Predictive value of C-reactive protein, ultrasound and Alvarado score in acute appendicitis: a prospective pediatric cohort

Ultrasound Assessment in Children With Suspected Appendicitis: Time to Revise Diagnostic Criteria: A Prospective Cohort Study

Background: Although ultrasound is considered the gold standard for the evaluation of children with suspected appendicitis, there is still much debate about the most accurate ultrasound findings. The purpose of this study was to define the best ultrasound signs that could ultimately improve the diagnostic accuracy of ultrasound for diagnosing pediatric acute appendicitis, and to differentiate between simple appendicitis and complicated appendicitis. Patients and Methods: After approval by our Institutional Review Board, a prospective study was carried out from January 1, 2022, to July 31, 2023, in a pediatric emergency department. We included all patients aged under 14 years with suspected appendicitis and ultrasound-visualized appendix. Results: A total of 550 patients presented with suspected appendicitis during the study period. Of these children, 411 had an ultrasound-visualized appendix. Our patients' mean age was 9.4 years. The best positive predictive value of ultrasound was found for appendiceal diameter ≥7.5 mm. The combination of an appendiceal diameter <6 mm and the lack of peri-appendiceal free fluid on ultrasound rules out the diagnosis of appendicitis. The best diagnostic accuracy of ultrasound, which was 92%, was achieved for appendix diameters ≥6.5 mm. The sonographic sign giving the best ultrasound accuracy for diagnosing complicated appendicitis was an appendix diameter ≥9 mm. Conclusions: In conclusion, our present study demonstrated that appendiceal diameter ≥6.5 mm is the gold standard for diagnosing appendicitis in pediatric patients. The combination of an appendiceal diameter <6 mm and the lack of peri-appendiceal free fluid on ultrasound would rule out appendicitis.

Predictive Factors of Acute Appendicitis in Children With Non-Visualized Appendix on Ultrasound: A Prospective Cohort Study

Background: Most studies have demonstrated the high accuracy of ultrasound for the diagnosis of acute appendicitis (AA) in children. However, the lack of visualization of the appendix on ultrasound is usually a challenge. The aim of this study was to identify any factors that might help the physician make the right decision when dealing with a child with suspected appendicitis and an appendix not seen on ultrasound. Patients and Methods: After receiving Institutional Review Board approval, we conducted a prospective study in a pediatric emergency department from January 1, 2022, to December 31, 2022. All children under 14 years of age with suspected AA and an appendix not visualized on ultrasound were included. Results: During the study period, 333 children presented with suspected AA. Of these patients, 106 had an appendix not seen on ultrasound. Our patients' median age was 10 years (interquartile range [IQR], 8-11 years), with 54.7% (n = 58) of children being female. Twenty-five (23.6%) were ultimately diagnosed with AA based on pathologic examination. Multivariable logistic regression analysis revealed that Alvarado score ≥6 and increased peri-appendiceal fat echogenicity were predictive for AA. The combination of these two factors provided a positive predictive value of 100%. A white blood cell (WBC) count ≤10 × 109/L and/or a C-reactive protein (CRP) level ≤6 mg/L makes the diagnosis of appendicitis unlikely. Conclusions: In conclusion, our study demonstrated that an Alvarado score at or above six and increased peri-appendiceal fat echogenicity are independent predictive factors of AA in children with non-visualized appendix on ultrasound. The combination of these two factors would confirm the diagnosis of AA in these patients.

Diagnosis and treatment of appendicitis: systematic review and meta-analysis

BACKGROUND

The optimal diagnosis and treatment of appendicitis remains controversial. This systematic review details the evidence and current best practices for the evaluation and management of uncomplicated and complicated appendicitis in adults and children.

METHODS

Eight questions regarding the diagnosis and management of appendicitis were formulated. PubMed, Embase, CINAHL, Cochrane and clinicaltrials.gov/NLM were queried for articles published from 2010 to 2022 with key words related to at least one question. Randomized and non-randomized studies were included. Two reviewers screened each publication for eligibility and then extracted data from eligible studies. Random effects meta-analyses were performed on all quantitative data. The quality of randomized and non-randomized studies was assessed using the Cochrane Risk of Bias 2.0 or Newcastle Ottawa Scale, respectively.

RESULTS

2792 studies were screened and 261 were included. Most had a high risk of bias. Computerized tomography scan yielded the highest sensitivity (> 80%) and specificity (> 93%) in the adult population, although high variability existed. In adults with uncomplicated appendicitis, non-operative management resulted in higher odds of readmission (OR 6.10) and need for operation (OR 20.09), but less time to return to work/school (SMD - 1.78). In pediatric patients with uncomplicated appendicitis, non-operative management also resulted in higher odds of need for operation (OR 38.31). In adult patients with complicated appendicitis, there were higher odds of need for operation following antibiotic treatment only (OR 29.00), while pediatric patients had higher odds of abscess formation (OR 2.23). In pediatric patients undergoing appendectomy for complicated appendicitis, higher risk of reoperation at any time point was observed in patients who had drains placed at the time of operation (RR 2.04).

CONCLUSIONS

This review demonstrates the diagnosis and treatment of appendicitis remains nuanced. A personalized approach and appropriate patient selection remain key to treatment success. Further research on controversies in treatment would be useful for optimal management.

The Value of the Alvarado Score for the Diagnosis of Acute Appendicitis in Children: A Systematic Review and Meta-Analysis

BACKGROUND

Relevant guidelines recommend the use of the Alvarado score (AS) to assist in the diagnosis of acute appendicitis (AA) in children. To provide reference evidence for the clinical application of AS, we performed a meta-analysis of studies related to the diagnostic accuracy of AS in children with AA.

METHODS

We searched the relevant literature from databases including CNKI, WanFangdata, VIP, CBM, the Cochrane Library, PubMed, Embase, and Web of Science databases from the date of database creation to April 30, 2022, and screened them according to nadir criteria, followed by data extraction and then combined effect sizes to assess the accuracy of AS for diagnosis in children.

RESULTS

Twenty-six studies involving 2579 cases were finally included, including 19 studies with Alvarado score and 8 studies with modified Alvarado Score (1 study included both Alvarado Score and modified Alvarado Score). The combined sensitivity (SE) of AS for diagnosing AA in children was 76.0% (95% CI 74.0-78.0%; I2 = 95.1%); combined specificity (SP) was 71.0% (95% CI 68.0-74.0%; I2 = 86.4%); combined positive likelihood ratio (LR+) was 2.43 (95% CI 1.92- 3.07; I2 = 78.7%); combined negative likelihood ratio (LR-) was 0.28 (95% CI 0.20-0.41; I2 = 94.2%); combined AUC = 0.8092, Q∗ = 0.7439; combined diagnostic ratio (DOR) was 8.96 (95% CI 5.65 -14.21; I2 = 76.2%). The combined effect size I2 was greater than 50% for all children with a modified AS diagnosis of AA, so all analyses used a random-effects model, which showed a combined SE of 87.0% (95% CI 85.0 - 88.0%; I2 = 85.5%); the combined SP was 47.0% (95% CI 43.0 - 51.0%. I2 = 88.7%); combined LR+ was 1.68 (95% CI 1.31-2.17; I2 = 85.9%); combined LR-was 0.28 (95% CI 0.20-0.39; I2 = 74.3%); combined AUC = 0.8672 and Q∗ = 0.7978. The combined DOR was 6.43 (95% CI 3.38-12.26; I2 = 80.0%).

CONCLUSION

The results of this meta-analysis suggest that the accuracy of AS in diagnosing AA in children is moderate, and AS can be an auxiliary tool for the diagnosis of AA in children, relying on AS alone for the diagnosis of AA is not recommended; AS can be further improved scientifically to increase its diagnostic value.

Pediatrik Apandisit Olgularında Ultrasonografinin Tanısal Duyarlılığı

Amaç: Çalışmamızda pediatrik yaş grubunda ultrasonografinin apandisit tanısındaki duyarlılığının araştırılması amaçlanmıştır. Gereç Yöntem: Operasyon sonucu apandisit tanısı alan, preoperatif USG tetkiki gerçekleştirilmiş olan ve akut batın nedeni olan ek patolojisi bulunmayan 87 pediatrik olgu çalışmaya dahil edildi. Olguların USG raporları retrospektif olarak incelenerek USG’ nin apandisit tanısındaki duyarlılığı araştırıldı. Ayrıca olguların lökosit sayıları, nötrofil oranları ve CRP değerleri hastane arşivinden ve varsa BT tetkikleri PACS sisteminden incelendi. Bulgular: Olguların %71’i akut apandisit, %29’u perfore apandisitti. Olguların %74’ünün USG’si apandisit ile uyumlu olup USG’nin tanı duyarlılığı %74’dü, %16 olguda USG’de sekonder apandisit bulguları izlenirken %10 olguda USG tetkiki tamamen normaldi. USG ile tanı konulamayan %26 olgudan %10 olgunun tanısı BT ile konulmuş olup %16 olguda tanıya klinik bulgularla gidilmişti. Olguların %62’sinde lökositoz, %84’ünde nötrofil oranında artış (sola kayma), %86’sında ise CRP yüksekliği bulunmaktaydı ve olguların tamamında bu parametrelerin en az biri yüksekti. Sonuç: Ultrasonografi her durumda tanı koymak için yeterli olmasa da çalışmamızda ulaşılan yüksek duyarlılık oranı, ultrasonografinin akut apandisit şüphesi bulunan pediatrik hastalarda ilk seçenek tanı aracı olarak kullanılabileceği bilgisini desteklemektedir.

Resource utilization and outcomes among children risk stratified by pediatric appendicitis risk calculator at a tertiary pediatric center

OBJECTIVES

Appendicitis is a common pediatric condition requiring surgery. The pediatric appendicitis risk calculator (pARC) was recently developed to guide clinical care. The objective of this study is to describe resource utilization and clinical outcomes among children with appendix ultrasound (US) scans risk stratified by pARC score.

METHODS

Prospective enrolled observational cohort single-center study of children aged 5-18, who had an US for suspected appendicitis. We estimated the rate of appendicitis, rate of equivocal US scans, and resource utilization by pARC score strata. Total adjusted charges were determined for low-risk pARC patients compared to discharged emergency department (ED) patients with abdominal pain and complete blood count (CBC) obtained without advanced abdominal imaging.

RESULTS

Over the 13-month study period, 407 children were enrolled. The overall rate of appendicitis was 33.4%, and 199 (49%) were male. The observed rate of appendicitis was 3.3% in those with a pARC score of <15% and 96.8% in those with a pARC score of ≥85%. Of enrolled patients, 152 (37.3%) had a pARC score <15%. Of those with a pARC score of <15%, the negative appendectomy rate was 28.6%, and the rate of equivocal US was 49.3%. The rate of CT scans and hospitalizations was 19% and 23%, respectively. Median total charges for patients with pARC <15% with usual care were $3756. Median total charges for patients presenting to the ED with abdominal pain who had a CBC but no advanced abdominal imaging performed was $2484, indicating a potential savings of $1272 per patient.

CONCLUSIONS

There is a high rate of resource utilization among patients who are low appendicitis risk by pARC score. Outcome variation by pARC scores presents future opportunity to selectively reduce resource utilization in pediatric patients.

Metabolomics and Inflammatory Mediator Profiling for the Differentiation of Life-Threatening and Non-Severe Appendicitis in the Pediatric Population

While children with appendicitis often have excellent clinical outcomes, some develop life-threatening complications including sepsis and organ dysfunction requiring pediatric intensive care unit (PICU) support. Our study applied a metabolomics and inflammatory protein mediator (IPM) profiling approach to determine the bio-profiles of children who developed severe appendicitis compared with those that did not. We performed a prospective case-control study of children aged 0-17 years with a diagnosis of appendicitis. Cases had severe disease resulting in PICU admission. Primary controls had moderate appendicitis (perforation without PICU); secondary controls had mild appendicitis (non-perforated). Serum samples were analyzed using Proton Nuclear Magnetic Resonance (¹H NMR) Spectroscopy and Gas Chromatography-Mass Spectrometry (GC-MS); IPM analysis was performed using plasma bead-based multiplex profiling. Comparisons were made using multivariate data statistical analysis. Fifty-three children were included (15 severe, 38 non-severe). Separation between severe and moderate appendicitis demonstrated excellent sensitivity and specificity (100%, 88%; 14 compounds), separation between severe and mild appendicitis also showed excellent sensitivity and specificity (91%, 90%; 16 compounds). Biomarker patterns derived from metabolomics and IPM profiling are capable of distinguishing children with severe appendicitis from those with less severe disease. These findings provide an important first step towards developing non-invasive diagnostic tools for clinicians in early identification of children who are at a high risk of developing severe appendicitis.

Diagnostic accuracy of combining C-Reactive protein and Alvarado Score among 2-to-20-year-old patients with acute appendicitis suspected presenting to Emergency Departments

OBJECTIVE

Main objective was whether the combination of C-Reactive Protein (CRP) and Alvarado Score (AS) increase the diagnosis accuracy of AS among 2-to-20-year-old patients with suspected acute appendicitis presenting to Emergency Departments.

METHODS

This is a secondary analysis of prospective cohort study consecutively including all patients from 2 to 20 years of age attended for suspected acute appendicitis in 4 Spanish Emergency Departments during 6-month period. We collected demographic, clinical, analytic and radiographic, and surgical data. AS categories were retrospectively calculated as low (0-4 points), intermediate (5-6 points) or high (7-10 points). The cut-off levels were >0.5 mg/dl for CRP. The outcome was diagnosis of acute appendicitis within 14 days of the index visit.

RESULTS

A total of 331 patients with suspected of acute appendicitis (mean age 11.8 (SD 3.8) years; 52.9% males) were recruited. According to AS, 108 (32.6%) were at low risk, 76 at (23.0%) intermediate risk and 147 (44.4%) at high risk of acute appendicitis. One hundred and sixteen (35.0%) cases had confirmed histopathological diagnosis of acute appendicitis. The AUCs of ROC were 0.76 (0.70-0.81) for AS and 0.79 (95% CI 0.75-0.84) for CRP-AS being the difference statistically significant (p=0.003). The CRP for diagnosis acute appendicitis in low risk AS group had negative predictive value of 95.8% (95%CI 87.3-98.9) and likelihood ratio negative of 0.4 (95%CI 0.2-1.0)..

CONCLUSIONS

CRP-AS has shown to increase the diagnostic accuracy of AS for acute appendicitis. This approach may be useful to rule out the diagnosis of acute appendicitis in paediatric patients attended for abdominal pain suggestive of acute appendicitis.

Predictive value of scoring systems for the diagnosis of acute appendicitis in emergency department patients: Is there an accurate one?

Background:

Acute appendicitis is one of the challenging surgical conditions presented in the emergency departments. Clinical scoring systems were developed to reduce the negative appendectomy rate and also to avoid unnecessary diagnostic evaluation.

Objectives:

The primary aim was to compare the clinical adequacy of the Alvarado, Acute Inflammatory Response, and the Raja Isteri Pengiran Anak Saleha Appendicitis scores in patients with right lower quadrant pain for the diagnosis of acute appendicitis.

Methods:

This was a prospective and observational study. All patients over the age of 18 years who presented with a complaint of right lower quadrant pain were enrolled. The Alvarado, Acute Inflammatory Response, and Raja Isteri Pengiran Anak Saleha Appendicitis scoring systems were compared. The patients were either admitted or followed-up as out-patient. Face-to-face or telephone follow-up visits were arranged for the patients who did not have surgery and who were not admitted.

Results:

232 patients were included and 14 patients were excluded from the study. Of the 218 patients, 114 patients underwent surgery. Of the 114 patients, 107 patients were pathologically diagnosed with acute appendicitis. It was determined that Raja Isteri Pengiran Anak Saleha Appendicitis score was the most valuable score with 0.88 accuracy, followed by Acute Inflammatory Response (area under the curve = 0.79) and Alvarado (area under the curve = 0.71) scores.

Conclusion:

The accuracy of Raja Isteri Pengiran Anak Saleha Appendicitis scoring system was higher for the diagnosis of acute appendicitis than the other scores. The cut-off of the Raja Isteri Pengiran Anak Saleha Appendicitis score from a 7.5-point threshold provides a practical, non-invasive, rapid diagnostic method that increases acute appendicitis discriminative power in patients presenting with right lower quadrant pain.

Is the platelet to lymphocyte ratio a promising biomarker to distinguish acute appendicitis? Evidence from a systematic review with meta-analysis

Background

Although several previous studies have examined the association between the platelet to lymphocyte ratio (PLR) and acute appendicitis (AA), findings have been controversial. We aimed to systematically assess the available evidence to elucidate the overall relationship between the PLR and AA.

Methods

Pubmed and Embase databases were searched for all available published literature before August, 2019 by two independent investigators for observational studies reporting the association between the PLR and AA. Random effects models were applied for all meta-analyses. Pooled standardized mean difference (SMD) and 95% confidence interval (CI) were calculated as effect estimates.

Results

Eleven articles met the inclusion criteria and included in this study. Meta-analysis showed that the level of PLR in the AA group was significantly higher than that in the control group (SMD: 1.19, 95% CI: 0.75 to 1.62, P<0.001). A series of subgroup analyses were conducted to investigate the heterogeneity, showing a significant increase in PLV levels in adults with age ≥30 years (SMD: 1.46, 95% CI: 0.89 to 2.02),compared to those in adult <30 years(SMD: 0.58, 95% CI: 0.12 to 1.04) or in children (SMD: 1.03, 95% CI: 0.51 to 1.56). Compared to non-AA controls, a significant increased PLR level was also observed in non-perforated AA (SMD: 1.23, 95% CI: 0.88 to 1.59) and in AA patients during pregnancy (SMD: 0.70, 95% CI: 0.36 to 1.04), while not in perforated AA (SMD: 2.28, 95% CI: -1.72 to 6.28).

Conclusions

A significant increase in PLR level is found in patients with AA, indicating that PLR is a promising biomarker for AA. PLR provides a convenient option for emergency department to quickly screen for clinically or radiologically confirmed AA awaiting appendectomy, especially for pregnant women suspected of having AA. More high-quality evidence is needed to further confirm the diagnostic accuracy of PLR for AA.

Improving the diagnostic accuracy of appendicitis using a multidisciplinary pathway

BACKGROUND/PURPOSE

Improvement opportunities exist in the accuracy and timeliness of the diagnosis of childhood appendicitis. The purpose of our study was to conduct a post-implementation audit of a diagnostic pathway for children with suspected appendicitis presenting to our pediatric emergency department.

METHODS

We adopted a diagnostic pathway that utilized a validated risk of appendicitis stratification tool (Alvarado Score) with protocolized use of abdominal ultrasound for moderate risk patients. We conducted a 10% convenience sample audit of pathway patients treated over the subsequent 18-month period. Outcome measures included false negative and positive rates, sensitivity, specificity, and overall pathway accuracy.

RESULTS

One hundred thirty-four pathway patients, of which 22 (16.4%) had appendicitis confirmed pathologically, were evaluated. The risk group distribution of patients was: low risk (29%), moderate risk (60%), and high risk (11%). The negative appendectomy rate was 4.4% (reduced from 14% pre-pathway), and the false negative (missed appendicitis) rate was 3.0%. No patients received CT scans. Pathway sensitivity was 81.8%% (95% CI 59.7% to 94.8%), specificity-92.9%% (95% CI 86.4%-96.9%), and overall accuracy-91.0% (95% CI 84.9%-95.3%).

CONCLUSION

Implementation of a diagnostic pathway achieved a high level of accuracy and reduced our institutional negative appendectomy rate by 67%. The audit identified additional pathway improvement opportunities.

LEVELS OF EVIDENCE

Level IV.

Does size matter? Correlation of ultrasound findings in children without clinical evidence of acute appendicitis

PURPOSE

The purpose of this study was to determine whether children with a positive ultrasound (US) for acute appendicitis but a negative clinical picture developed appendicitis requiring definitive management.

METHODS

After obtaining IRB approval, we conducted a retrospective review of patients ≤17years who presented with possible acute appendicitis between April 1st, 2014, and December 31st, 2015. We included patients with a US suggestive of acute appendicitis based on size criteria but without concerning clinical features. Patients were discharged from the emergency department (ED) or admitted for observation. Variables included demographic data, US characteristics, clinical findings, length of follow-up, and appendectomy.

RESULTS

Of the 31 patients identified, 45% were male and average age was 11.3yrs. On US, the average maximal diameter of the appendix was 6.93mm. The median length of follow-up was 16.8 months, including 10 returns to the ED by 9 patients. Three of these underwent immediate laparoscopic appendectomy, while one had interval appendectomy. There were no cases of perforated appendicitis, and only 2 cases demonstrated pathology consistent with appendicitis.

CONCLUSION

These findings demonstrate that it is safe to consider conservative measures such as observation or discharge in children with a positive US for appendicitis based on size criteria but a negative clinical picture.

LEVEL OF EVIDENCE

4.

Integration of radiology and clinical score in pediatric appendicitis

BACKGROUND

The efficacy of ultrasonography (US) and abdominal X-ray in combination with Pediatric Appendicitis Score (PAS) is complicated in the diagnosis of acute appendicitis. Abdominal X-ray is as useful as US with clinical assessment when evaluated by experienced pediatric radiologist in acute appendicitis. The aim of this study was to determine the value of US and abdominal X-ray for appendicitis in children when combined with clinical assessment based on PAS, and to establish a practical pathway for acute appendicitis in childhood.

METHODS

A prospective, observational cohort study was conducted at an urban, academic pediatric emergency department. Patients were classified at low (PAS 1-4), intermediate (PAS 5-7), or high (PAS 8-10) risk for appendicitis. Low-risk patients were discharged with telephone follow-up in ≤10 days; those at intermediate risk underwent X-ray and US. High-risk patients received immediate surgical consultation. Patients were grouped on histopathology as having either proven acute appendicitis or no appendicitis.

RESULTS

A total of 288 children were analyzed. Surgery was performed in 134 patients (46.5%), and 128 (95.5%) had positive histopathology. Mean PAS in the patients with and without appendicitis was 7.09 ± 1.42 and 4.97 ± 2.29, respectively (P = 0.00). The rate of missed cases was 6/288 (2%), and the negative appendectomy rate was 6/134 (4.4%). When the score cut-off was set at 6, the sensitivity and specificity of PAS was 86.7% and 63.1%, respectively. The diagnostic performance of daytime US had a sensitivity of 91.1% and specificity of 71.1%. Also, positive US or PAS >6 or both, had sensitivity and specificity 96.7% and 59.9%, respectively.

CONCLUSION

US or abdominal X-ray in children with possible appendicitis should be integrated with PAS to determine the next steps in management. In the case of discordance between the clinical findings and radiology, prolonged observation or further imaging are recommended.

Which One is Better? Comparison of the Acute Inflammatory Response, Raja Isteri Pengiran Anak Saleha Appendicitis and Alvarado Scoring Systems

Purpose

Acute appendicitis (AA) is one of the most common causes of an acute abdomen. The accuracies of the Alvarado and the acute inflammatory response (AIR) scores in the diagnosis of appendicitis is very low in Asian populations, so a new scoring system, the Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA) system, was designed recently. We applied and compared the Alvarado, AIR, and RIPASA scores in the diagnoses of appendicitis in the Iranian population.

Methods

We prospectively compared the RIPASA, Alvarado, and AIR systems by applying them to 100 patients. All the scores were calculated for patients who presented with right quadrant pain. Appendectomies were performed; then, the postoperative pathology reports were correlated with the scores. Scores of 8, 7, and 5 or more are optimal cutoffs for the RIPASA, Alvarado, and AIR scoring systems, respectively. The sensitivities, specificities, positive predictive values, negative predictive values (NPVs), positive and negative likelihood ratios (LRs) for the 3 systems were determined.

Results

The sensitivity and the specificity of the RIPASA score were 93.18% and 91.67%, respectively. The sensitivities of the Alvarado and the AIR scores were both 78.41%. The specificities of the Alvarado and the AIR scores were 100% and 91.67%, respectively. The RIPASA score correctly classified 93% of all patients confirmed with histological AA compared with 78.41% for the Alvarado and the AIR scores.

Conclusion

The RIPASA scoring system had more sensitivity, better NPV, a positive LR, and a less negative LR for the Iranian population whereas the Alvarado scoring system was more specific.

Pediatric emergency medicine point-of-care ultrasound: summary of the evidence

The utility of point-of-care ultrasound is well supported by the medical literature. Consequently, pediatric emergency medicine providers have embraced this technology in everyday practice. Recently, the American Academy of Pediatrics published a policy statement endorsing the use of point-of-care ultrasound by pediatric emergency medicine providers.  To date, there is no standard guideline for the practice of point-of-care ultrasound for this specialty. This document serves as an initial step in the detailed "how to" and description of individual point-of-care ultrasound examinations.  Pediatric emergency medicine providers should refer to this paper as reference for published research, objectives for learners, and standardized reporting guidelines.

Ultrasound for Appendicitis: Performance and Integration with Clinical Parameters

Objective. To evaluate the performance of ultrasound in pediatric appendicitis and the integration of US with the pediatric appendicitis score (PAS) and C-reactive protein (CRP). Method. An institution-based, retrospective study of children who underwent abdominal US for suspected appendicitis between 2012 and 2015 at a tertiary pediatric surgery center. US results were dichotomized, with a nonvisualized appendix considered as a negative examination. Results. In total, 438 children were included (mean 8.5 years, 54% boys), with an appendicitis rate of 29%. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for US were 82%, 97%, 92%, and 93%, respectively, without significant age or gender differences. Pediatric radiologists had significantly higher sensitivity compared to general radiologists, 88% and 71%, respectively (p < 0.01), but no differences were seen for specificity, PPV, and NPV. The sensitivity, NPV, and negative likelihood ratio for the combination of negative US, PAS < 5, and CRP < 5 mg/L were 98%, 98%, and 0.05 (95% CI 0.03–0.15). Conclusion. US may be a useful tool for evaluating children with suspected appendicitis, regardless of age or gender, and should be the first choice of imaging modalities. Combining US with PAS and CRP may reduce several unnecessary admissions for in-hospital observation.