Clinical correlation needed: what do emergency physicians do after an equivocal ultrasound for pediatric acute appendicitis?

Clinical course in children with equivocal appendicitis on computed tomography: a retrospective cohort study

Purpose

Appendectomy is one of the most common surgeries in children. Although various radiological examinations are performed, they do not always reveal a definitive diagnosis of appendicitis. This study aimed to investigate the clinical course of equivocal appendicitis, identify the factors associated with appendectomy, and suggest appropriate management for these patients.

Methods

Patients younger than 19 years who visited Seoul National University Bundang Hospital with a differential diagnosis of appendicitis from January 2013 to December 2017 were included. All participants conducted 'appendiceal CT' with a scoring scale of 1-5. The higher the score, the higher the likelihood of a radiologic diagnosis of appendicitis. We defined the appendicitis CT score of 2-4 as equivocal appendicitis (n = 143). Medical records were reviewed retrospectively for demographics, further examination as abdominal ultrasonography, and appendectomy status (yes or no). The mean follow-up period was 15.6 ± 71 days.

Results

Equivocal appendicitis accounted for 16.7%. Additional ultrasonography test was performed in 24.5% (35 of 143). In total, 34 patients (23.8%) underwent appendectomy. Among the patients with appendiceal CT scores 2, 3, and 4, 4.9%, 50.0%, and 87.5% underwent appendectomy, respectively. Higher WBC count, higher appendicitis CT score, and readmission were significantly associated with appendectomy in patients with equivocal appendicitis.

Conclusion

Higher appendicitis CT score and WBC level were positively associated with appendectomy. Careful observation can be a treatment option in appendicitis CT score 2 or 3 groups. Appendectomy is the first-line treatment for patients with appendicitis score 4. Additional ultrasonography test is advisable to determine treatment modality for equivocal appendicitis.

Re-Assessment in Patients with Suspected Acute Appendicitis

Background: The effect of diagnosing appendicitis at re-assessment on post-operative outcomes is not clear. This study aims to compare patients diagnosed with appendicitis at initial presentation versus patients who were diagnosed at re-assessment. Patients and Methods: Data from the Dutch SNAPSHOT appendicitis collaborative was used. Patients with appendicitis who underwent appendectomy were included. Effects of diagnosis at re-assessment were compared with diagnosis at initial presentation. Primary outcomes were the proportion of patients with complicated appendicitis and the post-operative complication rate. Results: Of 1,832 patients, 245 (13.4%) were diagnosed at re-assessment. Re-assessed patients had a post-operative complication rate comparable to those diagnosed with appendicitis at initial presentation (15.1% vs. 12.7%; p = 0.29) and no substantial difference was found in the proportion of patients with complicated appendicitis (27.9% vs. 33.5%; p = 0.07). For patients with complicated appendicitis, more post-operative complications were seen if diagnosed at re-assessment than if diagnosed initially (38.2% vs. 22.9%; p = 0.006). Conclusions: For patients in whom appendicitis was not diagnosed at first presentation, but at re-assessment, both the proportion of complicated appendicitis and the post-operative complication rate were comparable to those who were diagnosed with appendicitis at initial presentation. However, re-assessed patients with complicated appendicitis encountered more post-operative complications.

ACR Appropriateness Criteria® Suspected Appendicitis-Child

Acute appendicitis represents the most common abdominal surgical urgency/emergency in children. Imaging remains a central tool in the diagnosis of acute appendicitis and has been shown to facilitate management and decrease the rate of negative appendectomies. The initial consideration for imaging in a child with suspected acute appendicitis is based on clinical assessment, which can be facilitated with published scoring systems. The level of clinical risk (low, intermediate, high) and the clinical scenario (suspicion for complication) define the need for imaging and the optimal imaging modality. In some situations, no imaging is required, while in others ultrasound, CT, or MRI may be appropriate. This review frames the presentation of suspected acute appendicitis in terms of the clinical risk and also discusses the unique situations of the equivocal or nondiagnostic initial ultrasound examination and suspected appendicitis with suspicion for complication (eg, bowel obstruction). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Accuracy of ultrasound exam performed by emergency medicine versus radiology residents in the diagnosis of acute appendicitis

BACKGROUND

Although the traditional approach to the diagnosis of acute appendicitis (AA) is using clinical methods, experience has shown that strict reliance on clinical data can lead to mismanagement or unnecessary surgery.

OBJECTIVE

The objective of this study was to determine the total agreement of ultrasound (US) results in AA performed by emergency medicine (EM) versus radiology residents in emergency department.

PATIENTS AND METHODS

In this cross-sectional study, 121 patients with AA suspicion underwent an US exam by both trained EM and radiology residents in emergency department. The training course for EM residents consisted of attending an 8-h-workshop and then practicing an US exam on real patients within a 2-month period. The gold standards were either histopathologic or follow-up results. Total agreement of the results in both specialties was compared.

RESULTS

There were 67 men and 54 women, with a mean age of 33.6 ± 16.1 years (18.2-88.7 years). Fifty-four (44.6%) patients underwent surgery with the initial diagnosis of AA and the rest were evaluated by follow-ups. On the basis of our gold standards, the diagnosis was finally confirmed in 46 (38%) cases. There was a high total agreement in AA diagnosis [96% agreement, κ = 0.90; 95% confidence interval (CI) = 0.81-0.99] between the two groups. The specificity and sensitivity of EM and radiology groups were 99% (95% CI = 93-100), 63% (95% CI = 48-77), 97% (95% CI = 91-100), and 72% (95% CI = 57-84), respectively.

CONCLUSION

US has a high diagnostic specificity in patients suspected of having AA and EM residents can perform this modality as accurately as radiologists after training in the emergency setting.

Falling through the worm hole: an exploration of the imaging workup of the vermiform appendix in the pediatric population

Despite the thousands of articles discussing appendicitis in the literature, the dilemma of how to best diagnosis and manage pediatric appendicitis remains unsettled. Over the past decade, evidence has been mounting about the use of antibiotics as the sole therapy in uncomplicated appendicitis in the adult population. This debate has even recently bled over into the lay press. While this change in practice pattern is still in its infancy for the pediatric population, radiologists should be aware of this change in therapy and how it can impact the imaging work-up and relevant findings. This article concisely summarizes the imaging findings and various imaging pathways to arrive at the diagnose of appendicitis with an emphasis of how to best be of use to our surgical colleagues in this evolving paradigm. It also highlights venues for further research, namely increasing accuracy of differentiating complicated from uncomplicated appendicitis.

Cytokines and Chemokines in Pediatric Appendicitis: A Multiplex Analysis of Inflammatory Protein Mediators

OBJECTIVES

We aimed to demonstrate the potential of precision medicine to describe the inflammatory landscape present in children with suspected appendicitis. Our primary objective was to determine levels of seven inflammatory protein mediators previously associated with intra-abdominal inflammation (C-reactive protein-CRP, procalcitonin-PCT, interleukin-6 (IL), IL-8, IL-10, monocyte chemoattractant protein-1-MCP-1, and serum amyloid A-SAA) in a cohort of children with suspected appendicitis. Subsequently, using a multiplex proteomics approach, we examined an expansive array of novel candidate cytokine and chemokines within this population.

METHODS

We performed a secondary analysis of targeted proteomics data from Alberta Sepsis Network studies. Plasma mediator levels, analyzed by Luminex multiplex assays, were evaluated in children aged 5-17 years with nonappendicitis abdominal pain (NAAP), acute appendicitis (AA), and nonappendicitis sepsis (NAS). We used multivariate regression analysis to evaluate the seven target proteins, followed by decision tree and heat mapping analyses for all proteins evaluated.

RESULTS

185 children were included: 83 with NAAP, 79 AA, and 23 NAS. Plasma levels of IL-6, CRP, MCP-1, PCT, and SAA were significantly different in children with AA compared to those with NAAP (p < 0.001). Expansive proteomic analysis demonstrated 6 patterns in inflammatory mediator profiles based on severity of illness. A decision tree incorporating the proteins CRP, ferritin, SAA, regulated on activation normal T-cell expressed and secreted (RANTES), monokine induced by gamma interferon (MIG), and PCT demonstrated excellent specificity (0.920) and negative predictive value (0.882) for children with appendicitis.

CONCLUSIONS

Multiplex proteomic analyses described the inflammatory landscape of children presenting to the ED with suspected appendicitis. We have demonstrated the feasibility of this approach to identify potential novel candidate cytokines/chemokine patterns associated with a specific illness (appendicitis) amongst those with a broad ED presentation (abdominal pain). This approach can be modelled for future research initiatives in pediatric emergency medicine.

Diagnostic performance of emergency physician-performed point-of-care ultrasonography for acute appendicitis: A meta-analysis

OBJECTIVE

To assess the sensitivity and specificity of emergency physician-performed point-of-care ultrasonography (EP-POCUS) for diagnosing acute appendicitis (AA).

MATERIAL AND METHODS

The PubMed and EMBASE databases were searched, and the diagnostic performance of EP-POCUS was evaluated using bivariate modeling and hierarchical summary receiver operating characteristic curves. Subgroup analysis was performed for pediatric patients to compare EP-POCUS and radiologist-performed ultrasonography (RADUS). Meta-regression analyses were performed according to patient and study characteristics.

RESULTS

In 17 studies (2385 patients), EP-POCUS for diagnosing AA exhibited a pooled sensitivity of 84% (95% confidence interval [CI]: 72%-92%) and a pooled specificity of 91% (95% CI: 85%-95%), with even better diagnostic performance for pediatric AA (sensitivity: 95%, 95% CI: 75%-99%; specificity: 95%, 95% CI: 85%-98%). A direct comparison revealed no significant differences (p = 0.18-0.85) between the diagnostic performances of EP-POCUS (sensitivity: 81%, 95% CI: 61%-90%; specificity: 89%, 95% CI: 77%-95%) and RADUS (sensitivity: 74%, 95% CI: 65%-81%; specificity: 97%, 95% CI: 93%-98%). The meta-regression analyses revealed that study location, AA proportion, and mean age were sources of heterogeneity. Higher sensitivity and specificity tended to be associated with an appendix diameter cut-off value of 7 mm and the EP as the initial operator.

CONCLUSION

The diagnostic performances of EP-POCUS and RADUS were excellent for AA, with EP-POCUS having even better performance for pediatric AA. Accurate diagnoses may be achieved when the attending EP is the initial POCUS operator and uses a 7-mm cut-off value.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level II, Study of Diagnostic Test.

Predictors and Outcomes of Nondiagnostic Ultrasound for Acute Appendicitis in Children

Ultrasound assessments of children with possible acute appendicitis (AA) are often nondiagnostic. We aimed to identify the predictors of nondiagnostic ultrasound and to investigate the outcomes. A retrospective review was conducted on children aged 4 to 17 years evaluated in 2013 for AAwith ultrasound at a tertiary hospital pediatric emergency department. Demographics, clinical data, and outcomes were analyzed. Of 528 children, 194 (36.7%) had diagnostic ultrasounds and 334 (63.3%) had nondiagnostic ultrasounds. Nondiagnostic ultrasounds were more common after-hours (7 pm–7 am weekdays and on weekends, 70.7%) than during business hours (7 am–7 pm weekdays; 29.3%). After-hours timing and female sex were identified as independent predictors of non-diagnostic ultrasounds (P < 0.05 for both). AA was diagnosed in 35 children with a nondiagnostic ultrasound (10.5%; P < 0.05). No child who underwent a nondiagnostic ultrasound was found to have AA with laboratory values of white blood cell < 11 x 103/μL and c-reactive protein (CRP) < 5 mg/dL. Children with nondiagnostic ultrasounds have a low likelihood of AA if white blood cell < 11 and CRP < 5. We propose a management algorithm that we hope will help reduce admissions and decrease the use of computed tomography scans.

A highly sensitive and specific combined clinical and sonographic score to diagnose appendicitis

BACKGROUND

Computed tomography (CT) scanning reduces the negative appendectomy rate however it exposes the patient to ionizing radiation. Ultrasound (US) does not carry this risk but may be nondiagnostic. We hypothesized that a clinical-US scoring system would improve diagnostic accuracy.

METHODS

We conducted a retrospective review of all patients (age, >15 years) who presented through the emergency department with suspected appendicitis and underwent initial US. A US score was developed using odds ratios for appendicitis given appendiceal diameter, compressibility, hyperemia, free fluid, and focal or diffuse tenderness. The US score was then combined with the Alvarado score. Final diagnosis of appendicitis was assigned by pathology reports.

RESULTS

Three hundred patients who underwent US as initial imaging were identified. Thirty-two patients with evident nonappendiceal pathology on US were excluded. In 114 (38%), the appendix was not visualized and partially visualized in 36 (12%). Fifty-seven (21.3%) had an appendectomy with 1 (1.7%) negative. Six nonvisualized appendicies underwent appendectomy, with no negative cases. Sensitivity and specificity for the sonographic score were 86% and 90%, respectively, at a score of 1.5. The combined score demonstrated 98% sensitivity and 82% specificity at 6.5, and 95% sensitivity, and 87% specificity at a score of 7.5. Sensitivity and specificity were confirmed by bootstrap resampling for validation. Area under receiver operating characteristic (ROC) curves for our new US score were similar to the ROC curve for the Alvarado score (91.9 and 91.1, p = 0.8). The combined US and Alvarado score yielded an area under the ROC curve of 97.1, significantly better than either score alone (p = 0.017 and p < 0.001, respectively).

CONCLUSION

Our scoring system based entirely on US findings was highly sensitive and specific for appendicitis, and it significantly improved when combined with the Alvarado score. After prospective evaluation, the combined US-Alvarado score might replace the need for computed tomography imaging in a majority of patients.

LEVEL OF EVIDENCE

Diagnostic Test, Level III.

How to diagnose an acutely inflamed appendix; a systematic review of the latest evidence

Acute appendicitis is the most common condition that presents with an acute abdomen needing emergency surgery. Despite this common presentation, correctly diagnosing appendicitis remains a challenge as clinical signs or positive blood results can be absent in 55% of the patients. The reported proportion of missed diagnoses of appendicitis ranges between 20% and 40%. A delay or mis-diagnosis of appendicitis can result in severe complications such as perforation, abscess formation, sepsis, and intra-abdominal adhesions. Literature has shown that patients who had a negative appendectomy suffer post-op complications and infections secondary to hospital stays; there have even been reported cases of fatality. It is therefore crucial that timely and accurate diagnosis of appendicitis is achieved to avoid complications of both non-operating as well as unnecessary surgical intervention. The aim of this review is to systematically report and analyse the latest evidence on the different approaches used in diagnosing appendicitis. We include discussions of clinical scoring systems, laboratory tests, latest innovative bio-markers and radiological imaging.

Imaging Utilization for the Diagnosis of Appendicitis in Stand-Alone Children's Hospitals in the United States: Trends and Costs

OBJECTIVE

To describe the imaging utilization patterns for the diagnosis of appendicitis among children's hospitals in the United States over the last 10 years (2005-2014).

METHODS

All patients with a primary discharge diagnosis of appendicitis included in a large administrative database of 45 pediatric institutions in the United States between 2005 and 2014 were selected. Demographics, imaging utilization, and costs were described.

RESULTS

In all, 96,786 children with appendicitis (59% boys, 41% girls; mean age: 9.9 years) were studied. The average length of stay decreased from 5.0 days in 2005 to 3.4 days in 2014 (P < .01). The percentage of patients undergoing CT increased between 2005 and 2007 from 59.1% to 62.6%, respectively, followed by a decrease from 62.6% to 32.7% in 2014 (r² = 0.93). Radiograph utilization decreased from 14.2% in 2005 to 3.6% in 2014 (r² = 0.93), and ultrasound and MRI increased from 25% and 0.03% in 2005 to 61% and 1.0% in 2014 (r² = 0.97 and 0.64), respectively. The mean total hospital costs increased from $11,700 in 2005 to $16,500 in 2014; imaging costs increased only slightly from $3,205 to $3,259. The imaging fraction of hospital costs decreased from 27.5% to 19.8%.

CONCLUSION

There has been a significant decrease in utilization of CT and radiographs for the management of appendicitis in children, and ultrasound has continued to increase. Imaging costs have remained stable in comparison to rising hospital costs, generating a drop in the fraction of costs related to imaging.

Abdominal ultrasonography of the pediatric gastrointestinal tract

Ultrasound is an invaluable imaging modality in the evaluation of pediatric gastrointestinal pathology; it can provide real-time evaluation of the bowel without the need for sedation or intravenous contrast. Recent improvements in ultrasound technique can be utilized to improve detection of bowel pathology in children: Higher resolution probes, color Doppler, harmonic and panoramic imaging are excellent tools in this setting. Graded compression and cine clips provide dynamic information and oral and intravenous contrast agents aid in detection of bowel wall pathology. Ultrasound of the bowel in children is typically a targeted exam; common indications include evaluation for appendicitis, pyloric stenosis and intussusception. Bowel abnormalities that are detected prenatally can be evaluated after birth with ultrasound. Likewise, acquired conditions such as bowel hematoma, bowel infections and hernias can be detected with ultrasound. Rare bowel neoplasms, vascular disorders and foreign bodies may first be detected with sonography, as well. At some centers, comprehensive exams of the gastrointestinal tract are performed on children with inflammatory bowel disease and celiac disease to evaluate for disease activity or to confirm the diagnosis. The goal of this article is to review up-to-date imaging techniques, normal sonographic anatomy, and characteristic sonographic features of common and uncommon disorders affecting the gastrointestinal tract in children.

Accuracy of Magnetic Resonance Imaging and Ultrasound for Appendicitis in Diagnostic and Nondiagnostic Studies

OBJECTIVES

Suggestive radiographic studies with nonvisualization of the appendix can present a challenge to clinicians in the evaluation of pediatric abdominal pain. The primary objective of this study was to quantify the accuracy of magnetic resonance imaging (MRI) and of ultrasound (US) in the setting of nonvisualization of the appendix. Secondary objectives reported include sensitivity of MRI and US overall and correlation between MRI and US for diagnosis of appendicitis.

METHODS

Records of pediatric emergency department patients aged 3 to 21 years undergoing MRI and/or US for the evaluation of appendicitis were retrospectively reviewed. Radiographs were categorized as a normal appendix, neither demonstrating the appendix nor demonstrating abnormalities consistent with appendicitis; equivocal, not demonstrating the appendix but showing evidence of appendicitis; demonstrating an abnormal appendix consistent with appendicitis; or demonstrating an alternate pathology. The reading was compared with the final diagnosis for accuracy.

RESULTS

Of the 589 patients included, 146 had appendicitis. Diagnostic accuracy for studies with a nonvisualized appendix without secondary signs of appendicitis was 100% for MRI and 91.4% (95% CI = 87.3% to 94.2%) for US. Diagnostic accuracy for studies with a nonvisualized appendix with secondary signs of appendicitis was 50% (95% CI = 2.5% to 97.5%) for MRI and 38.9% (95% CI = 18.2% to 64.5%) for US. Appendicitis was ultimately diagnosed in 8.6% of patients with an otherwise negative right lower quadrant (RLQ) US that failed to directly identify the appendix. There was a moderate correlation between US and MRI (ρ = 0.573, p = 0.0001) when all studies were considered.

CONCLUSIONS

Magnetic resonance imaging without secondary signs of appendicitis is effective in excluding appendicitis regardless of whether the appendix is directly visualized, while otherwise negative RLQ US that fail to identify the appendix are less useful. Secondary signs of appendicitis without visualization of the appendix were not helpful regardless of radiographic modality. Results of MRI and US correlated moderately well.

Ultrasound of paediatric appendicitis and its secondary sonographic signs: providing a more meaningful finding

Sonography is an important clinical tool in diagnosing appendicitis in children as it can obviate both exposure to potentially harmful ionising radiation from computed tomography scans and the need for unnecessary appendicectomies. This review examines the diagnostic accuracy of ultrasound in the identification of acute appendicitis, with a particular focus on the the utility of secondary sonographic signs as an adjunct or corollary to traditionally examined criteria. These secondary signs can be important in cases where the appendix cannot be identified with ultrasound and a more meaningful finding may be made by incorporating the presence or absence of secondary sonographic signs. There is evidence that integrating these secondary signs into the final ultrasound diagnosis can improve the utility of ultrasound in cases where appendicitis is expected, though there remains some conjecture about whether they play a more important role in negative or positive prediction in the absence of an identifiable appendix.

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.

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.

Diagnosing appendicitis: evidence-based review of the diagnostic approach in 2014

Introduction

Acute appendicitis is the most common abdominal emergency requiring emergency surgery. However, the diagnosis is often challenging and the decision to operate, observe or further work-up a patient is often unclear. The utility of clinical scoring systems (namely the Alvarado score), laboratory markers, and the development of novel markers in the diagnosis of appendicitis remains controversial. This article presents an update on the diagnostic approach to appendicitis through an evidence-based review.

Methods

We performed a broad Medline search of radiological imaging, the Alvarado score, common laboratory markers, and novel markers in patients with suspected appendicitis.

Results

Computed tomography (CT) is the most accurate mode of imaging for suspected cases of appendicitis, but the associated increase in radiation exposure is problematic. The Alvarado score is a clinical scoring system that is used to predict the likelihood of appendicitis based on signs, symptoms and laboratory data. It can help risk stratify patients with suspected appendicitis and potentially decrease the use of CT imaging in patients with certain Alvarado scores. White blood cell (WBC), C-reactive protein (CRP), granulocyte count and proportion of polymorphonuclear (PMN) cells are frequently elevated in patients with appendicitis, but are insufficient on their own as a diagnostic modality. When multiple markers are used in combination their diagnostic utility is greatly increased. Several novel markers have been proposed to aid in the diagnosis of appendicitis; however, while promising, most are only in the preliminary stages of being studied.

Conclusion

While CT is the most accurate mode of imaging in suspected appendicitis, the accompanying radiation is a concern. Ultrasound may help in the diagnosis while decreasing the need for CT in certain circumstances. The Alvarado Score has good diagnostic utility at specific cutoff points. Laboratory markers have very limited diagnostic utility on their own but show promise when used in combination. Further studies are warranted for laboratory markers in combination and to validate potential novel markers.