Introduction

Acute appendicitis remains one of the most common medical emergencies worldwide, and its standard treatment is appendectomy. Its maximum incidence occurs between the second and third decade of life [1], which underlines its relevance in the child population. It is estimated that between 1% and 8% of children who come to the emergency room with acute abdominal pain are diagnosed with this condition [2]. Despite its frequency, diagnosis in children can be challenging [3].

For a certain diagnosis, in addition to the clinical history, physical examination and laboratory tests, an abdominal ultrasound must be performed [4]. However, sometimes advanced diagnostic tools are not available and it is necessary to resort to predictive clinical scales. Among these, the Alvarado scale, the pediatric appendicitis scale, and the inflammatory response to appendicitis scale stand out [5]. All are based on clinical and laboratory findings to categorize patients as low, moderate or high risk, facilitating a timely diagnosis.

It is essential to consider acute appendicitis when evaluating abdominall pain in children, as missing it can result in serious health consequences and legal implications. Although several clinical scoring systems exist, there is still no consensus on the exact criteria for its diagnosis, presenting a challenge for emergency professionals. This review aims to identify, detail and analyze all the scales used in the diagnosis of acute appendicitis in children.

Methods

An exhaustive literature search was carried out following the orderly and systematized approach recommended by the PRISMA guideline. First, a precise search expression was developed: («Children» OR «child» OR «pediatric patient*») AND («scale*» OR «score» OR «scoring system» OR «clinical prediction score» OR «clinical prediction model» OR «calculator») AND («appendicitis» OR «acute appendicitis» OR «appendectomy»). This expression was used to search articles in the PubMed, Scopus and Embase databases. The execution of this search was carried out on August 11, 2023, with the purpose of identifying the various scales that can be used for the diagnosis of acute appendicitis in the pediatric population.

The documents recovered from each of the databases were imported into the Rayyan software, which was used in various stages of the process. In the first stage, duplicates were identified and eliminated. Subsequently, a preliminary review was carried out based on the titles and abstracts of the articles. Finally, a more detailed evaluation was carried out by completely reviewing the selected texts.

The inclusion criteria were established based on the population studied, restricting the selection exclusively to pediatric patients, and those studies that used appendicitis risk scales that integrated various parameters to determine a risk score and a clinical management recommendation were considered. On the other hand, research that involved an adult population and that used indices in isolation, without complementing them with other data for diagnosis, was excluded.

In total, a total of 1521 documents were identified during the search process. After completing the screening process, it was possible to identify 73 articles that met the previously established selection criteria; Of all of them, it was possible to identify 22 prediction scales used for the diagnosis of acute appendicitis in children.

Development

Epidemiology of AA in children

Acute appendicitis currently continues to be one of the most common surgical pathologies in the population, and pediatric patients are no exception. In fact, although it usually occurs more frequently in the second decade of life, in pediatric patients it can represent up to 16% of all emergencies, having an overall incidence of around 10% for children and 8% for girls [6], so obviously making an early diagnosis is essential to provide adequate management of the pathology and thus prevent it from progressing to more severe stages.

Pathophysiology of acute appendicitis

The onset of appendiceal pathology is through obstruction of its lumen, the main cause of which in the general population is the impaction of fecaliths; however, in the case of children, the first cause is lymphoid hyperplasia. Other less common causes may include impacted stools and cecal or appendicular tumors [7].

Obstruction of the appendiceal lumen initially causes a congestive phase in which distension and inflammation of the appendix occurs, which in turn causes lymphatic and venous obstruction, then the suppurative or phlegmonous phase appears, in which bacterial proliferation of The area, mainly caused by Gram negatives such as E. coli, subsequently follows the necrotic or gangrenous phase in which an obstruction of arterial flow has occurred, becoming an ideal environment for the proliferation of anaerobic bacteria with a predominance of Bacteroides fragilis and causing ischemia. visceral that will finally lead to the perforation phase in which the appendix has spilled its contents into the peritoneal cavity, thus becoming the main complication of acute appendicitis [7, 8].

Diagnosis

Although the treatment of acute appendicitis is well established, which is through surgical removal of the anatomical piece, the diagnosis usually presents certain difficulties, especially in the pediatric population. This is because the clinical presentation of appendicitis in children usually differs from the presentation in adults. In particular, children often may not express classic symptoms such as abdominal pain, nausea, vomiting, etc.; and they may even manifest other unusual symptoms, making early diagnosis difficult and causing an increase in the rate of complications as a result of delayed diagnosis, with rates of up to 30% reported for perforated appendicitis [9].

The decision whether or not to operate on pediatric patients has not only led to a high rate of perforated appendicitis, but also an increase in the rate of negative appendectomies from around 20% to 54% [7, 10].

Currently, although the Gold standard for diagnosis is histopathology, this cannot be performed until after removing the appendix, so the best way to diagnose acute appendicitis is through different elements such as an adequate clinical history, physical examination, as well as laboratory and image studies, for this reason, for many years predictive scales for appendicitis in children have been implemented that unify these elements and, by obtaining a score, provide a guide to guide the decision to perform or not. a surgical intervention.

Some of these scales are relatively simple to apply, since they only include clinical and laboratory data (Table 1), others that are a little more complex use indices or mathematical formulas (Table 2) and there are others that complement not only clinical and laboratory data., but also imaging studies such as ultrasound (Table 3). These scales assign values to each of the variables they include, to subsequently obtain a score, which is accompanied by a recommendation for patient management. The most used scales worldwide are the Alvarado and Tzanakis scales, PAS. and Heidelberg Appendicitis Score (HAS), the first two being initially created for a more generalized population, while the other two are specific for pediatric patients [10].

Table 1. Clinical and laboratory scores for pediatric acute appendicitis

Note. ALV: Alvarado, mod: modified, PAS: pediatric appendicitis score, APPE: pediatric appendicitis score, AIR: appendicitis inflammatory response, (): Points, Mod: Modified, LRQ: Lower Right Quadrant, WBC: White Blood Cells.

Table 2. Scores for pediatric appendicitis with formulas or indices

Note. CRP: C-Reactive Protein, M: Male, F: Female, H: Hours, ANC: Absolute Neutrophil Count, WBC: White blood cells, LRG: Leucine-Rich alpha-2-Glycoprotein.

Table 3. Scores for pediatric appendicitis with imaging studies

Note. RLQ: right lower quadrant, PUAS: pediatric ultrasound appendicitis score, PAS: pediatric appendicitis score, SII: systemic immune inflammation index, ANC: absolute neutrophil count, APC: absolute platelet count, ALC: absolute lymphocyte count.

Final considerations

At the end of this narrative review, we realize that we currently have up to 22 acute appendicitis scales in pediatric patients, consequently, the question arises about which one to choose; Thus, we consider it appropriate to mention that the choice of a scale will depend not only on its high diagnostic performance, but also on the availability of auxiliary imaging and laboratory tests to satisfy its criteria, this being an individual factor for each Health establishments. Thus, there are scale options that mostly only require a good history and physical examination and other more complex ones that use imaging studies, urine tests, acute phase reactants, indices, formulas, etc.

Ethical aspects: All authors certify that they meet the current authorship criteria of the International Committee of Medical Journal Editors (ICMJE).

Funding Sources: The authors declare that this work has not received any funding from funding agencies in the public, commercial, or non-profit sectors.

Author Contributions:

Elías Atoche J, Caballero-Alvarado J: Conceptualization, Formal research analysis, Methodology, Resources, Software, Validation, Visualization, Approval of the final manuscript.

Elías Atoche J, Caballero-Alvarado J, Lozano-Peralta K, Zavaleta-Corvera C: Writing, Review and editing, Approval of the final manuscript.