Improving ultrasound for appendicitis through standardized reporting of secondary signs

General Information

Institution Name: Emory University School of Medicine

Division of Pediatric Surgery, Department of Surgery, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, GA, USA

Department of Pediatrics, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, GA, USA

Division of Pediatric Radiology, Department of Radiology and Imaging Services, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, GA, USA

Description of Institution: The QI effort took place at the Egleston Campus of the Children’s Healthcare of Atlanta (Atlanta, GA), a free-standing, university-affiliated, tertiary care pediatric hospital where more than 300 appendectomies are performed annually.

Primary Author and Co-Authors Name and Title: Mehul Raval MD, MS, Kristin N. Partain, MD, Adarsh U. Patel, BS, Curtis Travers, MPH, Heather L. Short, MD, Kiery Braithwaite, MD, Jonathan Loewen, MD, Kurt F. Heiss, MD

Name of Case Study: Improving ultrasound for appendicitis through standardized reporting of secondary signs

This case study is published in the Journal of Pediatric Surgery; PMID: 27939802

Problem Detailing

Local Issue

Ultrasound (US) reports were dictated in an unstructured fashion by radiologists when evaluating a patient with right lower quadrant (RLQ) pain. Wide practice variation exists within and between children’s hospitals and non-children’s hospitals, resulting in inconsistent costs and resource utilization(16-18). When the appendix was not visualized, the impression often re-stated non-visualization of the appendix and recommended clinical correlation. This process resulted in follow up imaging in the form of computed tomography scans (CT), admission to the surgical service for observation, or both.

In an effort to increase the diagnostic accuracy of US, investigators proposed combining equivocal US studies with additional data such as secondary signs (SS) of appendicitis(15,19-22). SS are sonographic descriptions of inflammation surrounding the appendix and include fluid collections, free fluid, echogenic fat, hyperemia, abnormal lymph nodes, abnormal adjacent bowel, bowel wall edema, and appendicoliths(19,23).

Problem Statement

Despite the prevalence of appendicitis, the leading cause of pediatric abdominal pain requiring emergent surgery(1), the clinical diagnosis remains challenging resulting in the use of diagnostic imaging. The American College of Radiology and the American Academy of Pediatrics recommend US of the RLQ as the initial imaging modality in evaluating pediatric appendicitis(2,3). Clinicians may doubt the US findings if the appendix is not visualized, and may then utilize CT or admissions for observation to assist in the diagnosis. CTs are an accurate diagnostic tool with reports of sensitivity (SN) ranging from 95 to 97% and specificity (SP) ranging from 94 to 97%(4), however, they are more expensive than US and expose children to ionizing radiation, increasing their risk of subsequent cancer development(5-8).  When the appendix is fully visualized, US can be as sensitive, specific, and accurate as CT(4,9-11); however, US is user-dependent as reflected by a wide appendix visualization rate ranging from 40% to 89%(11-15).

Results

The study period was divided into three stages based on the implementation practices: pre-template stage (January 2014 to December 2014), post-template stage (January 2015 to July 2015), and sustainability stage (August 2015 to December 2015). There was no difference in race, gender, or age between the pre- and post-template period. Overall CT use (33/387(8.5%) vs 34/483(7.0%), p=0.413) and the negative appendectomy rate remained low (4/387(1.0%) vs (5/483)1.0%, p=1.0). Prior to the implementation of the report template, only 4/387(1.0%) of free-handed US reports mentioned all seven SS and only 21/387(5.4%) mentioned at least 5 of the 7 SS. In the post-template period, the reporting of at least 5 of the 7 SS (384/483(79.5%), p<0.001) and the reporting of all seven SS (333/483(69.8%), p<0.001) significantly increased. CT utilization for patients with an equivocal ultrasound and SS present decreased (16/44(36.4%) vs 4/45(8.9%), p=0.002). Overall admissions for observations decreased (83/387(21.5%) vs 74/483(15.3%), p=0.020).

Test characteristics of US as a diagnostic test improved in the post-template period. Equivocal US with no SS was defined as a negative US for appendicitis, and equivocal US with SS present as a positive US for appendicitis. The final pathology as transmural inflammation was used as our gold standard. With the implementation of the standardized US template, sensitivity, specificity, and accuracy increased. The negative predictive value increased and positive predictive value decreased in 2015 as compared to 2014 as expected given the decrease in the prevalence of appendicitis. When the US diagnostic result categories are stratified by gender, we observed that males are more likely to be a true positive US than females (33.1% vs 16.8%, p<0.001); however, males were more likely to have appendicitis in general. There were no differences in false positive US or false negative US rates between genders. Using the presence of SS on US, the diagnosis of appendicitis can be made equally as well in males and females (84.9% vs 87.5% accuracy). When the US diagnostic result categories are stratified by race, there is no difference between races.

Aim Specification of QI Project

SMART Goal

Specific: An aim to reduce CT use by 50% for patients (5-18 years old) with equivocal US.

Measurable: Increase the reporting of SS in RLQ US. The outcomes of interest were captured by the electronic medical record, and each admission note was reviewed to determine the clinical indication for admission. Concurrently, we tracked the number of patients undergoing CT and the number of patients being admitted for observation.

Achievable: Incorporation of the standardized report was facilitated by close collaboration with colleagues in the Radiology department.

Relevant: Optimize utility of US at our institution

Timeline: 6-month timeframe (post-template period) with an additional 6 months of observation (sustainability period).

Strategic Planning

Description of QI Activity

Implementation of the standardized US report began with personal communication of the successful implementation of similar programs at other children’s hospitals. A standardized US report template was adopted and uploaded to the electronic medical record reporting system(20).

Pre-template stage (January 2014 to December 2014) consisted of 387 patients in the pre-template period.

Post-template stage (January 2015 to July 2015) consisted of 483 patients in the post-template period.

Description of Intervention

Development and validation of an ultrasound template that reported SS and categorized diagnostic confidence and disease severity for acute appendicitis in children was developed.

Standardized reporting of US findings has been suggested to provide clinicians with as much information as possible of many sonographic details and could assist in diagnosis even when the appendix is not fully visualized(19,20,22,24,25).

Limitations

• It was the responsibility of the individual radiologist to comply with the standardized reporting. The standardized reports were considered “value-added” with negligible risk of adverse effects.
• The use of the report did not limit a physician’s ability to order a subsequent CT or admission if determined to be clinically necessary.

• Our study includes several limitations including the fact that this work is a retrospective analysis of data collected from a single hospital system. Interestingly, our results may be generalizable due to our diverse patient population since we are a tertiary referral center. Though retrospective, we carefully selected a cohort in which there was a high clinical suspicion for appendicitis by thoroughly examining emergency department notes and manually abstracting details from operative and pathology reports. For patients who were deemed not to have appendicitis, we tracked their clinical course to ensure they were not readmitted after discharge and found two patients that were re-admitted and diagnosed with appendicitis. Interestingly, these two readmissions only occurred in the pre-template period. Based on our status as the pediatric referral center, patients were expected to return to our system if medical care was needed. Our study did not include the patients who had clinical presentations that were so highly suggestive of appendicitis that they did not undergo preoperative imaging, so our patients represent those whose diagnosis was challenging and required diagnostic imaging. Despite this being a retrospective review, we attempted to ensure highly accurate data collection by using two reviewers to abstract the data (KP, AP) and used two radiologists to review imaging (KB, JL). We were impressed by the ready implementation of the standardized report usage on the part of the Radiology Department. Having two champions and departmental leadership support of this endeavor facilitated success.

Resources Used

1. Staff- The standardized report was aimed to improve the outcomes of all patients with suspected appendicitis: however, it was the responsibility of the individual radiologist to comply.
2. IT- A standardized US report template was adopted and uploaded to the electronic medical record reporting system(20).

Knowledge Acquisition

Key Takeaways

The success of the implementation of the standardized report was assessed by the increase in compliance of radiologists using the US report over time and the relative decrease in the proportion of patients with equivocal US studies undergoing CT or being admitted for observation. We defined compliance both as all seven SS mentioned and at least 5 of the 7 SS mentioned as we wanted to acknowledge improved reporting even if it was imperfect.          

End-of-Project Decision-Making

Conclusions

We implemented a focused QI initiative to incorporate a standardized US report for all patients undergoing RLQ US for diagnosis of appendicitis in a tertiary pediatric hospital setting. As intervention compliance improved, facilitated by close collaboration with colleagues in the Radiology Department, CT use and admissions for observation among patients with equivocal US results decreased demonstrating improved resource utilization; however, we observed an increase in the rate of ultrasonography for patients that did not have appendicitis. We recommend an accompanying quality improvement project in the judicious use of ultrasonography if the goal is to decrease cost. Our institution’s CT rate was low prior to the implementation of a standardized report. The implementation of a standardized US report would be expected to be even more transformative in pediatric hospitals with a high CT utilization rate.

References

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