Current Approach to the Diagnosis and Emergency Department Management of Appendicitis in Children

Quality Improvement Campaign Improved Utilization of Rapid Sequence MRI for Diagnosis of Pediatric Appendicitis

INTRODUCTION

Appendicitis is the most common indication for emergency general surgery in the pediatric population. Computed tomography (CT) or magnetic resonance imaging (MRI) may be used for diagnosis when ultrasound findings are equivocal. However, CT involves unnecessary radiation exposure if MRI is available. After introducing a rapid sequence MRI (rsMRI) appendicitis protocol at our institution, CT was still preferentially used. We therefore implemented a quality improvement (QI) campaign to reduce the rate of CTs and increase the rate of rsMRI. Here, we assess the effectiveness of the QI campaign while evaluating potential barriers to using rsMRI.

METHODS

We conducted a mixed methods study, first performing stakeholder interviews which informed the design of a QI campaign initiated in May 2021 and a midway feedback survey in December 2021. A retrospective cohort study was then performed of children evaluated for appendicitis at our institution between January 1, 2016, and April 30, 2022. CT and rsMRI rates were compared before and after QI campaign implementation.

RESULTS

There was a significant decrease in rate of CTs and increase in rate of rsMRIs performed following the initiation of the QI campaign (p < 0.0001). The rate of CT scans decreased by a factor of 0.4 while the rate of rsMRI increased by a factor of 9.5.

CONCLUSION

A successful QI campaign was initiated at our institution, resulting in decreased utilization of CT and increased use of rsMRI for the evaluation of suspected appendicitis. These results highlight the potential impact of QI projects.

LEVEL OF EVIDENCE

III.

Magnetic Resonance Imaging Availability Reduces Computed Tomography Use for Pediatric Appendicitis Diagnosis

OBJECTIVES

To determine if introducing magnetic resonance imaging (MRI) as an imaging option for children with suspected appendicitis and an inconclusive ultrasound reduces computed tomography (CT) use.

METHODS

This is a retrospective cohort study of patients aged 5 to 18 years who presented to a pediatric emergency department (ED) with suspected appendicitis. Rates of CT use 1 year before and 1 year after MRI availability are compared. Secondary outcomes include missed and negative appendectomies, imaging charges, time to antibiotics and surgery, time to radiology read, ED length of stay, and test characteristics of MRI and CT.

RESULTS

Of the 981 patients screened, 499 patients met inclusion criteria. There was an absolute reduction of CT use of 25% from 38% in year 1 to 13% in year 2 (95% confidence interval, 18% to 33%). Advanced imaging charges were $371 higher in year 2 (MRI) than year 1 (CT), and median time to radiologist reads was longer in MRIs than CTs (129 versus 62 minutes; difference 53 minutes, 95% confidence interval, 23 to 74 minutes). All other secondary outcomes, including ED length of stay and test characteristics, were statistically similar.

CONCLUSIONS

Introducing MRI for as an imaging option for children with suspected appendicitis and an inconclusive ultrasound markedly reduced CT use, but did result in a small increase in imaging charges and time to preliminary radiology read.

A QI Partnership to Decrease CT Use for Pediatric Appendicitis in the Community Hospital Setting

The primary aim of this quality improvement initiative was to decrease the use of computerized tomography (CT) in the evaluation of pediatric appendicitis in a community general emergency department (GED) system by 50% (from 32% to 16%) in 1 year.

Methods

Colleagues within a State Emergency Medical Service for Children (EMSC) community of practice formed the quality improvement team, representing multiple stakeholders across 3 independent institutions. The team generated project aims by reviewing baseline practice trends and implemented changes using the Model for Improvement. Ultrasound (US) use and nondiagnostic US rates served as process measures. Transfer and "over-transfer" rates served as balancing measures. Interventions included a GED pediatric appendicitis clinical pathway, US report templates, and case audit and feedback. Statistical process control tracked the main outcomes. Additionally, frontline GED providers shared perceptions of knowledge gains, practice changes, and teamwork.

Results

The 12-month baseline revealed a GED CT scan rate of 32%, a US rate of 63%, a nondiagnostic US rate of 77%, a transfer to a children's hospital rate of 23.5%, and an "over-transfer" rate of 0%. Project interventions achieved and sustained the primary aim by decreasing the CT scan rate to 4.5%. Frontline GED providers reported positive perceptions of knowledge gains and standardization of practice.

Conclusions

Engaging regional colleagues in a pediatric-specific quality improvement initiative significantly decreased CT scan use in children cared for in a community GED system. The emphasis on the community of practice facilitated by Emergency Medical Service for Children may guide future improvement work in the state and beyond.

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.

Cost-effectiveness of Imaging Protocols for Suspected Appendicitis

BACKGROUND

Inaccurate diagnosis of appendicitis leads to increased costs and morbidity. Ultrasound costs less than computed tomography (CT) or MRI but has lower sensitivity and may not visualize the appendix.

METHODS

We conducted a cost-effectiveness analysis using a decision-analytic model of 10 imaging strategies for suspected appendicitis in a hypothetical cohort of patients: no imaging with discharge or surgery; CT only; MRI only; or staged approach with CT or MRI after 1) negative ultrasound result or ultrasound without appendix visualization, 2) ultrasound without appendix visualization, or 3) ultrasound without appendix visualization but with secondary signs of inflammation. Inputs were derived from published literature and secondary data (quality-of-life and cost data). Sensitivity analyses varied risk of appendicitis and proportion of visualized ultrasound. Outcomes were effectiveness (quality-adjusted life-years [QALYs]), total direct medical costs, and cost-effectiveness (cost per QALY gained).

RESULTS

The most cost-effective strategy for patients at moderate risk for appendicitis is initial ultrasound, followed by CT if the appendix is not visualized but secondary signs are present (cost of $4815.03; effectiveness of 0.99694 QALYs). Other strategies were well above standard willingness-to-pay thresholds or were more costly and less effective. Cost-effectiveness was sensitive to patients' risk of appendicitis but not the proportion of visualized appendices.

CONCLUSIONS

Tailored approaches to imaging based on patients' risk of appendicitis are the most cost-effective. Imaging is not cost-effective in patients with a probability <16% or >95%. For moderate-risk patients, ultrasound without secondary signs of inflammation is sufficient even without appendix visualization.

Acute Abdomen in Pediatric Patients With Lassa Fever: Prevalence and Response to Nonoperative Management

Few reports on the prevalence of acute abdomen (AAbd) in pediatric patients with Lassa fever (LF) are available, and no firm policy on its management exists. Here, we report on its prevalence in and the response to treatment among a cohort of children with confirmed LF. Six (10.3%) of 58 children with LF had AAbd, whereas 6 (2.8%) of 215 children with AAbd had LF. Nonoperative treatment was successful in 5 of the 6 children with both AAbd and LF. We conclude that AAbd is not uncommon in pediatric patients with LF, and it could be responsive to nonoperative treatment. Testing for LF in all children with febrile AAbd might be justified in areas in which LF is endemic.

Utility of applying white blood cell cutoffs to non-diagnostic MRI and ultrasound studies for suspected pediatric appendicitis

BACKGROUND

Non-contrast magnetic resonance imaging (MRI) and ultrasound studies in pediatric patients with suspected appendicitis are often non-diagnostic. The primary objective of this investigation was to determine if combining these non-diagnostic imaging results with white blood cell (WBC) cutoffs improves their negative predictive values (NPVs).

METHODS

A retrospective chart review was conducted including patients ≤18 years old with suspected appendicitis who had MRI performed with or without a preceding ultrasound study in a pediatric emergency department. Imaging results were sorted into 2 diagnostic and 5 non-diagnostic categories. NPVs were calculated for the non-diagnostic MRI and ultrasound categories with and without combining them with WBC cutoffs of <10.0 and <7.5 × 10⁹/L.

RESULTS

Of the 612 patients with MRI studies included, 402 had ultrasound studies performed. MRI with incomplete visualization of a normal appendix without secondary signs of appendicitis had an NPV of 97.9% that changed to 98.1% and 98.2% when combined with WBC cutoffs of <10.0 and <7.5, respectively. Ultrasound studies with incomplete visualization of a normal appendix without secondary signs had an NPV of 85.3% that improved to 94.8% and 96.5% when combined with WBC cutoffs of <10.0 and <7.5, respectively.

CONCLUSIONS

In pediatric patients with suspected appendicitis, MRI studies with incomplete visualization of a normal appendix without secondary signs have a high NPV that does not significantly change with the use of these WBC cutoffs. In contrast, combining WBC cutoffs with ultrasound studies with the same interpretation identifies low-risk groups.

Noninvasive monitoring of physiologic compromise in acute appendicitis: New insight into an old disease

INTRODUCTION

Physiologic compromise in children with acute appendicitis has heretofore been difficult to measure. We hypothesized that the Compensatory Reserve Index (CRI), a novel adjunctive cardiovascular status indicator, would be low for children presenting with acute appendicitis in proportion to their physiological compromise, and that CRI would rise with fluid resuscitation and surgical management of their disease.

METHODS

Ninety-four children diagnosed with acute appendicitis were monitored with a CipherOx CRI™ M1 pulse oximeter (Flashback Technologies Inc., Boulder, CO). For clarity, CRI=1 indicates supine normovolemia, CRI=0 indicates hemodynamic decompensation (systolic blood pressure<80mmHg), and CRI values between 1 and 0 indicate the proportion of volume reserve remaining before collapse. Results are presented as counts with proportion (%), or mean with 95% confidence interval (CI).

RESULTS

Mean age was 11years old (95% CI: 10-12), and 49 (52%) of the children were male. Fifty-four (57%) had nonperforated appendicitis and 40 (43%) had perforated appendicitis. Mean initial CRI was significantly higher in those with nonperforated appendicitis compared to those with perforated appendicitis (0.57, 95% CI: 0.52-0.63 vs. 0.36, 95% CI: 0.29-0.43; P<0.001). The significant differences in mean CRI values between the two groups remained throughout the course of treatment, but lost its significance at 2h after surgery (0.63, 95% CI: 0.57-0.70 vs. 0.53, 95% CI: 0.46-0.61; P=0.05).

CONCLUSION

Low CRI values in children with perforated appendicitis are indicative of their lower reserve capacity owing to peritonitis and hypovolemia. CRI offers a real-time, noninvasive adjunctive tool to monitor tolerance to volume loss in children.

LEVEL OF EVIDENCE

Study of diagnostic test; Level of evidence: Level III.