding (8, 15.1%), appendicolith (2, 3.8%), and peri-appendiceal abscess (1, 1.9%). The observed agreement between magnetic resonance imaging results and final diagnosis was 94.9% (kappa = 0.89).

NSQIP Based Predictors of False Negative and Indeterminate Ultrasounds in Adults With Appendicitis

BACKGROUND

It has been well established that ultrasound (US) is the initial screening tool for children with suspected acute appendicitis. However, computed tomography (CT) has become the standard screening modality for adults presenting with abdominal pain. A recent review of National Surgical Quality Improvement Program (NSQIP) data revealed US is being utilized as a screening modality in adults. We aimed to assess the diagnostic performance of US in evaluating adults with acute appendicitis.

STUDY DESIGN

The American College of Surgeons NSQIP and NSQIP Procedure Targeted Data Files were accessed and examined for all patients in 2016 and 2017 who received an US and underwent an appendectomy. The US results were then correlated to the pathology in order to determine the diagnostic performance. Additionally, we identified predictors for indeterminate and false negative US results.

RESULTS

Our study included 3607 appendectomy patients of which 1135 (30%) had an indeterminate US, 683 (18%) had an US not consistent with appendicitis, and 1789 (49%) had an US consistent with appendicitis. Sensitivity and Specificity were 74.3% and 53.0%, respectively. Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were 95.9% and 12.2%, respectively. On regression analysis, clinically relevant predictors for false negative and indeterminate studies included age, sex, and BMI.

CONCLUSIONS

Ultrasound is an effective initial imaging modality for acute appendicitis in the adult population. Females, age >30 y, and elevated BMI were more likely to have indeterminate or false negative results. These patients may benefit from CT as their initial screening test.

Ultrasound features and the diagnostic strategy of subhepatic appendicitis

Background

This study aimed to compare the differences of ultrasound findings between subhepatic appendicitis and appendicitis at a normal position, then discuss the diagnostic strategies and improve the accuracy of diagnosis.

Methods

A retrospective analysis was performed in our hospital. One thousand five hundred ninety-one patients with appendicitis were diagnosed from January 2014 to January 2018. Eighteen patients with subhepatic appendicitis and 25 patients with appendicitis with regular positions were selected randomly as the control group. The difference in ultrasound features between the two groups was studied. Comparisons between the two groups showed statistically significant differences in the frequencies of the fishbone sign, enlarged appendix, appendicoliths, and hyperechoic omental cap (P<0.05).

Results

Statistical significance was not observed with the difference in the frequency of whether there was lymphadenectasis (P>0.05) in the abdominal cavity between the two groups. The Pareto chart was drawn to look for the main factors associated. The results of interpretation on the critical points of diagnosis for subhepatic appendicitis: (I) the fishbone sign of a dilated ileum in the right lower abdomen; and (II) the fishbone sign of a dilated ileum in the right lower abdomen + presence of an enlarged appendix in the right upper abdomen.

Conclusions

An abnormally dilated ileum in the right lower abdomen – the fishbone sign, is a vital sign leading to the diagnosis of subhepatic appendicitis. The fishbone sign of a dilated ileum in the right lower abdomen + whether there is a vermiform structure is an important diagnostic indicator for subhepatic appendicitis.

Bayesian Approach to Predicting Acute Appendicitis Using Ultrasonographic and Clinical Variables in Children

Objectives

Ultrasound has an established role in the diagnostic pathway for children with suspected appendicitis. Relevant clinical information can influence the diagnostic probability and reporting of ultrasound findings. A Bayesian network (BN) is a directed acyclic graph (DAG) representing variables as nodes connected by directional arrows permitting visualisation of their relationships. This research developed a BN model with ultrasonographic and clinical variables to predict acute appendicitis in children.

Methods

A DAG was designed through a hybrid method based on expert opinion and a review of literature to define the model structure; and the discretisation and weighting of identified variables were calculated using principal components analysis, which also informed the conditional probability table of nodes.

Results

The acute appendicitis target node was designated as an outcome of interest influenced by four sub-models, including Ultrasound Index, Clinical History, Physical Assessment, and Diagnostic Tests. These sub-models included four sonographic, three blood-test, and six clinical variables. The BN was scenario tested and evaluated for face, predictive, and content validity. A lack of similar networks complicated concurrent and convergent validity evaluation.

Conclusions

To our knowledge, this is the first BN model developed for the identification of acute appendicitis incorporating imaging variables. It has particular benefit for cases in which variables are missing because prior probabilities are built into corresponding nodes. It will be of use to clinicians involved in ultrasound examination of children with suspected appendicitis, as well as their treating clinicians. Prospective evaluation and development of an online tool will permit validation and refinement of the BN.

Point-of-Care Ultrasonography (POCUS) in a Community Emergency Department: An Analysis of Decision Making and Cost Savings Associated With POCUS

OBJECTIVES

Point-of-care ultrasonography (POCUS) is an increasingly integral part of emergency medicine. This study investigated community emergency department physicians' choices regarding ultrasonography as a branch point in clinical decision making.

METHODS

During shifts covering all days of the week and all time-spans over a 3-month period, emergency department physicians were interviewed whenever POCUS was used. Questions focused on the role of POCUS in clinical management and on tests avoided because of ultrasonography use. Cost savings attributable to POCUS were calculated using Center for Medicare and Medicaid Services and FairHealth data. Anonymization of data precluded follow-up testing to account for misdiagnosis.

RESULTS

On average, POCUS use eliminated $1134.31 of additional testing for privately insured patients, $2826.31 for out-of-network or uninsured patients, and $181.63 for Center for Medicare and Medicaid Services patients. Differences were significant when the total cost of eliminated additional testing was compared to a baseline of no savings (p < .001). Aggregate cost savings remained significant when analyses were broadened to include POCUS encounters that did not yield changes in management (p < .001).

CONCLUSIONS

When physicians' clinical expertise suggests that POCUS may be indicated, its use results in significant cost savings, even in encounters in which management is not directly impacted. POCUS, when incorporated earlier and more frequently into community hospital emergency medicine diagnostic protocols, can lower direct and indirect costs associated with diagnostic workups. Community emergency departments, in particular, would benefit from additional investigation informing specific guidelines for the integration of POCUS into clinical management and the role that this has in cost savings.

Absolute neutrophil count as a diagnostic guide for the use of MRI in the workup of suspected appendicitis in children

BACKGROUND/PURPOSE

To assess the additive value of magnetic resonance imaging (MRI) in the setting of an equivocal US (Eq-US) with or without an elevated absolute neutrophil count (ANC).

METHODS

Single-institution, retrospective review of children ages 5-18 years who presented to the ER with suspected appendicitis from 9/2015 to 8/2016. US, ANC, and MRI results were reviewed. Imaging was identified as positive/suspicious, normal, or equivocal and ANC <8000/mm³ was defined as normal.

RESULTS

738 patients with a median age of 11 years (IQR 8-14) met inclusion criteria. US was equivocal in 61.4%. Among 304 (67.1%) patients with an Eq-US and normal ANC, only 5 (1.6%) had acute appendicitis. In contrast, 28 of 149 patients (18.8%) with Eq-US and elevated ANC had appendicitis. MRI was performed in 125 patients with Eq-US and was positive/suspicious in 2.9% (2/69) with normal ANC and 25.0% (14/56) with elevated ANC. MRI had 94.7% sensitivity and 100% specificity for acute appendicitis in patients with an Eq-US.

CONCLUSIONS

MRI has high sensitivity and specificity for diagnosing acute appendicitis in children. Patients with Eq-US plus a normal ANC have a very low likelihood of appendicitis and do not typically require further imaging. MRI may have utility for children with Eq-US and elevated ANC.

LEVEL OF EVIDENCE

Level III.

Hospital type predicts computed tomography use for pediatric appendicitis

BACKGROUND

Evidence-based guidelines recommend ultrasound (US) over computed tomography (CT) as the primary imaging modality for suspected pediatric appendicitis. Continued high rates of CT use may result in significant unnecessary radiation exposure in children. The purpose of this study was to evaluate variables associated with preoperative CT use in pediatric appendectomy patients.

METHODS

A retrospective cohort study of pediatric patients who underwent appendectomy for acute appendicitis in 2015-2016 at National Surgical Quality Improvement Program for Pediatrics (NSQIP-P) hospitals was conducted. Pediatric (<18 years old) patients who underwent appendectomy for acute appendicitis in an NSQIP-P hospital from 2015 to 2016 were included. Patients were excluded if they underwent interval or incidental appendectomy or did not have a final diagnosis of appendicitis. Variables associated with imaging evaluation, including age, body mass index (BMI), race/ethnicity, gender and hospital of presentation (NSQIP-P vs. non-NSQIP-P hospital) were evaluated. The primary outcome was receipt of preoperative CT. Secondary outcomes include reimaging practices and trends over time.

RESULTS

22,333 children underwent appendectomies, of which almost all were imaged preoperatively (96.5%) and 36% of whom presented initially to a non-NSQIP-P hospital. Overall, US only was the most common imaging modality (52%), followed by CT only (27%), US+CT (16%), no imaging (3%), MRI +/- CT/US (1%) and MRI only (<1%). On regression, older age (>11 years), obesity (BMI >95th percentile for age), and female gender were associated with increased odds of receiving a CT scan. However, initial presentation to a non-NSQIP-P hospital was the strongest predictor of CT use (OR 9.4, 95% CI 8.1-10.8). Reimaging after transfer was common, especially after US and MRI at a non-NSQIP-P hospital. CT use decreased between 2015 and 2016 in non-NSQIP-P hospitals but remained the same (25%) in NSQIP-P facilities.

CONCLUSIONS

Though patient characteristics were associated with different imaging practices, presentation at a referral, nonchildren's hospital is the strongest predictor of CT use in children with appendicitis. NSQIP-P hospitals frequently reimage transferred patients and have not reduced their CT use. Novel strategies are required for all hospital types in order to sustain reduction in CT use and mitigate unnecessary imaging.

LEVEL OF EVIDENCE

Level III.

TYPE OF STUDY

Retrospective comparative study.

The non-visualized appendix and secondary signs on ultrasound for pediatric appendicitis in the community hospital setting

BACKGROUND

Secondary signs of appendicitis on ultrasound may aid with diagnosis in the setting of a non-visualized appendix (NVA). This role has not been shown in the community hospital setting.

MATERIALS AND METHODS

All right lower quadrant ultrasounds performed in children for clinical suspicion of appendicitis over a 5-year period in a single community hospital were evaluated. Secondary signs of inflammation including free fluid, ileus, fat stranding, abscess, and lymphadenopathy were documented. Patients were followed for 1 year for the primary outcome of appendicitis. These data were analyzed to determine the utility of secondary signs in the diagnosis of acute appendicitis when an NVA is reported.

RESULTS

Six hundred and seventeen ultrasounds were reviewed; 470 of these had an NVA. Of NVAs, 47 (10%) of patients were diagnosed with appendicitis. Sensitivity and specificity of having at least one secondary were 38.3% and 80%, respectively. The positive and negative predictive values of having at least one secondary sign were 17.3% and 92%, respectively.

CONCLUSION

These data suggest that the absence of secondary signs has a strong negative predictive value for appendicitis in the community hospital setting; however, the full utility of secondary signs may be limited in this setting.

Paediatric appendiceal ultrasound: a survey of Australasian sonographers' opinions on examination performance and sonographic criteria

INTRODUCTION

The objectives of this study were to identify knowledge gaps and/or perceived limitations in the performance of paediatric appendiceal ultrasound by Australasian sonographers. We hypothesised that: sonographers' confidence in visualising the appendix in children was poor, particularly outside predominantly paediatric practice; workplace support for prolonging examinations to improve visualisation was limited; and the sonographic criteria applied in diagnosis did not reflect contemporary literature.

METHODS

A cross-sectional survey of Australasian sonographers regarding paediatric appendicitis was conducted using a mixed methods approach (quantitative and qualitative data). Text responses were analysed for key themes, and quantitative data analysed using chi-square, Mann-Whitney U and Wilcoxon signed-rank tests.

RESULTS

Of the 124 respondents, 27 (21.8%) reported a visualisation rate of less than 10%. Workplace support for extending examination time was significantly related to a higher appendix visualisation rate (χ2 (2) = 16.839, P < 0.001). Text responses reported frustration locating the appendix and a desire for more time and practice to improve visualisation. Sonographers suggested a significantly lower maximum diameter cut-off in a 5-year-old compared to a 13-year-old (Z = -6.07, P < 0.001), and considered the presence of inflamed peri-appendiceal mesentery as the most useful sonographic criterion in diagnosing acute appendicitis.

CONCLUSIONS

Respondents had a low opinion of their ability to confidently identify the appendix. Confidence was greater in those centres where extending scanning time was encouraged. Application of echogenic mesentery as the most significant secondary sonographic criterion is supported by recent studies. Opinions of diameter cut-offs varied, indicating potential for improved awareness of recent research.

A simple algorithm to improve quality while reducing resource utilization in evaluation of suspected appendicitis in children

BACKGROUND

With similar effectiveness of ultrasonography, our institution replaced CT imaging with ultrasound for diagnosing appendicitis in children. An unexpected consequence was the overutilization of ultrasound. Our objective was to establish measures that could help prevent this overuse.

METHODS

A retrospective chart review of 327 consecutive pediatric patients evaluated for appendicitis between October 2014 and September 2015 at our institution was performed. Data on clinical, radiographic, and histopathologic findings were reviewed. Diagnostic accuracy of US and white blood cell (WBC) values was determined. An algorithm was created.

RESULTS

327 (100%) patients received an ultrasound for suspected appendicitis. WBC of 10,000/μl was determined to be the primary discriminant for management and ultrasound utilization. If a WBC ≥10,000/μL had been utilized as criteria for imaging, 49.5% fewer patients would have received an ultrasound.

CONCLUSIONS

Clinical exam, WBC count, and surgery consultation prior to ultrasonography can lessen then need for ultrasound utilization in children with suspected appendicitis.

Improving the value of ultrasound in children with suspected appendicitis: a prospective study integrating secondary sonographic signs

PURPOSE

The purpose of this study was to determine whether the awareness and inclusion of secondary sonographic signs of appendicitis, in combination with a structured evaluation as part of engagement and training for sonographers, improved appendix visualization rates and reduced equivocal findings in children with suspected acute appendicitis.

METHODS

This was a prospective study of 230 children at a tertiary children's hospital in Australia referred for an ultrasound examination of suspected appendicitis. The ultrasound findings, radiology reports, histology, clinical results, and follow-up were collated. Secondary signs were used as an additional assessment of the likelihood of disease where possible, even in the absence of an identified appendix.

RESULTS

The implementation of a structured evaluation as part of sonographer engagement and training resulted in a 28% improvement in appendix visualization (68.7%) compared with a prior retrospective study in a similar population (40.7%). The diagnostic accuracy was 91.7%, with likelihood ratios suggesting a meaningful influence of the pre-test probability of appendicitis in children studied (positive likelihood ratio, 11.22; negative likelihood ratio, 0.09.). Only 7.8% of the findings were equivocal. A binary 6-mm diameter cut-off did not account for equivocal cases, particularly lymphoid hyperplasia.

CONCLUSION

Engagement of sonographers performing pediatric appendiceal ultrasound through training in the scanning technique and awareness of secondary signs significantly improved the visualization rate and provided more meaningful findings to referrers.

Standardized reporting of appendicitis-related findings improves reliability of ultrasound in diagnosing appendicitis in children

PURPOSE

Our objective was to increase ultrasound reliability for diagnosing appendicitis in an academic children's hospital emergency department (ED) through a multidisciplinary quality improvement initiative.

METHODS

A retrospective review of ultrasound use in patients diagnosed with appendicitis in our ED from 1/1/2011 to 6/30/2014 established a baseline cohort. From 8/1/2014 to 7/31/2015 a diagnostic algorithm that prioritized ultrasound over CT was used in our ED, and a standardized template was implemented for the reporting of appendicitis-related ultrasound findings by our radiologists.

RESULTS

Of 627 patients diagnosed with appendicitis in the ED during the retrospective review, 46.1% (n=289) had an ultrasound. After implementation of the diagnostic algorithm and standardized ultrasound report, 88.4% (n=236) of 267 patients diagnosed with appendicitis had an ultrasound (p<0.01). The frequency of indeterminate results decreased from 44.3% to 13.1%, and positive results increased from 46.4% to 66.1% in patients with appendicitis (p<0.01). The sensitivity of ultrasound (indeterminate counted as negative) increased from 50.6% to 69.2% (p<0.01).

CONCLUSIONS

Ultrasound reliability for the diagnosis of appendicitis in children can be improved through standardized results reporting. However, these changes should be made as part of a multidisciplinary quality improvement initiative to account for the initial learning curve necessary to increase experience.

LEVEL OF EVIDENCE

Level II, Study of Diagnostic Test.

Clinical Ultrasound Is Safe and Highly Specific for Acute Appendicitis in Moderate to High Pre-test Probability Patients

Introduction

Clinical ultrasound (CUS) is highly specific for the diagnosis of acute appendicitis but is operator-dependent. The goal of this study was to determine if a heterogeneous group of emergency physicians (EP) could diagnose acute appendicitis on CUS in patients with a moderate to high pre-test probability.

Methods

This was a prospective, observational study of a convenience sample of adult and pediatric patients with suspected appendicitis. Sonographers received a structured, 20-minute CUS training on appendicitis prior to patient enrollment. The presence of a dilated (>6 mm diameter), non-compressible, blind-ending tubular structure was considered a positive study. Non-visualization or indeterminate studies were considered negative. We collected pre-test probability of acute appendicitis based on a 10-point visual analog scale (moderate to high was defined as >3), and confidence in CUS interpretation. The primary objective was measured by comparing CUS findings to surgical pathology and one week follow-up.

Results

We enrolled 105 patients; 76 had moderate to high pre-test probability. Of these, 24 were children. The rate of appendicitis was 36.8% in those with moderate to high pre-test probability. CUS were recorded by 33 different EPs. The sensitivity, specificity, and positive and negative likelihood ratios of EP-performed CUS in patients with moderate to high pre-test probability were 42.8% (95% confidence interval [CI] [25–62.5%]), 97.9% (95% CI [87.5–99.8%]), 20.7 (95% CI [2.8–149.9]) and 0.58 (95% CI [0.42–0.8]), respectively. The 16 false negative scans were all interpreted as indeterminate. There was one false positive CUS diagnosis; however, the sonographer reported low confidence of 2/10.

Conclusion

A heterogeneous group of EP sonographers can safely identify acute appendicitis with high specificity in patients with moderate to high pre-test probability. This data adds support for surgical consultation without further imaging beyond CUS in the appropriate clinical setting.