Pediatric appendicitis in "real-time": the value of sonography in diagnosis and treatment

Outcomes for Children With a Nonvisualized Appendix on Ultrasound

OBJECTIVES

Oftentimes while pursing the diagnosis of appendicitis, an ultrasound cannot visualize the appendix, and physicians must utilize other resources for evaluation. The primary objective of this study was to determine if there was a lower rate of appendicitis when the appendix was not visualized on ultrasound. Furthermore, we assessed the importance of specific clinical predictors in this population.

METHODS

We conducted a retrospective chart review of all children who presented to our pediatric emergency department from 2011 to 2013 and had an abdominal ultrasound. We identified total numbers of ultrasounds with a nonvisualized appendix and then assessed follow-up for a randomly selected group of patients. We performed logistic regression to assess the predictive value of different clinical factors.

RESULTS

A total of 3245 ultrasounds were analyzed, and in 54% of these, the appendix was nonvisualized. In total, 28% of the total patients and 11.9% of patients who received a nonvisualized ultrasound had appendicitis (95% confidence interval [CI], 8.3%-16.2%). Among those patients who had follow-up studies performed during the same visit, 21.2% had appendicitis (95% CI, 14.9%-28.8%), and of those discharged without a diagnosis, 1.5% had appendicitis (95% CI, 0.2%-5.4%). Male sex, leukocytosis, and an elevated absolute neutrophil count were each significantly associated with appendicitis after a nonvisualized appendix on ultrasound.

CONCLUSIONS

A significant proportion of patients with suspected appendicitis who had an initial nonvisualized appendix on ultrasound were ultimately diagnosed with appendicitis. Clinicians must be vigilant about pursuing a definitive diagnosis if an initial ultrasound is nondiagnostic.

Useful Ultrasound Findings of Pediatric Patients with Equivocal Results of Appendicitis: Analysis Based on a Structured Report Form

Purpose

Materials and Methods

Results

Conclusion

Ultrasonography in diagnosis of appendicitis and its complications in pediatric patients: a cross-sectional study

Background

Appendicitis is a common cause of acute abdomen in pediatrics. Although various criteria have been suggested in early diagnosis of appendicitis, these criteria are not as applicable for pediatric patients. Because of this, imaging has an important role in the diagnosis of appendicitis in pediatric patients. The present study was conducted on 121 pediatric patients with possible diagnosis of appendicitis. All of the patients underwent initial evaluation and then underwent sonographic imaging. Sonography was used to assess the existence of signs associated with appendicitis, or its complications. Imaging findings were compared in patients with complications with those with complications. True false positive, false negative, true positive, and true negative values were calculated. Sensitivity and specificity of ultrasonography in determining appendicitis was evaluated.

Results

The mean age of children was 8.08 ± 3.25 years, with ages ranging from 3 to 14 years. Of the 121 children, 74(61.2%) were male and 47(38.8%) were female. In total, there were 3(2.4%) false positives and 2(1.6%) false negatives based on sonographic findings. There were also 54(44.6%) true positive and 62(51.2%) true negative based on sonographic findings. Based on the findings of ultrasound in this study, ultrasound sensitivity was 96.4%, specificity was 95.3%, positive predictive value was 94.7%, and negative predictive value was 96.8%.

Conclusion

Ultrasonography is indicated in the diagnosis of appendicitis in pediatric patients and has optimal sensitivity and specificity in the diagnosis. Furthermore, it is a suitable diagnostic method for evaluating complications of appendicitis.

Factors Influencing the Result of Sonographic Diagnosis of Acute Appendicitis in a Large Hospital in the Netherlands

Objective:

Appendicitis is a common surgical emergency, for which sonography is widely used to assess the presence of absence of appendicitis. The objective of this study was to identify factors associated with the diagnostic accuracy of sonography in patients with a suspected case of acute appendicitis.

Methods:

A retrospective review was conducted in all patients who were assessed for acute appendicitis (with sonography) in two emergency rooms of a large hospital. The sonography result was compared with the pathological report in patients who underwent surgery under suspicion of an acute appendicitis.

Results:

A multivariate analysis revealed that operator (radiologist or resident), time of the sonogram, site (hospital), and body mass index were independent variables significantly influencing the sonographic result. Correctly diagnosing suspected appendicitis with sonography is 2.2 times more likely when performed by a radiologist compared to a resident.

Conclusions:

Sonography is widely used in diagnosing appendicitis in the emergency room. In this study, the probability of sonography being correctly diagnosed decreases during on-call hours or when conducted by a resident in patients with suspected appendicitis. Furthermore, increasing body mass index decreases the probability of a sonogram being correct when conducted by a resident compared to a radiologist.

The Modified Heidelberg and the AI Appendicitis Score Are Superior to Current Scores in Predicting Appendicitis in Children: A Two-Center Cohort Study

Background: Acute appendicitis represents the most frequent reason for abdominal surgery in children. Since diagnosis can be challenging various scoring systems have been published. The aim of this study was to evaluate and validate (and improve) different appendicitis scores in a very large cohort of children with abdominal pain. Methods: Retrospective analysis of all children that have been hospitalized due to suspected appendicitis at the Pediatric Surgery Department of the Altonaer Children's Hospital and University Medical Center Hamburg-Eppendorf from 01/2018 until 11/2019. Four different appendicitis scores (Heidelberg Appendicitis Score, Alvarado Score, Pediatric Appendicitis Score and Tzanakis Score) were applied to all data sets. Furthermore, the best score was improved and artificial intelligence (AI) was applied and compare the current scores. Results: In 23 months, 463 patients were included in the study. Of those 348 (75.2%) were operated for suspected appendicitis and in 336 (96.6%) patients the diagnosis was confirmed histopathologically. The best predictors of appendicitis (simple and perforated) were rebound tenderness, cough/hopping tenderness, ultrasound, and laboratory results. After modifying the HAS, it provided excellent results for simple (PPV 95.0%, NPV 70.0%) and very good for perforated appendicitis (PPV 34.4%, NPV 93.8%), outperforming all other appendicitis score. Discussion: The modified HAS and the AI score show excellent predictive capabilities and may be used to identify most cases of appendicitis and more important to rule out perforated appendicitis. The new scores outperform all other scores and are simple to apply. The modified HAS comprises five features that can all be assessed in the emergency department as opposed to current scores that are relatively complex to utilize in a clinical setting as they include of up to eight features with various weighting factors. In conclusion, the modified HAS and the AI score may be used to identify children with appendicitis, yet prospective studies to validate our findings in a large mutli-center cohorts are needed.

Variations and morphometric features of the vermiform appendix: A systematic review and meta-analysis of 114,080 subjects with clinical implications

Determining the true and indisputable data regarding the vermiform appendix (VA) morphology is of a great clinical interest. The aim of this study was to provide the best evidence-based anatomical overview of the variations in location and size of VA using a systematic and meta-analytical approach. A systematic review with meta-analysis was performed of studies reporting variants of the location and morphometric data regarding the VA. The MEDLINE/PubMed, ScienceDirect, EMBASE, BIOSIS, SciELO, and Web of Science databases were thoroughly searched throughout June 2018. The reported locations of the body of the VA were re-classified into a new, standardized classification system divided into nine categories. The AQUA tool was used to assess the quality of included studies. The research was conducted following PRISMA guidelines and registered at PROPSERO database. Our meta-analysis included 242 studies (n = 114,080). Overall, the VA was most commonly found in the retrocecal location (32.1%, 95%CI: 29.2-35.1), followed by the pelvic (28.5%, 95%CI: 26.7-30.4) and ileal (14.5%, 95%CI: 11.8-17.7) locations. Subjects without known appendiceal pathologies had significantly smaller VA outer diameters (5.84 mm, 95%CI: 5.68-5.99) than patients diagnosed with acute appendicitis (10.64 mm, 95%CI: 10.14-11.15). The overall pooled mean length of the VA was 80.29 mm (95%CI: 76.68-83.89). Significant differences were found in size of the VA between imaging modalities. The results obtained from this evidence-based anatomy study will improve the clinical understanding of the VA anatomy, which in turn will have major implications for clinical practice. Clin. Anat. 32:85-98, 2019. © 2019 Wiley Periodicals, Inc.

Association of Delay in Appendectomy With Perforation in Children With Appendicitis

OBJECTIVE

The aim of this study was to assess whether increased time from emergency department (ED) triage to appendectomy is associated with a greater risk of children developing appendiceal perforation.

METHODS

We performed a multicenter retrospective cohort study of children younger than 18 years hospitalized with appendicitis. To avoid enrolling patients who had perforated prior to ED arrival, we included only children who had a computed tomography (CT) scan demonstrating nonperforated appendicitis. Time to appendectomy was measured as time from ED triage to incision. The main outcome was appendiceal perforation as documented in the surgical report. Variables associated with perforation in bivariate analysis (P < 0.05) were adjusted for using logistic regression.

RESULTS

Overall, 857 patients had a CT scan that demonstrated nonperforated appendicitis. The median age was 12 years (interquartile range, 9-15 years), and 500 (58%) were male. The median time to appendectomy was 11 hours (interquartile range, 8-15 hours). In total, 111 patients (13%) had perforated appendicitis at operation. Children who developed perforation were more likely to require additional CT scans and return to the ED and had a significantly longer length of stay. After adjusting for potential confounders, every hour increase in the time from ED triage to incision was independently associated with a 2% increase in the odds of perforation (P = 0.03; adjusted odds ratio, 1.02; 95% confidence interval, 1.00-1.04).

CONCLUSIONS

Delays in appendectomy were associated with an increase in the odds of perforation. These results suggest that prolonged delays to appendectomy might be harmful for children with appendicitis and should be minimized to prevent associated morbidity.

Bedside Sonography Performed by Emergency Physicians to Detect Appendicitis in Children

OBJECTIVE

The aim of this study was to evaluate the ability of emergency physicians with various levels of point-of-care ultrasound (POCUS) experience to detect appendicitis with POCUS among children visiting a pediatric emergency department (ED).

METHODS

A prospective cohort study was conducted in an urban, tertiary care pediatric ED. Children aged 2 to 18 years old who presented with acute abdominal pain suggesting appendicitis were included. Patients were excluded if they had a history of appendectomy or hemodynamic instability requiring resuscitation or were transferred with proven diagnosis of appendicitis. Participating physicians had various levels of POCUS experience. Four of the 22 physicians were experienced in bowel sonography while the others had basic experience in abdominal POCUS. All the participating physicians received a 1-hour didactic and practical training session on appendix ultrasound. The treating physician performed POCUS following initial physical examination, before further radiologic evaluation. POCUS examinations were recorded as positive for appendicitis, normal, or inconclusive, with normal or inconclusive studies considered negative. Final outcomes were determined by pathology and/or operative reports for surgical cases and telephone follow-up at 3 weeks for those who did not have surgery. The primary analysis was a simple proportion for sensitivity and specificity for POCUS. Expecting a sensitivity of 80% based on previous studies, we calculated that a sample size of 50 cases would provide a 95% confidence interval (CI) ranging from 66% to 90%.

RESULTS

Of the 140 approached patients, 121 accepted to participate and were recruited. After four patients were excluded for missing POCUS data, 117 patients were included in the primary analysis, of whom 51 (44%) had appendicitis. Twenty-two physicians performed between one and 20 POCUS procedures. The POCUS was positive in 39, negative in nine, and inconclusive in 69 patients. POCUS was interpreted as positive in 27 of 51 appendicitis for a sensitivity of 0.53 (95% CI = 0.40-0.66). A negative or inconclusive POCUS was reported for 54 of 66 patients without appendicitis (specificity = 0.82; 95% CI = 0.71-0.89).

CONCLUSION

This study shows limited sensitivity and specificity of POCUS for appendicitis in children, with a high proportion of inconclusive examinations, when performed by emergency physicians with various level of experience in POCUS.

Diagnostic Accuracy of History, Physical Examination, Laboratory Tests, and Point-of-care Ultrasound for Pediatric Acute Appendicitis in the Emergency Department: A Systematic Review and Meta-analysis

BACKGROUND

Acute appendicitis (AA) is the most common surgical emergency in children. Accurate and timely diagnosis is crucial but challenging due to atypical presentations and the inherent difficulty of obtaining a reliable history and physical examination in younger children.

OBJECTIVES

The aim of this study was to determine the utility of history, physical examination, laboratory tests, Pediatric Appendicitis Score (PAS) and Emergency Department Point-of-Care Ultrasound (ED-POCUS) in the diagnosis of AA in ED pediatric patients. We performed a systematic review and meta-analysis and used a test-treatment threshold model to identify diagnostic findings that could rule in/out AA and obviate the need for further imaging studies, specifically computed tomography (CT) scan, magnetic resonance imaging (MRI), and radiology department ultrasound (RUS).

METHODS

We searched PubMed, EMBASE, and SCOPUS up to October 2016 for studies on ED pediatric patients with abdominal pain. Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2) was used to evaluate the quality and applicability of included studies. Positive and negative likelihood ratios (LR+ and LR-) for diagnostic modalities were calculated and when appropriate data was pooled using Meta-DiSc. Based on the available literature on the test characteristics of different imaging modalities and applying the Pauker-Kassirer method we developed a test-treatment threshold model.

RESULTS

Twenty-one studies were included encompassing 8,605 patients with weighted AA prevalence of 39.2%. Studies had variable quality using the QUADAS-2 tool with most studies at high risk of partial verification bias. We divided studies based on their inclusion criteria into two groups of "undifferentiated abdominal pain" and abdominal pain "suspected of AA." In patients with undifferentiated abdominal pain, history of "pain migration to right lower quadrant (RLQ)" (LR+ = 4.81, 95% confidence interval [CI] = 3.59-6.44) and presence of "cough/hop pain" in the physical examination (LR+ = 7.64, 95% CI = 5.94-9.83) were most strongly associated with AA. In patients suspected of AA none of the history or laboratory findings were strongly associated with AA. Rovsing's sign was the physical examination finding most strongly associated with AA (LR+ = 3.52, 95% CI = 2.65-4.68). Among different PAS cutoff points, PAS ≥ 9 (LR+ = 5.26, 95% CI = 3.34-8.29) was most associated with AA. None of the history, physical examination, laboratory tests findings, or PAS alone could rule in or rule out AA in patients with undifferentiated abdominal pain or those suspected of AA. ED-POCUS had LR+ of 9.24 (95% CI = 6.24-13.28) and LR- of 0.17 (95% CI = 0.09-0.30). Using our test-treatment threshold model, positive ED-POCUS could rule in AA without the use of CT and MRI, but negative ED-POCUS could not rule out AA.

CONCLUSION

Presence of AA is more likely in patients with undifferentiated abdominal pain migrating to the RLQ or when cough/hop pain is present in the physical examination. Once AA is suspected, no single history, physical examination, laboratory finding, or score attained on PAS can eliminate the need for imaging studies. Operating characteristics of ED-POCUS are similar to those reported for RUS in literature for diagnosis of AA. In ED patients suspected of AA, a positive ED-POCUS is diagnostic and obviates the need for CT or MRI while negative ED-POCUS is not enough to rule out AA.

Sonographic Detection of the Normal Appendix

The purpose of this study was to determine if the application of tissue harmonic imaging (THI) and real-time spatial compounding (RTSC) would result in a significant difference in the rate of detection and quality of visualization of the normal appendix. Subjects were scanned using the experimental method (the combination of THI and RTSC) and the conventional method (without THI and RTSC). The rate of detection was 85% with the experimental method and 66% with the conventional method. The quality of visualization was measured across three scales—visualized length, walls, and lumen—with a total score equal to the sum of the three scales. The experimental method demonstrated a significant difference in visualized length and total score. The mean score for length using the conventional method was 2.18 compared with 2.56 for the experimental method. The mean score for all three scales for the conventional method was 7.97 compared with 8.67 for the experimental method.

The non-diagnostic ultrasound in appendicitis: is a non-visualized appendix the same as a negative study?

PURPOSE

The purpose of this retrospective study was to investigate outcomes in children who underwent a non-diagnostic ultrasound (US) evaluating for appendicitis and to identify predictors of a negative diagnosis.

METHODS

An IRB-approved retrospective chart review was performed on patients age 0-18, who underwent an abdominal US evaluating for acute appendicitis from 2004 through 2013. Clinical data and specified outcomes were recorded, and exams were categorized into non-diagnostic studies and further separated into studies where the appendix was non-visualized.

RESULTS

Of the 1383 studies included for analysis, 876 were non-diagnostic for acute appendicitis (63.34%) with 777 specifically because the appendix was non-visualized. Seven hundred forty of the 876 non-diagnostic studies and 671 of the 777 non-visualized studies were ultimately considered true negatives, corresponding to a negative predictive value (NPV) of 84.47 and 86.36%, respectively. In patients with WBC <7.5×10(9)/L, the NPV of non-diagnostic and non-visualized studies increased to 97.12 and 98.86%, respectively. Patients with WBC <11.0×10(9)/L have similarly high NPVs of 95.59 and 96.99% (non-diagnostic and non-visualized).

CONCLUSION

Based on the high NPV of a non-diagnostic US in children without leukocytosis, these patients may safely avoid further diagnostic imaging for the workup of suspected appendicitis.

Improvement in diagnostic accuracy of ultrasound of the pediatric appendix through the use of equivocal interpretive categories

OBJECTIVE

The purpose of this article is to evaluate the diagnostic performance of ultrasound of the pediatric appendix using standardized structured reports that incorporate equivocal interpretive categories.

MATERIALS AND METHODS

Standardized structured appendix ultrasound reports using a five-category interpretive scheme were reviewed. Interpretive categories were positive, intermediate likelihood, or negative when the appendix was visualized, and secondary signs or no secondary signs when the appendix was not visualized. Interpretations were compared with clinical and pathologic follow-up. Diagnostic accuracy was compared with the accuracy of a simulated binary interpretive scheme based on the same data.

RESULTS

One thousand three hundred fifty-seven examinations were included, with appendicitis present in 16.9% (230/1357) of cases. The appendix was visualized in 47.2% (641/1357) of cases, with interpretations as follows: positive, 27.5% (176/641); intermediate likelihood, 9.7% (62/641); and normal, 62.9% (403/641). The appendicitis rate in each group was 92.6% (163/176), 25.8% (16/62), and 0.5% (2/403), respectively. The appendix was not visualized in 52.8% (716/1357) of cases, with secondary findings identified in 8.5% (61/716) and no secondary findings in 91.5% (655/716) of cases. The appendicitis rate was 39.3% (24/61) and 3.8% (25/655) in these groups, respectively. Appendicitis was present in 32.5% of equivocal (intermediate likelihood and not visualized, secondary findings) cases and 2.6% of negative (normal and not visualized, no secondary findings) cases. Diagnostic accuracy of a five-category scheme was 96.8% versus 94.1% for a binary scheme.

CONCLUSION

Appendix ultrasound examinations interpreted according to a scheme that incorporates equivocal categories better convey diagnostic certainty and increase diagnostic accuracy compared with a binary interpretive scheme.

Appendiceal diameter as a predictor of appendicitis in children: improved diagnosis with three diagnostic categories derived from a logistic predictive model

OBJECTIVES

To develop and assess the performance of a diameter-based logistic predictive model and a derived 3-category interpretive scheme for the sonographic diagnosis of paediatric appendicitis.

METHODS

Appendiceal diameters were extracted from reports of ultrasound examinations in children and young adults. Data were used to generate a logistic predictive model which was used to define negative, equivocal and positive interpretive categories. Diagnostic performance of the derived 3-category interpretive scheme was compared with simulated binary interpretive schemes.

RESULTS

Six hundred forty-one appendix ultrasound reports were reviewed with appendicitis present in 181 (28.2 %). Cut-off diameters based on the logistic predictive model were ≤6 mm = normal, >6 mm-8 mm = equivocal and >8 mm = positive with appendicitis present in 2.6 % (11/428), 64.9 % (72/111) and 96.1 % (98/102) of cases in each group. These cut-offs conferred 97.2 % accuracy with 17.3 % (111/641) of cases considered equivocal. Of the binary cut-offs, a 6 mm cut-off performed best with 91.6 % accuracy. AIC analysis favoured the logistic model over the binary model for prediction of appendicitis.

CONCLUSIONS

A 3-category interpretive scheme based on a logistic predictive model provides higher accuracy in the diagnosis of appendicitis than traditional binary diameter cut-offs. Inclusion of an equivocal interpretive category more accurately reflects the probability distribution of prediction of appendicitis by ultrasound.

KEY POINTS

• Three diameter categories outperform a 6-mm cut-off to diagnose appendicitis • Three categories allow more confident exclusion of appendicitis • Three categories allow more confident diagnosis of appendicitis • Three categories more accurately reflect the probability of appendicitis by ultrasound.

Diagnostic imaging for acute appendicitis: interfacility differences in practice patterns

PURPOSE

To evaluate trends and factors associated with interfacility differences in imaging modality selection in the diagnosis and management of children with suspected acute appendicitis.

METHODS

We conducted a retrospective review of diagnostic imaging selection and outcomes in patients <20 years of age who underwent appendectomy at a single Children's Hospital from June 2008 to June 2013. These results were then compared with those of referring hospitals.

RESULTS

A total of 232 children underwent appendectomy during the study period. Imaging results contributed to diagnostic and management decisions in 95.3 % of cases. CT scan was utilized as first-line imaging in 50 % of cases. CTs were preferentially performed at referring institutions (78 vs. 46 %, p < 0.001). Children were five times more likely to undergo CT at referring institutions (OR = 5.5, CI 3.0-10.2). Adjusting for demographics and Alvarado score, diagnostic imaging choice was independent of patient's clinical status.

CONCLUSION

This study demonstrates that initial presentation to a referring hospital independently predicts the use of CT scan for suspected acute appendicitis. Further efforts should be undertaken to develop a clinical pathway that minimizes radiation exposure in the diagnosis of acute appendicitis, with focus on access to pediatric abdominal ultrasound.

Diagnostic accuracy of emergency physician performed graded compression ultrasound study in acute appendicitis: a prospective study

PURPOSE

Accurate early diagnosis of appendicitis can decrease its complications and minimize the mortality, morbidity and costs. This prospective study evaluates the accuracy of bedside emergency physician performed ultrasound study diagnosis in acute appendicitis.

METHODS

Patients who were suspicious to have appendicitis based on their clinical findings were included and underwent emergency physician performed ultrasound study. Then they were followed up until the recognition of final diagnosis based on pathology report or identification of an alternative diagnosis. Ultrasound studies were done by post-graduate year three emergency medicine residents or emergency medicine attending physicians who were attended in a 4 h didactic and practical course and with 7.5 MHz linear probe both in longitudinal and axial axes.

RESULTS

Ninety-seven patients were included and analyzed. 27 (27.8 %) of patients had appendicitis according to the results of emergency physicians performed ultrasound studies. 19 (70.37 %) of them had appendicitis according to their pathologic reports too. Forty-three (44.3 %) of patients had appendicitis according to pathology reports. Only 19 (44.18 %) of them were diagnosed by emergency physicians. Emergency physician performed ultrasound study had a sensitivity of 44.18 %, specificity of 85.18 %, positive predictive value of 70.37 %, negative predictive value of 65.71 % and overall accuracy of 67.01 % in diagnosing appendicitis in patients clinically suspicious to have acute appendicitis.

CONCLUSION

Emergency physician performed bedside ultrasound has an acceptable overall accuracy but its sensitivity is low thus it can help emergency physicians to diagnose the acute appendicitis when used in conjunction with other clinical and para-clinical evaluations but not per se.

False-negative appendicitis at ultrasound: nature and association

The objective was to describe nature and factors associated with false-negative ultrasound (US) for adult appendicitis. Patients with pathologically proven appendicitis and pre-operative US from January 2011 to May 2013 were included in this retrospective case-control study. They were divided into true-positive and false-negative groups, matched by age and gender. There were 112 patients (40 men, mean age = 40 y, 56 true positives) included. Two factors were found differ significantly: abdominal wall thickness and pain score. Greater abdominal wall thickness (18.6 mm vs. 14.9 mm, p = 0.001) and lower pain score (6.6 vs. 7.5, p = 0.018) were statistically associated with false negativity. The two groups did not differ significantly in terms of weight, height, body mass index, symptom duration, Alvarado score, US examination time, appendix position/size, perforation rate and operator. In conclusion, lower pain score and increased abdominal wall thickness are associated with false negativity in US examinations.

Evaluation of acute appendicitis by pediatric emergency physician sonography

STUDY OBJECTIVE

We investigate the accuracy of pediatric emergency physician sonography for acute appendicitis in children.

METHODS

We prospectively enrolled children requiring surgical or radiology consultation for suspected acute appendicitis at an urban pediatric emergency department. Pediatric emergency physicians performed focused right lower-quadrant sonography after didactics and hands-on training with a structured scanning algorithm, including the graded-compression technique. We compared their sonographic interpretations with clinical and radiologic findings, as well as clinical outcomes as defined by follow-up or pathologic findings.

RESULTS

Thirteen pediatric emergency medicine sonographers performed 264 ultrasonographic studies, including 85 (32%) in children with pathology-verified appendicitis. Bedside sonography had a sensitivity of 85% (95% confidence interval [CI] 75% to 95%), specificity of 93% (95% CI 85% to 100%), positive likelihood ratio of 11.7 (95% CI 6.9 to 20), and negative likelihood ratio of 0.17 (95% CI 0.1 to 0.28).

CONCLUSION

With focused ultrasonographic training, pediatric emergency physicians can diagnose acute appendicitis with substantial accuracy.

Ultrasound assessment of acute appendicitis in paediatric patients: methodology and pictorial overview of findings seen

Acute appendicitis is a common surgical emergency in the paediatric population. Computed tomography (CT) has been shown to have high accuracy and low operator dependence in the diagnosis of appendicitis. However, with increased concerns regarding CT usage in children, ultrasound (US) is the imaging modality of choice in patients where appendicitis is suspected. This review describes and illustrates the step-wise graded-compression technique for the visualisation of the appendix, the normal and pathological appearances of the appendix, as well as the imaging characteristics of the common differentials.

• A step-wise technique improves the chances of visualisation of the appendix.

• There are often several causes for the non-visualisation of the appendix in children.

• A pathological appendix has characteristic US signs, with several secondary features also identified.

• There are multiple common differentials to consider in the paediatric patient.

Appendix not seen: the predictive value of secondary inflammatory sonographic signs

BACKGROUND

Acute appendicitis is the most prevalent emergency surgical diagnosis in children. Although traditionally a clinical diagnosis, the diagnosis of acute appendicitis is uncertain in approximately 30% of pediatric patients. In attempts to avoid a misdiagnosis and facilitate earlier definitive care, imaging modalities such as ultrasonography have become important tools. In many pediatric studies, the absence of a visualized appendix with no secondary sonographic features has been reported as a negative study result, and a study where the appendix is not seen but demonstrates secondary features is often deemed equivocal. With ultrasound appendiceal detection rates reported at 60% to 89%, the dilemma of the nonvisualized appendix or equivocal study is frequently faced by clinicians.

OBJECTIVE

This study aimed to assess the value of the nonvisualized appendix on ultrasound and the association of secondary sonographic findings in pediatric patients with acute right lower quadrant pain undergoing ultrasound, in whom acute appendicitis was a diagnostic consideration.

METHODS

Retrospective case review of 662 consecutive children (age < 18 years) presenting to a pediatric emergency department with clinically suspected appendicitis, who had graded compression sonographic studies during the 24-month study period, was performed.

RESULTS

The appendix could not be visualized in 241 studies (37.7%). An alternate diagnosis was identified via sonography in 47 patients (19.5%). Twenty-five patients (12.9%) were taken for surgery where 17 (8.8%) had acute appendicitis confirmed via pathology. The specificity of moderate-to-large amounts of free fluid is 98%, phlegmon at 100%, pericecal inflammatory fat changes at 98%, and any free fluids with prominent lymph nodes at 81%. The odds ratio of appendicitis increases from 0.56 to 0.64 to 2.3 and 17.5, respectively, when there were 2 and 3 ultrasonographic inflammatory markers identified.

CONCLUSIONS

Although uncommonly seen, large amounts of free fluid, phlegmon, and pericecal inflammatory fat changes were very specific signs of acute appendicitis. In the absence of a distinctly visualized appendix, the presence of multiple secondary inflammatory changes provides increasing support of a diagnosis of acute appendicitis.

Reevaluating the sonographic criteria for acute appendicitis in children: a review of the literature and a retrospective analysis of 246 cases

RATIONALE AND OBJECTIVES

There has been little rigorous evaluation of the sonographic criteria for acute appendicitis in children. Our clinical experience has called the traditional diagnostic criteria into question. We set out to review the literature, evaluate the most commonly applied diagnostic criteria for acute appendicitis, and identify those criteria that best predict the presence of disease.

MATERIALS AND METHODS

A critical review of the literature concerning the sonographic diagnosis of acute appendicitis was performed. Based on diagnostic criteria identified in that review, two independent, blinded pediatric radiologists retrospectively reviewed 246 right lower quadrant ultrasound examinations in which the appendix was identified with attention to commonly described diagnostic criteria for acute appendicitis. Multivariate and classification and regression tree analysis were performed to identify criteria that predict appendicitis.

RESULTS

In a multivariate analysis, inflammation of the periappendiceal fat is the only finding that statistically significantly predicts acute appendicitis (OR = 68.93, P < .0001). Other criteria such as diameter, noncompressibility, hyperemia, the presence of an appendicolith, and loss of stratification of the appendiceal wall do not independently predict appendicitis.

CONCLUSION

Periappendiceal fat infiltration is the most important diagnostic criterion for acute appendicitis in children. Strict application of other criteria such as diameter should be avoided.

A critical evaluation of US for the diagnosis of pediatric acute appendicitis in a real-life setting: how can we improve the diagnostic value of sonography?

BACKGROUND

We have observed that day-to-day use of US for acute appendicitis does not perform as well as described in the literature.

OBJECTIVE

Review the diagnostic performance of US in acute appendicitis with attention to factors that influence performance.

MATERIALS AND METHODS

Retrospective review of all sonograms for acute appendicitis in children from May 2005 to May 2010 with attention to the rate of identification of the appendix, training of personnel involved and diagnostic accuracy.

RESULTS

The appendix was identified in 246/1,009 cases (24.4%), with identification increasing over time. The accuracy of US was 85-91% with 35 false-positives and 54 false-negatives. Pediatric sonographers were significantly better at identifying the appendix than non-pediatric sonographers (P < 0.0001). Increased weight was the only patient factor that influenced identification of the appendix (P = 0.006). CT use was stable over the 5 years but declined in cases where the appendix was identified by US.

CONCLUSION

In day-to-day use, US does not perform as purported in the literature. We do not visualize the appendix as often as we should and false-negative and false-positive exams are too common. To improve the diagnostic performance of this modality, involvement by experienced personnel and/or additional training is needed.

Single-port appendectomy in obese children: an optimal alternative?

INTRODUCTION

The aim of this study was to evaluate our experience with single-port appendectomy (SPA) in obese children.

METHODS

From January 2003 to June 2009, 94 SPA (65 women and 29 men, mean age of 12.4 years) were performed in children with appendicitis. Sixty-five of these patients were found to have normal weight, whereas 29 were obese. Patients' records were evaluated regarding operative time, intra- and post-operative complications, initiation of oral intake and histopathological findings.

RESULTS

There was no significant difference in operative time between obese and normal weight patients. In the obese group, one wound healing disturbance was documented. In the normal weight group, there were one post-operative bleeding and one wound infection. There was no difference with regards to the introduction of feeds following appendectomy between the groups. Histological examinations revealed 15 normal, 32 acute, 21 phlegmonous, 20 chronic and two perforated cases of appendicitis, three neurogenic appendicopathies and one case of enterobius vermicularis related appendicitis.

CONCLUSIONS

Our results indicate that the advantages of single-port appendectomy in the evaluation of the peritoneal cavity, the minimal rate of intra-operative incidents with this technique and superior cosmetics validate this alternative approach of minimal access appendectomy in obese children.

Incidence and significance of inconclusive results in ultrasound for appendicitis in children and teenagers

PURPOSE

Frustratingly, sonography to assess for appendicitis in children often leads to an inconclusive report (eg, "suspicious for appendicitis") or nonvisualization of the appendix. To aid in planning who to image and how to interpret the results, we investigated whether these 2 results were more frequent in teenagers than preteens and the prevalence of appendicitis associated with each result.

METHODS

We retrospectively reviewed sonographic and surgical findings in patients <18 years (n = 189) referred with clinical suspicion of appendicitis over a 12-month period. Children (≤12.0 years old; n = 86) and teens (>12.0 years old; n = 103) were compared.

RESULTS

Prevalence of appendicitis was 34% in each group, similar to other centres; 0% for those with negative ultrasound reports (0/35), 10% for nonvisualized appendix (8/84), 68% for inconclusive report (15/22), and 85% for positive ultrasound (41/48). Teens were significantly more likely to have an inconclusive ultrasound. Inconclusive reports were because of borderline findings (eg, appendix size near 6 mm; 9/22), body habitus, bowel gas, or unusual findings due in retrospect to perforation. The rate of nonvisualization of the appendix did not vary significantly with age (42% vs 47%).

CONCLUSION

An inconclusive result of ultrasound for appendicitis was significantly more frequent in teens than in preteens and carried a high (68%) likelihood of appendicitis. Conversely, a nonvisualized appendix was equally frequent in teens and preteens, and had a low likelihood of appendicitis (only 10% positive). These findings encourage the use of ultrasound in preteens in particular and can assist interpretation of these common results.

US examination of the appendix in children with suspected appendicitis: the additional value of secondary signs

This study evaluated the additional value of secondary signs in the diagnosing of appendicitis in children with ultrasound. From May 2005 to June 2006, 212 consecutive paediatric patients with suspected appendicitis were examined. Ultrasonographic depiction of the appendix was classified into four groups: 1, normal appendix; 2, appendix not depicted, no secondary signs of appendicitis; 3, appendix not depicted with one of the following secondary signs: hyperechoic mesenteric fat, fluid collection, local dilated small bowel loop; 4, depiction of inflamed appendix. We classified 96 patients in group 1, 41 in group 2, 13 in group 3, and 62 in group 4. Prevalence of appendicitis was 71/212 (34%). Negative predictive values of groups 1 and 2 were 99% and 100%, respectively. Positive predictive values of groups 3 and 4 were 85% and 95%, respectively. In groups 3 and 4, hyperechoic mesenteric fat was seen in 73/75 (97.3%), fluid collections and dilated bowel loops were seen in 12/75 (16.0%) and 5/75 (6.6%), respectively. This study shows that in case of non-visualization of the appendix without secondary signs, appendicitis can be safely ruled out. Furthermore, secondary signs of appendicitis alone are a strong indicator of acute appendicitis.

Prospective evaluation of emergency physician performed bedside ultrasound to detect acute appendicitis

OBJECTIVES

To evaluate the accuracy of emergency physicians using bedside ultrasound to detect appendicitis (BUSA).

METHODS

Patients presenting to the emergency department with a clinical suspicion of appendicitis were prospectively enrolled and received a 5-min BUSA. Patients received routine work-up for acute appendicitis as deemed appropriate by the attending physician. Radiologists and consulting surgeons were blinded to BUSA results. The criterion standard for the presence or absence of acute appendicitis was the pathology report for patients who received appendectomies, and telephone follow-up for patients discharged home without surgical intervention.

RESULTS

A total of 132 patients were enrolled. In 44 cases BUSA was positive. Of these, 37 had surgical pathology reports consistent with acute appendicitis, whereas seven did not have appendicitis. In 82 cases, BUSA was negative. Of these, 62 were determined not to have appendicitis, whereas 20 had appendicitis by pathology. Sensitivity for BUSA was 65% [95% confidence interval (CI) 52-76], specificity was 90% (95% CI 81-95), positive predictive value was 84% (95% CI 71-92), and negative predictive value was 76% (95% CI 65-84). The likelihood ratio of a positive BUSA was 6.4 (95% CI 3.1-13.2). Five patients discharged home with a diagnosis other than appendicitis were unable to be reached by telephone, and were excluded from data analysis.

CONCLUSION

Our study gives insufficient evidence to support the use of bedside ultrasound by emergency physicians to rule out appendicitis. The high specificity in our study, however, suggests that with further training, BUSA may be useful to rule-in appendicitis in some patients.

US or CT for Diagnosis of Appendicitis in Children and Adults? A Meta-Analysis

PURPOSE

To perform a meta-analysis to evaluate the diagnostic performance of ultrasonography (US) and computed tomography (CT) for the diagnosis of appendicitis in pediatric and adult populations.

MATERIALS AND METHODS

Medical literature (from 1986 to 2004) was searched for articles on studies that used US, CT, or both as diagnostic tests for appendicitis in children (26 studies, 9356 patients) or adults (31 studies, 4341 patients). Prospective and retrospective studies were included if they separately reported the rate of true-positive, true-negative, false-positive, and false-negative diagnoses of appendicitis from US and CT findings compared with the positive and negative rates of appendicitis at surgery or follow-up. Clinical variables, technical factors, and test performance were extracted. Three readers assessed the quality of studies.

RESULTS

Pooled sensitivity and specificity for diagnosis of appendicitis in children were 88% (95% confidence interval [CI]: 86%, 90%) and 94% (95% CI: 92%, 95%), respectively, for US studies and 94% (95% CI: 92%, 97%) and 95% (95% CI: 94%, 97%), respectively, for CT studies. Pooled sensitivity and specificity for diagnosis in adults were 83% (95% CI: 78%, 87%) and 93% (95% CI: 90%, 96%), respectively, for US studies and 94% (95% CI: 92%, 95%) and 94% (95% CI: 94%, 96%), respectively, for CT studies.

CONCLUSION

From the diagnostic performance perspective, CT had a significantly higher sensitivity than did US in studies of children and adults; from the safety perspective, however, one should consider the radiation associated with CT, especially in children.

The AIDS patient with abdominal pain: a new challenge for the emergency physician

As the prevalence of HIV infection continues to increase, EPs will be called upon to evaluate increasing numbers of AIDS patients who have abdominal pain, some of whom will require emergent surgical intervention. In addition to the myriad causes of abdominal pain in the nonimmunocompromised patient, the differential diagnosis in the AIDS patient includes a wide variety of opportunistic infections and neoplasms (Table 5). Evaluation frequently requires extensive laboratory studies and cultures and advanced imaging (CT, ultrasound, and so forth). A low threshold for surgical and other subspecialty consultation should be in place because of the often subtle presentation of surgical emergencies in AIDS patients.