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Background: Literature comparing different alternatives for pain control in the immediate postoperative period of pediatric acute appendicitis (PAA) is scarce., Materials and Methods: We prospectively compared the analgesic and emetogenic profile of intravenous ibuprofen and metamizole in the immediate postoperative period of PAA. For this purpose, we used a sample of patients operated on in 2021 in our center. Participants were recruited on arrival at the Emergency Department and histopathological confirmation of the diagnosis was obtained in all of them. Pain was evaluated every 8 hours after the surgery with validated visual analog scales ranging from 0 to 10 points. Repeated measures ANOVA was used to compare the evolution of pain in the 48 hours after surgery between the two groups., Results: The sample included 95 patients (65% males) with a mean age of 9.7 years (sd: 3.14). 41 patients were treated with Ibuprofen (group 1) and 54 with metamizole (group 2). No significant differences were found in the level of pain either in the comparisons of point measurements or in its evolution in the 48 hours after surgery (p= 0.58). After adjusting for the received fluid therapy, children in the metamizole group had significantly more emetic episodes and needed significantly more doses of ondansetron., Conclusions: In our cohort, ibuprofen had a similar analgesic efficacy and a better emetogenic profile than metamizole in the immediate postoperative period of PAA. Future prospective, adequately controlled studies with larger sample sizes are needed to validate these findings.

Introduction: Scientific literature regarding the characterization of lymphocyte subpopulations of the cecal appendix is sparse, with few precedents limited to immunohistochemical techniques., Methods: We conducted a prospective pilot study to characterize lymphocyte subpopulations of the cecal appendix in children. Participants were divided into three groups: (1) patients without histological acute appendiceal inflammation, (2) patients with histological uncomplicated acute appendicitis, and (3) patients with histological complicated acute appendicitis (gangrenous, perforated). A fresh sample of the base of the appendix was taken from all patients and a flow cytometric study was performed. Quantitative variables were compared using Kruskal-Wallis test and Mann-Whitney U test., Results: This study included 57 patients divided into Group 1 (n = 5), Group 2 (n = 37), and Group 3 (n = 15). Median values (IQR) of the percentage of B-lymphocytes were 67.8 [66.8-68.1] in group 1, 61.15 [53.74-66.4] in group 2, and 52.1 [33-62.02] in group 3 (p = 0.02). Median values (IQR) of the percentage of NK-lymphocytes were 0.26 [0.2-0.3] in group 1, 0.55 [0.37-0.66] in group 2, and 0.84 [0.35-1.45] in group 3 (p = 0.008). Median values (IQR) of the percentage of T-lymphocytes were 31.9 [31.7-33.1] in group 1, 37.68 [32.15-45.69] in group 2, and 46.9 [37.03-67] in group 3 (p = 0.02). Pair comparisons of groups 2 and 3 also showed significant differences in the percentage of B lymphocytes (p = 0.03) and NK-lymphocytes (p = 0.02)., Conclusions: Significant differences in lymphocyte subpopulations were identified according to the histologic grade of the cecal appendix. More specifically, a lower percentage of B-lymphocytes and a higher percentage of T- and NK-lymphocytes were observed in cases of acute appendicitis. These findings must be confirmed and their etiopathogenic, diagnostic, and prognostic implications elucidated in future studies with larger sample sizes., (© 2023. The Author(s).)

Background: Pediatric acute appendicitis (PAA) involves a substantial consumption of health and economic resources. The identification of serum biomarkers that may help predict the post-surgical evolution of these patients is a field of great interest. Patients and Methods: This was a prospective, observational substudy within the Biomarkers for the Diagnosis of Appendicitis in Pediatrics (BIDIAP) cohort aimed at evaluating the association between post-surgical increase in serum IL-6 and different outcomes related to the clinical evolution of children operated on for PAA. Sixty-nine children with a confirmed diagnosis of acute appendicitis and both pre-operative and post-operative serum IL-6 were included in the study. Three multivariable-adjusted linear regression models were fitted to analyze the association between an increase of >10% in post-operative serum IL-6 level with the length of stay, the number of post-operative emetic episodes, and the onset of oral feeding. Two multivariable-adjusted logistic regression models were fitted to assess the association of the same exposure with the indication of antibiotherapy at discharge and with positivity in peritoneal fluid culture. Results: Thirteen children showed an increase of >10% in the post-operative serum IL-6 value (group 1) whereas 56 showed only a minor increase, or no change (group 2). After accounting for potential confounders, children in group 1 had a mean of three-day longer hospital stay (difference, 3.33; 95% confidence interval [CI], 0.57-6.09) and higher odds of a positive result in peritoneal fluid culture (odds ratio [OR], 37.43; 95% CI, 1.02-1361.28) than children in group 2. Conclusions: An increase of >10% in post-operative serum IL-6 value could predict longer hospital stay and higher odds of positive peritoneal fluid culture. Future prospective studies are needed to replicate these findings and to broaden the range of biomarkers that could predict the post-operative evolution of children operated on for PAA.

The aim of this study was to analyze the diagnostic performance of Leucine-Rich Alpha-2-Glycoprotein (LRG1) in pediatric acute appendicitis (PAA). We conducted a systematic review of the literature in the main databases of medical bibliography. Two independent reviewers selected the articles and extracted relevant data. Methodological quality was assessed using the QUADAS2 index. A synthesis of the results, standardization of the metrics and 4 random-effect meta-analyses were performed. Eight studies with data from 712 participants (305 patients with confirmed diagnosis of PAA and 407 controls) were included in this review. The random-effect meta-analysis of serum LRG1 (PAA vs control) resulted in a significant mean difference (95% CI) of 46.76 μg/mL (29.26-64.26). The random-effect meta-analysis for unadjusted urinary LRG1 (PAA vs control) resulted in a significant mean difference (95% CI) of 0.61 μg/mL (0.30-0.93). The random-effect meta-analysis (PAA vs control) for urinary LRG1 adjusted for urinary creatinine resulted in a significant mean difference (95% CI) of 0.89 g/mol (0.11-1.66).   Conlusion: Urinary LRG1 emerges as a potential non-invasive biomarker for the diagnosis of PAA. On the other hand, due to the high between-study heterogeneity, the results on serum LRG1 should be interpreted with caution. The only study that analyzed salivary LRG1 showed promising results. Further prospective studies are needed to confirm these findings. What is Known: • Pediatric acute appendicitis continues to be a pathology with a high rate of diagnostic error. • Invasive tests, although useful, are a source of stress for patients and their parents. What is New: • LRG1 emerges as a promising urinary and salivary biomarker for the noninvasive diagnosis of pediatric acute appendicitis., (© 2023. The Author(s).)

Background: The literature regarding alterations in the coagulation profile in pediatric acute appendicitis (PAA) is scarce and mainly limited to retrospective studies. Evidence on the diagnostic yield of coagulation parameters is limited to fibrinogen. Patients and Methods: This is a prospective study with 151 patients divided into two groups: patients with nonsurgical abdominal pain (NSAP) in whom the diagnosis of PAA was excluded (n = 53) and patients with a confirmed diagnosis of PAA (n = 98). In 93 patients (62%), a coagulation study was obtained at the time of diagnosis and international normalized ratio (INR), activated partial thromboplastin time (aPTT), d-dimer, platelets, mean platelet volume, and platelet-to-lymphocyte ratio were analyzed. The PAA group was further classified into complicated (n = 19) and non-complicated PAA (n = 40). Quantitative variables were compared between groups using the Mann-Whitney U test. Diagnostic performance of the coagulation profile was evaluated with the area under the receiver operating characteristic (ROC) curves. Results: Patients with NSAP had lower median levels of INR, fibrinogen and d-dimer than those with PAA. Moreover, patients with complicated PAA had higher median values of INR and fibrinogen. None of the patients needed specific treatment for the correction of coagulopathy. Fibrinogen was the parameter with the highest diagnostic yield for distinguishing between NSAP and PAA (area under the curve [AUC], 0.74; 95% confidence interval [CI], 0.65-0.85), as well as between complicated versus non-complicated PAA (AUC, 0.71; 95% CI, 0.57-0.86). Conclusions: This study found a moderate extrinsic pathway coagulopathy in patients with PAA, especially in complicated PAA. Fibrinogen is a parameter with moderate diagnostic yield for the diagnosis of PAA.

Background: The aim of this study was to analyze the diagnostic performance of total platelet count (PC), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) in pediatric acute appendicitis (PAA). Methods: We conducted a systematic review of the literature in the main databases of medical bibliography. Two independent reviewers selected the articles and extracted relevant data. Methodological quality was assessed using the QUADAS2 index. A synthesis of the results, a standardization of the metrics, and four random effect meta-analyses were performed. Results: Thirteen studies including data from 4,373 participants (2,767 patients with confirmed diagnosis of PAA and 1,606 controls) were included. Five studies compared PC, and the meta-analysis including three of them showed a non-significant mean difference of -34.47 platelets/1 × 10 9 /L (95% confidence interval [CI], -88.10 to 19.16). Seven publications compared PLR and the meta-analysis of those studies showed significant mean differences between patients with PAA and controls (dif: 49.84; 95% CI, 25.82-73.85) as well as between patients with complicated and uncomplicated PAA (dif: 49.42; 95% CI, 25.47-73.37). Four studies compared LMR and the meta-analysis including 3 of them showed a non-significant mean difference of -1.88 (95% CI, -3.86 to 0.10). Conclusions: Although existing evidence is heterogeneous and limited, PLR appears to be a promising biomarker for the diagnosis of PAA and for the discrimination between complicated and uncomplicated PAA. Our results do not support the use of PC or LMR as biomarkers in PAA.

Background: Pediatric acute appendicitis (PAA) continues to be a diagnostic challenge today. The diagnostic performance of classical indices is only moderate, especially in pediatric population. This study aimed to define a clinical, radiological and analytical index for the diagnosis of PAA., Materials and Methods: This prospective study included 151 patients divided into two groups: (1) 53 patients with non-surgical abdominal pain (NSAP) and (2) 98 patients with a confirmed PAA. Sociodemographic and clinical characteristics were compared between groups using the Mann-Whitney U test and the Fisher exact test. To identify the predictors of PAA, we performed a multivariable logistic regression using a forward stepwise analysis and we assigned multiples of integer values to the selected variables. The diagnostic performance of the index was assessed by calculating the area under the receiver operating characteristic curve. Intra-cohort calibration was assessed with the Hosmer-Lemeshow test., Results: We developed the BIDIAP index (BIomarkers for the DIagnosis of Appendicitis in Pediatrics), which included three variables that independently predicted higher odds of PAA: appendiceal caliber (≥ 6.9 mm), systemic immune-inflammation index (≥ 890) and peritoneal irritation, which scored 4, 3 and 2 points, respectively. Mean (SD) score of the participants was 2.38 (2.06) in group 1 and 7.89 (1.50) in group 2. The area under the ROC was 0.97 (95% CI 0.95-0.99). The cut-off point was established at 4 points, resulting in a sensitivity of 98.98% and a specificity of 77.78%., Conclusions: The BIDIAP index has an exceptional diagnostic performance in PAA. The importance of these results lies in its novelty and in the simplicity of the index. Although external validation will be necessary, initial results look promising., (© 2023. The Author(s).)

Background: Pediatric acute appendicitis (AA) is a challenging pathology to diagnose. In the last decades, multiple biomarkers have been evaluated in different human biological samples to improve diagnostic performance. This study aimed to examine the diagnostic performance of serum, fecal and urinary calprotectin as well as the role of the APPY-1 biomarker panel in pediatric acute appendicitis., Methods: We conducted a systematic review of the literature that involved an extensive search in the main databases of medical bibliography (Medline, PubMed, Web of Science and SciELO). Two independent reviewers selected the relevant articles based on the previously defined inclusion and exclusion criteria. Methodological quality of the selected article was rated using the QUADAS2 index. Data extraction was performed by two independent reviewers. A synthesis of the results, a standardization of the metrics and two random-effect meta-analyses, one for serum calprotectin and one for APPY-1, were performed., Results: The research resulted in 173 articles. Thirty-eight duplicates were removed. Among the remaining 135 articles, we excluded 125 following the inclusion and exclusion criteria, resulting in the 10 studies included in this review. This systematic review included data from of 3901 participants (1276 patients with confirmed diagnosis of AA and 2625 controls). The age of the participants ranged from 0 to 21 years. Four of the studies compared serum calprotectin values and reported significant differences between groups, but inconsistent results regarding cutoff points, sensitivity and specificity. Two publications compared urinary values of calprotectin and presented inconsistent results regarding sensitivity and specificity as well. One publication evaluated the diagnostic performance of fecal calprotectin, but it did not provide data on measured values. Four studies evaluated the diagnostic performance of APPY-1 test in pediatric acute appendicitis. The calculated pooled sensitivity and specificity of those studies were 97.37 (95% CI 95.60-98.44) and 36.74 (95% CI 32.28-41.44), respectively, and the calculated pooled NLR, 0.0714 (95% CI 0.041-0.115)., Conclusion: Serum calprotectin has limited diagnostic yield in pediatric acute appendicitis. Its performance seems to increase with the hours of clinical evolution and in advanced AA, although the evidence is limited. There is not enough evidence on the usefulness of urinary or fecal calprotectin in the diagnosis of pediatric acute appendicitis. On the other hand, the APPY-1 is a reliable test to exclude the diagnosis of AA in patients at low or moderate risk according to PAS and Alvarado Score., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

This study aimed to examine the ability of serum total bilirubin (STB) to discriminate between complicated and uncomplicated paediatric acute appendicitis (PAA). We conducted a systematic review of the literature that involved an extensive search in the main databases of medical bibliography (Medline, PubMed, Web of Science, OVID, Scopus, Cochrane Library). Two independent reviewers selected the relevant articles based on the previously defined inclusion and exclusion criteria. Methodological quality of the selected articles was assessed using the QUADAS2 index. Data extraction was performed by two independent reviewers. A synthesis of the results, a standardization of the metrics and a random-effect meta-analysis were performed. Between-study heterogeneity was assessed in subgroup analysis by study design. In addition, a diagnostic test accuracy (DTA) meta-analysis was performed. This review included 8 studies with data from 3634 participants aged between 0 and 18 years (2230 with uncomplicated PAA and 1404 with complicated PAA). The random-effects meta-analysis showed significantly higher mean STB in the complicated PAA group than in the uncomplicated PAA group (difference = 0.27; 95% CI 0.06-0.48) and high heterogeneity (I 2  = 96%). In subgroup analyses by study design, the difference remained significant in prospective studies. The DTA meta-analysis resulted in an AUC of 0.83 (95% CI 0.79-0.86) and pooled sensitivity and specificity of 68.53% (95% CI 48.35%-83.51%) and 81.12% (95% CI 67.76%-89.78%), respectively. Mean values of STB are higher in children with complicated than uncomplicated acute appendicitis, and the diagnostic yield of STB seems to be high. Due to the high heterogeneity between studies, these results must be interpreted with caution., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: The diagnostic performance of capillary ketonemia (CK) has been previously evaluated in context of pediatric acute gastroenteritis. To our knowledge, there is no literature on its performance in the setting of pediatric acute appendicitis (PAA)., Materials and Methods: In this study, 151 patients were prospectively included and divided into two groups: (1) patients with non-surgical abdominal pain in whom the diagnosis of PAA was excluded (n = 53) and (2) patients with a confirmed diagnosis of PAA (n = 98). In 80 patients (Group 1, n = 23 and group 2, n = 57) a CK was measured at the time of diagnosis. The PAA group was further classified into complicated (n = 18) and uncomplicated PAA (n = 39). Quantitative variables were compared between groups using the Mann-Whitney U test. Diagnostic performance of CK was evaluated with ROC curves., Results: CK values were 0.3 [0.1-0.9] mmol/L in group 1 and 0.7 [0.4-1.4] mmol/L in group 2 (p = 0.01). Regarding the type of PAA, CK values were 0.6 [0.4-0.9] mmol/L in uncomplicated PAA and 1.2 [0.8-1.4] mmol/L in complicated PAA (p = 0.02). The AUC for the discrimination between groups 1 and 2 was 0.68 (95% IC 0.53-0.82) (p = 0.24) and the AUC for the discrimination between uncomplicated PAA and complicated PAA was 0.69 (95% IC 0.54-0.85) (p = 0.04). The best cut-off point (group 1 vs group 2) resulted in 0.4 mmol/L, with a sensitivity of 80.7% and a specificity of 52.2%. The best cut-off point (non-complicated vs complicated PAA) resulted in 1.1 mmol/L, with a sensitivity of 61.1% and a specificity of 76.9%., Conclusions: This study found significantly higher levels of CK in patients with PAA than in those with NSAP. Similarly, significantly higher levels were observed in patients with complicated than in those with uncomplicated PAA. Nevertheless, the diagnostic performance of CK was only moderate in the two settings analyzed. The potential usefulness of CK determination as a tool to guide the preoperative rehydration regimen of patients with PAA to prevent postoperative hyporexia and vomiting is a promising line of research and should be evaluated in future studies., (© 2022. The Author(s).)

Background: Serum interleukin-6 (IL-6) has a moderate diagnostic performance in pediatric acute appendicitis (PAA). The evidence regarding its capacity to discern between complicated and uncomplicated PAA is scarce., Methods: We designed a prospective observational study to validate serum IL-6 as a marker for diagnostic classification between complicated and uncomplicated PAA. This study included 205 patients divided into three groups: (1) patients who underwent major outpatient surgery (n = 57); (2) patients with non-surgical abdominal pain (NSAP) in whom the diagnosis of PAA was excluded (n = 53), and (3) patients with a confirmed diagnosis of PAA (n = 95). The PAA patients were further classified as uncomplicated or complicated PAA. IL-6 concentration was determined in all patients at diagnosis. Comparative statistical analysis was performed using the Mann-Whitney U test, the Fisher exact test and the Kruskall Wallis test. The area under the receiver operating characteristic curves (AUC) were calculated., Results: Median (interquartile range, IQR) serum IL-6 values were 2 pg/mL (2.0-3.4) in group 1, 3.9 pg/mL (2.4-11.9) in group 2, and 23.9 pg/mL (11.1-61.0) in group 3 (P < 0.001). Among the participants in group 3, those with uncomplicated PAA had median (IQR) serum IL-6 values of 17.2 pg/mL (8.5-36.8), and those with complicated PAA had 60.25 pg/mL (27.1-169) serum IL-6 (P < 0.001). At the cut-off point of 19.55 pg/mL, the AUC for the discrimination between patients in group 2 vs. 3 was 0.83 [95% confidence interval (CI) 0.76-0.90], with a sensitivity of 61.3% and a specificity of 86.8. The AUC for the discrimination between patients with uncomplicated and complicated PAA was 0.77 (95% CI 0.68-0.86) and the cut-off point was 25.90 pg/mL, with a sensitivity and specificity of 84.6% and 65.6%, respectively., Conclusions: Serum IL-6 has a good performance in discerning between complicated and uncomplicated PAA. A score including clinical and radiological variables may increase the diagnostic performance of this molecule., (© 2022. The Author(s).)

Introduction: Pediatric acute appendicitis (PAA) is a pathology with a high rate of diagnostic error. The search for new diagnostic tools is justified by the high morbidity and healthcare costs associated with diagnostic error., Methods: We designed a prospective study to validate serum pentraxin-3 (PTX3) as a diagnostic tool in PAA. Participants were divided into three groups: (1) patients with no underlying pathology (2) patients with non-surgical abdominal pain and (3) patients with a confirmed diagnosis of PAA. For further analyses, patients in group 3 were divided into complicated or uncomplicated PAA. Quantitative variables were expressed as medians and interquartile ranges and categorical variables as percentages. Quantitative variables were compared using the Kruskal-Wallis test and the Mann-Whitney U test. Diagnostic performance was evaluated with ROC curves., Results: This study included 215 patients divided into group 1 (n = 63), group 2 (n = 53) and group 3 (n = 99). Median serum PTX3 values were 2.54 (1.70-2.95) ng/mL, 3.29 (2.19-7.64) ng/mL and 8.94 (6.16-14.05) in groups 1, 2 and 3, respectively (p = 0.001). Patients with complicated PAA showed significantly higher values than patients with uncomplicated PAA (p = 0.04). The AUC (group 2 vs. 3) was 0.77 (95% CI 0.69-0.85) and the best cut-off point was at 7.28 ng/mL, with a sensitivity of 61.3% and a specificity of 73.1%. The AUC (complicated vs. uncomplicated PAA) was 0.65 (95% CI 0.54-0.77) and the best cut-off point was 12.33 ng/mL, with a sensitivity of 51.72% and a specificity of 72.73%., Conclusions: The diagnostic ability of serum PTX3 in PAA is only moderate and therefore it cannot be considered a definitive diagnostic test. The discriminatory ability of PTX3 between complicated and uncomplicated PAA is poor. These findings, which contrast with those reported to date, should be validated with future properly designed prospective studies., (© 2022. The Author(s).)

Introduction: NGAL has recently been studied as a biomarker in the diagnostic context of pediatric acute appendicitis (PAA), although existing series are scarce and have limited sample sizes., Materials and Methods: A prospective observational study was designed to validate serum NGAL as a diagnostic tool in PAA. This study included 215 patients, divided into 3 groups: (1) patients undergoing major outpatient surgery (n = 63), (2) patients with non-surgical abdominal pain in whom a diagnosis of PAA was excluded (n = 53) and (3) patients with a confirmed diagnosis of PAA (n = 99). Patients in group 3 were divided into complicated or uncomplicated appendicitis. In 201 patients, a serum sample was obtained at the time of diagnosis and NGAL concentration was determined by ELISA. The Kolmogorov-Smirnov test was used to assess normality. Comparative statistical analyses were performed using the Mann-Whitney U test, the Kruskal-Wallis test and the Fisher's exact test. To calculate the discriminative ability of the molecule, the area under the receiver-operating characteristic curves (AUC) was calculated. A p value < 0.05 established statistical significance., Results: Median (interquartile range) of serum NGAL values were 38.88 (27.15-48.04) ng/mL (group 1), 51.84 (37.33-69.80) ng/mL (group 2) and 65.06 (50.50-86.60) ng/mL (group 3). The AUC (group 2 vs 3) was 0.642 (95% CI 0.542-0.741) (p < 0.001) and the best cutoff point was found to be at 40.97 ng/mL, with a sensitivity of 89% and a specificity of 34.6%. No statistically significant differences in serum NGAL values were found between patients with uncomplicated PAA and those with complicated PAA., Conclusions: This prospective validation study with a large sample size confirms that the diagnostic yield of NGAL in the context of PAA is only moderate, and therefore, it should not be used as a unique diagnostic tool. Furthermore, NGAL is not a valid biomarker to discern between uncomplicated and complicated PAA., (© 2022. The Author(s).)

Background: Despite the radiological and analytical advances of the last decades, there is still a significant rate of diagnostic error in pediatric acute appendicitis. In recent years, multiple biomarkers have emerged as potential diagnostic tools. This study aimed to examine the diagnostic performance of serum interleukin-6 in pediatric acute appendicitis., Methods: We conducted a systematic review of the literature that involved an extensive search in the main databases of medical bibliography (Medline, PubMed, Web of Science and SciELO). Two independent reviewers selected the relevant articles based on the previously defined inclusion and exclusion criteria. Methodological quality of the selected article was rated using the QUADAS2 index. Data extraction was performed by two independent reviewers., Results: The research in the medical bibliography databases resulted in 68 articles. We removed 26 duplicates. Among the remaining 42 articles, we excluded 33 following the inclusion and exclusion criteria. Of the final 9 studies included in this review, 8 provided measured serum interleukin-6 values, and all of them reported significant differences between groups, but inconsistent results regarding sensitivity and specificity., Conclusions: The diagnostic performance of interleukine-6 alone for the diagnosis of acute appendicitis in children is limited. The sensitivity and specificity of interleukine-6 for the diagnosis of non-complicated acute appendicitis in the pediatric population are moderate but increased in complicated appendicitis. There seems to be a direct relationship between serum level of interleukin-6 and the hours of evolution of abdominal pain in children with acute appendicitis. The increasingly widespread use of non-operative management of acute appendicitis warrants further exploration of the classificatory potential of this marker between complicated and uncomplicated appendicitis. We consider that this may be an avenue of research to explore in the future., (© 2021. Children's Hospital, Zhejiang University School of Medicine.)

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