Alvarado score: a guide to computed tomography utilization in appendicitis

Validation of the modified Alvarado score on patients attending A&E units with suspected appendicitis

INTRODUCTION

The aim of our prospective study was to confirm validity and diagnostic accuracy of the modified Alvarado score, which was developed at the Department of Surgery, University of Szeged, on patients presenting with symptoms suggestive of acute appendicitis (right lower quadrant complaints) at the A&E department.

PATIENT POPULATION, METHODS

138 patients were included in our study between 01.01.2019 and 01.01.2020. For patients attending A&E, the first medic calculated and recorded the modified Alvarado score before surgical consultation. The consulting surgeon decided on further treatment without knowing the score. Validation of the score was based on the pathology report of the removed appendix (whether the operation was warranted, and if the score also supported indication for surgery), if there was readmission or surgery due to worsening symptoms after discharge from A&E. We also examined if there was any connection between the value of the Alvarado score and the severity of inflammation. Our aim was to prove that using modified Alvarado score at the A&E Units helps to reduce patient's waiting time and avoid unnecessary surgical consultations. Furthermore our study included measuring the diagnostic accuracy of the ultrasound examination (specificity, sensitivity).

RESULTS

Based on the results, patients presenting at A&E had a mean modified Alvarado score of 6.5. Comparing the score to histological results showed that the specificity of the modified Alvarado score was 100%, and its sensitivity was 80.7%. Based on Spearman's rank correlation (0.796) and ROC analysis (AUC 0.968), the modified Alvarado score has an excellent predictive value in diagnosing acute appendicitis. When comparing the patients' waiting times with the use of modified Alvarado score and without it we found that there was a significant difference in group also in group under 4 points and in group over 7 points when using modified Alvarado score, so the diagnostic and therapeutic algorithm should be much quicker with the help of the score. We found a correlation between the severity of inflammation based on the Fisher's exact test. Rank correlation of the same question also showed a significant connection. All patients had an US examination during their diagnostic course, its sensitivity was 82.6%, specificity was 87%. Based on this, we can conclude that the predictive value of the imaging method is good.

CONCLUSIONS

We can conclude according to our results that the predictive value of the modified score is excellent, and it can be safely applied by non-surgeons in urgent care in the differential diagnosis of acute appendicitis. The new score incorporates the results of an easily obtainable, ionising radiation free imaging method, the ultrasound, which was not included in previous scores. With the help of the new score, the number of unnecessary surgical referrals and waiting times for patients are reduced, excess examinations will become avoidable.

Correlation of clinical decision-making with probability of disease: A web-based study among general practitioners

BACKGROUND

Medical decision-making relies partly on the probability of disease. Current recommendations for the management of common diseases are based increasingly on scores that use arbitrary probability thresholds.

OBJECTIVE

To assess decision-making in pharyngitis and appendicitis using a set of clinical vignettes, and the extent to which management is congruent with the true probability of having the disease.

DESIGN

We developed twenty-four clinical vignettes with clinical presentations corresponding to specific probabilities of having disease defined by McIsaac (pharyngitis) or Alvarado (appendicitis) scores. Each participant answered four randomly selected web-based vignettes.

PARTICIPANTS

General practitioners (GP) working in primary care structures in Switzerland and the USA.

MAIN MEASURES

A comparison between the GP's management decision according to the true probability of having the disease and to the GP's estimated probability, investigating the GP's ability to estimate probability of disease.

KEY RESULTS

The mean age of the GPs was 48 years (SD 12) and 66% were men. The correlation between the GP's clinical management decision based on the vignette and the recommendations was stronger for appendicitis than pharyngitis (kw = 0.74, 95% CI 0.70-0.78 vs. kw = 0.66, 95% CI 0.62-0.71). On the other hand, the association between the clinical management decision and the probability of disease estimated by GPs was more congruent with recommendations for pharyngitis than appendicitis (kw = 0.70, 95% CI 0.66-0.73 vs. 0.61, 95% CI 0.56-0.66). Only a minority of GPs correctly estimated the probability of disease (29% for appendicitis and 39% for pharyngitis).

CONCLUSIONS

Despite the fact that general practitioners often misestimate the probability of disease, their management decisions are usually in line with recommendations. This means that they use other approaches, perhaps more subjective, to make decisions, such as clinical judgment or reasoning that integrate factors other than just the risk of the disease.

Which appendicitis scoring system is most suitable for pregnant patients? A comparison of nine different systems

BACKGROUND

Acute appendicitis is the most common non-gynecological emergency during pregnancy. The diagnosis of appendicitis during pregnancy is challenging due to changes in both physiological and laboratory variables. Guidelines suggest patients with suspected acute appendicitis should be stratified based on clinical scoring systems, to optimize the use of diagnostic imaging and prevent unnecessary surgery. Surgeons require additional information beyond that provided by imaging studies before deciding upon exploratory laparoscopy in patients with a high suspicion of appendicitis. Various scoring methods have been evaluated for the diagnosis of acute appendicitis. However, there is no consensus on a method to use during pregnancy, and a detailed comparison of existing scoring methods for this purpose has not yet been conducted. The purpose of this study was to evaluate the efficacy of the most popular scoring systems applied to diagnose acute appendicitis during pregnancy.

METHODS

This single-center retrospective study included 79 pregnant patients who were admitted to the emergency department with abdominal pain between May 2014 and May 2019. The patients were diagnosed with acute appendicitis and underwent an appendectomy. As a control group, the study also included 79 non-pregnant patients who underwent appendectomy within the last 1.5 years. To ensure that the groups were similar, women in the case group were stratified according to age, and the proportions of women in the strata were determined. The women in the control group were similarly stratified. Women were randomly selected from the strata to prevent bias. Both laboratory and examination findings required for each scoring method were obtained and assessed separately for each patient. Negative appendectomy rates were evaluated according to pathology results. Categorical variables were compared using the chi-square test. A p value < 0.05 was considered to indicate significance. Receiver operator characteristic curve analysis was used to identify the best threshold value and to assess the performance of the test scores in terms of diagnosing appendicitis.

RESULTS

Among all scoring systems, the Tzanakis score was most efficacious at predicting appendicitis in non-pregnant women. The positive predictive value (PPV) of the Tzanakis score was 90.6%, whereas the negative predictive value (NPV) was 46.7%. The RIPASA score performed the best among the scoring systems in pregnant women. It was associated with a PPV of 94.40%, NPV of 44%, and sensitivity and specificity of 78.46% and 78.57%, respectively.

CONCLUSION

Although the RIPASA score can be used to efficaciously diagnose acute appendicitis in pregnant women, a specific scoring system is needed for diagnosis during the gestation period.

Computed tomography for diagnosis of acute appendicitis in adults

BACKGROUND

Diagnosing acute appendicitis (appendicitis) based on clinical evaluation, blood testing, and urinalysis can be difficult. Therefore, in persons with suspected appendicitis, abdominopelvic computed tomography (CT) is often used as an add-on test following the initial evaluation to reduce remaining diagnostic uncertainty. The aim of using CT is to assist the clinician in discriminating between persons who need surgery with appendicectomy and persons who do not.

OBJECTIVES

Primary objective Our primary objective was to evaluate the accuracy of CT for diagnosing appendicitis in adults with suspected appendicitis. Secondary objectives Our secondary objectives were to compare the accuracy of contrast-enhanced versus non-contrast-enhanced CT, to compare the accuracy of low-dose versus standard-dose CT, and to explore the influence of CT-scanner generation, radiologist experience, degree of clinical suspicion of appendicitis, and aspects of methodological quality on diagnostic accuracy.

SEARCH METHODS

We searched MEDLINE, Embase, and Science Citation Index until 16 June 2017. We also searched references lists. We did not exclude studies on the basis of language or publication status.

SELECTION CRITERIA

We included prospective studies that compared results of CT versus outcomes of a reference standard in adults (> 14 years of age) with suspected appendicitis. We excluded studies recruiting only pregnant women; studies in persons with abdominal pain at any location and with no particular suspicion of appendicitis; studies in which all participants had undergone ultrasonography (US) before CT and the decision to perform CT depended on the US outcome; studies using a case-control design; studies with fewer than 10 participants; and studies that did not report the numbers of true-positives, false-positives, false-negatives, and true-negatives. Two review authors independently screened and selected studies for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently collected the data from each study and evaluated methodological quality according to the Quality Assessment of Studies of Diagnostic Accuracy - Revised (QUADAS-2) tool. We used the bivariate random-effects model to obtain summary estimates of sensitivity and specificity.

MAIN RESULTS

We identified 64 studies including 71 separate study populations with a total of 10,280 participants (4583 with and 5697 without acute appendicitis). Estimates of sensitivity ranged from 0.72 to 1.0 and estimates of specificity ranged from 0.5 to 1.0 across the 71 study populations. Summary sensitivity was 0.95 (95% confidence interval (CI) 0.93 to 0.96), and summary specificity was 0.94 (95% CI 0.92 to 0.95). At the median prevalence of appendicitis (0.43), the probability of having appendicitis following a positive CT result was 0.92 (95% CI 0.90 to 0.94), and the probability of having appendicitis following a negative CT result was 0.04 (95% CI 0.03 to 0.05). In subgroup analyses according to contrast enhancement, summary sensitivity was higher for CT with intravenous contrast (0.96, 95% CI 0.92 to 0.98), CT with rectal contrast (0.97, 95% CI 0.93 to 0.99), and CT with intravenous and oral contrast enhancement (0.96, 95% CI 0.93 to 0.98) than for unenhanced CT (0.91, 95% CI 0.87 to 0.93). Summary sensitivity of CT with oral contrast enhancement (0.89, 95% CI 0.81 to 0.94) and unenhanced CT was similar. Results show practically no differences in summary specificity, which varied from 0.93 (95% CI 0.90 to 0.95) to 0.95 (95% CI 0.90 to 0.98) between subgroups. Summary sensitivity for low-dose CT (0.94, 95% 0.90 to 0.97) was similar to summary sensitivity for standard-dose or unspecified-dose CT (0.95, 95% 0.93 to 0.96); summary specificity did not differ between low-dose and standard-dose or unspecified-dose CT. No studies had high methodological quality as evaluated by the QUADAS-2 tool. Major methodological problems were poor reference standards and partial verification primarily due to inadequate and incomplete follow-up in persons who did not have surgery.

AUTHORS' CONCLUSIONS

The sensitivity and specificity of CT for diagnosing appendicitis in adults are high. Unenhanced standard-dose CT appears to have lower sensitivity than standard-dose CT with intravenous, rectal, or oral and intravenous contrast enhancement. Use of different types of contrast enhancement or no enhancement does not appear to affect specificity. Differences in sensitivity and specificity between low-dose and standard-dose CT appear to be negligible. The results of this review should be interpreted with caution for two reasons. First, these results are based on studies of low methodological quality. Second, the comparisons between types of contrast enhancement and radiation dose may be unreliable because they are based on indirect comparisons that may be confounded by other factors.

Unexpected Appendiceal Pathologies and Their Changes With the Expanding Use of Preoperative Imaging Studies

Purpose

The preoperative diagnosis of acute appendicitis is often challenging. Sometimes, pathologic results of the appendix embarrass or confuse surgeons. Therefore, more and more imaging studies are being performed to increase the accuracy of appendicitis diagnoses preoperatively. However, data on the effect of this increase in preoperative imaging studies on diagnostic accuracy are limited. We performed this study to explore unexpected appendiceal pathologies and to delineate the role of preoperative imaging studies in the diagnosis of acute appendicitis.

Methods

The medical records of 4,673 patients who underwent an appendectomy for assumed appendicitis between 1997 and 2012 were reviewed retrospectively. Pathological results and preoperative imaging studies were surveyed, and the frequencies of pathological results and preoperative imaging studies were investigated.

Results

The overall rate of pathology compatible with acute appendicitis was 84.4%. Unexpected pathological findings, such as normal histology, specific inflammations other than acute appendicitis, neoplastic lesions, and other pathologies, comprised 9.6%, 3.3%, 1.2%, and 1.5%, respectively. The rate of unexpected pathological results was significantly reduced because of the increase in preoperative imaging studies. The decrease in normal appendices contributed the most to the reduction while other unexpected pathologies did not change significantly despite the increased use of imaging studies. This decrease in normal appendices was significant in both male and female patients under the age of 60 years, but the differences in females were more prominent.

Conclusion

Unexpected appendiceal pathologies comprised 15.6% of the cases. Preoperative imaging studies reduced them by decreasing the negative appendectomy rate of patients with normal appendices.

WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis

Acute appendicitis (AA) is among the most common cause of acute abdominal pain. Diagnosis of AA is challenging; a variable combination of clinical signs and symptoms has been used together with laboratory findings in several scoring systems proposed for suggesting the probability of AA and the possible subsequent management pathway. The role of imaging in the diagnosis of AA is still debated, with variable use of US, CT and MRI in different settings worldwide. Up to date, comprehensive clinical guidelines for diagnosis and management of AA have never been issued. In July 2015, during the 3rd World Congress of the WSES, held in Jerusalem (Israel), a panel of experts including an Organizational Committee and Scientific Committee and Scientific Secretariat, participated to a Consensus Conference where eight panelists presented a number of statements developed for each of the eight main questions about diagnosis and management of AA. The statements were then voted, eventually modified and finally approved by the participants to The Consensus Conference and lately by the board of co-authors. The current paper is reporting the definitive Guidelines Statements on each of the following topics: 1) Diagnostic efficiency of clinical scoring systems, 2) Role of Imaging, 3) Non-operative treatment for uncomplicated appendicitis, 4) Timing of appendectomy and in-hospital delay, 5) Surgical treatment 6) Scoring systems for intra-operative grading of appendicitis and their clinical usefulness 7) Non-surgical treatment for complicated appendicitis: abscess or phlegmon 8) Pre-operative and post-operative antibiotics.

Monitoring C-reactive protein levels during medical management of acute appendicitis to predict the need for surgery

PURPOSE

To clarify the role of medical treatment in the management of acute appendicitis and the value of C-reactive protein (CRP) for predicting its failure.

MATERIALS AND METHODS

Patients with clinically diagnosed acute appendicitis, confirmed by imaging studies, were enrolled in this study. We measured leukocyte counts and CRP levels and recorded success and recurrence rates and the efficiency of medical treatment during follow-up. The efficiency of CRP values to predict failure of medical treatment was evaluated using receiver operating characteristics (ROC) curve analysis.

RESULTS

The subjects comprised 193 patients (mean age 30.9 years) who received medical treatment for acute appendicitis. The mean follow-up period was 12.3 (6-24) months and the early success rate of medical treatment was 86.5 % (160/185). Fifteen (9.3 %) patients suffered recurrence during follow-up. The leukocyte and CRP levels in these two groups of patients were not significantly different at the beginning of the treatment, but the increase in the CRP value differed significantly between the two groups during the follow-up period (p < 0.001). ROC curve analysis suggested that the optimum CRP cut-off point for unsuccessful medical treatment was 80.8 mg/L, with 81.82 % sensitivity and 84.34 % specificity (p < 0.001).

CONCLUSION

The success rate for treating acute appendicitis medically is high, with antibiotic treatment being effective as the firstline therapy for many unselected patients. An increase in CRP levels to 80.8 mg/L and above seems to be a meaningful parameter for determining a lack of response to medical treatment.